Q&A on Purification Technology [041]
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What conditions must be met for the propylene compressor unit to be started? A. The separator oil level is normal ； B. The liquid level in the gas-liquid separator is normal (it’s best if there is no liquid level at all; it should not reach the level switch set for alarm) ； C. The level of the economizer fluid is normal (it is best to keep it within a section of glass plate at the bottom, and it should not reach the level switch set for alarm) ； D. The liquid level in the condenser tank is normal (at least 30%) ； If there is no liquid level or the liquid level is low in the evaporator, the tank liquid level can be relatively high. ) E. Verify that all oil heaters are operating properly, and that the oil temperature in the oil separator is at least 30 degrees ； F. The unit control cabinet shows normal operation, with no alarm or shutdown messages. Coal chemical processing – Purification technology section; 2017’s “My Technical Upgrades” in the coal chemical industry (great rewards available). http://bbs.hcbbs.com/thread-1786290-1-1.html. Registration for chemical engineers – Experience sharing event titled “Learning from Others’ Experiences”. http://bbs.hcbbs.com/thread-1808158-1-1.html
A. The separator oil level is normal； B. The liquid level in the gas-liquid separator is normal (it’s best if there is no liquid level at all; it should not reach the level switch set for alarm) ； C. The level of the economizer fluid is normal (it is best to keep it within a section of glass plate at the bottom, and it should not reach the level switch set for alarm) ； D. The liquid level in the condenser tank is normal (at least 30%) ； If there is no liquid level or the liquid level is low in the evaporator, the tank liquid level can be relatively high. ) E. Verify that all oil heaters are operating properly, and that the oil temperature in the oil separator is at least 30 degrees ； F. The unit control cabinet shows normal operation, with no alarm or shutdown messages (Note: the “Low Motor Current Sensor Warning” message that appears during shutdown does not affect startup) ； Capacity location display is less than 10% ； The pressure difference between exhaust and intake air is less than 600 KPA ； The compressor mode, capacity mode, and volume mode are all set to “Manual”” ； The oil pump mode is “automatic”. All pressure and temperature values are within the specified limits. G. The oil temperature in the gearbox’s light oil tank is normal (above 20 degrees and below 35 degrees) ； The fuel supply pressure is normal (2-3 kilograms; the pressure normal indicator light is on) ； The oil levels in the sight glasses of the front and rear bearing housings of the motor are normal (between 1/2 and 2/3), and oil flow can be observed in the return oil sight glasses of the front and rear bearings ； The high-position emergency fuel tank overflow return oil sight glass allows visibility of the oil flow. H. Once all the above conditions are met, notify the high-voltage electrical start cabinet to supply power, thereby initiating the startup procedure.
A. The separator oil level is normal； B. The liquid level in the gas-liquid separator is normal (it’s best if there is no liquid level at all; it should not reach the level switch set for alarm) ； C. The level of the economizer fluid is normal (it is best to keep it within a section of glass plate at the bottom, and it should not reach the level switch set for alarm) ； D. The liquid level in the condenser tank is normal (at least 30%) ； If there is no liquid level or the liquid level is low in the evaporator, the tank liquid level can be relatively high. ) E. Verify that all oil heaters are operating properly, and that the oil temperature in the oil separator is at least 30 degrees ； F. The unit control cabinet shows normal operation, with no alarm or shutdown messages.
