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H275—6.5/0.97 Centrifugal Air Compressor: Safety Operation Procedures 1. After the unit is installed or when it is restarted after maintenance, it is necessary to carefully check whether the motor, electrical systems, instrument lights, and signals are functioning properly. In particular, it is important to ensure that all accident interlock systems operate correctly (including those related to water shortage, voltage issues, shaft vibration, shaft temperature, and overpressure). II. Check whether the unit is ready for startup (including examining the reason for the last shutdown and the maintenance carried out, checking for any obstacles around the unit, and ensuring that the tools required for startup, listening rods, and record sheets are ready). III. Before starting, the oil pressure, oil temperature, guide vane opening, valve opening, water pressure, and the operation of the exhaust fan must be carefully adjusted in accordance with the operating instructions, so as to meet the interlock conditions for starting the unit. IV. Before starting, perform a crank rotation to check whether the rotating parts move smoothly. V. After startup, observe the sound and vibration during operation as well as the oil supply situation. If everything is normal, adjust the inlet guide vanes to 40 or 50 degrees and operate without increasing pressure, while checking for any abnormalities. VI. If it operates normally, conduct an 8-hour no-load test run in this state, taking operation records every 30 minutes, and pay attention to the temperatures, pressures, and vibrations of all components. VII. After the unit has operated under light (no) load for 8 hours with no abnormalities, it can then proceed to operate under normal load. When shutting down without maintenance and starting up again, operating under light (no) load for 5–10 minutes is sufficient before proceeding to normal load operation. VIII. Load operation must be carried out strictly in accordance with the steps specified in the operating instructions. 9. After operation under load, and once it is confirmed that everything is normal, the outlet gate valve of the compressor can be gradually opened while the vent valve is closed, allowing normal production operations to resume and gas supply to proceed. However, the valve should be operated slowly to prevent pressure pulsations. 10. During operation, attention should be paid to changes in the resistance of the oil filter as well as the oil level in the tank; the oil filter should be back-blown in a timely manner, or the tank should be refilled with oil. 11. The oil supply temperature for the bearings should be maintained between 35°C and 45°C. Closely monitor the shaft vibration monitoring system of the unit, with the standard being that the bearing temperature be 10°C to 20°C higher than the oil supply temperature. 12. During unit operation, adjust the cooling water flow rates of each stage of intermediate coolers to ensure isothermal compression of the unit, so that the temperature of the cooled air does not exceed the allowable value. 13. At regular intervals each hour, during each shift, a thorough inspection of all operating conditions of the unit must be carried out to ensure safe operation, and records must be kept. 14. Each shift shall carry out routine maintenance during the operation or shutdown of the unit, keeping the working area of the unit clean, free of oil stains on the floor, and ensuring good order in unit operations. 15. Operators in each shift should be proficient in the procedures for normal shutdown and emergency shutdown of the unit, as well as the relevant operating parameters; they must closely monitor these parameters to stay aware of the unit’s operating status at all times. 16. The process of introducing gas into the air separation system should be carried out slowly; pay attention to changes in the exhaust pressure of the air compressor to ensure stable pressure. 17. Regularly check the condensate water of the exhaust intercooler. 18. Carefully keep records of unit operation, and ensure that the records of shift handovers are accurate and clear. 19. Strictly implement the regular maintenance and inspection system; during shutdown periods, the compressor should be turned over 1–2 times a day, for several revolutions each time. ZW—38/16 Oxygen Compressor Safety Operation Regulations: 1. When starting up the unit after installation or after maintenance and shutdown, it is necessary to carefully check the instruments, electrical controls, and lighting signals, in particular to ensure that all accident interlock alarm devices are functioning properly and are reliable. II. During startup or shutdown, the unit should be turned by hand to check for any abnormal interferences in its moving parts. III. During the operation of the unit, the oil temperature should not exceed 60°C, and the oil pressure should not be lower than 0.15 Mpa. IV. After the installation of the unit and completion of shutdown maintenance, a no-load test run (4–8 hours) is required. Normal operation can only be commenced after a successful load test run; normal start-up and shutdown procedures must be followed strictly in accordance with the steps outlined in the operation manual. V. All components of the unit that come into contact with oxygen must be thoroughly degreased. VI. Special attention should be paid to the inspection and maintenance of air valves during operation; if any abnormalities are detected, the machine must be stopped immediately for inspection, and repairs or replacements must be carried out if necessary. VII. Regularly clean and replace the metal mesh of the intake filter to prevent an increase in air flow resistance and ensure the purity of oxygen. 