Operating Procedures for Producing Methanol from 100,000 Tons of Coke Oven Gas

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Complete set of operating procedures for 100,000 tons of methanol production – Article 1: Operating procedures for the synthesis unit – Chapter 1: Process principles 1. Principles of the synthesis process Methanol is synthesized at a pressure of 5.0 MPa, with the help of catalysts, through the reaction of carbon monoxide, carbon dioxide, and hydrogen in gas form to produce methanol. The basic reaction equations are as follows: CO + 2H2 = CH3OH + Q; CO2 + 3H2 = CH3OH + H2O + Q. During the methanol synthesis process, the following side reactions also occur: 2CO + 4H2 = (CH3)2O + H2O; 2CO + 4H2 = C2H5OH + H2O; 4CO + 8H2 = C4H9OH + 3H2O. In addition, methyl formate, methyl acetate, as well as other higher alcohols and higher alkanes are formed. Copper-based catalysts, which are based primarily on copper, exhibit extremely high selectivity for methanol synthesis. They require thorough purification of the syngas at relatively low pressures and temperatures; otherwise, their activity is lost rapidly. Their heat resistance is also poor, necessitating operation of the catalyst at an optimal and stable temperature. Copper-based catalysts can generally operate at temperatures between 210–280°C; the optimal operating temperature range varies slightly depending on the catalyst type and reactor design. The optimal operating temperature for shell-and-tube reactors is between 230–260°C. For the synthesis of methanol using copper-based catalysts, an appropriate operating pressure is 5.0–10.0 MPa; in cases where the carbon dioxide content in the syngas is high, increasing the pressure has a significant effect on accelerating the reaction rate. The composition of syngas has a significant impact on the methanol synthesis reaction. As can be seen from the aforementioned reaction equation, to reduce energy consumption, syngas with an appropriate concentration of carbon dioxide should be used. If the carbon dioxide content in the syngas is too high, it will increase the burden on the distillation process and raise energy consumption; whereas if the carbon dioxide content is too low, it will result in low catalyst activity and conversion rates. The hydrogen-to-carbon ratio of the theoretical synthesized fresh gas should satisfy the following value: f = (H2 – CO2) / (CO + CO2) = 2.05. In actual operation, this ratio should be increased slightly, to a range of approximately 2.05–2.15. The air velocity is generally maintained at around 8,000–10,000 h-1. Methanol synthesis is a highly exothermic reaction; heat must be continuously removed during the reaction for it to proceed properly. Shell-and-tube reactors utilize the medium-pressure steam generated as a byproduct between the tubes and the shell to remove heat. As a result, maintaining the appropriate temperature conditions for the synthesis reaction relies almost entirely on the proper and stable operation of the pressure of this medium-pressure steam byproduct. Chapter 2: Brief Description of the Process Flow The recycled gas from the compression stage is preheated to 225°C in the inlet gas preheater (C0401), and then enters the shell-and-tube isothermal methanol synthesis reactor (D0401) from the top. Under the action of a copper-based catalyst, CO, CO2, and H2 react to produce methanol and water; simultaneously, small amounts of other organic impurities are also formed. The gas exiting the synthesis tower is cooled to 40°C through the exit gas preheater (C0401), the exit gas cooler (C0402), and the methanol water cooler (C0403); at this point, most of the methanol in the gas is condensed. The gas then enters the methanol separator (F0401) where crude methanol is separated out. Part of the gas exiting F0401 is discharged as vent gas to maintain the inert gas level in the synthesis loop ； Another portion of the gas is sent as recycle gas to the compression process. The discharged purge gas is depressurized by the pressure control valve PICA-1406 and then sent to the conversion process as fuel for the steam reformer. The crude methanol coming out of the bottom of the methanol separator enters the flash tank (F0402) after its level is controlled by the level control valve LICA-1403 and the pressure is reduced; most of the dissolved gases are vaporized in this process, and the flashed crude methanol is then sent to the distillation unit. The flash vapor is sent to the conversion process as fuel for the low-pressure burners in the conversion furnace. The reaction temperature in the methanol synthesis tower is controlled by the pressure of the by-product steam on the shell side; depending on the usage time of the synthesis catalyst, its active temperature ranges from 230 to 260°C, while the pressure of the by-product steam varies between 2.5 and 4.0 MPa. The steam generated in the methanol synthesis tower is reduced in pressure to 2.5 MPa by the pressure control valve PRCA-1402, and then sent to the convection section of the steam reformer in the conversion process for superheating; it is also used to power the steam turbine that drives the boiler feed water pump. The boiler feed water for the synthesis drum (F0403) is supplied from the conversion process, and the phosphate solution used to prevent scaling in the boiler water is also provided by the conversion process. To ensure the quality of the boiler water, a portion of the water at the surface of the drum is continuously discharged, and sludge is regularly removed from the bottom of the drum as well as from the bottom of the synthetic side shell; this sludge is sent to the continuous sludge expansion vessel in the conversion process. The boiler water between the synthesis drum and the methanol synthesis tower generates steam through natural circulation. To meet the temperature rise requirements of the synthesis tower during operation, a start-up injector (L0401) is also provided. While the plant is in operation, medium-pressure steam drives the circulation of boiler water in the space outside the synthesis tower through the ejector (L0401), thereby raising the temperature of the synthesis tower. Chapter 3: Operating Parameters
I. Process Operating Parameters
Temperature:
TR-1402: Temperature of gas entering the tower – 225°C
TRA-1407: Temperature of gas leaving the tower – Determined based on the condition of the catalyst
TI-1410: Temperature of gas exiting the methanol separator – 40°C

Pressure:
PI-1403: Pressure in the synthesis vapor drum – 2.4–3.9 MPa
PR-1404: Pressure of gas entering the tower – 5.1 MPa
PDI-1405: Pressure difference in the synthesis tower – 0.2 MPa
PICA-1406: Pressure of recycle gas – 4.63 MPa
PICA-1407: Pressure of vapor exiting the flash tank – 0.4 MPa

Flow Rate:
FI-1401: Steam generation rate in the synthesis vapor drum – 8.87 t/hr
FR-1402: Flow rate of recycle gas – 289,766 Nm3/hr

Liquid Level:
LICA-1401: Liquid level in the synthesis vapor drum – 50%
LICA-1403: Liquid level in the methanol separator – 50%
LICA-1405: Liquid level in the flash tank – 50%

II. Key Analysis Parameters and Values:
S405: Crude methanol
CH3OH: 80.26% (vol%)
H2O: 18.75% (vol%)
Specific gravity: 0.8
pH value: 4–6.5