I. Unit startup procedure: Turbine lubrication system → Condensate system → Pipe warming → Vacuum system → Shaft seal system → Startup of the compressor → Check that pressures, temperatures, and flow rates are all within normal ranges. II. Startup procedures for the compressor unit
1. Turbine lubricating oil system:
Check that the level in the lubricating oil tank is at the normal level. Check the oil temperature; if it is too low, start the fuel tank heater to warm the oil in the tank. Once the oil temperature reaches 22°C, start the main oil pump. At the same time, conduct an interlock test on the oil system to ensure that the pressure at the outlet of the oil pump is around the normal value of 0.90 MPa (G), the pressure in the lubrication main line is 0.105 MPa (G), and the control oil pressure for the turbine is between 0.67 and 0.74 MPa (G). When the oil temperature at the outlet of the oil cooler is 35°C, the electric heater shuts off automatically. Open the oil filling valve to fill the high-level oil tank until the liquid level reaches the operating condition. 2. Condensate system a. Verify that the condensate pump is ready for operation, and set the start mode to local control. b. Add deionized water to the condenser, and raise the level in the hot well to the upper limit. c. Open the inlet valves of the main and auxiliary condensate pumps to vent the pumps; close them once continuous water flow is observed. d. Manually turn the main and auxiliary condensate pumps to ensure smooth rotation with no sticking. e. Start the main condensate pump. 1) Press the start button of the main condensate pump to start it. 2) Once the current has subsided, slowly open the outlet valve. 3) The PLC opens the condensate circulation valve to enable full reflux, and checks for any leaks in the system ； Check whether the pressure, current, vibration, and noise are normal, as well as whether there are any leaks in the pump’s seal. 4) Set the standby pump to automatic mode. 3. Warm the pipes: Open the steam vent valve and the TTV valve to drain condensate. Slightly open the isolation valve to warm the pipes at low pressure (0.2–0.3 MPa(G)). Be careful that the rate of increase in steam temperature should not exceed 5°C/min. Once the pipe temperature reaches 120–130°C, the pressure inside the pipes can be increased at a rate of 0.1 MPa/min. The warming process is complete when the steam pressure reaches 2.5 MPa(G) and the temperature exceeds 300°C. 4. Shaft seal and vacuum system 1) Verify that water is overflowing from the water seal of the exhaust safety valve, and activate the condensate water from the pump. 2) Gradually open the inlet valve of the start-up vacuum pump; the pressure behind the valve should be around 0.2 MPa. After warming up the pipes for 5 minutes, increase the opening of the inlet valve to reach the normal operating pressure. Then slowly open the air valve between the start-up vacuum pump and the condenser to create a vacuum in the system. 3) When the vacuum level reaches -0.075 MPa and after the main exhaust pipes have been warmed up, start the main exhaust pump (first start the secondary exhaust pump, then the primary one). Once the main exhaust pump is operating properly (the vacuum level in the condenser should reach -0.06 MPa, with a minimum of not lower than -0.053 MPa), the auxiliary exhaust pumps can be turned off. Before stopping the pump, the exhaust valve should be closed first, and then the steam supply should be stopped. 4) While evacuating the system, warm up the shaft seal ejector by introducing start-up steam. Open the air valve; after verifying that the drain line of the shaft seal piping is under negative pressure and drawing in air, open the shaft seal steam valve to establish the shaft seal system. 5. System startup a. Before starting the machine, ensure that the liquid level in the heat exchanger of the purification system is above 40%; the liquid level control valve should be in the closed position, and the inlet and outlet valves should be open. b. Contact the dispatcher to confirm that steam supply is stable and that the condensate discharge system is unobstructed. c. On the PLC, open the “Start-up Conditions” screen; all the conditions for starting the compressor (except for the compressor oil pressure) are met, and the PLC indicates that the compressor is ready to start. d. Notify the scheduler to prepare for startup. e. By pressing the compressor start button, the compressor auxiliary oil pump starts automatically, and it gradually opens the TTV valve at a constant rate within one minute; the turbine then starts up, beginning low-speed