8. The return water temperature of each heat exchanger should be below 40°C to prevent scaling, which could affect the heat exchange efficiency. IX. During compressor maintenance, the dirt on the inner and outer walls of the heat exchange tubes in the heat exchanger core should be cleaned regularly, depending on the specific circumstances; it is strictly prohibited to allow oil to be present on the gas side during maintenance. 10. Each operator shall carry out proper maintenance of the unit, regularly clean the oil filter, and replace the lubricating oil (once every 4,000–8,000 hours). 11. During the extremely cold seasons, it is necessary to drain all water from the cylinders, heat exchangers, and other equipment and pipelines when parking, to prevent the equipment from being damaged by freezing. 12. When the unit is out of use for an extended period, anti-rust measures should be taken for the unit and its piping (by filling them with dry nitrogen or air), and the shaft should be turned regularly (manually 1–2 times a day, turning it several revolutions each time). 13. Safety valves should be inspected regularly; during use, they should be tested at least once a year, and the opening pressure during testing must not exceed the specified value. 14. Each shift shall conduct thorough inspections of all operating conditions of the unit on schedule, paying attention to whether the piston rods are lubricated, whether the pressures at various stages are normal, and whether there are any changes in the pressure ratios at those stages; inspection records must be kept. 15. The operator shall promptly clean up oil spills in the unit’s operation area to keep the working surface clean and free of safety hazards. 16. Operators must carefully monitor the operating parameters to stay aware of the unit’s operational status at all times. 17. Keep accurate records of unit operation, ensuring that the information provided during shift handovers is clear and truthful. 18. Strictly implement the regular maintenance and inspection system. Safety Operating Procedures for ZW-18/16 Type Nitrogen Presses: 1. After the unit has been installed or repaired and before it is started up, it is necessary to carefully check the instruments, electrical controls, and lighting signals. In particular, it is important to ensure that all accident interlock alarm devices are functioning properly and are reliable. II. During startup or shutdown, the unit should be turned several times to check for any interference or abnormalities in its moving parts. III. During the operation of the unit, the oil temperature should not exceed 60°C, and the oil pressure should not be lower than 0.15 Mpa. IV. After installation and shutdown for maintenance, the unit must undergo a no-load test run (4–8 hours). It can be put into normal operation only after a comprehensive inspection during the load test shows satisfactory results. Normal start-up and shutdown operations must be carried out strictly in accordance with the procedures specified in the operation manual. V. Special attention should be paid to the inspection and maintenance of air valves during operation; if any abnormalities are detected, the machine must be stopped immediately for inspection, and repairs or replacements may be necessary. VI. Regularly clean and replace the metal mesh of the intake filter to prevent an increase in air flow resistance and ensure the purity of oxygen. VII. The return water temperature of each heat exchanger should be below 40°C to prevent scaling, which could affect the heat exchange efficiency. VIII. During compressor maintenance, depending on the specific circumstances, the dirt on the inner and outer walls of the heat exchange tubes in the heat exchanger core should be cleaned regularly. 9. Each operator shall ensure the proper maintenance of the unit, regularly clean the oil filters, and replace or top up the lubricating oil. 10. During winter parking (when the temperature is below 5°C), all water in the cylinders, heat exchangers, as well as other equipment and pipelines must be drained to prevent the equipment from being damaged by freezing. 11. During long-term shutdown of the unit, anti-rust measures should be taken for the unit and its piping (by filling them with dry nitrogen or air), and the shaft should be turned manually 1–2 times a day, turning it a few revolutions each time. 12. Safety valves should be inspected regularly; during use, they should be tested at least once a year, and the opening pressure during testing must not exceed the specified value. 13. Each shift shall conduct thorough inspections of all operating conditions of the unit on schedule, and keep proper records of these inspections. 14. The operator shall promptly clean up the adverse conditions in the unit’s operation area, ensuring that the work surface is free of oil stains and dirt, and free from any safety hazards. 15. Operators must carefully monitor the operating parameters, fill in the unit operation records on time and accurately, ensure that the data is true, and stay informed at all times of the unit’s operating status. 