S407: Boiler water
pH value: 7–9 (at 25°C)
Na3PO4: 5–10 mg/L
SiO2: <1 mg/L

Chapter 4: Operating Procedures
Section 1: Preparations Before Startup
Since this process is being started for the first time, a separate plan must be developed for tasks such as pipeline and equipment preparation, purging, individual unit tests, airtightness tests, cleaning and leak testing of the synthesis tower shell and vapor drum, catalyst installation, and joint operation tests. If starting the machine again after maintenance, the aforementioned tasks related to the specific situation must be completed before starting it. 1. Check whether the safety equipment is complete, such as oxygen respirators, filter masks, fire extinguishers, etc. 2. Notify the maintenance staff to inspect the electrical and instrumentation equipment associated with this process, ensuring that such equipment is in standby mode; also check the operation of the DCS system to confirm that it is functioning properly. 3. Check whether the associated pipelines and equipment are intact, whether insulation and anti-corrosion measures have been applied, and whether the valves operate smoothly; apply butter to the valve stems to ensure that all valves are in a position suitable for safe operation. 4. Check whether the safety valve is properly adjusted and in place, whether it has a lead seal, and confirm the setting value for activation. 5. Check whether all the associated instruments are present and in good condition, and whether the control system is flexible and reliable. 6. Inform the analysts to make all necessary analytical preparations for starting up the synthesis process. 7. The utility services are ready, including circulating water, demineralized water, electricity, low-pressure steam, medium-pressure steam, nitrogen, instrument air, and reforming gas for reduction. 8. Check whether the blind flange is in its proper position, and ensure that all access holes are properly sealed. 9. Prepare a phosphate solution at about 5% concentration for use in the conversion process. 10. Prepare spare tools and operation logs; the driving plan has been discussed and approved. Section 2: Driving I. Basic Driving ㈠ System Replacement 1. The air separation and air compression units supply nitrogen of “49” quality as a backup ； 2. On-site, the blind flange of the pipeline (N-002) used to fill this system with nitrogen will be connected ； 3. Shut off the upstream and downstream isolation valves as well as the bypass valve of the liquid level control valve of the methanol separator (LICA-1403) and the liquid level control valve of the flash tank (LICA-1405) on site ； 4. Close all vent valves, drain valves, sampling valves, and sewage discharge valves of the synthesis system ； 5. Open the inlet and outlet isolation valves of the synthesis system, and close the vent valve ； 6. Once the above steps have been verified to be correct, open the nitrogen inlet valve at the site and pressurize the system to 0.5 MPa ； 7. Open the compressor outlet vent valve, as well as all sampling valves and other discharge ports, and use intermittent pressurization and discharge to remove oxygen from the system, until the oxygen content measured at any of the sampling points such as S402, S403, S404, etc., is ≤0.1% ； 8. Open the bypass lines MG-0304 and MG-0305 of the combined compressor to allow flow several times, and use the circulating gas pressure control valve PICA-1406 to purge the venting system (when it is not possible to discharge to the flare system, discharge can be done through on-site venting) ； 9. After the high-pressure system has been properly purged, the bypass lines for the flash vapor pressure control valve PICA-1407, the methanol separator level control valve LICA-1403, and the flash tank level control valve LICA-1405 are opened in order to purge the low-pressure system (the valves leading to the distillation unit are closed). This process continues until oxygen content in samples taken from all discharge points in the system is ≤0.1%, at which point it is considered satisfactory. (ii) Valve settings: 1. The isolation valves and bypass valves in front of and behind the on-site circulating gas pressure control valve PICA-1406, the methanol separator level control valve LICA-1403, the flash tank level control valve LICA-1405, and the flash vapor pressure control valve PICA-1407; the isolation valve for the vent gas going to the conversion process; as well as the isolation valves and bypass valves in front of and behind the hydrogenation flow control valve FIC-1403. 2. The main controller controls PV-1406, PV-1407, LV-1403, LV-1405, LV-1402, and FV-1403. 3. Close all discharge ports, pressurize the system (excluding flash tank F0402; close the valve on the liquid pipeline between separator F0401 and flash tank F0402) to 0.6 MPa, and then close the nitrogen inlet isolation valve. (III) Establishing a nitrogen cycle: 1. Notify the compression system to start the combined compressor, thereby establishing a nitrogen cycle and maintaining the gas space velocity in the synthesis tower at 1000–1500 h-1 (or maintaining the circulation rate at 31,000–46,500 Nm3/h). 2. When the circulating gas volume is significantly low, open the nitrogen inlet valve to supply nitrogen to the system, and then close the nitrogen shut-off valve. ㈣. Establish the drum level: 1. Open the valve at the base of the drum safety valve on-site, as well as the valve at the base of the pressure gauge on-site. 2. Close the isolation valves before and after the drum level control valve LICA-1401 on site, as well as the isolation valves before and after the drum pressure control valve PRCA-1402 and the bypass valve. 3. Close the steam inlet isolation valve of the startup injector L0401, and close the steam outlet isolation valve of the steam drum. 4. Open the drum vent valve, and close the drum and synthesis tower shell-side drain valves. 5. Open the drain of injector L0401, start air cooler C0402, and open the inlet and outlet valves of methanol water cooler C0403. 6. Connect to the conversion process to supply water to the boiler; manually adjust LV-1401 via the main control, and once the liquid level is established, switch to automatic control. 7. Connect the boiler in operation to supply starting steam, and warm the pipes for standby use. 8. Notify the conversion process to start the phosphate pump and adjust the flow rate so that the quality of the boiler water meets the standards. (v) Temperature increase and reduction for synthetic catalysts – Reduction medium: Gas used in the conversion process. 1. Start the air cooler C0402 for the gas exiting the tower on-site; at the same time, open the inlet and outlet butterfly valves of the methanol water cooler C0403 to allow cooling water to flow through it. 2. After all the condensate has been drained, turn on the pilot drain of the start-up injector on-site, and slowly open the medium-pressure steam intended for starting up the injector L0401. Use the injector’s handwheel to carefully control the amount of steam added, ensuring that the temperature rise rate does not exceed 25°C/h. 3. If vibration of the start-up injector is detected during heating, the injector handwheel can be adjusted. When the outlet temperature of the synthesis tower rises to 100°C, reduce the steam supply and maintain a constant temperature in the synthesis tower for 2 hours. 4. When the outlet temperature of the synthesis tower reaches 120°C, reduce the amount of steam added further, and maintain this temperature for more than 4 hours. Monitor the liquid level in the methanol separator F0401; once the liquid level in the separator stops rising, the maintenance at this temperature can be concluded. On-site, the bottom drain valve of the methanol separator was opened to discharge the physical water identified in separator F0401, and it was weighed and measured (compared with the theoretical amount of water to be discharged) until nitrogen gas began to flow out. 5. On-site, open the isolation valves before and after FIC-1403 in the conversion gas feed system, and manually adjust FV-1403 via the main control unit to control the amount of conversion gas fed in. When the concentration of (CO+H2) in the gas before the inlet of the preheater C0401 in the tower reaches 0.5–0.8%, and the flow rate of FV-1403 is kept constant, the catalyst is reduced at this concentration. At this temperature (120°C) and this (CO+H2) concentration (0.5–0.8%), the catalyst is continued to be reduced until the (CO+H2) concentrations in the inlet and outlet towers are equal. 6. Maintain the (CO+H2) concentration at 0.5–0.8%, and gradually increase the steam supplied to injector L0401 in order to raise the temperature of the system step by step at a rate of 10–15°C per hour. Before each temperature increase, the (CO+H2) concentrations at the inlet and outlet of the synthesis tower must be identical. (The concentration difference ΔH2 of the inlet and outlet reducing gas shall be ≤0.1%), to ensure that the catalyst is fully reduced at each temperature level; one must not act hastily – the temperature should be increased without increasing (CO+H2), and (CO+H2) should be increased without raising the temperature. 7. The temperature range of 150–200°C constitutes the main reduction period; temperature is increased in stages, with each increase being of about 10°C. The temperature remains constant at each stage until no more (CO+H2) gas is consumed, after which the temperature is raised further. Inform the analysts to analyze the content of reducing gas in the feed gas and recycle gas every half hour ； Furthermore, during the catalytic reduction process, the amount of water generated during reduction is collected after the methanol separator F0401, thereby enabling monitoring of the reduction progress of the catalyst. 8. When the outlet temperature of the synthesis tower reaches 190–200°C, the catalyst is nearly completely reduced; at this point, the steam flow to the start-up injector L0401 can be increased further. When it is determined that the concentrations of (CO+H2) at the inlet and outlet of the synthesis tower are equal, the main control system adjusts FV-1403 to raise the concentration of (CO+H2) in the gas entering the tower to 2.0%, resulting in an outlet temperature of the synthesis tower of around 215–225°C. 9. Maintain the (CO+H2) concentration at 2.0% and carry out reduction for 2 hours; at the same time, increase the feed steam as much as possible to keep the temperature of the gas exiting the synthesis tower at around 230°C. 10. Increase the concentration of (CO+H2) to 5% and carry out reduction at this concentration for more than 2 hours until the reduction is complete. Pay attention to the amount of condensate collected in the methanol separator F0401; when the liquid level in F0401 stops rising or approaches the theoretical water output of the catalyst, it indicates that the reduction is complete. Record the amount of water generated. 11. Shut down FV-1403 by the control system; on-site, close the isolation valves before and after the FICA-1403 control valve to seal off the pipeline used for reduction. Gradually reduce the steam supply to the injector, lowering the temperature of the synthesis tower to 210°C, and maintain this temperature (with a cooling rate of ≤10°C/h). Precautions: A. Strictly follow the operating instructions and procedures provided by the catalyst manufacturer when carrying out the temperature-raising reduction of the catalyst. B. The combined compressor must be in optimal operating condition; during catalyst reduction, if the operating compressor stops for some reason, FV-1403 must be shut down immediately to reduce the steam supplied to the start-up injector L0401, the vent valve must be opened promptly, and the entire system must be purged with nitrogen. C. The addition of conversion gas should be done carefully; since it is difficult to obtain accurate readings at low hydrogen concentrations, several control analyses should be conducted before ending any stage of reduction, in order to avoid errors resulting from analytical inaccuracies. D. During reduction, if the system pressure drops, nitrogen (or desulfurized natural gas) should be added ； Maintain the CO2 level in the system at <15%; when it rises too high, increase the emission rate and add nitrogen to maintain system pressure. E. The addition of reducing gas is crucial for the entire reduction process; it must be strictly controlled within allowed limits, and the principle of \"increasing hydrogen flow without raising temperature, and increasing temperature without increasing hydrogen flow\" should be followed. F. During the reduction process, it is necessary to closely monitor changes in the bed temperature (or inlet and outlet temperatures). When the bed temperature rises sharply, it is essential to immediately stop or reduce the amount of reducing gas used, as well as decrease the amount of steam supplied; simultaneously, the pressure in the steam drum should be lowered and nitrogen circulation increased. G. During reduction, the temperature at the outlet of the synthesis tower must not exceed 240°C. After the reduction is complete, the pressure in the system is reduced to 0.15 MPa, and the temperature at the outlet of the synthesis tower is maintained at the final reduction temperature. When the concentrations at the inlet and outlet are equal, meaning that the catalyst no longer consumes hydrogen nor produces water, it can be considered that the synthesis catalyst has been reduced to its final state. H. During catalytic reduction, the conversion gas should be adjusted via FV-1403 and then added continuously. Appendix: Temperature rise and reduction procedure table for the synthesis catalyst. (vi) Receiving syngas: 1. Maintain a normal liquid level in the syngas drum F0403; simultaneously add phosphate solution to the drum and activate the drain system. The main control system sets the steam pressure control valve (PRCA-1402) at the outlet of drum F0403 to keep the steam pressure at 3.0 MPa, thereby maintaining the gas temperature at the outlet of the synthesis tower at 210°C. 2. Close the isolation valves before and after the on-site recycle gas pressure control valve (PICA-1406) as well as the vent valve. 3. Control the circulation volume to keep the gas flow rate through the synthesis tower at around 40% of the normal level. 4. Gradually add fresh syngas; if the temperature of the gas leaving the tower drops below 210°C, the conversion gas supply should be stopped, the amount of circulating gas reduced to a minimum, and the steam flow to the injector increased again to raise the temperature. Once the temperature at the outlet of the synthesis tower reaches 210°C, the conversion gas can be fed in again following the steps mentioned earlier. 5. When there is a liquid level in the methanol separator F0401, open the shut-off valves before and after the separator’s level control valve (LICA-1403) on site; set the main control value to 50% and activate automatic control. 6. Once pressure is indicated at the flash steam pressure control valve (PICA-1407), the main controller will set the target pressure to 0.4 MPa and activate automatic control. 7. When there is a liquid level in flash tank F0402, the isolation valves before and after the flash tank level control valve (LICA-1405) are opened on-site; the main controller sets the value to 50% and activates automatic control. 8. When the system pressure rises to 4.0 MPa, activate the circulating gas pressure control valve (PICA-1406) and the pressure control valve for the vent gas entering filter F0203 (PIC-1205) to discharge some gas and maintain the system pressure at 4.0 MPa. Control the pressure until it reaches the specified value, and then maintain low-load operation for 72 hours. 9. Sample and analyze the crude methanol produced every half hour; once the analysis shows it meets the requirements, notify the distillation process to accept the crude methanol. 10. Gradually increase the system pressure, slowly raise the flow rate of the converted gas, and adjust the flow rate of the recycle gas accordingly; in this sequence, gradually bring the system operating conditions back to normal levels. 11. When the synthesis system can maintain its own heat, shut down injector L0401 (disconnect the external medium-pressure steam and drain any water accumulated in the pipe), at which point the synthesis system enters normal operation. Precautions: A. In the initial stage of gas introduction, to prevent the catalyst from heating up too rapidly after gas is introduced, the rate at which the amount of converted gas is increased should be slow, and this process should be carried out alternately with increasing the system pressure, in order to avoid the catalyst being damaged due to excessive heating of the synthesis tower. Generally, the pressure increase rate should be ≤0.5 MPa/hr. B. The crude methanol produced in the early stages of operation may contain relatively high levels of organic amines and other impurities. It can be diverted through temporary pipelines from the methanol separator F0401 or the flash tank F0402, and placed in separate tanks for further treatment; it should not be sent to the methanol distillation process to avoid affecting the operation of the distillation system and the quality of the product. C. During driving, all control valves should be in manual mode; only after their control parameters have stabilized can they be switched to automatic control mode. D. When the outlet temperature of the synthesis tower is <210°C, it is not allowed to feed syngas in, in order to prevent the formation of paraffin during the reaction process (as paraffin tends to form at temperatures of 180–190°C), which would reduce the activity of the synthesis catalyst, affect product quality, and lead to the accumulation of paraffin in the coolers and separators, thereby impacting operations. II. Driving Again ㈠. Driving Again After a Short-Term Parking Period: During a short-term parking period, the system maintains its temperature and pressure, and the catalyst remains active; therefore, the following steps can be followed. 1. Start the air cooler for the gas exiting the tower on-site, open the butterfly valves at the inlet and outlet of the circulating water for the methanol-water cooler, and supply cooling water. 2. Notify the compression process to open the cycle gas inlet valve and start the combined compressor, so as to maintain the gas flow rate in the synthesis tower at 40% of the normal level. 3. Adjust the amount of steam supplied to the start-up injector, in order to raise the temperature of the gas exiting the synthesis tower to 210°C at a rate of ≤25°C/hr. 4. Notify the conversion process to open the cut-off valve for the conversion gas at the inlet separator, slowly introduce the conversion gas, and adjust the steam flow rate of the injector to maintain the outlet temperature of the synthesis tower at 210–215°C. 5. Raise the system pressure to 4.0 MPa at a pressure increase rate of ≤0.5 MPa/hr, activate the circulating gas pressure control (PV-1406), and vent the gas to the flare. (Once the synthesis system is operating stably, the off-gas is sent to the conversion process.) 6. Notify the distillation process to receive crude methanol. 7. Gradually increase the system pressure to the normal operating pressure, slowly raise the amount of converted gas, and adjust the amount of circulating gas accordingly. 8. When the synthesis system can maintain its own heat, turn off the start-up ejector and drain the water accumulated in the pipeline; at this point, the synthesis system enters normal operation. 9. As long as the outlet temperature of the synthesis tower is not lower than 210°C, it can be started directly in accordance with the operating requirements for syngas. (ii) Restarting after long-term parking: During the period of long-term parking, the catalyst was not passivated, and the synthesis system was properly protected by purging it with pure nitrogen. To restart the system, an start-up injector is used to raise the temperature, with the rate of temperature increase being such that the temperature at the exit of the synthesis tower does not exceed 25°C per hour. Once the temperature at the exit of the synthesis tower reaches 210°C, syngas can be introduced (see the procedures for introducing syngas for details). The various parameters of the system are then gradually adjusted to their normal values, and once stability is achieved, the system is switched to automatic operation mode. Section 3: Parking. Planned parking is divided into short-term parking and long-term parking; parking for a period of up to 24 hours is considered short-term parking, while parking for more than 24 hours is classified as long-term parking. 1. Short-term parking 1.1 Notify the compression process to shut off the conversion gas and switch to venting. 1.2 Adjust the drum pressure according to the results of the visual synthesis reaction in order to reduce the circulation volume. 1.3 Properly operate the start-up injector, using medium-pressure steam from the steam pipeline to maintain the temperature at the exit of the synthesis tower between 210 and 215°C. 1.4 If the conversion process has been stopped, start the boiler in operation to maintain the temperature of the synthesis tower. 1.5 If medium-pressure steam supply cannot be guaranteed, when (CO+CO2) in the cycle gas is ≤0.1%, stop the combined compressor and maintain the insulation and pressure in the synthesis system. 2. Long-term parking 2.1 Notify the compression unit to shut off the conversion gas and activate the steam injector, so as to maintain the temperature at the outlet of the synthesis tower above 210–215°C and continue the reaction. 2.2 The main control unit uses PV-1406 to regulate the synthesis system, allowing it to release pressure at a rate of ≤0.5 MPa/hr until the pressure reaches 0.5 MPa, with the gas being sent to the flare. 2.3 After controlling the levels in the methanol separator and flash tank to low levels, close the control valves LICA-1403 and LICA-1405, as well as the upstream and downstream isolation valves. 2.4 Upon analysis, when (CO+H2) in the recycle gas is ≤0.1%, cooling begins at a rate of ≤25°C/hr. Once the temperature at the outlet of the synthesis tower drops to 100°C, the recycle pump is stopped and the large valves at the inlet and outlet of the synthesis system are closed. 2.5 If maintenance is required, the system shall be purged with nitrogen; the purity of the nitrogen must be 99.9%, and this purification process shall continue until the H2 concentration in the system is ≤1.0% (V), after which the pressure shall be raised to 0.5 MPa using nitrogen. 2.6 If it is necessary to reduce the temperature at the outlet of the synthesis tower to room temperature, activate the compressor to circulate fluid and cool the system to room temperature; thereafter, shut down the compressor and close the inlet and outlet valves of the synthesis tower, thereby keeping the system under a nitrogen seal to protect the synthesis catalyst. 2.7 Shut off the drum level control valve LV-1401 to stop the supply of deionized water; close the drum pressure control valve PV-1402, and open the vent valve at the top of the drum on site to relieve pressure. 2.8 If maintenance is required for the boiler water system, the water in the boiler is drained through the drain valve; if no maintenance is needed, the boiler is filled with water again and treated with chemicals for protection. 3. Passivation of synthetic catalysts: Catalyst passivation is required when removing the catalyst or opening equipment within the system, as well as between pipes. The specific procedure is as follows: Conditions prior to passivation: On the basis of long-term shutdown, the temperature of the gas exiting the tower is <50°C, and the content of reducing gases is <0.5%. 3.1 Start the combined compressor and control the gas circulation rate in the synthesis tower at around 40,000 Nm3/hr. 3.2 Establish the normal liquid level in the drum, and open the on-site vent valve of the drum. 3.3 Turn on the air cooler C0402, and open the inlet and outlet butterfly valves of the circulating water in the water cooler C0403 to supply cooling water. 3.4 On-site, remove the blind flange from the instrument air pipeline PA-0002 connected to the outer tube (this is done with both the upstream and downstream valves closed), and slowly introduce instrument air into the synthesis system until the oxygen content in the gas entering the synthesis tower reaches 0.1%. Meanwhile, closely monitor changes in conditions such as the temperature at the outlet of the synthesis tower; a sharp rise in temperature must not occur. This process takes approximately 3 hours or more. 3.5 Over a period of 7 hours or more, gradually increase the oxygen concentration in the gas entering the tower to 1%. It is important to ensure that the temperature of the gas exiting the tower does not exceed 60°C; if this temperature is exceeded, the supply of instrument air should be stopped. 3.6 Then, within 3 to 4 hours, the oxygen concentration is increased to 4%, and the temperature of the gas leaving the tower is kept below 60°C. At this concentration, the passivation process continues for another 2 hours or more, after which the passivation is essentially complete. 3.7 Finally, use 3 to 4 hours to replace the entire system with instrument air, and maintain this condition for more than 2 hours to reduce the synthesis temperature to ambient temperature. 3.8 Stop the combined compressor, shut down the air cooler fans, and stop the cooling water supply to the water cooler; slowly release the pressure in the system to atmospheric levels. During this pressure release, venting should be carried out through the vent pipe at the outlet of separator F0401. Precautions: A. Throughout the passivation process, especially during pressure relief, the exhaust gas must not be directed to the flare; it should be vented on-site to prevent explosions. B. During the passivation process, if the temperature of the gas leaving the tower exceeds 60°C, the following measures should be taken immediately: stop the supply of instrument air; if the temperature still does not drop, depressurize the system to a slight positive pressure and continuously fill it with nitrogen. 4. Removal of the synthetic catalyst 4.1 Open the manhole at the top of the synthesis tower; check the descent of the catalyst from the upper orifice plate and keep a record of it. 4.2 Open the discharge port at the bottom of the synthesis tower to sequentially remove the alumina balls and catalyst. If the unloaded catalyst heats up and burns due to incomplete passivation, it can be cooled by spraying water on it. 4.3 Check whether the catalyst in each reaction tube inside the synthesis tower has been completely removed. 4.4 Purge the synthesis tower with oil-free air to remove all catalyst dust. 5. Emergency shutdown: An emergency shutdown is required in any of the following situations: A. Disruption of cooling water, boiler water, power supply, or instrument air. B. Interruption in the supply of feed gas. C. The liquid level in the methanol separator is too high and cannot be lowered. D. The drum liquid level is too low to rise. E. The compressor has failed. F. Excessively low pressure or interruption of externally supplied medium-pressure steam (during startup). G. Major leakage, fire, or explosion of the system. H. When this process must be stopped urgently due to an accident in another process. Section 4: Key Points for Normal Maintenance and Operation 1. Always pay attention to various process parameters in this operation step, and strictly control the process specifications. 2. Conduct a patrol inspection once per hour to check whether all equipment, instruments, and electrical devices in this process are operating normally; verify that there are no leaks at the flange seals, valve packing areas, instrument connections, and sampling points, that there are no unusual odors present, and that there are no leaks or ruptures in the equipment and pipelines. In winter, special attention should be paid to preventing freezing at the site. 3. Pay attention to the readings of parameters such as temperature, pressure, and liquid level on site, and check whether there are any discrepancies compared with the readings recorded by the DCS system; report any abnormalities promptly and take appropriate action. 4. When starting up the machine for the first time, it is necessary to maintain low-load operation initially, gradually transitioning to full-load operation. 5. The liquid level in the methanol separator is a fundamental parameter that must be maintained properly during synthesis operations; it is essential to avoid either too high or too low a liquid level, as this can lead to liquid entrainment or gas leakage. 6. The outlet temperature of the methanol water cooler should be ≤40°C; if it exceeds this value, the amount of cooling water used must be increased, otherwise the methanol in the gas phase will not be separated completely. 7. The liquid level in the synthesis drum is a key parameter; its changes are closely related to the steam production rate, tower temperature, and circulation gas volume. When adjusting the liquid level, attention must be paid to the changes in these parameters. 8. To ensure the quality of the boiler water, adjustments should be made promptly based on changes in the PO4-3 concentration and pH value of the water in the drum. In addition to maintaining a certain opening degree for continuous drainage from the synthesis drum, it is necessary to carry out intermittent drainage twice or more per shift, depending on the analysis results (note: it is important to control the opening degree of the valves and the timing of drainage). 9. The gas generation rate in the drum is an important indicator of the amount of heat released during the reaction. Under normal conditions, about 0.8 to 1.0 ton of gas is produced per ton of pure methanol. The CH4 content in the syngas, changes in the effective components, and variations in the circulation volume all affect the gas generation rate. 10. Control of the temperature in the synthesis tower: The temperature of the synthesis tower is primarily controlled by regulating the steam pressure in the drum. A change of 0.1 MPa in steam pressure corresponds to a temperature change of approximately 1.35°C. 11. Control of the inert gas content in the system: Inert gases are substances that are unnecessary in the system; they include components such as CH4, N2, and Ar. Their presence affects both the operation of the synthesis tower and the power consumption of the compressors. Therefore, it is necessary to keep the level of inert components in the system as low as possible. This is achieved by releasing some of the circulating gas (i.e., vent gas). Excessive gas release represents a significant waste of raw material gas. Therefore, the emission of purge gas should be controlled based on the conditions of the different raw materials; generally, the inert gas content should be kept at around 16% (V). At the beginning of catalyst use, its activity is high, and the content of inert gases can be kept at around 20% (V); as the catalyst’s activity declines over time, the content of inert gases can be reduced to around 12% (V). If high yield is required, the content of inert gas can be appropriately reduced; if low consumption is desired, the content of inert gas can be appropriately increased. 12. Control of space velocity: The value of space velocity is related to the activity of the catalyst as well as the reaction temperature; it has a direct impact on the yield and quality of the product. A low space velocity leads to the formation of higher alcohols and other impurities, while a high space velocity increases production capacity but reduces the one-pass conversion rate, increases energy consumption, and makes methanol separation more difficult. At the same time, it increases the compressor pressure difference. Therefore, the space velocity should be adjusted appropriately based on the production load, the temperature of the synthesis tower, and the pressure difference in the synthesis tower. Under normal conditions, the air velocity should be maintained at around 8000–1000 h-1. Chapter 5 Abnormal Conditions and Handling 1. Handling Principles: 1.1 When process parameters deviate, take timely action to make adjustments. 1.2 In the event of a failure in the automatic regulator, switch to manual operation and promptly inform the instrument technician to repair the automatic regulator. 1.3 When the control valve becomes clogged, activate the bypass promptly, carry out on-site control operations, and immediately repair or replace the control valve; if it is the filter that is clogged, clean the filter. 1.4 When the equipment malfunctions, a maintenance technician should be notified immediately to carry out repairs. 1.5 In the event of any abnormality, it is necessary to first determine the cause before deciding on the appropriate actions to take. In the case of serious accidents, an emergency shutdown must be carried out, and the system should only be restarted after the fault has been resolved. 2. Specific steps for handling abnormal situations: (1) Severe over-temperature in the synthesis tower. Causes: A. Excessively high pressure in the vapor drum; B. Low liquid level in the vapor drum (or dry operation of the drum). Solution: A. Reduce the pressure in the vapor drum according to the actual situation. B Supplementary deionized water (used for emergency shutdown in cases where the liquid level is too low and it is not possible to add water). C If the temperature in the synthesis tower continues to rise, the fresh gas should be cut off. (2) Excessive temperature at the outlet of the synthesis tower. Causes: A. The injector is open (under normal conditions). B. Excessively high pressure in the drum. C. Oxygen entering the system. D. Insufficient amount of recycled gas or excessive amount of fresh gas. E. Insufficient amount of waste gas discharged. Solutions: A. Shut down the injector. B. Reduce the pressure in the drum. C. Check the source of oxygen and cut off that source promptly. D. Increase the amount of recycled gas or reduce the amount of fresh gas. E. Maintain a normal level of waste gas discharge.

(3) Low temperature at the outlet of the synthesis tower. Causes: A. Reduced pressure in the drum. B. Excessively high space velocity. C. Excessive waste gas discharge from the drum. D. Decreased amount of fresh gas. E. High content of inert gases. F. Excessive amount of recycled gas. Solutions: A. Increase the pressure in the drum. B. Slightly reduce the gas space velocity. C. Reduce the amount of waste gas discharged from the drum. D. Coordinate with the previous process stage to increase the amount of fresh gas. E. Increase the amount of gas released as off-gas. F. Reduce the amount of recycled gas.

