Displacement measuring device for main steam isolating valve and pressure release valve of nuclear power plant
By designing a pressure relief valve displacement measurement device for the main steam isolation valve of nuclear power plant, the continuous measurement of the pressure relief valve core is achieved by using the LVDT sensor, which solves the frequent jamming of the quick-closing solenoid valve and the pressure relief valve during operation. Leakage and other problems improve the timeliness and accuracy of the pressure relief valve operation and reduce maintenance costs.
Patent Information
- Application Number
- CN202411474343.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-22
- Publication Date
- 2025-02-14
AI Technical Summary
The main steam isolation valve is quick-closed solenoid valve and pressure relief valve often have problems such as jamming and leakage during unit debugging and normal operation, which affects the overall performance, and the replacement cost is high, affecting the maintenance cost.
A displacement measurement device for pressure relief valve of the main steam isolation valve of nuclear power plant is designed, including coils, measuring rods, auxiliary measuring rods, flange covers, fixing screws, aviation plugs, springs and other components, and the pressure relief valve core is realized by using LVDT sensors. Continuous measurement ensures the device to operate stably under high-voltage environment.
The device can realize continuous measurement of the valve core of the pressure relief valve under a high pressure environment, ensure the stable structure of the device, and have a certain adjustment range, and can perform electrical zero adjustments according to the on-site situation, avoid blind maintenance and incorrect repairs, and improve pressure relief valves Timeliness and accuracy of actions.
Smart Images
Figure CN119437017A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of nuclear power, and in particular relates to a displacement measuring device for a main steam isolation valve and a pressure relief valve of a nuclear power plant. Background Art
[0002] The main steam isolation valve (MSIV) is used in the secondary circuit main steam system of a pressurized water reactor nuclear power plant. It is one of the important and critical valves in a nuclear power plant. Under normal operating conditions, the valve is in an open state. Under shutdown and accident conditions, the main steam isolation valve automatically closes quickly within 5 seconds after receiving the main steam isolation signal to quickly isolate the main steam.
[0003] In the related technology, in order to realize the rapid closing of the main steam isolation valve, its electro-hydraulic part is designed with a rapid pressure relief function. The core components of the rapid pressure relief are two groups of four redundant fast-closing solenoid valves and the four pressure relief valves controlled by them. Under normal conditions, the main steam isolation valve opens slowly. Under accident conditions, the two groups of four solenoid valves are energized at the same time, and the corresponding pressure relief valves are opened to realize the 5-second rapid closing function.
[0004] During the commissioning and normal operation of the unit, the fast-closing solenoid valve and the pressure relief valve often get stuck or leak, which affects the overall performance of the main steam isolation valve. Due to the high replacement cost and long procurement cycle of the fast-closing solenoid valve and the pressure relief valve, the commonly used overall replacement greatly increases the maintenance cost of the unit. Therefore, it is urgent to carry out the function test of the fast-closing solenoid valve and the pressure relief valve to timely and accurately understand the actual operating status of the fast-closing solenoid valve and the pressure relief valve of the nuclear power plant. Summary of the invention
[0005] In order to overcome the problems existing in the related art, a displacement measuring device for a main steam isolation valve and a pressure relief valve of a nuclear power plant is provided.
[0006] According to one aspect of an embodiment of the present disclosure, a displacement measuring device for a main steam isolation valve and pressure relief valve of a nuclear power plant is provided, the device comprising: a coil, a measuring rod, an auxiliary measuring rod, a flange cover, a fixing screw, an aviation plug, and a spring;
[0007] One end of the coil is arranged in the flange cover and pressed against the boss in the flange cover. A through hole is reserved at one end of the flange cover for installing an aviation plug. The aviation plug can seal the through hole of the flange cover, thereby realizing the overall sealing of the device. The aviation plug also has a sealing hole for leading the signal cable at one end of the coil out from the inside of the flange cover.
[0008] The other end of the coil is fixedly connected to the coil side spring fixing sleeve, and the flange cover is installed on the pressure relief valve measuring module by fixing screws. One end of the measuring rod is a core package, which is located in the through hole in the center of the coil side spring fixing sleeve and can move axially relative to the coil. The other end of the measuring rod is connected to the auxiliary measuring rod, and the spring is wrapped around the outside of the measuring rod and the auxiliary measuring rod. One end of the spring is fixedly connected to the coil side spring fixing sleeve, and the other end of the spring is fixedly connected between the two ends of the auxiliary measuring rod. The other end of the auxiliary measuring rod passes through the positioning ring and directly reaches the valve core of the pressure relief valve installed on the pressure relief valve control module. The measuring rod and the auxiliary measuring rod can move with the axial movement of the valve core. The coil includes a primary coil and two secondary coils, which can react to the position change of the measuring rod according to the differential electromotive force induced by the two secondary coils, and output a measurement information number.
[0009] In a possible implementation, a baffle side spring fixing sleeve, a spring baffle plate, and a second fixing nut are arranged between the two ends of the auxiliary measuring rod in an order away from the coil one by one. The baffle side spring fixing sleeve is clamped with the other end of the spring, and the end of the baffle side spring fixing sleeve is embedded in the groove of the spring baffle plate. The baffle side spring fixing sleeve and the spring baffle plate can move relative to the auxiliary measuring rod. The second fixing nut is threadedly connected to the auxiliary measuring rod to block the spring baffle plate. The expansion and contraction of the spring can be adjusted by rotating the second fixing nut.