warming-up at 750 rpm and 1500 rpm. The warm-up procedure can be switched to manual control via “505”. f. Drain the compressor at 750 rpm, drain it again at 1500 rpm, and set the guide vanes at around 25% to reduce vibration levels. g. As the speed continues to rise to around 4050 rpm, adjust the liquid levels in the suction tank, separator, and high/low temperature subcoolers in order to control the outlet temperature and prevent interlock due to excessively high outlet temperatures. At the same time, always monitor the liquid level to prevent interlock due to high levels. h. Increase the speed to between 4150 rpm and 4500 rpm, while gradually raising the load on the unit. The guide vanes are gradually opened fully, while the anti-surge valve is gradually closed (to maintain the inlet pressure at around 1.24–1.26 bar). i. Monitor whether the temperatures of the bearing shells, shaft vibration, and shaft displacement are within normal ranges; if the temperature of the bearing shells rises too rapidly, stop increasing the speed and conduct an inspection ； In emergency situations, the operator can shut down the machine at any time. j. During operation of the compressor, the oil temperature reaches 65.56°C, and this is controlled by the compressor’s temperature control device; the oil temperature of the turbine oil is maintained between 46 and 53°C, while the oil temperature of the thrust bearings is kept between 60 and 65°C. k. Depending on the load requirements, the rotational speed is increased, the anti-surge valve is further closed, and the liquid level at the inlet is adjusted. Ensure an inlet superheat and maintain the outlet temperature above 80°C. 1. Check that the system pressure, temperature, and flow rates are all within normal ranges; the temperature of the 2.5MPa superheated steam should be above 320°C, and its pressure should be above 2.3MPa. The control system should set the liquid level in the evaporation unit of the purification system to automatic control, and the pressure of the A4 gas seal should be checked and adjusted as necessary. Driving is over. 6. Driving after short-term parking No propylene needs to be added during short-term parking. The back-pressure isolation air is put into use; the oil system and condensate system are operating, allowing the unit to run in self-circulation at low speed (with the anti-surge valve PCV-42106A fully open). Proceed with starting the vehicle following the normal steps.
1. Turbine lubricating oil system:
Check that the level in the lubricating oil tank is at the normal level. Check the oil temperature; if it is too low, start the fuel tank heater to warm the oil in the tank. Once the oil temperature reaches 22°C, start the main oil pump. At the same time, conduct an interlock test on the oil system to ensure that the pressure at the outlet of the oil pump is around the normal value of 0.90 MPa (G), the pressure in the lubrication main line is 0.105 MPa (G), and the control oil pressure for the turbine is between 0.67 and 0.74 MPa (G). When the oil temperature at the outlet of the oil cooler is 35°C, the electric heater shuts off automatically. Open the oil filling valve to fill the high-level oil tank until the liquid level reaches the operating condition. 2. Condensate system a. Verify that the condensate pump is ready for operation, and set the start mode to local control. b. Add deionized water to the condenser, and raise the level in the hot well to the upper limit. c. Open the inlet valves of the main and auxiliary condensate pumps to vent the pumps; close them once continuous water flow is observed. d. Manually turn the main and auxiliary condensate pumps to ensure smooth rotation with no sticking. e. Start the main condensate pump. 1) Press the start button of the main condensate pump to start it. 2) Once the current has subsided, slowly open the outlet valve. 3) The PLC opens the condensate circulation valve to enable full reflux, and checks for any leaks in the system ； Check whether the pressure, current, vibration, and noise are normal, as well as whether there are any leaks in the pump’s seal. 4) Set the standby pump to automatic mode. 3. Warm the pipes: Open the steam vent valve and the TTV valve to drain condensate. Slightly open the isolation valve to warm the pipes at low pressure (0.2–0.3 MPa(G)). Be careful that the rate of increase in steam temperature should not exceed 5°C/min. Once the pipe temperature reaches 120–130°C, the pressure inside the pipes can be increased at a rate of 0.1 MPa/min. The warming process is complete when the steam pressure reaches 2.5 MPa(G) and the temperature exceeds 300°C. 4. Shaft seal and vacuum system 1) Verify that water is overflowing from the water seal of the exhaust safety valve, and activate the condensate water from the pump. 2) Gradually open the inlet valve of the start-up vacuum pump; the pressure behind the valve should be around 0.2 MPa. After warming up the pipes for 5 minutes, increase the opening of the inlet valve to reach the normal operating pressure. Then slowly open the air valve between the start-up vacuum pump and the condenser to create a vacuum in the system. 