(4) Excessive pressure difference between the inlet and outlet of the synthesis system. Causes: A. Excessive synthesis load. B. Excessive amount of recycled gas. C. Severe catalyst degradation or blockages inside the reaction tubes. Solutions: A. Reduce the synthesis production load. B. Reduce the amount of recycled gas. C. For minor degradation, adjust operations; in severe cases, stop the system for maintenance or replace the synthesis catalyst. (5) The drum pressure is too high, causing the safety valve to activate. Treatment: Open the drum vent valve to relieve pressure, while checking for the cause of the high pressure. A If pressure buildup is caused by an excessively high drum liquid level, it is necessary to increase the drum blowdown and reduce the water supply to the drum in order to bring the drum liquid level back to normal. If it is due to a clogged steam pressure control valve at the drum outlet, operation should be switched to the bypass line, and the instrumentation technician should be contacted promptly for repairs. When the drum pressure is normal and the safety valve has automatically returned to its normal position, close the drum vent valve. (6) Overpressure in the flash tank: Causes: A. The pressure control valve is blocked or malfunctioning; B. Excessive impurities in the light components of the flash vapor; C. Lack of liquid level in F0401, resulting in air leakage into LV-1403. Solutions: A. Immediately open the bypass valve of the control valve to relieve pressure and arrange for maintenance by the instrumentation team; B. Close the shut-off valve of FV-1403 to establish a normal liquid level in F0401. (7) Excessively high liquid level in the methanol separator: Causes: A. The opening degree of LV-1403 is too low; B. The inlet temperature of the methanol separator is too high. Solutions: A. Increase the opening degree of LV-1403; B. Increase the cooling water flow to the water cooler to lower the temperature of the methanol after gas cooling. (8) Excessively low liquid level in the drum: Causes: A. Reduced water supply to the drum; B. Excessive drainage volume. Solutions: A. Slowly increase the opening degree of LV-1401 to boost the water supply to the drum; B. Reduce the amount of continuous drainage (but do not close it completely); C. If there is no indication of a liquid level in the drum, the system must be stopped immediately – forced water supply is strictly prohibited. (9) Leakage, fire, or explosion of high-pressure gas: In the event of such occurrences, the relevant valves upstream and downstream of the source of the problem must be closed immediately. If the situation is urgent, an emergency shutdown should be carried out. (10) Other abnormal conditions and handling are described in “Emergency Shutdown”. Article 2: Operating Procedures for Distillation Operations Chapter 1: Process Principles The distillation of pure methanol relies on the different volatilities of the various components in crude methanol, as these components do not form azeotropes. The method of multiple partial vaporizations and partial condensations is employed to achieve complete separation of the various components. This process uses three-column distillation and one-column recovery. Soluble gases and low-boiling-point impurities are removed in the pre-distillation column, while water and high-boiling-point impurities are removed in the pressurized column and the atmospheric column. Methanol contained in the recovered water is also recovered, thereby producing high-quality purified methanol product (the product from the top of the atmospheric column meets the GB338-92 standard, and the product from the top of the pressurized column meets the American O-M-232J standard). Chapter 2: Brief Description of the Process Flow. The crude methanol coming from the flash tank (F0402) in the synthesis process normally enters the crude methanol preheater (C0501) in this process, where it is preheated to 65°C before going on to the pre-tower (E0501). When the distillation process is shut down for a short period or the load is lower than that of the synthesis process, the crude methanol flows into the crude methanol storage tanks (F0508a, b). The crude methanol in these tanks is then sent to C0501 via the crude methanol pumps (J0509a, b). The steam exiting the top of tower E0501 has a temperature of 73.6°C and a pressure of 0.0448 Mpa. It first passes through the pre-tower condenser (C0503), where most of the methanol is condensed at around 68°C. The condensed methanol enters the pre-tower reflux tank (F0501), while the uncondensed gas goes to the expansion gas cooler (C0502), where it is cooled to 40°C by circulating water; more methanol condenses at this point and also enters F0501. The liquid in F0501 is sent back to E0501 as reflux via the pre-tower reflux pumps (J0501a, b), with a reflux flow rate of 12,095 Kg/h. The gas coming out of the expanded gas cooler, that is, the non-condensable gas, consists of gases dissolved in crude methanol as well as low-boiling substances such as dimethyl ether. It is sent to the conversion process as fuel, with a flow rate of 107.97 Nm3/h, a pressure of 0.03 Mpa, and a temperature of 37°C. The methanol solution at the bottom of the pre-tower (post-preparation methanol) has a temperature of approximately 85°C and a flow rate of 17,197.82 Kg/h; it is sent to the pressurized distillation tower by the feed pumps of the pressurized tower (J0502a, b). The heat required for the pre-distillation column is provided by the conversion gas from the conversion process, which is controlled via TIC-1501 to pass through the pre-column reboiler (C0504). To prevent the organic acids in crude methanol from corroding the equipment, a certain amount of dilute alkaline solution is added to the lower part of tower E0501, keeping the pH value of the methanol solution at the bottom of the tower around 8. The alkaline solution is prepared in the alkali preparation tank (F0505) and supplied via alkaline solution pumps (J0508a, b). The methanol with the desired properties, coming from J0502, enters the pressure tower (E0502). The methanol gas exiting the top of this tower has a temperature of 121°C and a pressure of approximately 0.574 Mpa. The methanol is condensed in the condenser/reboiler (C0506); this unit also serves as a reboiler for the atmospheric distillation tower (E0503), providing heat to that tower. The condensed methanol enters the pressurized reflux tank (F0502). Part of the methanol in F0502 is cooled by the reflux liquid cooler (C0513), and then pumped into E0502 by the pressurized reflux pumps (J0503a, b) at a flow rate of 14469 Kg/h ； The other portion of methanol is cooled to 40°C in the purified methanol cooler (C0507) of the pressure tower, and then sent as a product to the purified methanol metering tanks (F0509a, b). The heat required for the pressure tower is supplied by the conversion gas from the gas generation process, which is controlled via TIC-1228 and passed through the pressure tower reboiler (C0505). The liquid at the bottom of the tower is sent to the atmospheric distillation tower. The gas exiting the top of the atmospheric distillation column (E0503) has a temperature of 66°C and a pressure of 0.008 Mpa. It is condensed in the atmospheric column condenser (C0508), and the resulting methanol is cooled to 40°C by the atmospheric column pure methanol cooler (C0509) before being sent to the atmospheric column reflux tank (F0503). Part of this methanol is recycled to E0503 via the atmospheric column reflux pumps (J0504a, b), with a recycling rate of 14385 Kg/h; the remaining part is sent as a product to the pure methanol metering tanks (F0509c, d). The liquid at the bottom of the tower is sent to the methanol recovery tower (E0504) by the recovery tower feed pump (J0505a). The recovery tower (E0504) is of a combined type, with its stripping section being a floating valve tower and its distillation section being a packed tower. The vapor at the top of the tower is condensed in the recovery condenser (C0511), then enters the recovery reflux tank (F0504). It is subsequently pressurized by the recovery reflux pumps (J0506a, b); one part of this vapor returns to E0504, while the other part is cooled to 40°C in the recovery methanol cooler (C0512) before being sent to the purified methanol metering tanks (F0509c, d). The heat required by the recovery tower is supplied by low-pressure steam passing through the recovery tower reboiler (C0510) via FIC-1512; the steam flow rate is controlled at 1.5 T/h. The steam condensate is cooled to around 50°C in the condensate cooler (C0514), and then sent together with the turbine condensate from the compression process to the chemical water treatment plant for processing. The alcohol-containing wastewater at the bottom of the recovery tower is sent by wastewater pumps (J0507a, b) to the gas generation process, where it mixes with the process condensate and enters the stripping tower. The alcohol-containing waste liquid from this process is collected in an underground tank (F0511) via a closed system, and then sent to the crude methanol storage tank F0508 by an underground tank pump (J0512). This prevents the alcohol-containing liquid discharged during equipment and pipeline maintenance from contaminating the environment. During the production process, the accumulation of non-condensable gases at the top of the atmospheric pressure tower can affect the operation of the tower. This can be determined from the relationship between temperature and pressure at the top of the atmospheric pressure tower. The discharge of this non-condensable gas is carried out through the vent valve on the atmospheric pressure reflux tank; the discharged gas passes through the atmospheric pressure vent water seal tank (F0512) to have methanol absorbed from it before being vented at a higher point. Chapter 3: Process Operation Parameters
1. Temperature parameters:
TI-1503: Top temperature of the pre-tower – 73.6°C
TI-1507: Bottom temperature of the pre-tower – 84.8°C
TI-1508: Feed temperature to the pre-tower – 65°C
TI-1513: Bottom temperature of the pressure tower – 132.8°C
TI-1518: Bottom temperature of the atmospheric pressure tower – 107°C
TI-1519: Gas temperature at the top of the atmospheric pressure tower – 65.83°C
TI-1522: Gas temperature at the top of the recovery tower – 71°C
TI-1524: Bottom temperature of the recovery tower – 112.4°C
TI-1527: Gas temperature at the top of the pressure tower – 121°C

2. Pressure parameters:
PIC-1502: Top pressure control of the pre-tower – 0.045 MPa
PIC-1507: Top pressure control of the pressure tower – 0.574 MPa
PI-1508: Top pressure of the atmospheric pressure tower – 0.0083 MPa
PI-1510: Top pressure of the recovery tower – 0.029 MPa

3. Flow rate parameters:
FI-1503: Reflux flow rate in the pre-tower – 12,095 kg/hr
FI-1505: Reflux flow rate in the pressure tower – 14,469 kg/hr
FIC-1507: Reflux flow rate in the atmospheric pressure tower – 14,385 kg/hr
FI-1513: Flow rate in the recovery tower – 2,450 kg/hr

4. Level parameters:
LICA-1504: Liquid level in the pre-tower reflux tank – 50±5%
LICA-1505: Liquid level at the bottom of the pre-tower – 50±5%
LICA-1506: Liquid level at the bottom of the pressure tower – 50±5%
LICA-1507: Liquid level in the pressure tower reflux tank – 50±5%
LICA-1508: Liquid level at the bottom of the atmospheric pressure tower – 70±5%
LICA-1509: Liquid level in the atmospheric pressure tower reflux tank – 50±5%
LICA-1514: Liquid level at the bottom of the recovery tower – 50±5%
LICA-1515: Liquid level in the recovery tower reflux tank – 50±5%

5. Auxiliary analysis parameters:
SC504: pH value of methanol at the bottom of the pre-tower – 7–8
SC508: CH3OH content in water at the bottom of the atmospheric pressure tower – ≤ 5.4%
SC501: CH3OH content in water at the bottom of the recovery tower – ≤ 0.033%
S511: NaOH content in the alkaline solution – 4–6%

Technical standards for industrial methanol (GB338-92):
| Parameter | Excellent grade | First-class grade | Qualified grade |
|-----------|-----------------|-------------------|------------------|
| Colority (platinum-cobalt), unit – APHA | ≤ 5 | 10 | – |
| Density (20°C), g/ml | 0.791–0.792 | 0.791–0.793 | – |
| Temperature range (0°C, 101.325 KPa), °C | – | – | ≤ 64.0–65.5 |
| Boiling range (including 64.6±0.1°C), °C | ≤ 0.8 | 1.0 | 1.5 |
| Potassium permanganate test, minutes | ≥ 50 | 30 | 20 |
| Water solubility test | Clear | – | – |
| Moisture content, % | ≤ 0.10 | 0.15 | – |
| Free alkali (as NH3), % | ≤ – | – | 0.0002 |
| Free acid (as HCOOH), % | ≤ – | – | 0.0008, 0.0015, 0.0015, 0.0030, 0.0050 |
| Aldehyde compound content (as CH2), % | ≤ 0.002 | 0.005 | 0.010 |
| Evaporation residue content, % | ≤ 0.001 | 0.003 | 0.005 |