16. Ensure proper handover of duties, so that the details of the handover are recorded clearly and accurately. 17. Strictly implement the regular maintenance and inspection system. Safety Operating Procedures for Molecular Sieve Purifiers 1. Before putting the purification system into operation, all instruments must be adjusted and the switching procedures tested to ensure their accuracy and sensitivity; it is also necessary to verify that the positions and states of all switching butterfly valves are normal. II. When using a molecular sieve for the first time or when starting up an air separation system after a long period of shutdown, the molecular sieve must be thoroughly activated to remove the moisture absorbed during transportation, filling, as well as due to inadequate sealing of the shutdown valves and the intrusion of moist air. III. During the activation and normal operation of the molecular sieve, it is necessary to strictly control the temperature of the regeneration gas at 175°C and its flow rate at 2500 m3/h, so as to raise the outlet temperature to above 80°C. IV. The CO2 content in the air at the outlet of the molecular sieve purifier must be kept below 2 PPm; if this level is exceeded, it is necessary to increase the amount of contaminated nitrogen gas, raise the temperature of the regenerated gas, or adjust its switching cycle. V. During operation of the molecular sieve purifier, it is necessary to regularly monitor the molecular sieve temperature curve and the CO2 content at the outlet in order to determine whether the molecular sieve is functioning properly. VI. Each shift must closely monitor the switching procedure of the adsorbers to ensure that the switching pressure difference is normal. Any faults that occur must be addressed promptly, and attention should also be paid to checking for leaks in the various switching butterfly valves. VII. During operation, it is necessary to closely monitor the operation of each switching butterfly valve and check the oil level in the oil tanks located within the solenoid valve cabinet. If an alarm is triggered indicating the open or closed state of a switching butterfly valve, the switching process should be stopped immediately, and the valve should be inspected on-site to resolve the fault. VIII. Strictly control the air temperature entering the molecular sieve purifier to prevent excessive air temperature from increasing humidity and affecting the adsorption efficiency. 9. The pressurization of the molecular sieve should be carried out slowly, and the valve V1224 that leads the gas to the air separation unit should also be opened gradually, in order to prevent fluctuations in system pressure and excessive gas flow rates that could cause damage to the molecular sieve bed and lead to water contamination in the purified gas. 10. When the air handling system is shut down due to a power outage, all switching butterfly valves should be closed promptly to prevent wet air from entering, and the current operating status of the purifier should be recorded; meanwhile, the timer for the switching procedure should be stopped. 11. For each shift, V1253 must be opened to check whether there is free water in the air before it enters the molecular sieve, and the blow-off valve at the bottom of the purifier should be used regularly to remove impure water. XII. Regularly analyze the pressure difference before and after the air filter entering the tower, and promptly open V1254 to perform back-blowing on the filter in order to prevent an increase in resistance. Safety Operation Regulations for Expander Units: I. Before starting the expander, the pressure of the seal gas should be adjusted to 0.25 Mpa, and the seal gas should then be supplied. II. Test each instrument and control device, as well as the oil pump pressure interlock device, to ensure their reliable operation. III. Before starting the expander, the expansion end should be purged and heated through a purge valve. IV. After the oil pump starts, the oil pressure should be adjusted promptly; ensure that the oil level in the tank is not below 400 mmH2O, and if it is, the oil level should be topped up immediately. If the oil temperature is below 25°C before the oil pump starts, the electric heater should be activated to raise the oil temperature to above 25°C. V. When starting the expander by introducing air, the damper at the fan side should be in the fully open position. The outlet valve should be opened first, followed by the inlet valve, to prevent overspeeding after startup; At the same time, close attention should be paid to changes in the discharge pressure of the air compressor. VI. After startup, closely monitor changes in oil temperature and pressure, and make adjustments promptly. VII. Each shift must purge the air filter at the fan end to prevent excessive suction resistance, which could lead to overspeeding or surge at the fan end during unit operation. VIII. When increasing the capacity of the expander during unit operation, it is necessary to first reduce the speed, then increase the capacity, and finally adjust it to the optimal rated speed, in order to ensure stable and safe operation of the unit. IX. Operate with strict adherence to the unit’s operating parameters; the amount of expanded air should not exceed 25% of the amount of air used for processing. When increasing this amount, pay attention to changes in the temperature in the main heat exchanger to prevent fluctuations in its operating conditions. 