A method for troubleshooting frequent operation of the pneumatic pump of the main steam isolation valve

Abstract

The present application provides a method for troubleshooting the frequent operation of the pneumatic pump of the main steam isolation valve, which includes: isolating the hydraulic circuit part of the main steam isolation valve; judging and locating the corresponding defect according to the hydraulic logic and the change of the pneumatic pump operation frequency. The present application achieves the technical effect of online defect positioning based on the hydraulic logic and the change of the pneumatic pump without stopping the main steam isolation valve, so as to solve the problem that the abnormal phenomenon of frequent beating of the pneumatic pump of the main steam isolation valve on site is difficult to troubleshoot.

Description

Technical Field

[0001] The present application belongs to the technical field of nuclear power equipment maintenance, and specifically relates to a method for troubleshooting frequent operation of a pneumatic pump of a main steam isolation valve. Background Art

[0002] For nuclear power equipment, a large number of valve equipment still relies on foreign imports, among which the main steam isolation valve, a key equipment in the main steam system, is one of them. At present, some companies have independently developed the main steam isolation valve, but there is still a gap in the research on the main steam isolation valve actuator parts in China.

[0003] Since the main steam isolation valve mostly adopts a gas-liquid linkage structure, a pneumatic pump is arranged in the main steam isolation valve actuator parts to meet its working principle. Under abnormal working conditions, the pneumatic pump will cause the main steam isolation valve to lose its oil replenishment and pressurization function, thereby causing the main steam isolation valve to lose its nuclear safety function. At present, there is no systematic troubleshooting method for the frequent operation of the pneumatic pump. Summary of the invention

[0004] In view of this, the present application is dedicated to providing a method for troubleshooting the frequent operation of the pneumatic pump of the main steam isolation valve. By starting from the hydraulic logic of the main steam isolation valve without stopping the operation of the main steam isolation valve, and according to the changes of the pneumatic pump, the technical effect of online positioning defects is achieved, so as to solve the problem that the abnormal phenomenon of frequent beating of the pneumatic pump of the main steam isolation valve on site is difficult to troubleshoot.

[0005] The present application provides a method for troubleshooting the frequent operation of the pneumatic pump of the main steam isolation valve. The method for troubleshooting the frequent operation of the pneumatic pump of the main steam isolation valve includes: isolating the hydraulic circuit part of the main steam isolation valve; judging and locating the corresponding defect according to the hydraulic logic and the change of the operation frequency of the pneumatic pump.

[0006] In a specific embodiment of the present application, the corresponding defect is judged and located according to the changes in hydraulic logic and the frequency of operation of the pneumatic pump, including: confirming the valve closing direction of NV9, NV2 and NV3 in the hydraulic circuit of the main steam isolation valve, manually closing NV9, NV2 and NV3 and tightening the locking nut of the corresponding needle valve; if the number and frequency of operation of the pneumatic pump meet the troubleshooting requirements, it is determined that the normally closed valve is not closed properly, resulting in internal leakage.

[0007] In a specific embodiment of the present application, the corresponding defect is judged and located according to the changes in hydraulic logic and the frequency of operation of the pneumatic pump, including: closing NVA and NVB, NVA is the normally open isolation valve of the downstream return oil tank of DV1, and NVB is the normally open isolation valve of the downstream return oil tank of DV3; if the number and frequency of operation of the pneumatic pump meet the troubleshooting requirements, it is determined that DV1 and / or DV3 have internal leakage.

[0008] In a specific embodiment of the present application, the corresponding defect is judged and located according to the hydraulic logic and the change of the pneumatic pump operation frequency, including: closing the normally open isolation valve NV13 downstream of the pneumatic pump of column A, observing and recording the number of operations and the operation time interval of the two pumps AB, and the change trends of PG1, PG2 and PG3 respectively; if the pump of column A stops beating, it proves that the pneumatic pump of column A has no internal leakage; after the judgment is completed, the status of NV13 is restored.

[0009] In a specific embodiment of the present application, the corresponding defect is judged and located according to the hydraulic logic and the change of the pneumatic pump operation frequency, including: closing the normally open isolation valve NV14 downstream of the pneumatic pump of column B, observing and recording the number of operations and the operation time interval of the two pumps AB, and the change trends of PG1, PG2 and PG3 respectively; if the pump of column B stops beating, it proves that the pneumatic pump of column B has no internal leakage; after the judgment is completed, the status of NV14 is restored.

