Turbocharger startup and commissioning plan

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I. Conditions that must be met at the site prior to the startup and commissioning of the steam turbine generator set: 1. The area within the turbine building should be level, with unobstructed roads and fire access routes. 2. All suspended scaffolding within the commissioning area has been removed, the sanitary conditions have been cleaned up, the trenches and holes at the site are in order, and there are proper stairs, walkways, railings, and protective panels in place. 3. There is sufficient fire-fighting equipment on site; the fire water system is well-established and operates at adequate pressure in standby mode. 4. The site should have adequate regular lighting; the emergency lighting system must be safe, reliable, and in standby mode. 5. The drainage systems in the condensate pump pit, the pit beneath the condenser, the circulation pump pit, and the pit beneath the heater are well-developed, allowing water accumulation to be quickly drained outside the plant. 6. Communication equipment such as telephones has been installed and is ready for use during the trial operation. II. Conditions that must be met prior to the startup and commissioning of the steam turbine generator set: 1. All equipment and systems have been installed in accordance with the design requirements, the installation records are complete, and they have passed inspection by the relevant personnel. 2. All systems, equipment, and pipelines shall undergo tests such as oil immersion and hydrostatic pressure testing in accordance with regulations, and the test results must be satisfactory. 3. Complete all insulation equipment and insulation work. 4. The supports and hangers for all equipment and pipelines are complete, correct, and reliable, meeting the operational requirements. 5. The base concrete and secondary grouting have reached the strength required by the design. 6. The electric and hydraulic valves operate smoothly and correctly after adjustment, actuation, and testing. 7. It features a complete and reliable power supply, operation power supply, and protection power supply. 8. Determine the highest, lowest, and normal operating positions for each liquid level. 9. All transmission machinery shall be properly lubricated as required, with the oil quality and level being within normal ranges. 10. All indicator instruments and audio signal devices are fully installed and have been properly adjusted and calibrated. 11. License numbers for each valve, along with the name and operating direction of each switch. 12. There are operating procedures that suit the characteristics of this unit and its system, and which have been approved by the relevant authorities; the operators have passed the necessary examinations and are capable of carrying out practical operations promptly. III. Conditions required for turbine barring-in: 1. The chemical water system must be operating normally, capable of providing sufficient quantities of qualified demineralized water. 2. The chemical water make-up pipeline, condensate pipeline, and high-pressure heater drain pipeline have been flushed and passed inspection. 3. The main steam, steam seal feed steam, and extraction steam pipelines have been flushed and passed inspection. 4. The tightness test of the vacuum system for water filling has passed. 5. The separate trial runs of all auxiliary machinery have been completed successfully. 6. The sectional test run of the oil system has been completed and passed. 7. The vacuum pumping test passed. 8. The static tests of the control system and security system have passed. 9. The adjustment test of the barring device is complete. 10. The transmission tests for the relevant protection, interlocking, signal and audible devices, as well as operating control devices in conjunction with DCS control and electrical systems have been completed. 11. Prepare a tachometer, stethoscope, hook wrench, record sheet, vibration meter, etc. 12. The site should have actual system diagrams for systems such as the steam and water systems and oil systems. 13. There should be clear divisions of labor and job responsibility protocols for operators and installers, and defects must be addressed promptly and efficiently. 14. Contact the electrical staff to test the insulation of each motor; the tests passed ； The insulation of all its electric door motors was found to be satisfactory. 15. Connect to the thermal instrumentation and supply power to all display, protection, and interlock devices. IV. Complete startup of the steam turbine generator set: 1. Inspections before starting up: (1) Conduct a comprehensive and detailed inspection of all equipment and system components in accordance with the operating procedures for this unit, to ensure that all conditions for trial operation are met. (2) Electrical and thermal engineers check whether the electrical components and DCS control are functioning properly. (3) Inspect the main steam and drain systems; open the main drains before and after the stop valves, as well as those before and after the electric main valves, as well as the drains behind the high and medium pressure control valves. (4) Inspect the extraction steam and its drain system; open the inlet and water inlet valves of each low-temperature heater, as well as the drain valves