Chapter 4: Operating Procedures
Section 1: Preparations before startup
If this process is starting up for the first time, it is necessary to carry out tasks such as pipeline purging, cleaning, individual unit testing, airtightness testing, joint operation testing, system conversion, and tower heating (see the corresponding plan for specific steps). If starting the machine after maintenance, the aforementioned tasks must be completed according to the specific circumstances before starting it. Preparations before driving: 1. Adjust the safety valve and ensure it is installed safely ； 2. The individual tests of the machinery and pumps were successful, and the mechanical equipment is in good condition ； 3. Electrical equipment is in good condition ； 4. On-site instruments and control room instruments are installed and ready ； 5. The DCS system is properly calibrated ； 6. Desalinated water, circulating water, low-pressure steam, N2, instrument air, etc. have been supplied to the stations ； 7. The NaOH solution has been prepared ； 8. The synthesis process is operating normally ； 9. The storage tank is equipped to receive methanol ； 10. Warm up the steam system half an hour in advance ； 11. System N2 purging is successful ； 12. The safety facilities, fire-fighting equipment, and communication systems meet the operational requirements. 13. All control valves are in the manually closed state. Section 2: Startup (I) Initial Startup 1. Startup of the pre-tower, pressure tower, and atmospheric tower 1.1 E0501, E0502, and E0503 are started simultaneously, with intermittent feeding being used for the feed material ； 1.2 Conduct on-site inspections to verify that all drain valves, as well as the valves for low-pressure steam and nitrogen used in the distillation towers, are closed. Open the supply and return water valves for the coolers in this process, and also open the main cooling water valve for the pumps ； 1.3 Transfer the crude methanol from the synthesis process to the crude methanol storage tanks F0508a/b. Once the level in F0508 reaches 50%, open the inlet and outlet valves for the process condensate of the crude methanol preheater C0501, and inform the intermediate pump room to activate the crude methanol pumps J0509a/b. After being preheated by C0501, the crude methanol is fed into E0501 ； 1.4 On-site, open the inlet and outlet isolation valves of FI-1504, and start the alkali pump J0508a/b following the normal pump-starting procedures to feed alkali into E0501, controlling the pH value at 7–8 ； 1.5 The control room operator manually shuts off LV-1506 and closes the inlet and outlet isolation valves. Once the liquid level at the bottom of tower E0501 exceeds 1000 mm, the feed pumps J0502a/b for E0502 are started on-site, and the control room operator adjusts the opening degree of LV-1505 to feed material into E0502 ； 1.6 When the bottom liquid level in towers E0502 exceeds 700 mm, notify the conversion process to redirect the converted gas to the distillation process; by adjusting the amount of converted gas on-site and regulating TIC-1501 via the main control system, maintain the bottom temperatures of towers E0501 and E0502 at 84.8°C and 132.8°C respectively℃ ； 1.7 Start the pre-tower air cooling to establish the liquid level in F0501. Once the liquid level in F0501 reaches 800 mm, start the pre-tower reflux pumps J0501a/b on-site to create reflux at the tower top; then carry out full reflux operations throughout the tower. During these operations, pay attention to changes in the pressure at the tower top to prevent overpressure ； 1.8 During the water interconnection process in the distillation unit, a certain liquid level is maintained at the bottom of the atmospheric pressure tower; therefore, the steam at the top of E0502 can be condensed after passing through C0506. Once the liquid level in the pressurized tower’s reflux tank F0502 reaches 800 mm, the pressurized tower reflux pumps J0503a/b are started to establish reflux at the top of E0502. Operational adjustments are made throughout the tower to prevent overpressure ； 1.9 When the level of F0502 becomes excessively high and the reflux flow exceeds the designed value, the main controller activates LV-1507; the on-site shut-off valve is opened, and the product stream is directed to the crude methanol storage tank ； 1.10 Once the top pressure of tower E0502 is normal, the main controller opens LV-1507, and the product stream is diverted to the crude methanol storage tank ； 1.11 Start the air-cooled column C0508 on-site under normal pressure, and establish the liquid level in the reflux tank F0503 of the normal-pressure column. Once the liquid level reaches 800 mm, start the reflux pumps J0504a/b for the normal-pressure column on-site. The main control system then opens FV-1507 to establish reflux at the top of E0503, followed by operational adjustments for the entire column ； 1.12 When the level of liquid in F0503 remains high (when FI-1507 exceeds the designed return flow rate), the main controller opens LV-1509, and the output is directed to the crude methanol storage tank ； 1. Adjust the operations of towers E0501, E0502, and E0503 to keep temperature, pressure, liquid level, and flow rates within normal ranges. 1.14 Once the samples taken from S506 and S507 pass the analysis requirements, redirect the outputs from E0502 and E0503 to F0509a/b and F0509c/d respectively. 2. Commissioning of methanol recovery tower E0504 2.1 On-site, open the atmospheric pressure bottom extraction line and the isolation valves before and after control valve LICA-1508 ； 2.2 On-site, open the inlet valve of the feed pump (J0505) in the recovery tower, fill it with liquid to remove air, start the motor, and once the pressure at the pump’s outlet is normal, open the outlet valve of the pump ； Manually adjust LV-1508 by the controller to feed into the recovery tower ； 2.3 Once an overreading of the bottom liquid level in the recovery tower was detected, the main controller stopped feeding material into the recovery tower ； 2.4 Open the isolation valves before and after the FIC-1512 control valve on-site ； 2.5 Open the low-pressure steam inlet valve of the recycler reboiler (C0510) on-site ； The controller manually adjusts the opening of FV-1512 to supply steam to the reboiler of the recovery tower ； 2.6 The control system gradually increases the steam supply, maintaining the temperature at the bottom of the recovery tower at 112.4°C and the pressure at the top of the recovery tower at 0.029 MPa ； 2.7 Maintain the liquid level at the bottom of the recovery tower at 50%; if the level drops, replenish feed promptly ； 2.8 Once the liquid level in the recyclable sludge reflux tank (F0504) reaches 50%, the bottom discharge valve of the reflux tank shall be opened on-site ； 2.9 On-site, open the inlet valve of the recirculation pump J0506 to fill it with liquid and remove air; start the motor. Once the pressure at the pump’s outlet is normal, open the outlet valve of the pump to send the fluid back to the recovery tower ； 2.10 Control the top temperature of the recovery tower at 71℃ ； 2.11 The extraction line from the pre-tower is taken out of the recovery tower. 2.12 Once operation of the entire tower is stable, the extraction line valve at the bottom of the recovery tower is opened on-site ； 2.13 Open the inlet valve of the wastewater pump to fill it with liquid and remove air, start the motor, and once the pressure at the pump outlet is normal, open the outlet valve of the pump ； Adjust the stroke of pump J0507 on-site to regulate the waste water volume of F0206 ； 2.14 All control systems within this unit shall be set to automatic mode. (II) Driving again 1. Short-term parking: Driving again after parking for a period of time < 24 hours 1.1 Switch the respective control instruments to manual mode ； 1.2 Slowly open C0504, C0501, C0505, and C0506 to heat the conversion gas, steam, and process condensate ； 1.3 Open F0402 to reach the cut-off valve of the feed line to E0501, or use J0509a/b to supply feed to E0501, thereby raising the liquid level in E0501 to 80% ； 1.4E0501, E0502, E0503, and E0504 are started sequentially according to the startup procedure; full reflux operation is carried out, with feed being added intermittently ； 1.5 Once all system parameters are normal and the product passes the analysis, connect the system using a methanol feed pump and a recovery tower feed pump ； 1.6 As E0501 is fed continuously, the product is sent to F0509a/b or c/d ； 1.7 Change each controlled instrument to automatic mode. 2. Restarting after long-term parking (parking time > 24 hours): If the equipment and pipelines have been overhauled, they must first be purged with N2; once the purification is complete, the normal startup procedure can be followed. Section 3: Parking (I) Planned Parking: 1. Temporary Parking a. First, redirect the purified methanol obtained from the pressure tower, atmospheric tower, and recovery tower to the crude methanol storage tank ； b. (1) All instruments automatically switch to manual mode ； (2) On-site, close the downstream stop valve of FT-1502, close the inlet and outlet isolation valves for the process condensate in the crude methanol preheater, and open the bypass valve ； The controller manually adjusts the opening of FICQ-1502, to send crude methanol to the crude methanol storage tank ； (3) Close the outlet valve of the feed pump in the pressure tower on site, shut down the pump, and close the cut-off valve for the extraction line at the bottom of the pre-tower ； (4) The operator manually shuts off the valves LICA-1506 and LICA-1507; on-site, the cut-off valve for the extraction line at the bottom of the pressure tower is closed, as well as the cut-off valves before and after the control valve LICA-1507, and the cut-off valve connecting refined methanol to the refined methanol storage tank ； (5) The main controller manually shuts off the valve positions of LICA-1508 and LICA-1509 ； Close the outlet valve of the feed pump to the recovery tower on site and shut down the pump ； Close the isolation valves before and after the LICA-1509 control valve on site, and close the isolation valve for the recovery of pure methanol on site ； (6) The controller manually shuts off the LICA-1514 and LICA-1515 valves ； Close the outlet valve of the wastewater pump on site and shut down the pump ； Isolate the cut-off valves before and after the LICA-1514 control valve on site ； (7) Stop J0508a/b at the site; cease adding alkali ； (8) Full reflux operation is carried out for the four towers. 2. Long-term parking: In addition to temporary parking, the following actions are required: ① Slowly close the manual valve of the auxiliary line used to start up the conversion process, in order to cut off the heat source for the pre-tower and the reboiler in the pressure tower ； ②Close the low-pressure steam inlet cut-off valve to the recovery tower reboiler on site ； The controller shuts off the FIC-1512 valve ； Isolate the cut-off valves before and after the FIC-1512 control valve on site ； ③If the pressure inside the tower drops, open the nitrogen valves of the pre-tower, pressurization tower, atmospheric tower, and recovery tower on site to fill the tower with nitrogen and maintain a slight positive pressure in each tower ； ④When the liquid levels in the pre-tower, pressure tower, atmospheric tower, and recovery tower’s reflux tanks are reported to be too low, the reflux pump for these four towers shall be stopped on-site ； ⑤When the system temperature drops to room temperature, stop the top air coolers of towers E0501 and E0503, as well as the coolers themselves; stop the cooling water supply to these coolers ； ⑥If the distillation system needs to be cleaned, the following steps must also be carried out ； a. On-site, open the drain valve pipelines at the bottoms of the pre-tower, pressure tower, atmospheric tower, and recovery tower, as well as the drain pipeline at the pump outlet, to discharge the residual liquid into an underground tank ； When the level of the underground tank reaches 2/3, activate the underground tank pump to feed methanol into F0508a/b ； b. Conduct low-pressure steam cleaning of each tower; the wash water is discharged into underground tanks or gutters ； c. Analyze that CH3OH < 0.1%; the system is qualified for cleaning ； d. To enter the equipment, it is also necessary to replace the air so that O2 > 19%. (II) Emergency shutdown 1. Emergency shutdown measures shall be taken in the distillation process when one of the following situations occurs: 1.1 Accident-induced shutdown of the conversion process ； 1.2 Low cooling water pressure or interruption ； 1.3 Power supply system failure ； 1.4 Instrument air failure ； 1.5 The large fluctuations in steam pressure result in very unstable distillation operations ； 1.6 Severe leakage at equipment or pipeline connections, causing serious environmental pollution ； 1.7 Fire or explosion accidents occur in this process or other processes. 2. Emergency shutdown procedures: 2.1 Redirect the crude methanol from the synthesis unit to the crude methanol tanks F0508a/b ； 2.2 The product from the pressurized tower and the atmospheric tower is diverted to the crude methanol storage tank ； 2.3 Operate the manual valve of the conversion gas feed line associated with the conversion process, and cut off the heat sources for the reboilers in the pre-tower and pressure tower ； At the distillation site, close the inlet and outlet valves of LV-1506; keep the liquid level at LI-1506 ； 2.4 Close the low-pressure steam valve of the recovery tower ； 2.5 Stop the feed pumps and reflux pumps of each tower to maintain the liquid level in each tower; stop the alkali solution pump ； 2.6 Observe the pressure changes in each tower. If the pressure drops rapidly, open the N2 valve to fill it with N2 to a slightly positive pressure ； 2.7 On the DCS system, set all control systems for the distillation process to manual mode; thereby, the distillation process is brought to a stop. Once the conversion process is operating normally, start the distillation process following its startup procedures. Section 4: Key Points for Normal Maintenance and Operation 1. Adjustment of the feed temperature to the pre-tower: The feed temperature is adjusted by controlling the opening degree of the bypass valve for the process condensate line coming from the C0501 auto-conversion unit F0204. 2. Pre-top temperature control: ① Adjust the amount of reflux flow and the temperature of the reflux liquid ； ②Adjust tower top pressure PIC-1502 ； ③Adjust the bottom temperature and liquid level of the tower ； ④Adjust the feed position. 3. Pre-bottom-reactor temperature adjustment: ① Adjust the opening degree of valve TIC-1501 ； ②Adjust the liquid level at the bottom of the tower ； ③Adjust the amount of reflux at the tower top ； ④Adjust the opening degree of the converter gas main valve, as well as the temperature and pressure of the heating medium. 4. Ensure the composition of the feed to the pre-tower: Maintain stable conditions in the synthesis process, as well as a constant level of crude methanol coming from F0402 and F0508a/b; the amount of crude methanol from the latter should be added in small quantities slowly ； 5. How to ensure the control system’s pH value is within the acceptable range? ①First, prepare a qualified dilute NaOH solution, and contact the laboratory to analyze its concentration ； ②Adjust the amount of FI-1504 based on the analyzed pH value (by adjusting the percentage of the J0508a/b stroke regulator). 6. Control of pre-tower top pressure: ① Adjust the value of PIC-1502 ； ②Adjust the backflow rate and the top temperature of the tower ； ③Adjust the opening degree of the tower top non-condensable gas vent valve ； ④Adjust the opening degrees of the C0502 cooling water inlet and outlet valves as well as the bypass valves ； ⑤Adjust the opening degree of the alcohol-containing gas bypass valve in the tower top air cooler. 7. How to adjust the temperature of the pre-cooling reflux liquid: ① Adjust the tower top temperature, pressure, and reflux flow rate ； ②Adjust the opening degree of the bypass valve of the tower top air cooler ； ③Adjust the opening degrees of the C0502 cooling water inlet and outlet valves as well as the bypass valves. 8. Regulation of the pressure tower top temperature: ① Adjust the tower top reflux ratio and the temperature of the reflux liquid ； ②Adjust the tower top pressure ； ③Adjust the bottom temperature of the tower. 9. Regulation of the temperature of the pressurized reflux liquid: ① Adjust the tower top temperature, pressure, and reflux flow rate ； ②Adjust the opening degrees of the C0513 cooling water inlet and outlet valves as well as the bypass valves. 10. How to control the pressure at the top of the pressurized tower? ①Adjust PIC-1507 size ； ②Adjusting the tower top temperature and reflux ratio ； ③Adjust the amount of converted gas to regulate the bottom temperature of the tower. 11. How to adjust the temperature at the bottom of the pressurized tower? ①Adjust the amount of conversion gas and the settings of TIC-1228 and TIC-1501 ； ②Adjust the liquid level at the bottom of the tower ； ③Adjust the amount of return flow. 12. How to adjust the temperature at the top of the atmospheric pressure tower? ①Adjust the amount of reflux flow and the temperature of the reflux liquid ； ②Adjust the pressure at the top of the tower ； ③Adjust the bottom temperature of the tower (mainly the heat input to the reboiler). 13. How to adjust the pressure at the top of the atmospheric tower? ①Opening degree of F0503 non-condensable gas vent valve ； ②Opening degrees of C0509 cooling water inlet and outlet valves and their bypass valves ； ③Adjusting the tower top temperature and reflux rate ； ④Adjust the bottom temperature of the tower. 14. How to adjust the temperature of the atmospheric pressure Backflow of sludge liquid? ①Adjust the temperature, pressure, and reflux volume at the top of the tower ； ②Adjust the opening degrees of the C0509 cooling water inlet and outlet valves as well as the bypass valve. 15. How to adjust the bottom temperature of the atmospheric pressure tower? ①Adjust E0502 top temperature ； ②Adjust the liquid level at the bottom of the tower ； ③Adjust the pressure at the bottom of the tower ； ④Adjust the amount of return flow. 16. How to adjust the temperature at the top of the recovery tower? ①Adjust the reflux flow rate at the tower top and the temperature of the reflux liquid ； ②Adjust the tower top pressure ； ③Adjust the bottom temperature of the tower. 17. How to adjust the pressure at the top of the recovery tower? ①Adjust the opening degree of the vent valve for the non-condensable gas at F0504 to direct it to the discharge tank ； ②Opening degrees of C0511 cooling water inlet and outlet valves and their bypass valves ； ③Adjusting the tower top temperature and reflux rate ； ④Adjust the bottom temperature of the tower. 18. How to adjust the temperature of the recycled solvent reflux liquid? ①Adjust the opening degrees of the C0511 cooling water inlet and outlet valves as well as its bypass valves ； ②Adjust the temperature, pressure, and reflux volume at the top of the tower. 19. How to adjust the temperature of the recovery tower? ①Adjust the size of the heat source FIC-1512 for the bottom reboiler ； ②Adjust the liquid level at the bottom of the tower ； ③Adjust the pressure at the bottom of the tower ； ④Adjust the amount of return flow ； 20. How to adjust the pressure in the recovery tower? ①Adjust FIC-1512 size ； ②Adjust the liquid level at the bottom of the tower ； ③Adjust the reflux flow at the tower top. 21. How to adjust the liquid levels at the bottom of each tower? ①Adjust the bottom temperature of the tower ； ②Adjust the tower top temperature and the amount of reflux flow ； ③Adjust the discharge volume of the reactor liquid ； ④Adjust the feed rate and feed position. 22. How to start a centrifugal pump? (1) Preparations before starting the pump: ① Check whether the foundation bolts of the machine base are secure ； ②Check the lubricating oil of the pump; if the oil level is below 1/2 to 2/3 or if the oil is emulsified or degraded, add more oil or replace it ； ③Rotate the pump 2–3 times to check for any abnormalities such as sticking ； ④Check the opening and closing status of the pump’s inlet and outlet valves as well as the connecting valves, and test whether they operate smoothly ； ⑤Check whether the pressure gauge is appropriate ； ⑥Open the cooling water inlet and outlet valves to check whether the cooling water system is unobstructed ； ⑦Check the pump body and pump shaft for leaks ； ⑧Contact an electrician to supply power and briefly test whether the motor rotates in the correct direction ； (2) Pump startup steps: ① Open the pump inlet valve and the vent valve, fill the pump, then close the vent valve after completion ； ②Open the root valve of the pressure gauge ； ③Start the motor and check for any abnormalities ； ④Once the pump is running properly, slowly open the outlet valve ； ⑤Once the pump outlet pressure reaches the normal value, open the outlet valve fully ； (3) Pump shutdown procedure: ① Slowly close the outlet valve until it is fully shut off ； ②Stop the motor, close the pump inlet valve and the pressure gauge root valve ； ③For maintenance or in winter, the liquid accumulated inside the pump must be drained. 23. How to start a plunger metering pump? (1) Preparations before starting the pump: ① Check whether the bolts at all connections are tightened ； ②Inject HF20# mechanical lubricant into the transmission box ； ③Inject an appropriate amount of transformer oil into the safety automatic refueling valve assembly until it is about 10 mm above the overflow level; also inject transformer oil into the bracket located between the pump head and the transmission box, ensuring that the oil level covers the outer diameter of the plunger packing ； ④Rotate the coupling to move the plunger back and forth several times to check for any sticking, then align the pump’s zero position with the adjustment zero position in order to eliminate any drift in the adjustment gauge’s range during operation ； ⑤Check the motor wiring and contact an electrician to restore power. (2) Pump startup steps: ① Fully open the inlet and outlet valves (open the inlet valve first, then the outlet valve) ； ②Start the motor and check for any abnormalities ； ③Adjust the pump outlet pressure to the specified value. 24. How to stop a plunger metering pump? ①Turn off the power supply to stop the motor from running ； ②Close the inlet valve. Chapter 5: Abnormal Conditions and Their Handling 1. Excessive water content in the purified methanol product: Causes: ① Excessive water content in crude methanol ； ②The reflux ratios for E0502 and E0503 are too low, or the temperature of the reflux liquid is high ； ③Increased heat source flow rate or high pressure in reboilers E0502 and E0503 ； ④The moisture content in the E0502 feed is too high ； ⑤The top pressures of towers E0502 and E0503 are low. Treatment: ① Slightly increase the discharge of waste liquid at the bottom of F0401 and F0402; contact the synthesis process to adjust the composition of the syngas, which can reduce the water content in the feed to E0502 ； ②Appropriately increase the reflux ratio and lower the temperature of the reflux liquid ； ③Control the amount of heat source added to the reboiler as well as its pressure ； ④Properly increase and control the top pressures of E0502 and E0503 ； ⑤The extraction of pure methanol is diverted to F0508a/b; once it meets the requirements, it is then sent to the pure methanol metering tank. 2. Excessive alcohol content in the alcohol-containing wastewater at the bottom of the recovery tower: Causes: ① Incomplete extraction from E0503 and E0503 ； ②E0504: Low heat supply or low pressure in the reboiler ； ③The top pressure of Tower E0504 is too high ； ④The liquid level at the bottom of towers E0503 and E0504 is too high ； ⑤The liquid level at the bottom of Tower E0504 is too high. Treatment: ① Increase the production rate on the basis of tower equilibrium ； ②Slightly increase the FIC-1512 flow rate or pressure ； ③Appropriately reduce the top pressure of the tower ； ④Lower and control the liquid level at the bottom of the tower properly ； 3. The content of light hydrocarbon components in the product is not up to standard. Reason: ① The bottom temperature of E0501 is low; the amount of gas converted in the reboiler is small or the pressure is low, resulting in incomplete volatilization of the light components ； ②E0501: High top pressure ； ③The bottom liquid level of E0501 is too low ； ④Low top reflux temperature E0501 ； Treatment: ① Appropriately increase and control the bottom temperature and liquid level of E0501 ； ②Appropriately reduce the top pressure of E0501 ； ③Slightly increase the temperature of the top reflux liquid in E0501 ； ④The refined methanol pump has also been changed to F0508a/b; it will be switched to the refined methanol metering tank once it meets the requirements. 4. Excessive pressure inside the tower: Causes: ① High flow rate or high pressure of the heating medium in the reboiler ； ②The cooling effect at the top of the tower is poor, and the opening degree of the vent valve is too low ； ③The reflux ratio is low, and the tower top temperature is high ； ④Leak inside the reboiler. Treatment: ① Control the flow rate and pressure of the heating medium in the reboiler ； ②Increasing the flow rate and pressure of the cooling water, as well as appropriately opening the vent valve, can help reduce the pressure at the top of the tower ； ③Increase the reflux ratio, reduce the draw rate, or even operate in full reflux to lower the top temperature of the tower ； ④If the reboiler leaks, the plant should be shut down for maintenance. 5. Sudden interruption of reflux. Causes: ① Reflux pump trip ； ②The level of the reflux tank is too low or even empty ； ③The pump inlet filter is clogged ； ④The cooling effect at the top of the tower is poor, resulting in a high temperature of the reflux liquid ； Handling: ① Start the backup pump; if it cannot be started, the machine should be shut down ； ②Stop the extraction process, shut down the reflux pump, adjust the operations; once the liquid level in the reflux tank returns to normal, restart the reflux pump to establish reflux, and only then resume extraction once everything is satisfactory ； ③Switch to the backup pump and clean the pump inlet filter ； ④Increase the cooling water volume and appropriately raise the cooling water pressure, or add another air cooler. 6. Liquid flooding: Causes: ① Equipment problems, such as the floating valve being blown over ； ②Backflow interruption ； ③A sudden increase or decrease in the flow rate of the heating medium in the reboiler, or significant fluctuations in the pressure of the heat source ； ④The load inside the tower is too high ； ⑤The pressure inside the tower rises and falls suddenly. Handling: ① Stop the vehicle ； ②Find the cause of the backflow interruption and address it accordingly ； ③To address the causes of fluctuations, stabilize the flow rate and pressure of the heating medium in the reboiler ； ④Reduce the feed rate; if necessary, stop feeding and production, and operate in full reflux mode ； ⑤Identify the causes of the fluctuations and take targeted actions ； 7. Significant pressure fluctuations inside the tower: Causes: ① Large fluctuations in the flow rate and pressure of the heating medium in the bottom reboiler ； ②Large fluctuations in feed volume and composition ； ③Large fluctuations in Tawin ； Treatment: ① Contact other processes to stabilize the flow rate and pressure of the heating medium ； ②Control the feed flow rate and composition properly ； ③Take appropriate actions to address the causes of the fluctuations. 8. Large fluctuations in temperature inside the tower: Causes: ① Large fluctuations in pressure inside the tower ； ②The liquid level in the return tank is low, resulting in unstable discharge from the return pump, or the pump fails to deliver fluid ； ③Large fluctuations in feed volume ； ④Large fluctuations in the flow rate, temperature, and pressure of the heating medium in the bottom reboiler ； ⑤The liquid level at the bottom of the tower fluctuates significantly. Treatment: ① Based on the specific cause, strive to stabilize the pressure inside the tower and continue operations, but prevent overpressure ； ②Stop the extraction process and shut down the return pump; maintain the current operation. Once the liquid level in the return tank stabilizes and returns to normal, restart the pump to resume operations ； ③Stable feed rate ； ④Coordinate with other processes to stabilize the flow rate, pressure, and temperature of the heating medium ； ⑤Stabilize the bottom of the tower liquid level by manually controlling the bottom liquid level control valve. 9. The temperature at the bottom of the tower drops suddenly and fails to rise again: Reasons: ① Sudden interruption of the heating medium for the reboiler at the bottom of the tower ； ②Blockage of reboiler tubes ； ③The liquid level at the bottom of the tower is empty. Treatment: ① Contact other processes to initiate a shutdown ； ②Parking for maintenance ； ③Increase the feed rate and the reflux volume, appropriately lower the top temperature of the tower, stop product extraction to maintain operation, and resume operations once the liquid level at the bottom of the tower returns to normal. Chapter 6: Operating Procedures for the Tank Area – Section 1: Brief Description of the Process Flow 1. Diagram of the AA-grade pipeline layout: The AA-grade purified methanol coming from the distillation process enters tanks F0509a and F0509b via pipelines ML-0537-80-B2M07. From there, it exits these tanks through pipelines ML-0564-100-B2M07 and ML-0566-100-B2M07, respectively, and goes to pumps J0510a and J0510b (the two pumps serve as backups for each other). Through pipeline ML-0567-80-B2M07, the fluid then enters purified methanol tanks F0901a and F0901b via pipelines ML-0902-80 and ML-0901-80 respectively. Fluid exiting tank F0901a flows through pipeline ML-0903-250, while that exiting tank F0901b flows through pipeline ML-0904-250; both then go to the transfer pumps. The pipelines leading to the pumps are ML-0905-200 for tank a and ML-0906-200 for tank b. The pipelines leaving the pumps are ML-0907-150 for tank a and ML-0908-150 for tank b. After leaving the pumps, the fluid can take two paths: one is via ML-0909-200 to the dispatch platform when HV-903 is in operation, and the other is via HV-0905 and ML-0910-150 back to tanks F0901a and F0901b when HV-903 is closed. 2. Layout diagram of the primary purified methanol pipeline: The primary purified methanol from the distillation process enters the tank via pipeline ML-0544-80-B2M07; after exiting the tank, it flows through ML-0569-100-B2M07 (tank C) and ML-0571-100-B2M07 (tank d), respectively, to reach pumps J0511a and J0511b (the two pumps serve as backups for each other). After leaving the pumps, the fluid flows through ML-0572-80-B2M07, then via ML-0921-80 into the purified methanol tank. It further goes through ML-0922-80 to reach F0902a, and through ML-0921-80 again to reach F0902b. From there, it exits via ML-0923-250 and ML-0924-250. Pipeline ML-0923-250 leads to J0902a via ML-0925-200, while ML-0926-200 leads to J0902b. After leaving these pumps, the fluid combines via ML-0927-150 and ML-0928-150 before entering ML-0929-200. From there, it flows through HV-904 to the delivery point; when HV-904 is closed, HV-906 is opened, and the fluid then returns to F0902a via ML-0930-150, and to F0902b via ML-0931-150. 3. Description of the intermediate tank area: Fire arresters with a DN50 size are installed at the vent holes on the tops of all six tanks in the intermediate tank area, to ensure the safety of the methanol tanks. 4. Description of the finished product tank area: The four tanks in this area are equipped with internal floating roofs. Each tank has two light-transmitting holes, and six ventilation holes are evenly distributed around its tank wall. PC24 type foam fire extinguishers are also provided. Section 2: Operating Parameters
1. Pump operating parameters:
| Pump Name | J0510a, b | J0511a, b | J0901a, b | J0902a, b | J0509a, b |
| Normal Pressure | 0.64 Mpa | 0.2 Mpa | 0.65 Mpa | | |
| Operating Range | 0.60–0.70 Mpa | 0.18–0.28 Mpa | 0.6–0.8 Mpa | | |
| Flow Rate | 45 m3/h | 90 m3/h | 27.3 m3/h | | |
| Rated Current | 48 A | 39 A | 30 A | | |

2. Tank parameters:
| Tank Name | Normal Value (mm) | Alarm High Limit (mm) | Alarm Low Limit (mm) |
| Crude Methanol Tank | 4000 | 8000 | 300 |
| Pure Methanol Metering Tank | 2900 | 5400 | 200 |
| Finished Product Storage Tank | 12110 | 400 | |

For each tank:
- Intermediate Tank, Finished Product Tank: Operating pressure – slightly positive pressure: -50 to +200 mmH2O; atmospheric pressure; breathing valve activation pressure: +200 mmH2O.
- Operating temperature: 40–55°C; normal temperature.