10. When increasing the flow rate, if surge occurs at the fan side, the damper on that side should be opened promptly to move out of the surge zone under the current operating conditions. 11. During the operation of the expander, it is necessary to strictly control the temperature behind the machine from dropping too low, in order to prevent liquid slugging at the expansion end, and to ensure that the exit temperature of the expander does not approach the liquefaction temperature at the current operating pressure. 12. Each shift must conduct regular and thorough inspections of the unit’s operation, ensuring that the oil station and control room remain clean, tidy, and free from oil stains. Safety Operating Procedures for the Main Condensation Evaporator: 1. The main plate-type heat exchangers used in the KDON—2400/1000 air handling unit must be operated in a fully submerged manner; operation at low liquid levels is strictly prohibited. The liquid level should be maintained between (2400 mmH2O–2600 mmH2O) to prevent the accumulation and concentration of C–H compounds, which could lead to friction against the tube walls and cause dangerous incidents such as micro-explosions in the main condenser. II. Each shift must use the V311 blow-off valve to remove the non-condensable gases on the main cooling nitrogen side, in order to prevent the accumulation of such gases and avoid any impact on the heat exchange efficiency of the main cooling system. III. During operation, it is necessary to properly control the pressures in the upper and lower towers, as well as the temperatures of gaseous nitrogen and oxygen, as well as the level of liquid oxygen, in order to ensure stable operation of the main cooling system. IV. Adjust the cooling capacity of the expansion machine in a timely manner according to the main cooler operating conditions, so as to maintain a balance in cooling capacity and liquid product output during the operation of the main cooler, and keep the liquid oxygen level in the main cooler stable. V. During operation, pay attention to adjusting V1, V2, and V11 to maintain a balanced distribution of liquid volume and ensure the stable operation of the main cooling system. VI. During the production of liquid oxygen, when operating valve V15, it is necessary to consider the amount of liquid oxygen being produced; the valve should not be opened too wide. The opening degree should be controlled properly to match the amount of liquid oxygen produced, thereby maintaining a stable level of liquid oxygen. VII. As required, 1% of the liquid oxygen in the main cooling system is discharged during each shift on a daily basis, in order to remove certain impurities and ensure the safe operation of the main cooling system. 8. Regularly analyze the concentration of C–H compounds in the main cryogenic liquid oxygen; this concentration must be kept strictly below 0.1×10-6. If it exceeds this level, it is necessary to increase the amount of liquid oxygen discharged. When the concentration reaches 0.1×10-6, the system should be stopped immediately to discharge the liquid oxygen, after which it can be restarted after reheating to ensure stable and safe operation. Safety Operating Procedures for Electric Heaters: 1. When heating, ventilation should be ensured first before turning on the power; the gas flow rate should be adjusted to 2500 m3/h. When stopping heating, the power should be turned off first followed by cutting off the gas supply. It is strictly prohibited to operate the heater with no ventilation or with a very low gas flow rate. II. When a circuit failure occurs, resulting in automatic tripping or a blown fuse, and the temperature of the regenerated gas does not rise after power is restored, the electrical and instrumentation department should be notified immediately for inspection and repair. III. Temperature control instruments should be inspected regularly to ensure their sensitivity and accuracy, in order to prevent loss of control over the temperature of the electric heater due to instrument failure. IV. The non-live metal parts of the electric heater (enclosure, brackets) must be reliably grounded. V. Be careful not to let the temperature of the electric heater’s casing rise too high (operating temperature ≤ 60°C), to prevent the power cord from aging or its insulation from being damaged. VI. Before using an electric heater that has not been in use for a long time, its insulation resistance should be checked using a 500V megohmmeter; this value should not be lower than 0.38 megohms. The insulation resistance should also be measured every year during the thunderstorm season. VII. Operators should be familiar with electrical safety knowledge. VIII. When an electric heater is used in combination with a steam heater, it is necessary to allocate the flow rate properly to prevent the electric heater from being damaged due to insufficient steam supply. Safety Operating Procedures for Liquid Oxygen Storage Tanks: 1. The location where the storage tank is installed must have good ventilation; there should be no open flames within 5 meters, nor any flammable or explosive materials or low-lying areas. The floor of the work area must be clean and free of oil stains. II. The storage tank must be equipped with anti-static grounding devices and lightning protection systems; the anti-static grounding resistance should not exceed 10 ohms, while