of each low-temperature heater. (5) Inspect the condensate, water control, and make-up water systems; fill the hot water well of the condenser with demineralized water to about 2/3 of the level indicated by the gauge. (6) Inspect the shaft seal, air, and water injection systems; put the shaft seal heater and steam seal pressure regulator into service. (7) Inspect the circulating water system and industrial water system, and open the inlet and outlet valves for the condenser circulation. (8) Check the regulating oil system; the quality of the oil in the tank is good. The oil level is normal, with the level in the main fuel tank being no lower than +150mm. 2. Commissioning of auxiliary equipment: (1) Bring the oil control system online, start the lubricating oil pump, check that the oil circulation is operating properly, remove any air accumulated in the oil control system, ensure that the oil pressure is at least 0.055 Mpa, verify that the return oil flow to each bearing is normal, and keep the oil temperature in the cooler at around 50°C. Check whether the interlocking devices for the automatic main steam valve, hydraulic actuator, rotating baffle, and extraction valve close quickly. (2) Start the turning gear and engage continuous turning; check that there are no abnormal noises or friction inside the unit, and start the exhaust fan. (3) Start the speed control oil pump and stop the lubricating oil pump; check that the speed control oil pressure is not lower than 1.3 Mpa, and activate the oil pump interlock. (4) Start the circulating water pump to supply water to the condenser water side. (5) Start the condensate pump; open the recirculation valve appropriately, supply water to the shaft seal heater and the low-pressure heater. Check that the condenser water level is normal, and activate the interlock for the condensate pump. (6) Start the jet pump, check that the condenser vacuum gradually rises, and activate the jet pump interlock. 3. Pipe warming: Close the high-regulation valve, slightly open the main steam valve, warm the steam guide pipe, and warm it to the level at which the automatic main steam valve operates, in accordance with the operating procedures. (1) Pressure rise rate during pipe warming: (2) Precautions for pressure rise during pipe warming: ① Check that the expansion of the main steam pipe as well as the condition of the supports and hangers are normal; there should be no vibrations or knocking sounds in the pipes. If such issues exist, increase the drainage of water from the system, and if necessary, close the electric main steam valve. Restart the system only after all water inside has been drained. ②During the heating process, the drain trap valves should be appropriately closed according to the increase in pressure, in order to control the heating rate. ③The heating rate must be strictly controlled to no more than 3°C/min. ④When supplying steam to the steam seal, ensure that the drain from the turbine itself is unobstructed. 4. Cold-state pressure method sliding-parameter impulse for steam turbines: (1) Conditions required before impulse: ① The boiler must be ready, and the pressure and temperature must be increased as required by the shift supervisor, so that the main gas parameters remain at a pressure of 3.5 Mpa and a temperature of 350–400°C. ②The condenser vacuum should be above -63 KPa; it is not advisable for the vacuum to be too high. ③The regulated oil pressure is maintained at around 1.13; the lubricating oil pressure ranges from 0.08 to 0.147 MPa. The oil temperature at the outlet of the oil cooler is between 35 and 45°C. The oil flow to all bearings is normal. ④To reset the unit, press the “Reset” button on the control panel. At this point, the reset indicator light on the control panel should be on, while the trip indicator light should be off. Meanwhile, both the main valve and the governing valve should be completely closed ； The medium-pressure control valve and the low-pressure control valve should be fully open; after the flow control valve setting is applied, the high-pressure control valve should also be fully open. ⑤Both the generator and the exciter meet the startup conditions. ⑥Activate all protections of the steam turbine and deactivate the low vacuum shutdown protection. ⑦Before starting, install a dial indicator at the front end of the cylinder to measure the absolute expansion on the left and right sides of the cylinder. (2) Warm-up and speed increase: First, increase the speed evenly to 250 r/min, then apply the brake and listen to check the friction condition of the rotor. 5. Hot start time and classification: (1) A hot start shall meet the following conditions: ① If the shutdown time is within 12 hours and the wall temperature of the lower cylinder at the regulating stage is not lower than 200°C, it is considered a hot start; in all other cases, the turbine start is considered a cold start. ② The temperature of the steam entering the turbine should be 30–50°C higher than the temperature at the regulating stage; the temperature difference between the upper and lower parts of the cylinder should be within 50°C. ③ Before impulse starting the rotor, it must be turned continuously to prevent rotor bending. When the measured rotor deflection exceeds the original value by more than 0.03 mm, impulse starting is prohibited. ④ Steam should be supplied to the front shaft seal to increase rotor expansion, and then vacuum should be applied. ⑤ Maintain a vacuum of -4050 Kpa (2). To achieve a relatively fast speed, the rotation speed must be increased gradually in accordance with these procedures by raising the vacuum level, in order to reduce negative differential expansion. 