3) When the vacuum level reaches -0.075 MPa and after the main exhaust pipes have been warmed up, start the main exhaust pump (first start the secondary exhaust pump, then the primary one). Once the main exhaust pump is operating properly (the vacuum level in the condenser should reach -0.06 MPa, with a minimum of not lower than -0.053 MPa), the auxiliary exhaust pumps can be turned off. Before stopping the pump, the exhaust valve should be closed first, and then the steam supply should be stopped. 4) While evacuating the system, warm up the shaft seal ejector by introducing start-up steam. Open the air valve; after verifying that the drain line of the shaft seal piping is under negative pressure and drawing in air, open the shaft seal steam valve to establish the shaft seal system. 5. System startup a. Before starting the machine, ensure that the liquid level in the heat exchanger of the purification system is above 40%; the liquid level control valve should be in the closed position, and the inlet and outlet valves should be open. b. Contact the dispatcher to confirm that steam supply is stable and that the condensate discharge system is unobstructed. c. On the PLC, open the “Start-up Conditions” screen; all the conditions for starting the compressor (except for the compressor oil pressure) are met, and the PLC indicates that the compressor is ready to start. d. Notify the scheduler to prepare for startup. e. By pressing the compressor start button, the compressor auxiliary oil pump starts automatically, and it gradually opens the TTV valve at a constant rate within one minute; the turbine then starts up, beginning low-speed warming-up at 750 rpm and 1500 rpm. The warm-up procedure can be switched to manual control via “505”. f. Drain the compressor at 750 rpm, drain it again at 1500 rpm, and set the guide vanes at around 25% to reduce vibration levels. g. As the speed continues to rise to around 4050 rpm, adjust the liquid levels in the suction tank, separator, and high/low temperature subcoolers in order to control the outlet temperature and prevent interlock due to excessively high outlet temperatures. At the same time, always monitor the liquid level to prevent interlock due to high levels. h. Increase the speed to between 4150 rpm and 4500 rpm, while gradually raising the load on the unit. The guide vanes are gradually opened fully, while the anti-surge valve is gradually closed (to maintain the inlet pressure at around 1.24–1.26 bar). i. Monitor whether the temperatures of the bearing shells, shaft vibration, and shaft displacement are within normal ranges; if the temperature of the bearing shells rises too rapidly, stop increasing the speed and conduct an inspection ； In emergency situations, the operator can shut down the machine at any time. j. During operation of the compressor, the oil temperature reaches 65.56°C, and this is controlled by the compressor’s temperature control device; the oil temperature of the turbine oil is maintained between 46 and 53°C, while the oil temperature of the thrust bearings is kept between 60 and 65°C. k. Depending on the load requirements, the rotational speed is increased, the anti-surge valve is further closed, and the liquid level at the inlet is adjusted. Ensure an inlet superheat and maintain the outlet temperature above 80°C. 1. Check that the system pressure, temperature, and flow rates are all within normal ranges; the temperature of the 2.5MPa superheated steam should be above 320°C, and its pressure should be above 2.3MPa. The control system should set the liquid level in the evaporation unit of the purification system to automatic control, and the pressure of the A4 gas seal should be checked and adjusted as necessary. Driving is over. 6. Driving after short-term parking No propylene needs to be added during short-term parking. The back-pressure isolation air is put into use; the oil system and condensate system are operating, allowing the unit to run in self-circulation at low speed (with the anti-surge valve PCV-42106A fully open). Proceed with starting the vehicle following the normal steps.