[0010] In a specific embodiment of the present application, the corresponding defect is judged and located according to the hydraulic logic and the change of the pneumatic pump operation frequency, including: closing the normally open isolation valve NV1 upstream of the solenoid valve SV5, observing and recording the number of operations and the operation time intervals of the two pumps AB, and the change trends of PG1, PG2 and PG3; if the pump operation frequency meets the troubleshooting requirements, it is determined that the frequent operation of the pneumatic pump is caused by internal leakage of the solenoid valve SV5.

[0011] In a specific embodiment of the present application, the corresponding defect is judged and located according to the hydraulic logic and the change of the pneumatic pump operation frequency, including: shutting down NV4, observing for more than half an hour, recording the number of operations and the operation time interval of the two pumps AB, and the change trend of PG1, PG2 and PG3; if the pump no longer operates, it is confirmed that the frequent operation of the pneumatic pump is caused by the internal leakage of RV2.

[0012] In a specific embodiment of the present application, the corresponding defect is judged and located according to the hydraulic logic and the change of the pneumatic pump operation frequency, including: turning off NV11, observing for more than half an hour, recording the number of operations and the operation time interval of the two pumps AB, and the change trends of PG1, PG2 and PG3; if the pump no longer operates, it is confirmed that the frequent operation of the pneumatic pump is caused by internal leakage of RV3.

[0013] In a specific embodiment of the present application, the method for troubleshooting the frequent operation of the pneumatic pump of the main steam isolation valve also includes: restoring the closed normally open valve to fully open, and the troubleshooting work is completed.

[0014] The beneficial effect of the technical solution of the present application is that by isolating the hydraulic circuit part of the main steam isolation valve, the technical effect of online positioning of defects is achieved based on the hydraulic logic and the changes of the pneumatic pump without stopping the main steam isolation valve, thereby improving the efficiency of troubleshooting. The embodiment of the present application can complete the troubleshooting of the pneumatic pump of the main steam isolation valve online during the operation of the main steam isolation valve without losing the nuclear safety function, thus avoiding the unit from being dismantled for maintenance due to faults. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The figure is a flow chart of a method for troubleshooting frequent operation of a pneumatic pump of a main steam isolation valve provided by an embodiment of the present application.

[0016] Figure 2 Shown is a schematic diagram of the hydraulic principle of a main steam isolation valve provided in one embodiment of the present application.

[0017] Figure 3 Shown Figure 2 The enlarged schematic diagram of the part within the red frame line in the hydraulic principle diagram of the main steam isolation valve shown.

[0018] Figure 4 Shown Figure 2 The enlarged schematic diagram of the part within the green frame line in the hydraulic principle diagram of the main steam isolation valve shown.

[0019] Figure 5 Shown Figure 2 The enlarged schematic diagram of the part within the blue frame line in the hydraulic principle diagram of the main steam isolation valve shown. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] At least one embodiment of the present application provides a method for troubleshooting frequent operation of a main steam isolation valve pneumatic pump. Figure 1 The method for troubleshooting the frequent operation of the pneumatic pump of the main steam isolation valve includes the following steps.

[0022] S1: Isolate the hydraulic circuit of the main steam isolation valve.

[0023] S2: Determine and locate the corresponding defect based on the hydraulic logic and the change of the pneumatic pump operation frequency.

[0024] The embodiment of the present application isolates the hydraulic circuit of the main steam isolation valve, and without stopping the main steam isolation valve, based on its hydraulic logic, according to the changes in the pneumatic pump, achieves the technical effect of online positioning of defects, thereby improving the efficiency of troubleshooting. The embodiment of the present application can complete the troubleshooting of the pneumatic pump jump of the main steam isolation valve online during the operation of the main steam isolation valve without losing the nuclear safety function, thus avoiding the need for the unit to be dismantled for maintenance due to faults.

[0025] The method for checking the frequent action of the pneumatic pump of the main steam isolation valve can be used for checking the frequent action of the pneumatic pump of the main steam isolation valve of the Hualong One nuclear power unit, and can also be used for other equipment with similar structures. The following mainly takes the frequent action of the pneumatic pump of the main steam isolation valve of the Hualong One nuclear power unit as an example for explanation.