6. Precautions during the acceleration process: 1) The boiler must strictly control the increase in various parameters of the main steam, and this increase must be carried out gradually in accordance with these guidelines. 2) During the startup and speed-up process of the turbine, “manual control” should be used first; click the “Manual” button on the manual control panel to switch the control mode to manual, and then try automatic control. 3) It is strictly prohibited for the unit to remain at near the critical speed for an extended period of time; it is necessary to quickly and smoothly exceed the critical speed, and it should be checked that the bearing vibration at that point is ≤0.10 mm. 4) Carefully listen for any abnormal metallic friction sounds inside the turbine, check the oil return temperature of each bearing, as well as the condition of the turning gear. The vibration levels of all bearings should be within 0.03 mm; if these values are exceeded, the speed should be reduced until the vibration ceases, after which the speed can be increased again ； If the vibration does not disappear, it is necessary to reduce the speed again and then increase it once more ； If the vibration still does not disappear, the machine must be shut down for inspection. 5) Check that the expansion values on both sides of the cylinder are roughly the same, and that the expansion difference is within the specified range; otherwise, the time required for acceleration and warming up should be increased. During the automatic and ATC speed-up processes, if abnormalities such as excessive differential expansion or increased vibration are detected, the unit can still proceed with warming up according to the curve by using the “hold” function. 6) When the exhaust cylinder temperature exceeds 80, the water injection solenoid valve activates to spray water into the throat of the exhaust cylinder in order to cool it down; if necessary, the vacuum break valve is used to adjust the desired vacuum level. 7) Check that the drainage in the turbine unit and the extraction pipeline is unobstructed, with no water hammer or vibration phenomena. 8) Valve switching is carried out when the speed rises to 2950 r/min; the speed control valve should close smoothly while the automatic main valve opens fully, completing the switch. At this point, the speed is controlled by the main valve rather than by the speed control valve. 9) Increase the rotational speed to 3000 r/min. Once the main oil pump starts operating, gradually close the outlet valve of the speed control oil pump. Verify that the main oil pump is indeed working, then stop the speed control oil pump. After that, reopen the outlet valve of the speed control oil pump and activate the interlock switch. V. No-load test and adjustment 1. Manually operate the emergency shutdown handle to test the flexibility of the main steam valve and the control valve. 1. Tightness test of the automatic main steam valve and control steam valve. 2. Emergency circuit breaker overspeed test. 3. Emergency circuit breaker oil filling test. VI. Grid connection of the generator and operation under load 1. The turbine was tested under no-load conditions for 20 minutes, with all parameters being normal, and the unit’s speed was maintained at a constant level. 2. Electrical personnel shall conduct various tests on the generator, paying attention to its wind temperature; if it is too high, activate the air cooler in accordance with the machine’s operating procedures. 3. All tests have been completed; the conditions for grid connection are met. Preparation is underway for grid connection and loading, with confirmation that the temperature at the lower part of the turbine’s high-pressure cylinder is above 220°C. 4. Check whether the interconnection signals between the turbine and the generator are normal. 4. Parallel operation followed by operation under load: (1) Load of 3 MW is added at a rate of 0.1 MW/min (for a total of 30 minutes), after which a 40-minute pause is taken; then medium and low pressure extraction steam is activated to supply air to the deaerator and high-pressure heaters. During the evacuation process, pay attention to changes in electrical load; it is not allowed for both electrical and thermal loads to increase simultaneously. (2) Then, increase the load uniformly at a rate of 0.2 MW/min until it reaches 7 MW (over a total of 20 minutes), and remain at that level for 30 minutes. (3) Then increase the load uniformly at a rate of 0.1 MW/min to 12.5 MW (over a total of 75 min), and maintain it for 60 min. (4) Then, increase the load uniformly at a rate of 0.5 MW/min to 25 MW (over a total of 25 minutes), and hold it for 60 minutes. (5) In projects with loaded operations, it is necessary to closely monitor that the control system operates properly without any fluctuations; when the load is increased, the control valves of each hydraulic actuator should move smoothly without any sticking. Conduct acoustic inspections on the steam turbine unit, and check that the unit’s vibration, axial displacement, expansion difference, cylinder expansion, and temperatures of various metal components are all within normal ranges. Also, ensure proper regulation of oil temperature, air temperature, and condenser water level. (6) Rate of increase in temperature and pressure during operation under load: VII. Control of key parameters during operation 1. Range of variations in parameters of fresh steam: Main steam pressure: 8.83±0.49 Mpa; Main steam temperature: 525–540°C. When the fresh steam pressure exceeds 9.8 Mpa or the temperature exceeds 545°C, the operating time shall not exceed 0.5 hours each time. If the temperature and pressure exceed the specified values and cannot be reduced, an emergency shutdown should be initiated. 