Gas turbine high pressure bypass valve does not close troubleshooting and disposal method

Abstract

The present application relates to a kind of gas turbine high pressure bypass valve does not close troubleshooting and disposal method, it is related to gas turbine field, this method is based on the timing that two high pressure bypass valve abnormal does not close, according to the specific phenomenon of fault occurrence, positioning speed sensor fault, control system signal fault, start suspension fault and high pressure bypass valve jam fault, this method is practical, can efficiently investigate gas turbine high pressure bypass valve does not close fault, it is of great significance to restore the stable operation of gas turbine.

Description

Technical Field

[0001] This invention relates to the field of gas turbine technology, and in particular to a method for troubleshooting and handling faults caused by a gas turbine high-pressure bypass valve not closing. Background Technology

[0002] A gas turbine consists of a high-pressure compressor and a low-pressure compressor. The high-pressure compressor uses a high-pressure bypass valve to release gas in order to prevent surge in the high-pressure compressor.

[0003] During gas turbine startup, the high-pressure bypass valve needs to be opened to prevent surge. When the high-pressure speed approaches idle speed, the high-pressure bypass valve should be closed.

[0004] During the start-up of a gas turbine, repeated instances of the high-pressure bypass valve opening, failing to close, or continuously venting indicate a fault in the starter suspension. Without effective handling and rapid troubleshooting, this can pose significant risks to the stable operation of the gas turbine, such as surge and overheating of the turbine housing. Summary of the Invention

[0005] In response to the shortcomings of the existing production technology, the applicant provides a reasonable method for troubleshooting and handling faults in the high-pressure bypass valve of a gas turbine that is not closed. This method can effectively troubleshoot problems in various parts in a short time, is targeted, has high troubleshooting efficiency, and facilitates the rapid restoration of stable operation of the gas turbine.

[0006] The technical solution adopted in this invention is as follows:

[0007] A method for troubleshooting and handling a fault where the high-pressure bypass valve of a gas turbine is not closed, wherein, during the start-up to idle process of the gas turbine, if the high-pressure bypass valve is heard continuously opening and venting, the following steps are taken for troubleshooting and handling:

[0008] Step 1:

[0009] If the high-pressure speed is greater than the shut-off speed, it is determined that one of the two high-pressure bypass valves is closed while the other is not. The unclosed bypass valve is stuck. In this case, the machine should be stopped for inspection and replacement.

[0010] Step Two:

[0011] If both bypass valves are not closed, check for fluctuations in the high-pressure compressor speed; if the high-pressure compressor speed measurement value fluctuates, causing the high-pressure speed to be less than or equal to the shut-off speed, then shut down the compressor to troubleshoot the speed measurement fault.

[0012] Step 3:

[0013] If, assuming both bypass valves are not closed in step two, the high-pressure compressor speed is stable and the high-pressure speed is less than or equal to the closing speed, then the gas turbine is determined to be in a normal start-up process.

[0014] During startup:

[0015] If, during the gas turbine startup process, the acceleration stalls below the shut-off speed while the bypass valve remains open, and the fuel pressure is low at this time, the gas turbine will experience a cold start. It will need to be shut down, the fuel supply increased, and then restarted.

[0016] When the high-pressure speed rises to a level greater than the shut-off speed and the bypass valve is closed, and then drops to a level less than or equal to the shut-off speed, the bypass valve reopens, and the speed stops rising. If the gas temperature is high, a starting hot suspension will occur at this time. After the turbine is stopped and the gas temperature is reduced by cold blowing, the turbine will be restarted.

[0017] As a further improvement to the above technical solution:

[0018] In step two, when the gas turbine is in idle condition and the high-pressure speed is greater than the shut-off speed, first check whether the control signal of the control system is in the high-pressure bypass open command.

[0019] If the control system continues to issue start commands, check the control system. At this time, it is strictly forbidden to upgrade the operating condition until the start command is turned off.

[0020] If the control signal of the control system is in the high-pressure bypass switch command and the control circuit is intact, it is determined that both high-pressure bypass valves are stuck, and the system should be shut down for inspection and replacement.

[0021] A process for troubleshooting and handling gas turbine startup to idle conditions using the method of claim 1 includes the following steps:

[0022] When a gas turbine starts up to idle speed, the high-pressure speed is greater than the shut-off speed. For example, if the shut-off speed is 7500 and the high-pressure speed is 8000, the operator will hear an abnormal noise and determine that the high-pressure bypass valve is in the venting state. One of the high-pressure bypass valves is closed and the other is not closed. The unclosed high-pressure bypass valve is stuck.