[0026] refer to Figures 2 to 5 The main steam isolation valve of the Hualong One nuclear power unit uses a gas-liquid linkage actuator to control the valve. The valve is actuated and maintained in the open position by pressurizing the hydraulic circuit. When the valve needs to be closed, the hydraulic circuit is depressurized and the valve is actuated to the closed position under the nitrogen pressure on the gas side. Figures 2 to 5 Among them, NV2, NV3, NV4, NV8, NV9, NV11, NV13, NV14, NVA and NVB are all needle valves; PG1 is a nitrogen pressure gauge, PG2 and PG3 are oil pressure gauges; DV1 and DV2 are dump valves; PA and PB are pneumatic pumps; SV5 is a slow closing solenoid valve; RV2 is a pressure relief valve.

[0027] Among them, the function of the actuator hydraulic oil pump is: when the valve needs to be opened, the oil pump starts to replenish oil and pressurize the hydraulic circuit to move the valve to the open position; or when the valve is in the open position, if the hydraulic circuit pressure fluctuates and does not meet the normal valve opening pressure, the oil pump starts to replenish the hydraulic circuit pressure to keep the valve in the open position.

[0028] After careful study, it was found that the possible reasons for the frequent operation of the pneumatic hydraulic pump of the main steam isolation valve are:

[0029] 1. The pressure of the hydraulic circuit does not meet the actual working conditions, and the pneumatic pump starts to replenish oil and increase pressure. The specific possible reasons are analyzed as follows:

[0030] 1. Internal leakage in the hydraulic circuit causes the oil pressure in the hydraulic circuit to decrease and the hydraulic pump to start frequently.

[0031] 2. Leakage in the hydraulic circuit causes the oil pressure in the hydraulic circuit to decrease and the hydraulic pump to start frequently.

[0032] Leakage in the hydraulic circuit can be confirmed by direct visual inspection on the equipment. If the pneumatic pump still starts frequently after the leakage point has been tightened, the frequent operation of the pneumatic pump caused by leakage can be ruled out.

[0033] 3. The pressure drop in the hydraulic circuit is caused by the normal performance of the equipment's functions: Since the main steam isolation valve hydraulic circuit is equipped with two oil circuit overflow valves to control the oil pressure within a suitable working range, when the oil temperature fluctuates due to the influence of ambient temperature, the overflow valve may actually operate, causing the hydraulic circuit pressure to fluctuate, which in turn causes the pneumatic pump to operate frequently.

[0034] 2. Abnormal pump function. Due to abnormal performance of the pneumatic pump itself, the pump starts frequently.

[0035] Based on the above cause analysis, determine and locate the corresponding defects.

[0036] In at least one embodiment of the present application, S2.1 and S2.2 are a specific implementation of the above S2. S2.1 and S2.2 can be used to determine whether the normally closed valves NV9, NV2 and NV3 are not fully closed, resulting in internal leakage.

[0037] S2.1: Confirm the closing direction of NV9, NV2 and NV3 in the hydraulic circuit of the main steam isolation valve, manually close NV9, NV2 and NV3 and tighten the locking nut of the corresponding needle valve.

[0038] Based on the changes in hydraulic logic and the operating frequency of the pneumatic pump, determine whether the internal leakage is caused by the normally closed valve not being fully closed.

[0039] S2.2: If the number and frequency of pneumatic pump operations meet the troubleshooting requirements, it is determined that the normally closed valve is not fully closed, resulting in internal leakage.

[0040] For example, refer to Figure 2 , confirm the closing direction of NV9, NV2 and NV3, manually close NV9, NV2 and NV3 and tighten the locking nut of the corresponding needle valve. Observe and record the number of actions and time intervals of the two pumps, as well as the change trend of PG1 / 2 / 3. If the number and frequency of pneumatic pump actions meet the troubleshooting requirements, it is determined that the normally closed valves NV9, NV2 and NV3 are not closed properly, resulting in internal leakage, which causes the pneumatic pump to frequently beat.

[0041] In at least one embodiment of the present application, S2.3 and S2.4 are a specific implementation of S2. S2.3 and S2.4 are used to determine whether DV1 / DV3 has an internal leak.

[0042] S2.3: Close NVA and NVB. NVA is the normally open isolation valve of the downstream return tank of DV1, and NVB is the normally open isolation valve of the downstream return tank of DV3.

[0043] S2.4: If the number and frequency of pneumatic pump operations meet the troubleshooting requirements, it is determined that DV1 and / or DV3 have internal leakage.