2. Load limitation: When the parameters of the new steam decrease, the exhaust pressure drops, or for other reasons that require a reduction in load, it is possible to control the pressure in the monitoring section to a specified value. 3. Grid frequency: 50±0.5 Hz. 4. Lubricating oil pressure: 0.078–0.147 Mpa; oil pressure at the inlet of the main oil pump: 0.05–0.1 Mpa; oil pressure at the outlet of the main oil pump: 1.57 Mpa. 5. Axial displacement: +1.0 mm or -0.6 mm; relative expansion difference: +3 mm or -2 mm; bearing housing vibration: 0.03 mm. It is necessary to regularly monitor all the measuring instruments and keep records of them on a regular basis. In cases of changes in load or any abnormalities, detailed records should be kept. VIII. Shutdown due to disconnection 1. Notify the heat network and power grid dispatching teams, as well as the boiler and electrical teams, to prepare for shutdown. 2. Reduce the load at a rate that corresponds to the increase in load; ensure that the expansion difference during this process does not exceed the specified value, otherwise the reduction of load should be stopped. 3. When the load drops below 15 MW, stop steam extraction; as the load continues to decrease, activate #1 low-temperature economizer to the condenser drain valve and shut down the low-temperature economizer drain pump. 4. Precautions during the load reduction process: (1) During load reduction, it is necessary to strictly control the relative expansion so that it does not exceed -2 mm; otherwise, the load reduction should be paused until the expansion difference is under control before continuing with the reduction. (2) Adjust the opening degrees of the recirculation valve and the shaft seal heater bypass valve in accordance with the amount of condensate water to ensure the proper operation of the shaft seal heater. (3) Pay attention to the steam supply for the shaft seal; switch to manual mode if necessary. (4) Regularly check that the axial displacement, expansion difference, thrust bearing pads and oil return temperature, as well as the noise and vibration of the unit, are all normal. 5. Reduce the load to “0” and contact the electrical duty officer to isolate the generator. 6. After the main steam valve is closed, the coasting time should be measured. 7. Start the turning device; after 2 hours of continuous operation, turn it 180° every 15 minutes. After another 2 hours, turn it 180° every 30 minutes. After yet another 2 hours, if the temperature difference between the upper and lower cylinders is below 50°C, turn it 180° every 40 minutes until it has cooled down completely. To reduce operations, it is possible to continuously turn the shaft until it is completely cooled. IX. Accident Handling 1. The turbine should be shut down urgently by breaking the vacuum under the following conditions: (1) Sudden severe vibration or metal striking sounds occur in the unit. (2) The turbine speed increased to 3360 r/min while the emergency shutdown device did not function. (3) Water hammer occurs in the turbine. (4) Sparks are emitted from the shaft segment steam seal. (5) Oil interruption or smoking inside any bearing, or a sudden increase in the bearing return oil temperature. (6) The bearing return oil temperature rises above 75°C, and the bearing shell temperature exceeds 110°C. (7) A fire breaks out in the oil system and cannot be extinguished quickly. (8) The oil level in the tank suddenly drops below the minimum level. (9) The lubricating oil pressure dropped to 0.0196 Mpa. (10) The axial displacement of the rotor exceeds 1.3 mm. (11) Breakage of the main steam pipe. (12) Smoke is coming from the generator. (13) Operation of the rear cylinder exhaust valve. 2. The turbine shall not shut down due to a vacuum failure under the following conditions: (1) The inlet steam pressure is greater than 9.8 MPa or the steam temperature is greater than 545°C. (2) The steam inlet pressure is less than 5.88 MPa or the steam temperature is greater than 480°C. (3) The vacuum of the condenser is below -0.06 MPa. (4) The control valve or rotating baffle is stuck. (5) Bearing housing vibration is greater than 0.06 mm. 3. The turbine shall shut down due to a vacuum failure without damage under the following conditions if it cannot recover within 15 minutes: (1) The inlet steam pressure is lower than 6 MPa or higher than 5.88 MPa. (2) The steam inlet temperature is below 485°C and above 480°C. (3) The condenser vacuum is below -0.073 MPa and above -0.061 MPa. 4. Under load, any emergency shutdown must first stop the turbine before disconnecting the power supply!