the maximum impulse resistance of the lightning protection system should be 30 ohms. These devices must be inspected at least once a year, with proper records kept. III. The fill level of the storage tank shall not exceed 95%; overfilling is strictly prohibited. IV. The liquid level in the liquid oxygen storage tank must not be below 20% at any time. V. The pressure gauges used must be oil-proof, the safety valves must be made of stainless steel, and they must be regularly inspected and thoroughly degreased before installation. VI. When the low-temperature valves, instruments, pipes, etc. on the equipment freeze, they should be thawed using air, nitrogen, or steam at 70°C–80°C; it is strictly prohibited to use open flames for heating or to strike the frozen ice blocks with iron or metal objects. VII. When there is liquid in the storage tank, welding repairs are prohibited. The liquid must first be drained, and the tank must be heated to room temperature; furthermore, a test must be conducted to ensure that the oxygen content in the gas is at the normal level found in air (20.9%). Only after obtaining a welding permit can welding repairs be carried out under the supervision of qualified personnel. 8. Operators must receive professional training and pass the relevant assessments before they can start working. During operation, they must wear cotton work clothes, cotton gloves, and protective shoes; it is not allowed to wear clothing that contains oils or has static electricity properties, nor shoes with nails. When operating, valves should be moved slowly, and the pressure booster valve must be closed tightly when it is not in use. 9. Analyze the concentration of C–H compounds in the liquid oxygen within the tank on a regular basis (such as weekly or daily), keeping this concentration below 0.1×10-6; otherwise, the liquid oxygen should be discharged to ensure the safety of the storage tank. 10. The liquid in the tank should not be left unused for long periods; it must be regularly filled and drained to prevent the concentration and precipitation of C–H compounds. 11. When the storage tank is kept sealed, someone must regularly inspect the pressure inside the tank to prevent overpressure. 12. Liquid oxygen must not come into contact with unprotected skin to avoid severe frostbite. 13. When the storage tank has been emptied of liquid and heating cannot be carried out immediately, all valves must be closed right away. Since the temperature inside the tank is very low, moist air can enter the tank through the connected pipes, causing freezing and pipe blockages. 14. When using liquid oxygen in the tank, which is vaporized by a vaporizer and then supplied to users, it is important to ensure that the valve for delivering the liquid oxygen operates slowly, and that its opening degree matches the operating load of the vaporizer. This is to prevent incomplete vaporization of the liquid oxygen, which could result in extremely low temperatures in the gas exiting the vaporizer and cause damage to the steel high-pressure buffer tank. 15. When filling liquid oxygen into a tank truck at the storage tank, the tank truck’s engine should be turned off, and it is necessary to check whether the pre-cooling valve for filling with liquid oxygen is closed. Only after the filling connection pipes have been installed and checked to be in order can the booster be started slowly. Once the pressure reaches the filling pressure, the liquid supply valve should be opened gradually, with care taken to control the flow rate of the liquid. At the same time, it is important to monitor all valves and pipe connections for any signs of leakage. 16. After filling the tank truck with liquid oxygen, stop the operation of the booster, close the liquid supply valve, and open the pre-cooling valve to drain any remaining liquid oxygen from the filling connection pipes. Only then can the filling connection pipes be disconnected. Once the tank truck has left, relieve the pressure in the storage tank promptly; however, do not open the pressure relief valve too quickly. 17. Regularly inspect the safety valves of the storage tanks; measure the wall thickness every 3–5 years as required, and apply anti-corrosion and rust-prevention measures. Safety Operating Procedures for Low-Temperature Vaporizers: 1. When starting up the vaporizer, it is necessary to closely monitor the DCS vaporization system display, and keep the gas outlet temperature between 5°C and 30°C. If the outlet temperature drops below 0°C, the liquid supply valve should be shut off immediately. II. Set the pneumatic diaphragm control valve properly to maintain the water temperature between 25°C and 60°C; if the water temperature is too low, the oxygen supply valve should be turned off or the amount of steam supplied to the water tank adjusted. III. When adjusting the liquid supply valve, attention should be paid to the pressure in the oxygen passage of the carburetor; if the pressure is too high, the liquid supply valve should also be shut off. After the carburetor has been properly adjusted for operation, the gas supply valve should be opened slowly, the oxygen supply pipeline connected, and the purge valve closed, while keeping an eye on pressure stability. IV. When using the vaporizer, it is necessary to ensure that the water level inside the vaporizer is adequate, as indicated by the level indicator, and to adjust the water temperature before feeding