[0044] For example, close NVA and NVB. Since NVA and NVB are the normally open isolation valves of the downstream oil return tank of DV1 and DV3, they are manually closed and the number of actions and time intervals of the two pumps AB, as well as the change trends of PG1, PG2 and PG3 are observed and recorded. If the number and frequency of the pneumatic pump actions meet the troubleshooting requirements, it is determined that DV1 and / or DV3 have internal leakage, which causes the pneumatic pump to frequently beat.

[0045] In at least one embodiment of the present application, S2.5 to S2.7 are a specific implementation of the above S2. S2.5 to S2.7 can be used to determine whether the pneumatic pump PA has a fault.

[0046] S2.5: Close the normally open isolation valve NV13 downstream of the pneumatic pump in row A, and observe and record the number of actions and time intervals of the two pumps AB, as well as the changing trends of PG1, PG2 and PG3.

[0047] S2.6: If the pump in column A stops beating, it proves that the pneumatic pump in column A has no internal leakage.

[0048] S2.7: After the judgment is completed, the NV13 status is restored.

[0049] In at least one embodiment of the present application, S2.8 to S2.10 are a specific implementation of the above S2. S2.8 to S2.10 can be used to determine whether the PB is faulty.

[0050] S2.8: Close the normally open isolation valve NV14 downstream of the pneumatic pump in row B, and observe and record the number of actions and time intervals of the two pumps AB, as well as the changing trends of PG1, PG2 and PG3.

[0051] S2.9: If the pump in column B stops beating, it proves that there is no internal leakage in the pneumatic pump in column B.

[0052] S2.10: After the judgment is completed, the NV14 status is restored.

[0053] In at least one embodiment of the present application, S2.11 and S2.12 are a specific implementation of S2. S2.11 and S2.12 can be used to determine whether SV5 has internal leakage.

[0054] S2.11: Close the normally open isolation valve NV1 upstream of the solenoid valve SV5, and observe and record the number of actions and time intervals of the two pumps AB, as well as the changing trends of PG1, PG2 and PG3.

[0055] S2.12: If the pump operation frequency meets the troubleshooting requirements, it is determined that the frequent operation of the pneumatic pump is caused by internal leakage of the solenoid valve SV5.

[0056] It should be noted that SV5 is the solenoid valve of the slow closing circuit of the main steam isolation valve, which only affects the slow closing function of the main valve, and does not affect the main valve's open position holding and quick closing functions.

[0057] In at least one embodiment of the present application, S2.13 and S2.14 are a specific implementation of the above S2. S2.13 and S2.14 can be used to determine whether RV2 has internal leakage.

[0058] S2.13: Turn off NV4 and observe for more than half an hour, recording the number of actions and time intervals of the two pumps AB, and the changing trends of PG1, PG2 and PG3.

[0059] It should be noted that the closure of NV4 and NV11 will affect the normal pressure replenishment function of the pneumatic pump for the hydraulic circuit. If the main valve is found to be actuated during operation, NV4, NV11, and NV8 will be quickly restored to the open position. During this period, the main valve full-open signal may disappear, but it will not affect the valve quick-closing function.

[0060] S2.14: If the pump no longer operates, it is confirmed that the pneumatic pump is frequently operating due to internal leakage in RV2.

[0061] In at least one embodiment of the present application, S2.15 and S2.16 are a specific implementation of the above S2. S2.15 and S2.16 are used to determine whether NV9 / RV3 has internal leakage.

[0062] S2.15: Turn off NV11 and observe for more than half an hour, recording the number of actions and time intervals of the two pumps AB, and the changing trends of PG1, PG2 and PG3.

[0063] S2.16: If the pump no longer operates, it is confirmed that the pneumatic pump is frequently operating due to internal leakage of RV3.

[0064] In at least one embodiment of the present application, the method for troubleshooting the frequent operation of the pneumatic pump of the main steam isolation valve further includes S3.

[0065] S3: Restore the closed normally open valve to fully open, and the troubleshooting work is completed.

[0066] Normally open valves NV1, NV4, NV11, NVA, NVB, restore the corresponding valves according to the troubleshooting operation

[0067] Conduct troubleshooting according to the above troubleshooting contents, and observe for at least 30 minutes after each troubleshooting action. After completing any of the above steps, if the on-site observation shows that the pneumatic pump start-up interval is significantly extended, and the interval between the two most recent pneumatic pump start-ups is not less than 30 minutes, locate the cause of the frequent operation of the pneumatic pump and perform relevant operations to eliminate the abnormal phenomenon.

[0068] It should be noted that the combination of the various technical features in the embodiments of the present application is not limited to the combination described in the embodiments of the present application or the combination described in the specific embodiments, and all technical features described in the present application can be freely combined or combined in any way unless there is a contradiction between them.