[0023] After replacing the stuck high-pressure bypass valve, the engine was restarted and the problem was resolved.

[0024] A process for troubleshooting and handling gas turbine startup to idle conditions using the above method includes the following steps:

[0025] When a gas turbine is started to idle, the high-pressure speed is less than the shut-off speed. For example, if the shut-off speed is 7500 and the high-pressure speed is 7000, it is determined that there is a fault in the high-pressure speed measurement. The turbine is stopped to check the wiring between components. After tightening the wiring, the turbine is restarted and the fault is eliminated.

[0026] A process for investigating and handling the operating status of a gas turbine using the above method includes the following steps:

[0027] After the gas turbine completes standby and starts, the high-pressure bypass valve opens at the expected time. During the process of the gas turbine speed rising, it stops when it is below the closing speed. At this time, the high-pressure bypass valve remains open. The operator checks the fuel supply pressure. If the maximum fuel supply pressure is less than the fuel supply pressure required to start to idle, it is determined that the gas turbine is in a cold suspension state. The turbine is stopped and the throttle is increased to increase the fuel supply. The turbine is then restarted, and the fault is eliminated.

[0028] A process for investigating and handling the operating status of a gas turbine using the above method includes the following steps:

[0029] After the gas turbine completes standby and starts, the high-pressure bypass valve opens at the expected time. When the gas turbine speed reaches the shut-off speed, the high-pressure bypass valve closes, and then the gas turbine speed drops. When the gas turbine speed drops below the shut-off speed, the high-pressure bypass valve reopens, and the speed stops rising. If the high-pressure bypass valve remains open and the operator finds that the gas temperature after the turbine is higher than normal before and after starting, it is determined that a starting hot suspension has occurred. After stopping the turbine and cold blowing to reduce the gas temperature after the turbine, the turbine is restarted, and the fault is eliminated.

[0030] A process for investigating and handling the operating status of a gas turbine using the above method includes the following steps:

[0031] After the gas turbine completes standby and starts, the high-pressure bypass valve opens at the expected time. When the gas turbine speed is higher than the shut-off speed, the high-pressure bypass valve is in the open state. After the gas turbine successfully starts to idle, the high-pressure bypass valve is still in the open state. When the operator checks the control system, if the control signal is in the high-pressure bypass open command state, it is determined that the control signal distributor is faulty. After replacing the distributor, the high-pressure bypass valve is closed, and the fault is eliminated.

[0032] The beneficial effects of this invention are as follows:

[0033] This invention is based on the timing of two high-pressure bypass valves failing to close abnormally. According to the specific phenomena of the fault, it identifies faults such as speed sensor failure, control system signal failure, starting suspension failure, and high-pressure bypass valve jamming. It is highly practical and can efficiently troubleshoot faults of high-pressure bypass valves failing to close in gas turbines, which is of great significance for restoring stable operation of gas turbines.

[0034] While proposing a troubleshooting approach, this invention discloses several examples to demonstrate that the proposed troubleshooting approach is feasible, targeted, and can accurately locate faults at each stage, making it less likely to miss any faults. Attached Figure Description

[0035] Figure 1 This is a flowchart illustrating the troubleshooting process for a high-pressure bypass valve not closing, as described in this invention. Detailed Implementation

[0036] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0037] like Figure 1 As shown, the specific troubleshooting and handling methods for a gas turbine high-pressure bypass valve not closing are as follows:

[0038] If you hear the high-pressure bypass valve continuously opening and venting gas during the entire process of starting the gas turbine and idling, you should follow the steps below to handle and troubleshoot the problem.

[0039] Step 1: If the high-pressure rotation speed > N 关闭 If one of the two high-pressure bypass valves is closed while the other is not, the cause is determined to be a jammed bypass valve. An emergency shutdown should be initiated for inspection and replacement. 关闭 This refers to the rotational speed when the high-pressure bypass valve is closed.

[0040] Step 2: If the high-pressure rotation speed > N 关闭 If both bypass valves are not closed, check for fluctuations in the high-pressure compressor speed. If the high-pressure speed measurement fluctuates, ensure the high-pressure speed is ≤ N. 关闭 If the problem persists, the machine should be stopped immediately to troubleshoot the speed measurement malfunction.

[0041] Step 3: In Step 2 above, if the high-pressure compressor speed is stable and the measured value is accurate, i.e., the high-pressure speed is ≤ N... 关闭 The gas turbine is determined to be in the startup process.

[0042] If the acceleration during the gas turbine startup process stalls at N... 关闭 If the bypass valve remains open and the fuel pressure is low, it indicates that the gas turbine has experienced a cold start. The turbine should be shut down immediately, and the fuel supply should be increased before restarting.