liquid in. Before stopping the vaporizer, the liquid supply valve should be closed first, followed by the heating source. During operation, it is important to monitor the water level regularly and top up the water as needed. V. In operation, changes in flow rate can affect the temperature of the gas after vaporization; therefore, the water temperature must be adjusted promptly. VI. When the water temperature drops and the steam supply is insufficient, it is necessary to reduce the output flow rate as needed to ensure that the temperature of the gas after vaporization remains above 0°C. If sweating, freezing, or frosting occurs in the pipes downstream of the vaporizer, the liquid supply valve should be closed immediately to stop gas supply. VII. Regularly inspect the safety valves and vent valves on the carburetor and liquid oxygen storage tanks; the alarm devices of their respective control systems should also be checked frequently to ensure safe operation. Safety operating procedures for the main heat exchanger: I. Closely monitor the proper functioning of the pre-cooling system to prevent the inlet temperature of the molecular sieve purifier from becoming too high, which could result in excessive moisture content in the air. This would affect the adsorption efficiency of the adsorbent, allowing H2O and CO2 to enter the channels of the main heat exchanger and cause freezing, thereby impairing its heat exchange capabilities and affecting the amount of air that can be processed. II. When starting the expander or increasing the flow rate during production, V447 should be adjusted to control the flow rate of the intermediate extraction, in order to prevent an excessive flow rate in the main heat exchanger, which could cause the cold end to move upward and thus increase the temperature difference at the hot end. III. Adjust the valves for the WN2, N2, and O2 reflux gases exiting the tower to distribute the flow rates appropriately, ensuring that the temperature difference at the hot side of the main heat exchanger remains within 2°C–3°C. This helps to ensure complete recovery of the cooling capacity from each reflux gas within the tower, thereby reducing cooling losses due to insufficient reheat. Safety Operation Regulations for the Pre-cooling System: 1. When the pre-cooling system is in operation, it is necessary first to check before starting up whether all the operating equipment, control systems, and on-site level gauges are functioning properly, as well as whether all the control valves are in a proper and reliable state. II. Before starting the air induction in the air-cooled tower, the liquid level in the tower must not be at “0”; the V1138 automatic pressurized return water valve should not be activated at this time, to prevent air from entering the circulating water system and affecting its operation. III. Pumps for low-temperature and normal-temperature applications may have difficulty starting when there is air backpressure; in such cases, the outlet valve should be closed to eliminate the effect of backpressure as well as any residual air in the piping. After starting the pump by rotating it, the outlet valve should be opened slowly and gradually. Coordination with the operators of the DCS system is necessary to prevent the pressure from dropping too quickly. IV. During the initial operation phase, the system experiences significant fluctuations; during this time, the UZ-1101 interlock can be temporarily disabled, and it can be reactivated once the system is operating normally. However, a dedicated person must be assigned to monitor the system’s performance throughout this process. V. During the initial stage, it is difficult to control the liquid level in the water cooling tower (LICA-1111), and this is due to the lagging effect of the packed tower. Manual control should be used to stabilize the level at the design value before switching to automatic control in order to adjust the set value of V1111. VI. During operation, the flow rates of water at low and normal temperatures should be adjusted properly to ensure that the temperature exiting the air-cooled tower is between 8°C and 12°C, thereby guaranteeing that the air entering the molecular sieve purifier has a temperature suitable for the operating conditions of the adsorbent. VII. Each shift shall conduct thorough inspections of the operation of all water pumps, level gauges, and valves to ensure normal water supply by the pumps, as well as to confirm that the on-site level readings match those displayed on the DCS. And keep it within the following ranges: (800 mmH2O for air-cooled towers, 650 mmH2O for water-cooled towers), with proper recording. 8. During the system’s shutdown for maintenance, the fouling on the water distributors of the water-cooled towers and air-cooled towers should be cleaned out, depending on the length of the system’s operating cycle. It is also necessary to check whether the packing is in good condition and whether the partitions are loose. 9. Before entering the water-cooled tower for maintenance, the gases inside the tower must be thoroughly analyzed before entry, in order to prevent personnel from dying from nitrogen asphyxiation. X. Adjust the flow rate of nitrogen gas entering the water-cooled tower appropriately, so as to keep the water temperature in the tower between 11°C and 12°C; the flow rate should not be too high to prevent problems from occurring in the water-cooled tower.