3. Turnover parameters for the finished product tank area:
| Item | Tank Area Name | Methanol Source | Production Unit | Storage Capacity (m3) | Inlet Method | Outlet Method | Storage Days | Number of Tanks | Tank Volume | Tank Structure | Tank Volume Coefficient |
|------|----------------|-----------------|----------------|----------------------|---------------|---------------|--------------|----------------|--------------|----------------|--------------------------|

Section 3: Operating Procedures
I. Tank transfer procedures:
1. The pipeline identifier for the intermediate tank area is 5, while that for the finished product tank area is 9. 2. When taking over the shift, the personnel on duty should have a clear understanding of the conditions of each tank as well as their liquid level heights. 3. During shift change, a tank transfer operation is carried out as follows: (1) Transfer the liquid between F0509a and F0509b. If the previous shift used F0509a (the AA-grade purified methanol metering tank) for liquid intake, then this shift will use F0509b (the AA-grade purified methanol metering tank) for liquid intake. Open the inlet valve of F0509b and close the inlet valve of F0509a; at this point, liquid will flow into F0509b while F0509a becomes full. Then open the outlet valve of F0509a, and the liquid will be sent to the finished methanol storage tank via J0510a and J0501b. (2) F0509c and F0509d (Primary methanol metering tank c) form a set; the tank replacement procedure is the same as in (1). (3) F0509a and F0509b generally cannot be mixed with F0509c and F0509d. 4. Conduct a routine inspection of all equipment within the tank area once per hour, and accurately record the liquid level in each tank by referring to the magnetic float level gauge and differential pressure transmitter (displayed in the control room). 5. When the liquid level in each tank reaches the upper limit or an high-level alarm is triggered, immediately close the inlet valve of the tank and open the outlet valve to pump the liquid into a 2000 m3 storage tank; at the same time, transfer the purified methanol produced in the methanol workshop to another tank in the same group. 6. Before transferring methanol to the 2000 m3 finished product tank, it is necessary to contact the operators in the finished product tank area; only after the process in that area has been adjusted can the operators in the intermediate tank area proceed with the transfer. 7. During inspections, it is also necessary to check the process pipelines, tanks, various accessories, valves, and facilities; any issues found should be reported promptly for handling. 8. If a sudden increase or decrease in methanol is detected during measurement, it should be reported to the control room immediately, and efforts should be made to determine the cause. 9. Under normal circumstances, transporting the material to the finished product tank area once per shift is sufficient to ensure the proper operation of the intermediate tanks; however, when production increases sharply, it is necessary to transfer the methanol in those tanks to the finished product tank area promptly. 10. The drain valve is generally kept closed; it can be opened only upon receiving formal notification from the workshop. II. Operating Procedures for Pure Methanol Pumps 1. Usage Requirements (1) Operation without load is strictly prohibited ； (2) Thoroughly remove rust and solid foreign objects from the device ； (3) It can be operated only after all air has been removed ； (4) The shut-off operation must not last more than 30 seconds ； (5) Do not operate in reverse continuously ； (6) For shielded electric pumps equipped with cooling water jackets, the cooling water must first be supplied at the specified flow rate before starting the pump ； (7) During operation, if abnormal noises or vibrations are detected, they must be investigated promptly; the cause must be identified as soon as possible in order to resolve the fault ； (8) The TRG table indicates a red area, and further operation is not allowed ； (9) In the event that the protection device activates, operation shall not be resumed until the cause of the activation has been identified and completely eliminated ； (10) It should not operate when the flow rate is below the minimum value ； (11) The plant shall not be started up or kept running if the flow rate in the cooling water jackets, heat exchangers, and counterflow circuits is below the specified value ； (12) This electric pump shall be used at a voltage of 380V, a frequency of 50Hz, at an altitude not exceeding 1000m, in an environmental temperature range of -20°C to +40°C, with a humidity level not exceeding 85% (at 25°C), and under the specified explosion-proof rating ； (13) The pump must operate within the range of performance parameters specified in the contract; otherwise, it will affect the axial thrust ； 2. Structure: Basic type (F and FA types) – The shielded electric pump consists of a motor and a pump integrated together. The inner surface of the stator and the outer surface of the rotor are equipped with stator shields and rotor shields made of non-magnetic, corrosion-resistant metal plates; in addition, their respective sides are sealed off by welding them with thick sheets of corrosion-resistant metal, thereby creating a complete separation from the liquid being transported and preventing the stator core from being corroded. Flow path of the pump’s circulating fluid: from the pump’s discharge port → filter → circulation pipe → RB end cover → gap between the rear bearing and the side sleeve → air gap between the stator shield and the rotor shield → gap between the front bearing and the front sleeve → balance hole of the impeller → impeller inlet. The rotor that rotates in the liquid consists of a shaft supported by two bearings at the front and back; an impeller is mounted at the front end of the shaft, resulting in a shielded electric pump without an axial seal. The axial thrust generated by the impeller of the shielded electric pump acts on the front and rear thrust discs. As for the difference between the F type and the FA type, in the F type it is the FB end cover that combines the pump and the motor, while in the FA type there is a connecting element whose outer diameter matches that of both the pump body flange and the motor flange; the F type should be used in such cases, otherwise the FA type is preferred. 3. Trial operation (1) Setting of the current relay ； The rated current of shielded motors is slightly higher than that of ordinary motors with the same power; therefore, pay attention to the data on the nameplate. From the perspective of motor protection, it is desirable to set the current value at a relatively low level that will prevent false trips; it is recommended to use the following general criteria for setting it: when voltage and load changes are small... 1.1 times ； When voltage and load changes are significant... 1.25 times ； If the operating current of the motor is much lower than the rated current, it is recommended to use the operating current as a reference ； (2) Filling and venting ； Fill and vent in the following order: a. Close the valve on the discharge side ； b. Open the valve on the suction side ； c. Open the valve on the discharge side to release the gas from the pump and pipelines; wait for a while, then close only the valve on the discharge side again ； d. Operate the pump’s exhaust valve to release the gas. When transporting hazardous liquids, a hose should be installed at the exhaust valve to allow air to escape, and safety must be ensured. (3) Trial operation: Once all preparatory work is complete, the trial operation can be carried out. The sequence of operations is as follows: a. Open the valve on the suction side ； b. Close the valve on the discharge side ； c. Turn on the power supply ； d. Slightly open the valve on the discharge side ； e. Monitor the pressure on the discharge side ； f. TRG indicates how ； f1. Out of range... reverse, correct wiring ； f2. Yellow–Red……Identify the cause and take measures ； f3. Green... operating normally ； g. Keep the discharge side valve closed; after running for 1–2 minutes, stop the pump. After a few minutes (the longer the viscosity of the liquid being transported, the longer the stop time), operate the vent valve again to release air; repeat this process of starting up, stopping, and venting until all the gas has been removed. 4. Operation (1) After the trial run, it enters normal operation. First, slowly open the valve on the discharge side to achieve the specified flow rate ； (2) At this time, for those equipped with a bypass pipeline system, the bypass pipeline valve should also be opened in the same way ； (3) Others a. Check whether the current exceeds the rated current (FA type: 39A, F type: 48A) ； b. Check whether the gauge reading is at the specified value ； c. Whether the TRG gauge indicates normal operation ； d. Operating noise, any abnormalities in vibration ； Upon inspection, if any of the above items is found to be abnormal, the power supply should be disconnected to identify the cause. III. Operating Procedures for the Crude Methanol Pump 1. Pump Startup Procedure (1) Preparation work a. Check that the pump’s outlet pipelines, valves, flanges, filters, and check valves are in good condition and intact, with no leaks. b. Check that the pressure gauge and thermometer are sensitive and reliable. c. Check that the pump cooling water, floor drains, and floor channels are unobstructed and free of debris. d. Check that the foundation bolts are not loose, and that the couplings, motor grounding, and guards are all properly fixed in place. e. Turn the shaft several times; the rotation is even and smooth, with no abnormal noises, and there is no leakage at the shaft seal. f. Check that the lubricating oil is at least 2/3 of the way up in the oil cup. g. Contact an electrician to inspect the wiring and the entire system; power can be restored only after no issues are found. (2) Startup steps a: Carry out the preparatory work before starting the pump, and open the inlet valve. b. Close the outlet valve. c. Connect to power. d. Slightly open the outlet valve and observe the outlet pressure. e. When the outlet pressure reaches the operating pressure, gradually open the outlet valve, pay attention to the current, and adjust it slowly to the specified flow rate. f. After the pump starts, conduct a thorough inspection to check for any abnormalities. If severe leakage, vibration, sharp noises, or similar issues are detected, the pump should be stopped immediately for handling. 2. Pump shutdown procedure: (1) Close the pump outlet valve. (2) Press the button to stop the pump. (3) Close the pump inlet valve. (4) Stop the cooling water 15 minutes after stopping the pump. 3. Pump switching operation: (1) Start the standby pump following the startup procedure, bring it into operation, and adjust the pressure so that the flow rate remains stable. (2) Gradually close the outlet valve of the operating pump, and closely monitor whether the pressure and flow rate fluctuate; if so, suspend the switching process, conduct a thorough inspection, eliminate the cause, and then proceed with the switching. (3) For the activated pump, conduct a thorough inspection to check for any abnormalities. (4) Stop the running pump according to the pump shutdown procedure. 4. Daily maintenance: (1) Strictly implement the post responsibility system and routine inspection system; carefully fill in operation records; clean regularly to ensure that gutters, floors, pumps, and valves are free of oil stains, debris, and standing water. (2) The acid-resistant pump should have its shaft rotated every 8 hours. (3) Check whether the pump bearings are overheating. (4) Regularly check whether the machine pump bolts and back caps are tight. (5) Carefully listen for any abnormal noises from the motor, pump body, and bearings; the vibration of the pump should not exceed 0.06 mm. (6) Check that the valves, flanges, and joints are leak-free. (7) Check that the insulation of the pump casing, valves, and pipelines is intact, and that the grounding wire guards are properly fixed. (8) The standby pump is in good standby condition to ensure it can start promptly when switching pumps. (9) Carefully check that the medium pressure, flow rate, and temperature are within normal ranges, and that the motor and current remain stable without any fluctuations. (10) Regularly inspect the processes, valves, and equipment under the unit to ensure they are complete, functional, and in good working condition. (11) Strictly implement various systems, and report and address any issues discovered promptly. (12) The pump must not be scrubbed or adjusted while it is in operation. IV. Steps to drive again 1. Adjust the process ； 2. Start the pump using the shielded electric pump startup method ； 3. If the tank has reached the high alarm liquid level, it is necessary to change to another tank. V. Tank emptying procedure: 1. First, use a pump to lower the methanol level in the tank that is to be emptied to its lowest level. F0901a and F0901b can be used to pump liquid between each other, and the same applies to F0902a and F0902b. Use the return lines ML-0910-150-B2M07 and ML-0930-150-B2M07 at the pump outlet. 2. The methanol in the dead zone that cannot be pumped out should be drained through the discharge port into an underground tank or a drain, ensuring that as much of it as possible is removed. 3. Close the inlet and outlet of the tank. 4. Open the two ventilation holes on the top of the tank for air circulation. 5. Connect a steam belt to the bottom of the tank and heat it for over 48 hours in order to displace the methanol vapor inside the tank. 6. After stopping the steam supply, open the upper and lower manholes for cooling and ventilation; then test the concentration of methanol gas inside the tank. If the concentration is within the safe range, proceed with ventilation and turn off the oxygen supply. 7. Before entering the tank, one must wear a gas mask, rubber boots, and rubber gloves; the bottom of the tank as well as the areas where fire is used should be scrubbed with yellow earth. 8. When cleaning the methanol tank, a supervisor must be present outside the tank. 9. All connection pipelines to the methanol tank where welding will take place must be severed, and it should be isolated using asbestos boards so that the tank becomes completely independent (fire-fighting pipelines as well as nitrogen pipelines must also be isolated); if welding requires the use of electricity, the grounding wire must also be separated. Section 4: Abnormal Operations and Accident Handling I. Fires and explosions in storage tanks Causes: open flames, static electricity, sparks generated by impact, and spontaneous combustion due to the oxidation of ferrous sulfide, etc. Methods to prevent it: eliminate heat sources, remove static electricity, and reduce the speed at which vehicles depart. II. The tank is evacuated or overpressurized. Cause: The tank is subjected to negative pressure or excessive positive pressure. Prevention methods: Maintain a slight positive pressure in the tank; regularly inspect the tank’s safety accessories, such as vent holes, internal floating roofs, and vacuum valves. The maximum pressure should not exceed +200 mmH2O. III. Floating roof chuck inside the large tank, to prevent breakage of the anti-rotation wire rope and anti-static grounding wire. Reason: Poor lifting performance of the internal floating roof; the wire rope fixing clamps came loose from the tank bottom; the wire rope broke; and the static electricity grounding wire was broken. Prevention method: Regularly monitor the floating condition of the internal floating roof; if any jamming is detected, immediately stop feeding liquid into that tank and contact someone to carry out repairs. IV. Overflow incidents in large and small tanks: Causes include the liquid level reaching above safe limits, inadequate routine inspections, and a lack of responsibility. Prevention methods: Do not exceed the safe dimensions when introducing liquid, and strengthen routine inspections. V. Pump failures
1. Insufficient pump flow and low outlet pressure
Causes and solutions:
1. Blockage or condensation in the inlet pipeline or filter screen
– Switch to another pump and clean/repair it.
– The inlet valve may not be open or is partially closed, or its valve plate may have fallen off.
– Switch to another pump and carry out repairs.
– Air in the inlet pipeline or pump body
– Release air from the pump’s outlet vent.
– Leaks in the inlet pipeline or pump body
– Check the system and switch to another pump to fix the leak.
– Damaged or incorrectly installed impeller
– Switch to another pump and carry out repairs.
– Motor installed in the wrong direction
– Switch to another pump and contact an electrician for assistance.
– Insufficient suction height
– Raise the liquid level or increase the inlet pressure.
– Worn inlet ring or excessive gaps in various parts of the inner casing
– Switch to another pump and carry out repairs.

2. Motor overheating due to overload
Causes and solutions:
1. Excessive flow rate when the pump is used to handle methanol
– Slow down the outlet valve slightly to reduce the flow rate.
2. Motor rotating in the reverse direction
– Switch to another pump and contact an electrician to adjust the circuit.
3. Debris inside the impeller
– Switch to another pump and call for emergency repair.
4. Misalignment between the motor and the shaft
– Switch to another pump and call for emergency repair.
5. Damaged shaft pump
– Switch to another pump and call for emergency repair.
6. Excessively high or low voltage
– Contact an electrician to find the cause.
7. Motor failure; moisture damage to the stator, poor insulation, or one phase missing in the three-phase power supply
– Switch to another pump and contact an electrician for repairs.

3. Bearing overheating
Causes and solutions:
1. Misalignment between the pump shaft and the motor axis, or vibration
– Switch to another pump and call for emergency repair.
2. Excessive load on the motor, causing it to overheat
– Identify and address the cause.

4. Pump vibration or noise
Causes and solutions:
1. The pump is running dry and not producing any flow
– Adjust the settings; switch to another pump if necessary.
2. Loose foundation bolts
– Tighten them.
3. Actual flow rate exceeds the designed value
– Increase the flow rate setting.
4. Debris inside the impeller or the impeller being loose
– Switch to another pump and carry out emergency repairs.
5. Large deviation in alignment between the pump and the motor
– Switch to another pump and carry out emergency repairs.
6. Increased gaps in bearings after wear, or shaft misalignment
– Switch to another pump and carry out emergency repairs.
7. Air in the pump body or inlet pipeline
– Remove the air from the pump body.
8. Bent shaft or unbalanced rotor
– Switch to another pump and carry out repairs.
9. Friction between the rotor and the stator
– Switch to another pump and carry out emergency repairs.
10. Excessive heat in the pump body
– Identify and address the cause.

5. Motor fails to start
Causes and solutions:
1. Low voltage
– Contact an electrician to find the cause.
2. Faulty circuit or poor connections
– Contact an electrician to find the cause.
3. Excessive load on the motor
– Contact an electrician to find the cause.
4. Debris inside the pump or improper installation
– Contact a mechanic for repairs.
5. Faulty switch, non-functional buttons, or blown fuses
– Contact an electrician for repairs.

6. No water output from the pump, with the pressure gauge indicating abnormally high values
Causes and solutions:
1. Incorrect rotation direction of the impeller
– Adjust the impeller’s rotation direction.
2. Blockage in the impeller and pipelines
– Remove the blockage.
3. Outlet valve not opened
– Open the outlet valve.

7. Sudden increase or decrease in pressure
Causes and solutions:
Increase in pressure:
1. Sudden reduction in flow rate
– Adjust the pressure and reduce the number of pumps in operation.
2. Blockage in the outlet pipeline
– Identify and remove the blockage.
3. Outlet valve plate has fallen off
– Stop the pump and repair the outlet valve.

Decrease in pressure:
1. Air leakage or blockage in the suction pipe
– Stop the pump, drain the air, and remove the blockage.
2. Pipeline rupture
– Repair the leak or replace the pipeline.
3. Sudden increase in flow rate
– Increase the number of pumps in operation.

8. Excessively high or low current
Causes and solutions:
High current:
1. Excessive output flow rate
– Reduce the pump’s load and increase the number of pumps in operation.
2. Debris blocking the shaft housing
– Remove the debris from inside the pump.
3. Damaged bearings or other mechanical issues
– Replace the bearings and address the mechanical problems.
4. Low voltage or faulty ammeter
– Increase the voltage or repair the ammeter.

Low current:
1. Blockage at the pump’s suction inlet, preventing liquid from entering
– Remove the blockage at the suction inlet.
2. Air in the suction inlet
– Repair or adjust the area where air is leaking in.
3. Severe cavitation in the impeller
– Replace the impeller.
4. Low liquid level in the suction tank, allowing air to enter
– Raise the liquid level and remove the air.
5. Faulty ammeter
– Repair or replace it.