[0069] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the term "comprising" only indicates that the steps and elements that have been clearly identified are included, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0070] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for troubleshooting the frequent operation of the pneumatic pump of the main steam isolation valve, characterized in that: include: Isolate the hydraulic circuit of the main steam isolation valve; According to the changes in hydraulic logic and pneumatic pump operating frequency, the corresponding defects are judged and located.

2. A method for troubleshooting frequent operation of a main steam isolation valve pneumatic pump according to claim 1, characterized in that: According to the changes in hydraulic logic and pneumatic pump action frequency, the corresponding defects are judged and located, including: Confirm the closing direction of NV9, NV2 and NV3 in the hydraulic circuit of the main steam isolation valve of the nuclear power unit, manually close NV9, NV2 and NV3 and tighten the locking nut of the corresponding needle valve; If the number and frequency of pneumatic pump operations meet the troubleshooting requirements, it is determined that the normally closed valve is not fully closed, resulting in internal leakage.

3. A method for troubleshooting frequent operation of a main steam isolation valve pneumatic pump according to claim 1, characterized in that: According to the changes in hydraulic logic and pneumatic pump action frequency, the corresponding defects are judged and located, including: Close NVA and NVB. NVA is the normally open isolation valve of the downstream return tank of DV1, and NVB is the normally open isolation valve of the downstream return tank of DV3. If the number and frequency of pneumatic pump operations meet the troubleshooting requirements, it is determined that DV1 and / or DV3 have internal leakage.

4. A method for troubleshooting frequent operation of a main steam isolation valve pneumatic pump according to claim 1, characterized in that: According to the changes in hydraulic logic and pneumatic pump action frequency, the corresponding defects are judged and located, including: Close the normally open isolation valve NV13 downstream of the pneumatic pump in row A, and observe and record the number of actions and time intervals of the two pumps AB, as well as the changing trends of PG1, PG2 and PG3; If the pump in row A stops beating, it proves that the pneumatic pump in row A has no internal leakage; After the judgment is completed, the NV13 status is restored.

5. A method for troubleshooting frequent operation of a main steam isolation valve pneumatic pump according to claim 1, characterized in that: According to the changes in hydraulic logic and pneumatic pump action frequency, the corresponding defects are judged and located, including: Close the normally open isolation valve NV14 downstream of the pneumatic pump in row B, and observe and record the number of actions and time intervals of the two pumps AB, as well as the changing trends of PG1, PG2 and PG3; If the pump in row B stops beating, it proves that the pneumatic pump in row B has no internal leakage; After the judgment is completed, the NV14 status is restored.

6. A method for troubleshooting frequent operation of a main steam isolation valve pneumatic pump according to claim 1, characterized in that: According to the changes in hydraulic logic and pneumatic pump action frequency, the corresponding defects are judged and located, including: Close the normally open isolation valve NV1 upstream of the solenoid valve SV5, and observe and record the number of actions and time intervals of the two pumps AB, as well as the changing trends of PG1, PG2 and PG3; If the pump operation frequency meets the troubleshooting requirements, it is determined that the frequent operation of the pneumatic pump is caused by internal leakage of the solenoid valve SV5.

7. A method for troubleshooting frequent operation of a main steam isolation valve pneumatic pump according to claim 1, characterized in that: According to the changes in hydraulic logic and pneumatic pump action frequency, the corresponding defects are judged and located, including: Turn off NV4, observe for more than half an hour, and record the number of actions and time intervals of the two pumps AB, as well as the changing trends of PG1, PG2 and PG3; If the pump no longer operates, it is confirmed that the pneumatic pump is frequently operating due to internal leakage in RV2.

8. A method for troubleshooting frequent operation of a main steam isolation valve pneumatic pump according to claim 1, characterized in that: According to the changes in hydraulic logic and pneumatic pump action frequency, the corresponding defects are judged and located, including: Turn off NV11 and observe for more than half an hour, record the number of times pumps AB operate and the time interval between operations, as well as the changing trends of PG1, PG2 and PG3; if the pump no longer operates, it is confirmed that the frequent operation of the pneumatic pump is caused by internal leakage of RV3.

9. A method for troubleshooting frequent operation of a main steam isolation valve pneumatic pump according to any one of claims 2 to 8, characterized in that: Also includes: Restore the closed normally open valve to fully open, and the troubleshooting work is completed.

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