[0043] If as the speed of the high-pressure compressor increases, the high-pressure compressor speed > N 关闭 When the high-pressure bypass valve closes, the high-pressure compressor speed drops. When the high-pressure compressor speed is ≤ N 关闭 If the bypass valve reopens and the engine speed stops increasing, and the gas temperature is high, it is determined that a starting hot suspension has occurred. The engine should be stopped immediately and cooled to reduce the gas temperature after the turbine before restarting.

[0044] In step two above, the gas turbine is in idle mode, at which point the high-pressure compressor speed is greater than N. 关闭First, check if the control system signal is in the "high-voltage bypass open command" state. If the control system keeps issuing open commands, the control system should be investigated. At this time, it is strictly forbidden to increase the operating condition until the "high-voltage bypass open command" is closed. If the control system signal is in the "high-voltage bypass close command" state and the control circuit is intact, then both high-voltage bypass valves are stuck, and the machine should be stopped for inspection and replacement.

[0045] Specific application examples of this invention are as follows:

[0046] Case 1:

[0047] A gas turbine is started to idle condition, at which point the high-pressure compressor speed is 8000 r / min > N. 关闭 N 关闭为 7500 r / min; the operator heard that the high-pressure bypass valve was still venting. Upon inspection, it was found that high-pressure bypass valve A was closed and high-pressure bypass valve B was open. The machine was then stopped. Upon inspection, high-pressure bypass valve B was found to be stuck. After replacing high-pressure bypass valve B, the machine was restarted and the fault was resolved.

[0048] Case 2:

[0049] When a gas turbine was started to idle, the operators heard that the high-pressure bypass valve was still venting. Upon inspection, it was found that both high-pressure bypass valves A and B were open.

[0050] At this time, the high-pressure compressor speed is 7000 r / min < N 关闭 N 关闭为 If the high-pressure compressor speed is 7500 r / min and the normal high-pressure compressor speed value is too low at slow speed, it is determined that there is a fault in the high-pressure speed measurement. The machine is stopped, and after investigation, the wiring at the speed sensor terminal is found to be loose. After tightening, the machine is restarted and the fault is eliminated.

[0051] Case 3:

[0052] After a gas turbine completes standby and starts, the high-pressure bypass valve opens at a specified time. As it starts, the gas turbine speed reaches a certain speed and then stops increasing. At this point, the high-pressure compressor speed is ≤ N. 关闭 The high-pressure bypass valve remained open, and the operator checked that the oil supply pressure was up to 1.2 MPa. The oil pressure required to start at idle was 1.6 MPa. At this time, the gas turbine was in cold suspension. The operator then shut down the turbine in an emergency. After shutting down, the operator increased the throttle to increase the fuel supply and restarted the turbine. The gas turbine started successfully.

[0053] Case 4:

[0054] After a gas turbine completes standby and starts, the high-pressure bypass valve opens at a specified time. With startup, the gas turbine speed reaches N. 关闭When the high-pressure bypass valve closes, the high-pressure compressor speed drops. When the high-pressure compressor speed drops ≤ N... 关闭 At that time, the bypass valve reopened, and the speed stopped increasing. The high-pressure bypass valve remained open. The operators found that the gas temperature after the turbine reached 250°C before starting, which was much higher than the normal value; the normal value is no higher than 120°C. At this time, a starting hot suspension occurred. The operators stopped the machine in an emergency and used cold blowing to reduce the gas temperature after the turbine. Then, the machine was restarted and started successfully.

[0055] Case 5:

[0056] After a gas turbine completes standby and starts, the high-pressure bypass valve opens at a specified time. With startup, the high-pressure compressor speed of the gas turbine exceeds N. 关闭 At the time of the initial start-up, the high-pressure bypass valve remained open. Even after the gas turbine successfully started to idle, the high-pressure bypass valve remained open. Upon inspection, the control system signal was in the "high-pressure bypass open command" state. Further inspection revealed a fault in the control signal distributor. After replacing the distributor, the control system signal was in the "high-pressure bypass close command" state, and both high-pressure bypass valves closed, thus resolving the fault.

[0057] The above description is an explanation of the present invention and not a limitation thereof. The scope of the present invention is defined by the claims. Within the scope of protection of the present invention, any form of modification may be made.