VI. Failures of vortex flow meters, flow control devices, and pneumatic ball valves. Reason: Mechanical failure, improper human operation, or fault in the instrument itself. Prevention methods: Master the correct operating procedures, perform regular maintenance or contact the service team for equipment maintenance. VII. The level gauge for the large tank is faulty, as well as the magnetic flap type level gauge in the intermediate tank area. Reason: Mechanical failure, instrument failure. Prevention methods: Strengthen a sense of responsibility and master the correct operating procedures. Section 5: Safety Precautions Since methanol is flammable, explosive, and volatile, its vapors mix with air to form explosive mixtures; the explosive range is 6–36.5%. It is highly toxic to humans, with an exposure limit of 50 mg/m3. Ingesting 30 ml of it can be fatal, while 10 ml can cause blindness. Therefore, the following regulations are established: 1. Open flames and smoking are strictly prohibited within the tank area, and vehicles without flame arrestors are not allowed to enter. 2. Unrelated personnel are not allowed to enter the tank area. Operators must not wear synthetic fiber clothing or shoes with metal studs; they should wear protective gear while working. 3. When filling with methanol, protective goggles should be worn, and a gas mask should be used if necessary. If it gets into the eyes, they should be rinsed immediately with an eye wash station. 4. Operators should conduct regular inspections and report and address any issues found promptly. 5. In case of a fire, do not panic; immediately inform the fire department and the factory’s foam fire station. Foam must be used to extinguish the fire – it is strictly prohibited to use water. Article 3: Operating Procedures for Compression Units Chapter 1: Overview Our plant uses combined compressors for methanol synthesis gas circulation, which were manufactured by the American company DRESSER-RAND. It consists of a D8R6S centrifugal compressor and a “W”-type steam turbine. The compressor cylinder is divided into two sections; the gas enters through the compressor inlet and is compressed in one of these sections. It reaches the second inlet where it mixes with the recycled gas. Compress together and send to the synthesis section. For load adjustment and anti-surge, two return pipelines are designed, namely the outlet pipeline and the side material inlet pipeline. The unit speed is controlled by the governor SIC-301. This machine features a straight-through rotor structure. I. Working principle of the compressor: A centrifugal compressor is a type of rotary machinery that uses an impeller to rotate at high speed, thereby applying centrifugal force to the gas and enabling it to gain pressure energy. The process gas enters the inlet volute of each stage of the compressor, flows through the inlet vanes of that stage; these vanes direct the gas at an appropriate angle toward the impeller of that stage. Due to centrifugal force, the gas is expelled from the edges of the impeller at high speed into the channel formed by the inlet vanes of the next stage and a set of partitions. Then, the gas passes through a swirler and an annular channel to reach the impeller of the next stage. As the annular channels through the partition expand, the gas flow velocity slows down, thereby converting some of the kinetic energy into pressure energy. Through such repeated compression at various stages, a certain outlet pressure is achieved to meet the requirements of the process users. 2. Working principle of the turbine: Steam first passes through a fixed nozzle, where its initial pressure is reduced to enable steam expansion, converting thermal energy into mechanical energy. As a result, extremely high-speed steam jets are generated at each nozzle. Steam is directly injected onto the impeller; due to the transfer of force, when a sufficient amount is reached, the impeller causes the main shaft to rotate. Its working principle can be considered as the conversion of the thermal energy of steam into its kinetic energy, which is then, through the action of the impeller, converted into mechanical rotational energy of the main shaft. II. Introduction to the unit system 1. Oil system The oil system consists of three components: lubricating oil, seal oil, and control oil. The oil in the tank is pumped out by pumps (two in operation with one as a backup), cooled and filtered, before being sent to the lubricating oil, control oil, and sealing oil systems via PCV202, PCV203, and FCV201 respectively. The oil pressure at the pump outlet is controlled by PCV201, which is located on the pipeline from the pump outlet to the return pipeline to the oil tank. The pipeline is equipped with two coolers and two filters designed to be used in alternation. For lubricating oil, a lubricating oil emergency tank with a capacity of 0.416 m3 is provided in the lubrication system to ensure a supply of lubricating oil in case of an emergency. After lubricating each lubrication point, the lubricating oil returns to the tank after gathering at those points. A seal oil reservoir is provided in the seal oil system; by utilizing the difference in liquid levels, the pressure of the seal oil is kept higher than that of the seal gas. After entering the seal area, most of the seal oil is used for cooling, and it flows back to the oil tank through the gap between the outer seal ring and the shaft. Another portion of the oil flows through the internal seal ring to the area between the shafts, thereby preventing the leakage of process gas. The shaft sleeve features an oil-scattering ring structure, and any leakage of process gas through the gap around the internal seal ring also prevents oil from entering the gas stream. This mixture of oil and gas is then sent to an acidic oil catcher, where oil and gas are separated. The oil is discharged into the degasser and then returned to the tank for reuse. An accumulator equipped with nitrogen gas cushions is installed on the control oil pipeline to stabilize the control oil pressure and ensure the oil supply volume. Part of the control oil is used by the governor to regulate the power source, while another part is used to maintain the pressure in the main steam valve cylinder. An electromagnetic valve is also provided for remote control, enabling the shutdown of the system under low oil pressure conditions in the main steam valve. 2. Vacuum condensation system: The vacuum condensation system of this unit consists mainly of a surface condenser, a heat well, a condensate pump, an extractor (including a start-up ejector), and related instrumentation pipelines. The turbine steam is discharged into the condenser, where it undergoes phase change upon cooling; the condensed liquid is sent to the heat well, and a high vacuum is created within the condenser. The condensate in the hot well is pumped out, its level is regulated by LC-303 and controlled by FCV-303. Since the non-condensable gases present in the steam cannot be condensed, and a small amount of air also leaks in, a vacuum pump and a start-up ejector unit are installed to maintain a stable vacuum in the condenser. 3. Turbine seal system: The purpose of the seal is to prevent air from being drawn into the turbine casing through the stuffing box cover. The piping on the outermost side of the shaft end directs the escaping steam into the shaft seal cooler where it is condensed into water. An external steam inlet pipe is provided on the inner side of the shaft end; the stuffing box at the steam end has a pressure lower than atmospheric pressure during startup and under light load conditions, while the pressure in the stuffing box at the exhaust end remains at the vacuum level of the condenser. Steam is introduced into these stuffing boxes through pipes during startup. When the primary pressure rises above atmospheric pressure, steam is released to the sealing pipeline at the steam side. At this time, steam needs to be added only to the exhaust side stuffing box, and the pressure can be controlled using a manual valve, a pressure reducing valve, and a pressure regulator. 4. Train jump system: To protect the locomotive and prevent damage caused by factors such as overspeed and potential mechanical problems, the locomotive is equipped with automatic shutdown safety devices; when any of these devices activate, the main steam valve closes. In addition, a solenoid valve is provided, which is connected to the electrical trip signal. This valve is used as a remote control means for the device to derail. There are two ways of over-speed tripping: one is the tripping of the governor due to over-speed, which is set by the over-speed function built into the governor, with a value of 16173 r/m. Secondly, a two-out-of-three electronic overspeed monitor is used; it obtains the rotational speed from another sensor, with a set value of 16322 r/m. The device is also equipped with a solenoid valve that allows for the selection of specific tests; in addition to triggering the machine in response to an electrical stop signal, its main advantage is the ability to perform regular inspections on the solenoid valve without affecting the operation of the turbine. 5. Anti-surge system: To enable the unit to operate under varying conditions, keeping the operating point at a safe distance from the minimum flow rate and preventing and eliminating surge, the system uses a backflow method for anti-surge protection. III. Interlocks and Alarm Settings: When the shutdown signals listed in the interlock system are triggered, the unit will stop operating. The main interlocks and alarm settings are as follows:

| Tag Number | Name | Function | Alarm Value | Shutdown Value |
|-------------|------|----------|------------|---------------|
| LSH-203 | Pressure Switch | High level alarm for seal oil sump | <2.1 KpaG | — |
| LSH-303 | Level Switch | High level alarm for hot well | — | — |
| LSH-401 | Level Switch | Allow startup when lubricating oil sump is full | — | — |
| LSL-201 | Level Switch | Low level alarm for lubricating/seal oil tanks | — | — |
| Tag Number | Name | Function | Alarm Value | Shutdown Value |
| LSL-202 | Level Switch | Low level alarm for degassing tank | — | — |
| LSL-203 | Pressure Switch | Start backup pump when seal oil sump level is low | <102 KpaG | — |
| LSL-204 | Pressure Switch | Alarm when seal oil sump level is too low | <99 KpaG | — |
| LSL-303 | Level Switch | Low level alarm for hot well | — | — |
| LSL-402 | Level Switch | Low level alarm for lubrication accident tank | — | — |
| LSLL-501 | Level Switch | Low differential pressure between seal oil and gas | — | — |
| PDSH-201 | Differential Pressure Switch | Low differential pressure between seal oil and gas | >103 Kpa | — |
| PDSL-104 | Differential Pressure Switch | Low differential pressure between seal oil and gas | <6.9 Kpa | — |
| PDSL-104 | Differential Pressure Switch | Alarm for low differential pressure between oil and gas | <20.7 Kpa | — |
| PSH-203 | Pressure Switch | Alarm for high outlet pressure of oil pump “A”; start auxiliary pump | 2.76 Kpa | — |
| PSH-204 | Pressure Switch | Alarm for high discharge pressure of oil pump “B”; start auxiliary pump | 2.76 Kpa | — |
| PSL-304 | Pressure Switch | High pressure alarm for steam turbine condenser | >6.9 KpaG | — |
| PSL-101 | Pressure Switch | Low pressure alarm for lubricating oil | 82.8 KpaG | — |
| PSL-205 | Pressure Switch | Low pressure alarm for oil after filtration | 5.48 barg | — |
| PSL-206 | Pressure Switch | Low pressure alarm for oil after filtration | 5.48 barg | — |
| PSL-303 | Pressure Switch | Low pressure alarm for control oil | <621 KpaG | — |
| PSLL-101 | Pressure Switch | Trip the unit due to low lubricating oil pressure | <55.2 KpaG | — |
| TSH-205 | Temperature Switch | High temperature alarm for lubricating oil and seal oil main pipes | >54.4°C | — |
| TSL-201 | Temperature Switch | Low temperature alarm for lubricating/seal oil tanks; controls heater operation | <27°C | — |
| TSL-202 | Temperature Switch | Controls heater for degassing tank; set at 80°C | — | — |

In addition, high-level alarms and shutdown triggers are set for the vibration and displacement of the shaft bearings, thrust bearings, and radial bearings in the compressor and steam turbine. These values are directly configured by the instruments. A: Compressor journal bearings and thrust bearings TE-701A/B, TE-702A/B, TE-703A/B, and TE-704A/B. High temperature alarm: 110°C; Shutdown at high temperature: 121°C. B: Steam turbine journal bearings TE301A/B, TE302A/B. High temperature alarm: 110°C; Shutdown at high temperature: 121°C. C: Steam turbine thrust bearings TE303A/B/C, TE304A/B/C ； High-temperature alarm: 110°C; High-temperature shutdown: 121°C.
D: Radial vibration and shaft displacement
(1) Compressor (in mils):
Radial vibration: Alarm threshold: 1.95 (49.5 microns); Shutdown threshold: 2.4 (61 microns).
Axial displacement: Alarm threshold: 5 (127 microns); Shutdown threshold: 10 (254 microns).
(2) Steam turbine (in mils):
Radial vibration: Alarm threshold: 1.13 (28.7 microns); Shutdown threshold: 1.8 (45.7 microns).
Axial displacement: Alarm threshold: 17 (432 microns); Shutdown threshold: 22 (559 microns).

Chapter 2: Operating parameters of the compressor unit
1. Normal operating conditions
Stage 1 Stage 2
Inlet Outlet Inlet Outlet
Pressure (barg): 27.5 46.24 46.24 51.49
Temperature (°C): 40 100.6 49.5 61.3
Molecular weight: 10.08 7.67
Isentropic index: 1.377 1.377 1.374 1.374
Average pressure difference factor: 1.007 1.015 1.021 1.023
Flow rate (m³/h): 2145 8838
Flow rate (Nm³/h): 52018 341639
Flow rate (kg/h): 23392 116931
Operating speed: 14131 rpm
Polytropic head: 14773 3915
Polytropic efficiency: 78.2 79.9

Gas composition:
Component Molecular weight Mole percentage
Stage 1 Stage 2
Nitrogen 28.018 0.20 0.57
Water vapor 18.016 0.19 0.06
Carbon monoxide 28.010 12.57 3.11
Carbon dioxide 44.010 9.21 4.09
Hydrogen 2.016 71.94 74.75
Methane 16.042 5.39 16.78
Methanol 32.06 0.63
Average molecular weight: 10.059 7.243

2. Operating conditions during heating up of the synthetic nitrogen cycle
Stage 1 Stage 2
Inlet Outlet Inlet Outlet
Pressure (barg): 1.14 5.00 5.00 7.5
Temperature (°C): 40.0 186.3 58.6 100
Molecular weight: 27.67 27.97
Isentropic index: 1.395 1.395 1.400 1.400
Average pressure difference factor: 0.9999 1.000 1.000 1.000
Flow rate (m³/h): 2083 6576
Flow rate (Nm³/h): 3749 3206
Flow rate (kg/h): 4627 40007
Operating speed: 12684 rpm
Calculated power: 749 kW
Polytropic head: 12083 m 3710 m
Polytropic efficiency: 76.2 84.3

3. Operating conditions during heating up of the conversion nitrogen cycle:
Stage 1 Stage 2
Inlet Outlet Inlet Outlet
Pressure (barg): 3.5 7.39 7.39 8.00
Temperature (°C): 40.0 121.5 49.7 67.6
Molecular weight: 27.85 27.99
Isentropic index: 1.398 1.398 1.396 1.396
Average pressure difference factor: 0.999 1.000 1.000 1.000
Flow rate (m³/h): 1798 8601
Flow rate (Nm³/h): 6895 60258
Flow rate (kg/h): 8565 75248
Operating speed: 9956 rpm
Calculated power: 655 kW
Polytropic head: 6692 m 701 m
Polytropic efficiency: 76.7% 36.8%

4. Data related to the oil system
Grade of high-quality turbine oil: ISO VG32
Specific gravity (60°F/16°C): 0.87
Viscosity: SSU at 130°F/38°C: 80–94; SSU at 100°F/38°C: 140–170
Minimum viscosity index: 90
Kinematic viscosity (cs at 104°F/40°C): 28.8–35.2
Flash point: 356°F/180°C
Pour point: 23°F/-5°C
Maximum water content (V/V): 0.25%
Lubricating oil pressure (normal): 20 Psig/138 kPa; Operating range: 15–25 Psig/103–172 kPa
Seal oil pressure (normal): 409 Psig/28.20 barg

Temperature:
Minimum oil temperature during startup: 70°F/21°C
Normal operating oil temperature range: 120°F/49°C
Permissible oil temperature range: 110°F–130°F/43°C–54°C
Maximum allowable temperature difference between inlet and outlet oil: 30°F–50°F/17°C–28°C
Alarm threshold: 180°F/82°C; Shutdown threshold: 190°F/88°C
Maximum allowable bearing metal temperature: 245°F/118°C (alarm); 260°F/127°C (shutdown)
Normal temperature difference between inlet and outlet seal oil: 40–60°F/22–33°C
Maximum allowable temperature difference: 190°F/88°C (alarm); 200°F/93°C (shutdown)
Pre-charge pressure of the control oil accumulator: 414 kPaG