Answer: 1. The oil level in the oil separator is normal； 2. The liquid level in the gas-liquid separator is normal (it is preferable that there be no liquid level at all; it should not reach the alarm level switch) ； 3. The level of the economizer fluid is normal (it is best to keep it within a section of glass plate at the bottom, and it should not reach the level switch set for alarm) ； 4. The liquid level in the condenser tank is normal (at least 30%) ； If there is no liquid level or the liquid level is low in the evaporator, the tank liquid level can be relatively high. 5. Ensure that all oil heaters are functioning properly, and that the oil temperature in the oil separator is not below 30 degrees ； 6. The unit control cabinet shows normal operation, with no alarm or shutdown messages ； Capacity location display is less than 10% ； The pressure difference between exhaust and intake air is less than 600 KPA ； The compressor mode, capacity mode, and volume mode are all set to “Manual”” ； The oil pump mode is “automatic”. All pressure and temperature values are within the specified limits.
1. The separator oil level is normal； 2. The liquid level in the gas-liquid separator is normal (it is preferable that there be no liquid level at all; it should not reach the alarm level switch) ； 3. The level of the economizer fluid is normal (it is best to keep it within a section of glass plate at the bottom, and it should not reach the level switch set for alarm) ； 4. The liquid level in the condenser tank is normal (at least 30%) ； If there is no liquid level or the liquid level is low in the evaporator, the tank liquid level can be relatively high. ) 5. Ensure that all oil heaters are operating properly, and that the oil temperature in the oil separator is not below 30 degrees ； 6. The unit control cabinet shows normal operation, with no alarm messages indicating shutdown (Note: The “Low Motor Current Sensor Warning” message that appears during shutdown does not affect startup) ； Capacity location display is less than 10% ； The pressure difference between exhaust and intake air is less than 600 KPA ； The compressor mode, capacity mode, and volume mode are all set to “Manual”” ； The oil pump mode is “automatic”. All pressure and temperature values are within the specified limits. 7. The oil temperature in the oil tank of the motor’s light oil station is normal (above 20 degrees and below 35 degrees) ； The fuel supply pressure is normal (2-3 kilograms; the pressure normal indicator is lit) ； The oil levels in the sight glasses of the front and rear bearing housings of the motor are normal (between 1/2 and 2/3), and oil flow can be observed in the return oil sight glasses of the front and rear bearings ； The high-position emergency fuel tank overflow return oil sight glass allows visibility of the oil flow. 8. Once all the above conditions are met, notify the high-voltage electrical start cabinet to supply power, thereby initiating the startup procedure.
A. The separator oil level is normal； B. The liquid level in the gas-liquid separator is normal (it’s best if there is no liquid level at all; it should not reach the level switch set for alarm) ； C. The level of the economizer fluid is normal (it is best to keep it within a section of glass plate at the bottom, and it should not reach the level switch set for alarm) ； D. The liquid level in the condenser tank is normal (at least 30%) ； If there is no liquid level or the liquid level is low in the evaporator, the tank liquid level can be relatively high. ) E. Verify that all oil heaters are operating properly, and that the oil temperature in the oil separator is at least 30 degrees ； F. The unit control cabinet shows normal operation, with no alarm or shutdown messages (Note: the “Low Motor Current Sensor Warning” message that appears during shutdown does not affect startup) ； Capacity location display is less than 10% ； The pressure difference between exhaust and intake air is less than 600 KPA ； The compressor mode, capacity mode, and volume mode are all set to “Manual”” ； The oil pump mode is “automatic”. All pressure and temperature values are within the specified limits.