Claims

1. A method for troubleshooting and handling faults related to a gas turbine high-pressure bypass valve not closing, characterized in that: If, during the gas turbine startup to idle, the high-pressure bypass valve is heard continuously opening to vent gas, the following steps should be taken for handling and troubleshooting: Step 1: If the high-pressure speed is greater than the shut-off speed, it is determined that one of the two high-pressure bypass valves is closed while the other is not. The unclosed bypass valve is stuck. In this case, the machine should be stopped for inspection and replacement. Step Two: If both bypass valves are not closed, check for fluctuations in the high-pressure compressor speed; if the high-pressure compressor speed measurement value fluctuates, causing the high-pressure speed to be less than or equal to the shut-off speed, then shut down the compressor to troubleshoot the speed measurement fault. Step 3: If, assuming both bypass valves are not closed in step two, the high-pressure compressor speed is stable and the high-pressure speed is less than or equal to the closing speed, then the gas turbine is determined to be in a normal start-up process. During startup: If, during the gas turbine startup process, the acceleration stalls below the shut-off speed while the bypass valve remains open, and the fuel pressure is low at this time, the gas turbine will experience a cold start. It will need to be shut down, the fuel supply increased, and then restarted. When the high-pressure speed rises to a level greater than the shut-off speed and the bypass valve is closed, and then drops to a level less than or equal to the shut-off speed, the bypass valve reopens, and the speed stops rising. If the gas temperature is high, a starting hot suspension will occur at this time. After the turbine is stopped and the gas temperature is reduced by cold blowing, the turbine will be restarted.

2. The method for troubleshooting and handling faults related to the gas turbine high-pressure bypass valve not closing as described in claim 1, characterized in that: In step two, when the gas turbine is in idle condition and the high-pressure speed is greater than the shut-off speed, first check whether the control signal of the control system is in the high-pressure bypass open command. If the control system continues to issue start commands, check the control system. At this time, it is strictly forbidden to upgrade the operating condition until the start command is turned off. If the control signal of the control system is in the high-pressure bypass switch command and the control circuit is intact, it is determined that both high-pressure bypass valves are stuck, and the system should be shut down for inspection and replacement.

3. A process for troubleshooting and handling the start-up to idle condition of a gas turbine using the method described in claim 1, characterized in that, Includes the following steps: When the gas turbine starts up to idle speed, the high-pressure speed is greater than the shutdown speed. After hearing the abnormal noise, the operators determined that the high-pressure bypass valve was in the venting state, with one high-pressure bypass valve closed and the other not closed, and the not closed high-pressure bypass valve was stuck. After replacing the stuck high-pressure bypass valve, the engine was restarted and the problem was resolved.

4. A process for troubleshooting and handling the start-up to idle condition of a gas turbine using the method described in claim 1, characterized in that, Includes the following steps: When the gas turbine starts up to idle speed, the high-pressure speed is lower than the shutdown speed. The high-pressure speed measurement was found to be faulty. The machine was stopped and the wiring between the components was checked. After tightening the wiring, the machine was restarted and the fault was eliminated.

5. A process for investigating and handling the operating status of a gas turbine using the method described in claim 1, characterized in that, Includes the following steps: After the gas turbine completes standby and starts, the high-pressure bypass valve opens at the expected time. During the process of the gas turbine speed rising, it stops when it is below the closing speed. At this time, the high-pressure bypass valve remains open. The operator checks the fuel supply pressure. If the maximum fuel supply pressure is less than the fuel supply pressure required to start to idle, it is determined that the gas turbine is in a cold suspension state. The turbine is stopped and the throttle is increased to increase the fuel supply. The turbine is then restarted, and the fault is eliminated.

6. A process for investigating and handling the operating status of a gas turbine using the method described in claim 1, characterized in that, Includes the following steps: After the gas turbine completes standby and starts, the high-pressure bypass valve opens at the expected time. When the gas turbine speed reaches the shut-off speed, the high-pressure bypass valve closes, and then the gas turbine speed drops. When the gas turbine speed drops below the shut-off speed, the high-pressure bypass valve reopens, and the speed stops rising. If the high-pressure bypass valve remains open and the operator finds that the gas temperature after the turbine is higher than normal before and after starting, it is determined that a starting hot suspension has occurred. After stopping the turbine and cold blowing to reduce the gas temperature after the turbine, the turbine is restarted, and the fault is eliminated.

7. A process for investigating and handling the operating status of a gas turbine using the method described in claim 1, characterized in that, Includes the following steps: After the gas turbine completes standby and starts, the high-pressure bypass valve opens at the expected time. When the gas turbine speed is higher than the shut-off speed, the high-pressure bypass valve is in the open state. After the gas turbine successfully starts to idle, the high-pressure bypass valve is still in the open state. When the operator checks the control system, if the control signal is in the high-pressure bypass open command state, it is determined that the control signal distributor is faulty. After replacing the distributor, the high-pressure bypass valve is closed, and the fault is eliminated.

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