Chapter 3: Operating procedures
Section 1: Preparation work
I. Flushing of the oil system
To ensure the safe operation of the unit, the oil system must be flushed after initial installation or major maintenance. 1. Confirm that the installation and maintenance of the oil pump are complete, that the oil pump has passed individual testing, and is in a normal standby state. 2. Verify that the system pipelines and instruments have been installed; connect the bearing oil supply pipeline and the control oil supply pipeline using hoses, and direct the oil to the return oil pipeline. For now, the oil shall not be supplied to the bearing lubrication points or the control oil system. 3. All safety pressure relief valves should be sealed to prevent dirt from entering the valves; remove the orifice plates from the pipelines. 4. Clean the fuel tank thoroughly, and add lubricant of the same type as used under normal conditions to the working level. Install temporary 100-mesh filters on the flanges for supplying oil and returning it to the tank. 5. Start the oil pump in accordance with the electrical equipment operation procedures. Use the PCV-201 bypass valve to control the pump outlet pressure, gradually increase the oil circulation volume, and check for any leaks in the oil flushing pipeline, fixing them if present. 6. Operate continuously for 24 hours, heating the oil to 66–71°C every 4 hours, and then cooling it to ambient temperature, so that all pipelines can expand and contract due to temperature changes; during this cycle, the pipelines must be tapped continuously. 7. Once the above tasks are completed, the oil pump can be stopped, the bypass connection hose can be removed, and the pipelines can be reconnected following the standard procedure. At the same time, 100-mesh filters should be installed in front of the oil supply points for the turbine and compressor bearings as well as those for control oil. It is important to choose locations as close as possible to the lubrication points; the filters returning to the oil tank should be cleaned before being reinstalled. 8. Recheck the oil system to ensure it is in an acceptable condition for lubrication. 9. Restart the oil pump and proceed with cleaning again. After 4 hours of oil circulation, the pump can be stopped to inspect and clean the filter screen. This process is repeated until the cleaning is satisfactory. 10. Once the cleaning and inspection are successful, remove all temporary filters, reinstall the orifice plate, and restore the pressure relief valve. 11. Drain all the cleaning oil, paying special attention to areas where it has not been completely returned to the tank. 12. Clean or replace the pump inlet filter and oil filter, and clean the fuel tank again. 13. Refuel the tank; at this time, the oil used for cleaning can be filtered and then poured into the tank for use. The bearing should be disassembled and cleaned if necessary. Once the above tasks are completed, the next step is to commission the oil system, which should be carried out prior to the individual unit tests. Note that the seal oil cannot be fed into the unit until the compressor is pressurized to 4–5 barg. II. Individual testing of the turbine 1. Preparatory work before testing The preparatory work prior to startup is an important guarantee for the safe and normal operation of the turbine. The plant operators should conduct a thorough inspection of all equipment before starting the turbine, and carry out careful and meticulous preparation work. 2. Contents of the preparations before startup: 2.1 Inspect all areas that have been installed or repaired to ensure that all work is completed and approved. 2.2 The main and auxiliary equipment as well as the surrounding area should be cleaned thoroughly; any tools used for installation and maintenance, along with flammable materials, must be removed. 2.3 Check that there are no construction omissions in the process pipes, steam pipelines, and various auxiliary equipment of the unit; the insulation of valves, pipes, and equipment should be completed (the insulation of the turbine casing can be carried out after successful single-unit testing). 2.4 A thorough understanding of the improved equipment and systems after installation and maintenance is necessary, along with mastery of their operation methods. 2.5 The process system, steam system, cooling water system, oil system, vacuum and condensation systems, etc., must all be in condition for operation; any temporarily installed filters and blind flanges must be removed. 2.6 The oil pump and its drive unit were confirmed to be functioning properly after testing, and all bearings met the lubrication requirements. 2.7 The instrument air required by the unit, as well as the power supplies for instruments, propulsion, and lighting, are now in normal operation. 2.8 The instruments and signals associated with the unit (including pressure gauges, temperature gauges, level gauges, and various interlock alarm devices) have been installed and calibrated; they operate properly and are sensitive and reliable. 2.9 Prepare the necessary tools and forms, such as vibration tachometers, stethoscopes, wrenches, flashlights, fire-fighting equipment, shift handover logs, record forms, etc. 2.10 The communication signals between the compression station and the control room as well as related units have been tested, and it has been confirmed that the indicators are functioning properly and communication is unobstructed. 2.11 The operators have a thorough grasp of the operational data related to equipment, instruments, electrical appliances, etc. 3. Commissioning of the oil system: For specific details, see the appendix. 4. Pipe warming: For specific details, see the appendix. 5. Commissioning of the vacuum condensation system: For details, see the appendix. 6. Commissioning of the turbine shaft seal system: For specific details, see the appendix. 7. Warm-up: 7.1 All the preparatory work mentioned above has been completed, and the stop switch has been disengaged, resulting in a “PERMISSIVE TO START” status. Reset the PRO-TECH three-out-of-two redundant overspeed trip system. Set the speed of the governor to the minimum control speed of 9892 r/min, and press the “UNIT START” button to power on SV-303. 7.2 Observe that the governor has activated; manually operate the SV-303 handle to position it in the “CLOSE” position. 7.3 Once a safe oil pressure is established, turn the trip handle on the main steam valve handwheel clockwise, and then quickly turn it counter-clockwise to drive the steam turbine and rotate the rotor. 7.4 Adjust the opening of the main steam valve to keep the rotational speed stable at 600 r/min, and inspect the unit as follows: 7.4.1 Check whether the operating noise is normal. 7.4.2 Check whether the vibration of each bearing and the rotor displacement are normal. 7.4.3 Whether the condenser vacuum level meets the requirements. 7.4.4 The lubricating oil temperature should be between 46 and 52°C; check whether the return flow of oil to each bearing is normal. 7.4.5 Check whether the liquid levels in heat wells, oil tanks, and high-level oil sumps are normal. 7.4.6 Whether the thermal expansion of the turbine is normal. And all operational data of the unit are recorded in detail. In the event of any abnormality, the machine should be stopped immediately; it can be restarted only after the cause has been identified and resolved. 7.5 Stabilize at 600 r/m for 10 minutes, then manually trigger the shutdown to observe whether the emergency safety system operates properly. 7.6 Re-apply the brake to stabilize at 600 r/m, perform low-speed warm-up for about 30 minutes, and check and record the turbine operation conditions. 7.7 Increase the speed from 500 r/min to 2500 r/min at a rate of 500 r/min per minute, warm up the machine for 15 minutes, and check and record the operation status of the turbine. 7.8 Increase the rotational speed from 500 r/m to 5500 r/m at a rate of 500 r/m per minute, warm up the machine for 15 minutes, and check and record the operation status of the turbine. 7.9 Increase the rotational speed from 1000 r/m to 8000 r/m at a rate of 1000 r/m per minute, warm up the machine for 15 minutes, and check and record the operation status of the turbine. Note: A. The critical speed after compression at this stage (6400 r/m) and the critical speed of the turbine (7200 r/m) ； B. When passing through the critical speed, the speed should be increased rapidly. 7.10 Increase the rotational speed from 500 r/m to 9892 r/m at a rate of 500 r/m per minute. When the rotational speed approaches 9892 r/m, the speed should be increased gradually to check whether the governor has activated ； If the governor has already activated, slowly open the main steam valve to full open, and then close it again by one and a half turns. 7.11 Observe the operation of the turbine and record the unit’s operational data. 7.12 If the operating parameters are normal, the warm-up is complete. 8. Over-speed jump-out test 8.1 After operating for 30 minutes, increase the speed to 14,131 r/min and maintain it for 15 minutes; check and record the operation status of the turbine. 8.2 Use the overspeed test function on the governor to conduct an overspeed test of the governor, and observe and record the turbine speed at the time of trip. If it exceeds 16131 r/m and the vehicle has not stopped automatically at 100 r/m, manual shutdown should be performed. After shutting down, check and resolve the governor fault, then conduct the test again. 8.3 If the governor trips due to overspeed and operates normally, reapply the brake and use the bypass trip function to test the PRO-TECH backup trip system; increase the rotational speed to around 16322 r/m and observe whether the turbine trips. If it exceeds 16,332 r/m and the machine has not stopped automatically at 100 r/m, the brake should be applied manually to stop the machine and take corrective action. Then, the PRO-TECH backup overspeed shutdown system test was conducted again. Note: The operational tests of the turbine are conducted three times under the same conditions, and the results are considered acceptable if they fall within the specified 2% range. 8.4 If the operation is normal, reconnect the switch and increase the rotational speed to 9982 r/m; maintain this speed for 15 minutes, then check and record the turbine’s operating conditions. 8.5 Increase the rotational speed to 14,131 r/min and maintain it for 4 hours to conduct a single-unit test run of the turbine, while checking and recording the operation conditions of the turbine. 8.6 If the speed is reduced to 9982 r/min normally, then the main steam valve should be gradually closed, and the machine should be shut down manually; thus, the individual turbine test is completed. 8.7 If any abnormal situation occurs during the entire testing process, the machine should be stopped manually by engaging the brake, and after that the testing should be resumed. 8.8 After the testing is complete and the oil circulation for cooling is functioning properly, connect the coupling in order to proceed with load testing and commissioning the system. Section 2: Unit Startup I. Preparations before startup 1.1 The turbine unit has passed individual testing; the couplings have been installed, the system has passed a leak test, and all interlock safety devices have been verified to be functional. The utility systems are ready for operation. 1.2 Inspect the unit; the contents are the same as those for turbine commissioning inspection. 1.3 The process gas system is purged and pressurized to 4–5 barg. Note: During replacement, the anti-surge valve should be manually opened fully, and cooling water for C0301 should be supplied. 1.4 Commissioning the oil system 1.5 Pipe warming 1.6 Commissioning the vacuum condensate system. 1.7 Commission the turbine shaft seal system. II. Warm-up: The steps are the same as those for warm-up during turbine testing. III. Operation under Load: This unit is designed for three operating modes, and their parameters are provided in Section 3. 3.1 Throughout the entire process of loading the belt, the principle of \"increasing speed first when raising voltage, and reducing voltage first when slowing down\" should be followed. 3.2 During the process of connecting under load, voltage increase and speed increase should be carried out alternately. Generally, the pressure can be increased by 3–5 bar each time, and the speed can be raised by 50 r/min; it should not be done too quickly or abruptly. When boosting pressure, ensure that the compressor’s operating point does not come close to the surge line; if it is too close to this line, the operating speed of the unit should be increased. 3.3 During the process of connecting under load, the anti-surge valve should be set to the “AUTO” mode. 3.4 Be careful that the pressure increase rate should not exceed 10 bar/h. 3.5 Throughout the entire process, close attention should be paid to the operating conditions of the unit; if any abnormalities are detected, the pressure should be reduced immediately. Section 3: Normal Shutdown and Emergency Shutdown of the Unit I. Normal Shutdown 1.1 Reducing the pressure in the system ； 1.2 Reduce the speed to 9892 r/m using the governor ； 1.3 Throughout the entire process, the anti-surge valve should be set to the “AUTO” mode ； 1.4 The system voltage should be reduced, and the speed regulator should lower the speed gradually ； 1.5 Manually shut down the switch to stop the unit from operating ； 1.6 When the unit speed is 0 r/min, shut down the turbine shaft seal system and the vacuum condensate system ； 1.7 The oil system shall be shut down when the temperature difference between the return oil and the supply oil is not greater than 10°C ； 1.8 If the system is to be left idle for an extended period, all water and liquid stored within it should be drained ； 1.9 During the shutdown period, the unit should be inspected regularly. II. Emergency Shutdown 2.1 Emergency shutdown is carried out under the following circumstances: 2.1.1 When the shutdown interlock activates ； 2.1.2 The unit speed rises to the governor trip speed, but the emergency shutdown device does not activate. 2.1.3 The unit experiences vibration, or the shaft displacement is excessive, but the protection system does not activate as the threshold values have been exceeded. 2.1.4 The equipment experiences a significant mechanical failure or emits obvious abnormal noises. 2.1.5 Water hammer occurs in the unit. 2.1.6 When any bearing of the unit loses oil supply, starts to smoke, or the return oil temperature rises too rapidly beyond the specified limits. 2.1.7 A fault occurred in the oil system, but the interlock did not activate. 2.1.8 When the oil pipes, main steam pipes, or process pipes rupture or experience flange leaks that cannot be sealed. 2.1.9 When surge occurs and cannot be eliminated through treatment. 2.1.10 The vacuum level drops to an extreme value and cannot be restored. 2.1.11 When a steam system failure cannot be resolved. 2.1.12 The cooling water system failure cannot be resolved. 2.1.13 Situations such as emergency shutdown required by the process. The above situations do not cover all emergency shutdown scenarios; in short, an emergency shutdown should be initiated whenever an accident occurs that poses a threat to the safety of the equipment and personnel. 2.2 Emergency shutdown procedure: 2.2.1 The emergency shutdown button on the control console can be used to de-energize the control oil cut-off solenoid, thereby closing the main steam valve. 2.2.2 Open the compressor anti-surge valve simultaneously; the compressor gas is vented or circulated. Quickly close the process gas inlet and outlet isolation valves of the compressor to isolate the compressor from the process system. 2.2.3 The remaining procedures can be carried out according to the normal shutdown steps. Note: Regardless of the reason for stopping, the oil system should be kept running to facilitate cooling, and the pressure difference between the sealed oil and air should also be maintained. If this pressure difference cannot be maintained or if the machine stops due to a fault in the oil system, the oil system should also be shut down simultaneously. Section 4: Routine Maintenance I. Patrol Inspection: 1.1 During the operation of the unit, it is necessary to regularly check changes in various parameters such as temperature, pressure, vibration, and shaft displacement, ensuring that they remain within the allowable limits. 1.2 If any abnormalities are detected, the cause should be identified as soon as possible, and appropriate measures should be taken promptly. 1.3 Regularly check the oil level in the tank, the quality of the oil, and the differential pressure across the oil filter, and replenish oil as needed as well as clean the oil filter. 1.4 Regularly check the emission function of the acidic scrubber; if necessary, activate the bypass to isolate it for cleaning. 1.5 Regularly check and eliminate leaks and vibrations in the piping system. 1.6 If the auxiliary oil pump of the oil system starts operating, it is necessary to carefully check and eliminate the cause before restoring operation of one of the pumps. 1.7 For alarms issued by the safety devices, appropriate measures should be taken promptly. When the unit stops operating due to the activation of a safety device, it is necessary to confirm that all causes have been eliminated before restarting it. 1.8 Check the operation of the cooling water system, the vacuum in the condensing system, the operation of the condensate pump, and the level of liquid in the heat well. 1.9 Keep accurate operation records; in the event of any abnormalities, they should be carefully documented and reported promptly. 1.10 In case of any abnormal conditions, they should be recorded and reported during shift handover. The machine should be stopped immediately in the event of severe vibration or when a metallic sound can be clearly heard. II. Issues to note in daily maintenance. 2.1 The operating crew shall ensure the safe and economical operation of the equipment during their duties, and handle various abnormal situations properly. 2.2 Non-staff are prohibited from approaching the equipment, and no other personnel are allowed to work on it without notification and permission from the relevant authorities. 2.3 Important operations shall be carried out using operation tickets, which are filled out by the operators, approved by the relevant supervisors and responsible persons, and the completion of such operations is supervised by the plant’s chief mechanic. 2.4 The operating limits (values specified in the manufacturer’s documents) must not be changed easily. Chapter 4 Prevention and Handling of Common Unit Accidents I. Principles for Handling Accidents: 1.1 In the event of an accident, operators must remain at their posts and take immediate effective measures to prevent the accident from spreading and causing harm to personnel or equipment. Afterwards, they should identify the cause of the accident and eliminate any potential risks. 1.2 During accident handling, efforts should be made to maintain the normal operation of the process system. Report to the relevant personnel at the same time. 1.3 In the event of a fault in the unit, the operator should take action in the sequence described below to eliminate the fault. 1.3.1 Determine that a fault has indeed occurred in the equipment by referring to the indications of certain instruments regarding the safety devices and the process parameters of the unit, as well as external indicators. 1.3.2 Quickly eliminate safety incidents that pose a threat to personnel and equipment, and initiate emergency shutdown if necessary. 1.3.3 Ensure the normal operation of all units that are not damaged and cannot be shut down. 1.3.4 Quickly determine the nature of the incident and the extent of the damage before taking further action. 1.4 When receiving orders during an accident handling situation, they must be carried out accurately; after executing the orders, a report should be submitted to the person who gave the orders. 1.5 When any phenomenon that is not understood is encountered, it should be reported to the relevant department promptly. 1.6 Record in detail the cause, time, and process of the incident, as well as the measures taken to address it, in the operation log. II. Handling of Accidents 2.1 Insufficient Steam Turbine Speed Serial Number Possible Causes Solutions 1 Too small starting injector Adjust the steam volume to the injector 2 Faulty pressure gauges and instruments Contact the instrumentation team to resolve it 3 Low steam pressure and temperature Adjust the pressure and temperature in the steam system 4 Low vacuum, high steam exhaust pressure Adjust the vacuum in the vacuum condensation system 5 Incorrect adjustment or jamming of the governor linkage, excessive operation If it’s a problem with the governor valves or linkage, shut down the machine 6 Low oil pressure in the governor Adjust the control oil pressure 7 Incorrect stroke of the throttle valve, valve sticking Adjust it; if that doesn’t work, shut down the machine 8 Excessive debris inside the blades, damaged blade discs, severe internal corrosion Shut down for maintenance 9 Overload of the unit’s compressor Reduce the load on the system 2.2 Difficulty in Synchronization (Speed): Serial Number Possible Causes Solutions A Too small starting injector Adjust the starting injector B Incorrect stroke of the throttle valve Contact the instrumentation team to resolve it C Governor failure, instrument power failure Contact the instrumentation team to resolve it D Faulty main steam valve, leakage in governor valves, control panel failure Contact the instrumentation team to resolve it 2.3 Speed Fluctuations: Serial Number Possible Causes Solutions A Too small starting injector Adjust the starting injector B Incorrect adjustment of the governor linkage, linkage jamming, excessive movement of the linkage Re-adjust the linkage; shut down if necessary C Fluctuations in governor oil pressure Adjust the control oil pressure D Incorrect stroke of the valve (throttle valve), valve sticking Shut down the machine E Instrument power failure Contact the instrumentation team to resolve it F Control panel failure, wear and damage to governor components Contact the instrumentation team to resolve it; mechanical issues within the governor require shutdown 2.4 Compressor Surge Serial Number Possible Causes Solutions 1 Caused by governor system linkage and valves Re-adjust the governor linkage; shut down if necessary 2 Incorrect governor compensation, governor fluctuations, unstable air signals Contact the instrumentation team to address it 3 Caused by unstable process fluctuations Contact the control room to eliminate the process fluctuations 4 Caused by the compressor Adjust the compressor’s flow rate to eliminate surge 5 Control panel failure, speed fluctuations Contact the instrumentation team to address it; shut down if necessary 6 Fluctuations in governor oil pressure Adjust the oil pressure properly 2.5 Inability to Control Speed Reduction Serial Number Possible Causes Solutions 1 Jammed governor linkage Shut down the machine 2 Stuck throttle valve Shut down the machine 3 Instrument power failure Contact the instrumentation team to resolve it; if it cannot be fixed, shut down the machine 4 Leakage in the throttle valve Shut down the machine 5 Control panel failure Shut down the machine 2.6 High Turbine Vibration Levels Serial Number Possible Causes Solutions 1 Excessive debris inside the blades, unbalanced turbine rotor Shut down after identifying the cause 2 Misaligned coupling, excessive wear Shut down after identifying the cause 3 Bent turbine rotor Shut down after identifying the cause 4 Wear on bearings (radial thrust), bearings too tight Shut down after identifying the cause 5 Issues with pipes and foundations Shut down after identifying the cause 6 Caused by compressor surge or vibration Adjust through operational means 2.7 Excessively High Bearing Temperatures Serial Number Possible Causes Solutions 1 Instrument failure, incorrect readings Contact the instrumentation team to address it 2 Wear or damage to radial and thrust bearings, bearings too tight Shut down the machine 3 Insufficient lubricating oil