A. The separator oil level is normal； B. The liquid level in the gas-liquid separator is normal (it’s best if there is no liquid level at all; it should not reach the level switch set for alarm) ； C. The level of the economizer fluid is normal (it is best to keep it within a section of glass plate at the bottom, and it should not reach the level switch set for alarm) ； D. The liquid level in the condenser tank is normal (at least 30%) ； If there is no liquid level or the liquid level is low in the evaporator, the tank liquid level can be relatively high. ) E. Verify that all oil heaters are operating properly, and that the oil temperature in the oil separator is at least 30 degrees ； F. The unit control cabinet shows normal operation, with no alarm or shutdown messages (Note: the “Low Motor Current Sensor Warning” message that appears during shutdown does not affect startup) ； Capacity location display is less than 10% ； The pressure difference between exhaust and intake air is less than 600 KPA ； The compressor mode, capacity mode, and volume mode are all set to “Manual”” ； The oil pump mode is “automatic”. All pressure and temperature values are within the specified limits. G. The oil temperature in the gearbox’s light oil tank is normal (above 20 degrees and below 35 degrees) ； The fuel supply pressure is normal (2-3 kilograms; the pressure normal indicator is lit) ； The oil levels in the sight glasses of the front and rear bearing housings of the motor are normal (between 1/2 and 2/3), and oil flow can be observed in the return oil sight glasses of the front and rear bearings ； The high-position emergency fuel tank overflow return oil sight glass allows visibility of the oil flow. H. Once all the above conditions are met, notify the high-voltage electrical start cabinet to supply power, thereby initiating the startup procedure.
A. The separator oil level is normal； B. The liquid level in the gas-liquid separator is normal (it’s best if there is no liquid level at all; it should not reach the level switch set for alarm) ； C. The level of the economizer fluid is normal (it is best to keep it within a section of glass plate at the bottom, and it should not reach the level switch set for alarm) ； D. The liquid level in the condenser tank is normal (at least 30%) ； If there is no liquid level or the liquid level is low in the evaporator, the tank liquid level can be relatively high. ) E. Verify that all oil heaters are operating properly, and that the oil temperature in the oil separator is at least 30 degrees ； F. The unit control cabinet shows normal operation, with no alarm or shutdown messages
A. The oil level in the separator is normal； B. The liquid level in the gas-liquid separator is normal (it’s best if there is no liquid level at all; it should not reach the level switch set for alarm) ； C. The economizer liquid level is normal (it is best to keep it within a section of glass plates at the bottom, and it should not reach the alarm level switch) ； D. The liquid level in the condenser tank is normal (at least 30%) ； If there is no liquid level or the liquid level is low in the evaporator, the tank liquid level can be relatively high. ) E. Verify that all oil heaters are functioning properly, and that the oil temperature in the oil separator is not lower than 30 degrees ； F. The unit control cabinet displays normally, with no alarm or shutdown messages (Note: The message “Low Motor Current Sensor Warning” displayed during shutdown does not affect the unit’s startup.) ； The capacity level shows less than 10% ； The pressure difference between exhaust and intake air is less than 600 KPA ； The compressor mode, capacity mode, and volume mode are all set to “Manual”” ； The oil pump mode is “automatic”. All pressure and temperature values are within the specified limits. G. The oil temperature in the motor light oil station tank is normal (above 20 degrees, below 35 degrees) ； The fuel supply pressure is normal (2-3 kilograms; the pressure normal indicator is on) ； The oil levels in the sight glasses of the front and rear bearing housings of the motor are normal (between 1/2 and 2/3), and oil flow can be observed in the return oil sight glasses of the front and rear bearings ； The high-position emergency fuel tank overflow return oil sight glass allows visibility of the oil flow. H. Once all the above conditions are met, notify the high-voltage electrical start cabinet to supply power, thereby initiating the startup procedure.
There are two conditions for starting the compressor: 1. Start at equilibrium pressure. Regardless of whether the back pressure is high or low, and regardless of the type of refrigerant, the compressor starts at equilibrium pressure; it starts at 233V under high voltage conditions and at 187V under low voltage conditions. 2. Differential pressure start Sometimes a differential pressure start method is also used; the difference between the exhaust pressure and the intake pressure is taken into account – a differential pressure of 0.1 MPa is used at a high voltage of 242 V, while 0.2 MPa is used at a low voltage of 187 V.