pressure/flow, excessively high temperature Adjust the oil system 2.8 Low Oil Pressure at Pump Outlet Serial Number Possible Causes Solutions 1 Faulty pressure gauge Contact the instrumentation team to resolve it 2 Pump failure, unable to generate pressure Shut down the pump for maintenance 3 Improper control of the pump outlet pressure relief valve Adjust the control oil pressure of the outlet relief valve 4 Clogged filter at pump inlet Clean the inlet filter (shut down the pump) 5 Blockage or leakage in the oil line Identify and resolve the issue; if not possible, shut down the machine 2.9 High Oil Pressure at Pump Outlet Serial Number Possible Causes Solutions 1 Faulty pressure gauge, incorrect readings Contact the instrumentation team to calibrate it 2 Improper control of the pump outlet pressure relief valve Adjust the setting of the relief valve 3 Flow restriction in the oil pipe Identify and resolve the issue; if not possible, shut down the machine 4 Low oil temperature Adjust the oil supply temperature 2.10 Water in the Oil Tank Serial Number Possible Causes Solutions 1 Leak in the oil cooler Identify and repair the leak 2 Leak in the steam seal Adjust the vacuum of the steam seal 2.11 Severe Steam Seal Leakage Serial Number Possible Causes Solutions 1 Low steam pressure and temperature Contact the team to improve steam quality 2 Blocked leak lines in the cover Remove and clear them 3 Worn packing rings Shut down the machine for maintenance 4 Incorrect packing (sealing) gap Shut down the machine for maintenance 2.12 Low Turbine Output Efficiency Serial Number Possible Causes Solutions 1 Low steam pressure and temperature Adjust to improve steam quality 2 Faulty speed control system Contact the instrumentation team to address it; shut down if it cannot be fixed 3 Damaged turbine blades and discs, severe internal corrosion Shut down for maintenance to resolve it 2.13 Excessive Noise from the Unit Serial Number Possible Causes Solutions 1 Excessive load on the compressor Adjust the compressor load 2 Unstable process operation Contact the team to stabilize the process 3 Leakage in the speed control valve Contact a mechanic to fix it; shut down if it cannot be resolved 4 Misaligned coupling, excessive wear Shut down for maintenance to resolve it 5 Wear on internal components, foreign objects inside Shut down for maintenance 6 Steam seal leakage Adjust the vacuum of the shaft seal 2.14 Low Vacuum During Startup Serial Number Possible Causes Solutions 1 Cylinder leakage Identify and resolve the leak; if not possible, shut down the vacuum system for maintenance 2 Too small starting injector Increase the size of the starting injector 2.15 Compressor Surge Serial Number Possible Causes Solutions 1 Failure or incorrect setting of the compressor anti-surge system Contact the instrumentation team to inspect and adjust the anti-surge system 2 Blockage in the compressor outlet gas or malfunctioning outlet check valve, causing gas backflow Identify and address the issue; adjust it; if not possible, shut down the machine 3 Insufficient suction flow or low pressure in the compressor Open the anti-surge valve appropriately to eliminate surge; contact the team to increase the compressor inlet pressure 4 Operational misadjustment, compressor operating in the surge zone Open the anti-surge valve appropriately, reduce speed, and after eliminating surge, re-determine the safe operating point according to process requirements 5 Significant speed fluctuations Open the anti-surge valve, identify the cause, and eliminate the speed fluctuations 2.16 Drop in Condenser Vacuum Serial Number Possible Causes Solutions 1 Fault in the cooling water system, reduced water flow and pressure, increased temperature Restore the normal water supply and parameters; if the cooling water system is faulty and cannot be restored, shut down the machine 2 Reduced steam pressure in the injector, abnormal operation Adjust the steam valve of the speed control injector; contact the team to increase the steam pressure 3 Damage to the water seal of the atmospheric pressure safety valve, air leakage Eliminate the leakage and re-establish the water seal 4 System leakage Locate the leak point and eliminate it 5 Abnormal level of hot well fluid Identify the cause and restore the normal level The causes and solutions for accidents are not limited to these. Chapter 5: Description of the Control System for the Unit 1. Operator Interface Console – Control Devices and Indicators 1.1 Operator interface CRT (display screen), which is used to show unit operations, analog signals, digital signal alarms, and interlock signals. 1.2 Operator interface keyboard, used by the equipment operator to change analog and timer limits as well as to configure the operator interface. 1.3 The keyboard connector is used to connect the keyboard to the operator interface computer. 1.4 The mouse connector is used to select and view on the CRT. 1.5HORN is an audible indication of alarm or shutdown conditions controlled by MCP. Press the “Common Horn Silence” button to stop the sound. 1.6 Button: 1.6.1 “ACKNOWLEDGE” – to confirm; pressing this button confirms the “First Out Alarms” first output alarm. This alarm is displayed on the operator interface CRT, and the alarm indication remains active until the situation is resolved and the “Reset” button is pressed. 1.6.2 The “RESET” button – pressing this button performs the following functions. 1.6.2.1 Reset the eliminated alarms and stops. 1.6.2.2 Reset the “Fast Track Parking Relay Circuit”. 1.6.2.3 Execute the various functions in the “control logic”. 1.6.3 HORN SILENCE – Silences the alarm; pressing this button eliminates the alarm or the stop alarm. 1.6.4 LAMP TEST: Pressing this button causes the indicator light on the operator interface console to light up. 1.6.5 UNIT START: After all interlock switches have been cleared and the “Start Allowed” signal is obtained, press this button to initiate the turbine startup procedure. 1.6.6 SPEED LOWER: Reduces the rotational speed; pressing this button will lower the speed of the turbine. 1.6.7 SPEED RAISE – Increases the rotational speed; pressing this button speeds up the turbine’s rotation. 1.6.8 UNIT STOD device: Pressing this button will initiate the shutdown procedure. 1.6.9 SPEED CONTROL SELECTION (CCM/OIC): When the governor is in remote control mode, the turbine speed is controlled by this selection switch, allowing it to be set between the DCS setpoint or the suction pressure setpoint. 1.6.10 EMERGENCY SHUTDOWN: When this button is pressed, the device and the governor logic trigger an emergency shutdown. 1.7 Signal Lights 1.7.1 PERMISSIVE TO START: Indicates that startup is permitted; the green light comes on when all \"startup conditions\" are met, signaling that the device can be started. 1.8 “PLC FAILURE”: This red light comes on when all PLC CPUs fail. 2. Operator Instructions: 2.1 Obtain “permitted startup” by clearing all “startup permits”. Press the UNIT START button on the operator interface console or the one supplied from the DCS system to put the governor into the \"operational\" mode. When entering operation mode, the control oil solenoid valve (SV-303) opens the main steam valve and fully opens the governor control valve. At this point, the operator can manually open the main steam valve to bring the turbine to a warming-up speed of around 1000 r/min. 2.2 Once the turbine warming-up is complete, the turbine can transition from its \"idle\" speed to the regulator’s \"minimum operating speed\" of 9892 r/min. When the turbine reaches its minimum operating speed, the governor control valve begins to function. At this point, the main steam valve is fully opened. 2.3 Once the turbine reaches the lowest operating speed set by the governor, the compressor anti-surge controller comes into action. The anti-surge control can adjust the load on the compressor based on either manual or automatic settings; when the anti-surge valve is set to \"automatic\", it will close as much as possible without exceeding the designated control limit. 2.4 Operation mode of the speed regulator: 2.4.1 The remote control mode allows the speed to be adjusted using either the speed signal from the DCS system or a 4-20mA current signal output by the pressure regulator (i.e., 9892~14838 r/min). 2.4.2 Manual start mode: When the “RUN” mode is selected, the speed is controlled by the throttle valve ； When the speed reaches 9892 r/min, the governor takes over to control the speed. 2.4.3 Normal shutdown: Normal shutdown can be carried out either from the operator interface console or from the DCS system. That is, it is initiated by pressing the NORMAL STOP button on the operator console or on the DCS system. After normal stop-and-start, the speed will jump to the speed controlled by the \"minimum governor\" at the rate specified in the configuration. When 9892 r/min is reached, the \"Normal Shutdown\" timer is activated; at this point, the anti-surge controller is forced into \"Manual\" mode and shifted to \"Full Open\" to gradually reduce the compressor load. If the “minimum governor-controlled speed” is not reached within six minutes of initiating a “normal shutdown,” a “normal shutdown fault” is triggered. Pressing the “Unit Start” button will end the “normal shutdown”; the speed of the governor will stop dropping and will stabilize at the speed of the unit at the time the button is pressed. 2.4.4 Manual mode: The speed can be adjusted in manual mode. The speed can be adjusted by pressing the “Speed Raise” or “Speed Down” buttons on the operator interface console. By pressing the manual button, the setpoint of the governor’s speed will increase or decrease at a rate of 5 r/s. When the button is pressed for more than 3 seconds continuously, the speed will increase or decrease at a rate of 10 r/s. 2.4.5 Over-speed Test: To carry out this operation, select the “Over-speed Start” control button on the steam system screen to initiate the over-speed test; pressing the “Speed Raise” button will increase the speed of the governor to its maximum setting of 16215 r/min. When the speed reached the governor’s overspeed limit of 16,173 r/min, the turbine tripped. To test the backup overspeed trip system (a 3-out-of-2 system), the DITRONIC SR1V shutdown bypass function can be used to bypass the governor’s overspeed shutdown mechanism; thereafter, the “overspeed test” can be initiated by raising the rotational speed to 16,322 r/min, causing the turbine to trip. If the \"over-speed test\" is not activated and the speed of the governor exceeds its trip limit of 16,173 r/min, the turbine will trip. 2.4.6 Prevent the speed setting value from decreasing; that is, if the anti-stall controller crosses the stall control line, it prevents the governor’s speed setting value from dropping. This feature enables the compressor to maintain a constant speed change when it enters a surge condition, allowing the compressor to operate smoothly and ‘slide’ past the surge control line. 2.5 Control mode of the speed regulator: The turbine speed can be controlled either “on-site” or “remotely”. The operation features a PID panel, namely the governor DCS setpoint and the “inlet” PID. The speed is controlled according to the selected control method. 2.5.1 When the governor PID is in “LOCAL” mode, the speed of the turbine is controlled using the “RAISE” PB-603 and “Lower” PB-604 buttons located on the operator interface console, or the “Raise” and “Lower” buttons on the CMM. 2.5.2 When the governor PID is in the “remote” mode, the turbine speed is regulated by the SS-607 selector switch, via either the “DCS remote speed” setpoint or the output from the inlet pressure controller. 2.6 Oil System 2.6.1 General Overview of the System: The oil supply system consists of two oil pumps, which provide oil for the lubrication system, the sealing system, and the control system. The pump is operated using the “Hand-off-Auto” selector switch located on the control panel or in the “Oil System” section of the unit operations. During operation, the pump placed in the “Hand” position is called the main pump, while the other pump placed in the “Auto” position is called the auxiliary pump. If the pressure of the lubricating oil or control oil system drops, the pressure switch (PSL-205) activates and sends a signal to start the auxiliary pump. If the oil pressure continues to drop, the second oil pressure switch (PSL-206) activates and sends out a low oil pressure alarm signal. If both oil pumps are in use, the relevant pressure switches must be satisfied accordingly. Once the unit is shut down, the oil pump must be stopped using the “OFF” button on the operator interface. 2.6.2 Lubricating oil and seal oil heaters: The lubricating oil heater is activated only when the low oil level switch in the tank (LSL-201) is cleared and the low oil temperature switch in the tank (TSHL-201) activates. If a low liquid level or high temperature in the tank is detected, the lubricating oil heater turns off. Once the liquid level is above the set value of the switch and the oil temperature is below the set value of the oil temperature switch, the oil heater will start up again. The deaerator heater will only start once the lubricating oil pressure is established (PSH-203 and PSH-204), the low deaerator level (LSL-202) is cleared, and the low deaerator oil temperature switch (TSH-202) is activated. The heater will turn off if a low lubricating oil pressure, a low level in the degasser, or a high oil temperature is detected. 2.6.3 Accident oil sumps for lubricating oil and seal oil: In the event of an accident in either the lubricating oil or seal oil systems, these oil sumps help to protect the bearings within the system for a period of time after the system is shut down. To obtain the “Permissine To Start” signal, it is necessary for the high liquid level switch (LSH-401) in the lubricating oil tank to indicate a sufficient liquid level. 2.7 Condensate Pump: It consists of two identical condensate pumps, and the operation of starting and stopping them, as well as their settings, are similar to those of the oil pump. The auxiliary pump is started when LSH-303 is activated. Stop the auxiliary pump when LSL-303 operates. 2.8 Normal Shutdown: Normal shutdown can be initiated at any time from the operator interface console UNIT STOP or the DCS system. The turbine speed drops to the “idle” speed. When the turbine speed drops to 9892 r/min, the anti-surge valve opens and the axial inlet guide vanes shift to their lowest position. When the idling speed is reached, the \"normal shutdown\" timer starts counting. Once the timing of the \"normal shutdown\" timer is complete, the PLC shuts off the power to the oil solenoid valve to initiate shutdown; the main steam valve closes and the speed drops to zero. 2.9 Emergency Stop: An emergency stop can be initiated at any time from the operator interface console. Pull the “EMERGENCY STOP” button to initiate an emergency stop. The anti-surge valve opens during an emergency stop. The PLC initiates an emergency stop by cutting power to the oil solenoid valve, causing the main steam valve to close and the rotational speed to drop to zero. 2.10 Stop Bypass: A “stop bypass” function is provided to test and calibrate the stop device while the unit is in operation. When the stop function is bypassed, the “Stop Bypass Activation” alarm is activated, and the bypassed “stop” function is indicated by the operator interface on the “Stop Bypass” screen. “The only functional difference between “bypass” and “non-bypass” shutdown is that the device is not shut down by shutdown conditions from the bypass input device. Condensing vacuum system: 1. Check the atmospheric pressure safety valve to ensure it is closed; open the valve of the water seal supply pipe to establish a water seal. 2. Open the supply and return valves for the cooling water of the surface condenser to feed the cooling circulating water, and pay attention to venting on the water side. 3. Open the valve on the desalination water pipeline leading to the heat well, and adjust the level of liquid in the heat well to 2/3 of the level indicated by the glass gauge. 4. Open the upstream and downstream isolation valves of the hot well level control valve. 5. Start the condensate pump in accordance with the pump operation procedures, and feed water into the tubes of the vacuum pumping condenser, being careful to vent air from the tube side ； Adjust the hot well liquid level using the desalinated water inlet valve according to the specific conditions. Note: Startup of the condensate pump. (1) Check the lubrication condition of the pump and the readiness of the auxiliary instruments. (2) Open the pump inlet valve and the valve connecting the inlet to the condenser balance tube; open the pump outlet valve to exhaust air from the pump, then close the pump outlet valve. (3) Start the pump, and slowly open the pump outlet valve, adjusting the opening degree to 50–60%. (4) Once the load on the unit has reached normal levels, adjust the opening of the pump outlet valve and the valves in the desalination water pipeline based on the level of the hot well fluid. 6. Open the drain valve on the MS-0301 pipeline to warm it up, and close this valve once no condensate is discharged. 7. Jet injector unit: 7.1 Open the steam valve of the jet injector, then open the air valve for the same injector; adjust the opening degree of the steam valve to maintain a vacuum level of 30 Kpa in the condenser. 7.2 Once the low-speed cooling stage of the turbine is complete, activate the main injector and deactivate the start-up injector. Note: When starting the main injector, start the secondary one first, then the primary one ； Open the steam valve first, then the air valve. When stopping or starting the injector, close the air valve first, then the steam valve. 7.3 Use the steam valve to adjust the condenser vacuum to 88 Kpa. 8. Switching of the main injector unit 8.1 When switching the injector unit, the secondary level should be switched first, followed by the primary level. 8.2 When switching the ejector unit, the steam valve should be opened first, followed by the air valve. 8.3 During the switch-over, pay close attention to the vacuum level of the condenser; if a high vacuum level cannot be maintained after the switch-over, the original ejector operation mode should be restored. Heating pipes: 1. Check the heating pipe circuit: Valves that should be opened include the drain valve in front of valve PV-1603, the bypass valve of the steam inlet throttle valve, the direct drain valve in front of the main steam valve, and the root valves of all instruments. Valves to be closed: the upstream and downstream valves of valve PV-1603, the bypass valve, the steam inlet throttle valve, and the main steam valve. 2. Open the upstream valve of PV-1603 to warm the pipeline. 3. Until no condensate is discharged, slightly open the valve downstream of PV-1603; pressurize the downstream side to 2–3 barg to perform low-pressure pipe warming, with the warming time being no less than 30 minutes. 4. Adjust the valve downstream of PV-1603 to slowly increase the pressure to 34 barg. Note: The pressure increase rate should be controlled at around 1–1.5 bar/min. 5. During the pipe warming process, the rate of temperature and pressure increase must be strictly controlled ； Check the steam pipes and valves for any leaks of steam or water ； Check for abnormal conditions in the thermal expansion of the pipes, as well as in the pipe fittings, supports, hangers, and springs ； Problems should be resolved promptly once they are identified. 6. During the pipe warming process, it is necessary to prevent air leakage into the turbine. The drain valves located behind the automatic main steam valve, the drain valve on the first-stage turbine impeller, the drain valve in the exhaust cylinder, and any other drain valves in the cylinder should all be opened in order to remove steam and steam condensate. 7. Once pipe warming is complete and the pressure has risen to normal levels, the isolation gate valve in front of the automatic main steam valve should be fully opened. 8. The end of pipe warming is determined when the temperature in the pipeline is not less than 293°C. Commissioning of the turbine shaft seal system: 1. Check the condition of all instruments and valves according to the flow diagram (see E6015139) ； 2. Open the feedwater and return water valves for the cooling water of the shaft seal extraction condenser, and pay attention to venting on the water side. 3. Remove the respirator from the condensate collection tank XW-700.6, fill it with water to establish a liquid level. 4. Fill the water bodies of the pressure control valves PCV-600.4 and PCV-600.3 with soft water. 5. Open the steam traps on the LS-0302 and LS-0301 pipelines to warm the pipes; close these valves once no condensate is more discharged. 6. When the main injector is started, open the steam valve of the shaft seal injector PE-700.4 and adjust the steam flow so that the vacuum level at PI-700.7 is 510 mmH2O. 7. When opening the main steam valve to start the rotor, open the stop valve on the LS-0301 pipeline to supply steam to the shaft seal. Note that the opening degree of this valve should not be too large; it should be adjusted so as to achieve the desired vacuum in the condenser. Commissioning of the oil system: 1. In accordance with diagram 688-585 provided by D-R Company, it is necessary to check that all equipment, pipelines, instruments, and valves are in a standby condition, and to test the quality of the oil to ensure it meets the ISOVG32 standards. 2. Check the fuel tank and degasser levels. If the fuel tank level is low, top up the fuel to the shutdown level ； If the level of liquid in the degasser is low, add oil until it overflows into the tank. 3. Check whether the nitrogen seal in the fuel tank and degasser is operating properly; if not, open the nitrogen seal pipeline ； 4. Check the temperature of the fuel tank and degasser; if it is below 27°C, turn on the electric heater ； 5. Check the flow of the oil system: Valves that should be opened include the inlet and outlet valves of the oil pump, the shut-off valves and bypass valves before and after PCV-201, the shut-off valves before and after PCV-202, PCV-203, FCV-201, LCV-201, and TCV-203, as well as the valves on all instrument, measurement, and control signal pipelines, and the valves for the inlet of acidic oil to the trap and the outlets of oil and gas from the trap. Valves to be closed: PCV-202, PCV-203, FCV-201, LCV-201 bypass valves, all drain and vent valves, oil cooler cooling water and return water valves, and the quick filling valve for the lubricating oil reservoir. 6. Start the oil pump and use PCV-201 to adjust the pump outlet pressure to 55.85 BARG, while making sure to remove all gas from the oil cooler and oil filter. 7. Adjust PCV-202, PCV-203, and FCV-201 to control the lubricating oil pressure, control oil pressure, and seal oil flow respectively to their normal values. 8. Open the quick filling valve of the high-level lubricating oil tank to fill the crude oil tank, until oil overflows and returns; then close this valve. 9. Use LCV-201 to fill the seal oil high-level tank to the operating level, and activate the automatic mode of LCV-201. 10. Conduct valve position tests for each control valve. 11. Perform cross-calibration of the various switches. These switches include: LSH-203, LSH-401, LSL-201, LSL-202, LSL-203, LSL-204, LSL-402, LSLL-501, POSH-201, PDSLL-504, PDSL-104, PSH-203, PSH-204, PSL-101, PSL-205, PSL-206, PSL-303, PSLL-101, TSH-205, TSL-201, TSL-202. For switch data, see Section 3: Instrument Safety Devices. Note: For the PSL-205 startup synchronization test (i.e., the auxiliary pump’s auto-start test), on the operator interface under the oil system section, set the main pump to “Hand” mode and the auxiliary pump to “AUTO” mode; then shut down the main pump by setting it to “OFF”. Observe the value of the filtered oil pressure while the PSL-205 is operating. 12. Use various control valves and electric heaters to deactivate the interlock switches, thereby allowing the turbine to be started. 13. Activate the oil cooler based on the oil temperature, and adjust the cooling water flow so that TCV-201 can regulate the oil temperature