[0010] In a possible implementation, the measuring rod and the auxiliary measuring rod are made of stainless steel.
[0011] In a possible implementation, the outer side of the measuring rod is threadedly connected to a first fixing nut for adjusting the thread engagement length of the measuring rod and the auxiliary measuring rod.
[0012] In one possible implementation, the main actions of the spring are as follows: when the pressure relief valve is opened, the measuring rod and the auxiliary measuring rod closely follow the pressure relief valve to open under the action of the spring; in the initial stage of closing the pressure relief valve, the pressure difference at both ends of the pressure relief valve core caused by the throttle hole is mainly used to make the measuring rod and the auxiliary measuring rod follow the pressure relief valve to close; when the pressure relief valve is at the critical point of closing, the pressure difference at both ends of the pressure relief valve core is zero. At this time, the force difference between the built-in spring of the pressure relief valve and the spring in the device is mainly used to make the measuring rod and the auxiliary measuring rod follow the pressure relief valve to close completely.
[0013] In one possible implementation, bosses are axially arranged on the edges of both side end faces of the coil side spring fixing sleeve, one side end face of the coil side spring fixing sleeve can be stuck on the edge of the coil end, and the other side end face of the coil side spring fixing sleeve can fix the end of the spring to prevent the coil and the spring from relative radial movement.
[0014] In a possible implementation, a concave platform is provided in the middle of the end surface of the spring fixing sleeve on the baffle side, a circular hole is designed in the center, and a spring baffle and a concave platform are designed on one end surface, and the concave platform is used to embed the spring fixing sleeve on the coil side.
[0015] In a possible implementation, the positioning ring is fixed in the pressure relief valve measuring module to keep the measuring rod, the auxiliary measuring rod and the pressure relief valve core on a central axis.
[0016] The beneficial effects of the present disclosure are as follows: the displacement measurement device of the pressure relief valve of the main steam isolation valve of a nuclear power plant provided by the present disclosure can realize continuous measurement of the valve core of the pressure relief valve under high pressure environment. Based on the LVDT sensor measuring rod connection and adjustment components, the overall structure of the device is guaranteed to be stable and have a certain adjustment range, and the electrical zero position adjustment can be carried out according to the on-site installation conditions. The positioning valve block is designed to ensure that the sensor measuring rod and the valve core of the pressure relief valve are kept on a central axis and are not easily deformed. The device disclosed in the present disclosure can be applied to the displacement measurement of the pressure relief valve in the main steam isolation valve fast closing solenoid valve / pressure relief valve automatic calibration device, confirm the timeliness and accuracy of the action of the pressure relief valve during the MSIV fast closing process, and whether there are false operations, refusal to operate, and jamming, thereby effectively avoiding blind maintenance and wrong repairs; the spare parts of the newly commissioned pressure relief valve can also be inspected to confirm the availability of spare parts. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a schematic diagram of a displacement measuring device for a main steam isolation valve and a pressure relief valve of a nuclear power plant shown in an embodiment of the present disclosure.
[0018] Figure 2 It is a schematic diagram of a displacement measuring device for a main steam isolation valve and a pressure relief valve of a nuclear power plant in an application state, shown in an embodiment of the present disclosure.
[0019] In the figure:
[0020] 1. Coil; 2. Measuring rod; 3. Auxiliary measuring rod; 4. Fixing nut; 5. Flange cover;
[0021] 6. Fixing screws; 7. Aviation plug; 8. Spring; 9. Spring fixing sleeve;
[0022] 10. Spring fixing sleeve on baffle side; 11. Spring baffle; 12. Second fixing nut; 13. Positioning ring;
[0023] 14. Pressure relief valve measurement module; 15. Pressure relief valve control module; 16. Pressure relief valve; 17. Throttle hole. DETAILED DESCRIPTION
[0024] The present disclosure is further described in detail below with reference to the accompanying drawings and specific embodiments.
[0025] Unless otherwise defined, the technical and scientific terms used in the present disclosure have the same meanings as those generally understood by those skilled in the art to which the present disclosure belongs; the terms used in the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure; the term "including" and any variations thereof in the present disclosure are intended to cover non-exclusive inclusions. Obviously, the embodiments described in the present disclosure are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making creative efforts are within the scope of protection of the present disclosure.
[0026] Reference to "embodiments" in this disclosure means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the disclosure. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0027] Figure 1 is a schematic diagram of a displacement measuring device for a main steam isolation valve and pressure relief valve of a nuclear power plant shown in an embodiment of the present disclosure, Figure 2 Schematic diagram of a displacement measuring device for a main steam isolation valve and pressure relief valve of a nuclear power plant in an application state, shown in an embodiment of the present disclosure. Figure 1 to Figure 2 The device comprises: a coil 1, a measuring rod 2, an auxiliary measuring rod 3, a first fixing nut 4, a flange cover 5, a fixing screw 6, an aviation plug 7, a spring 8, a coil side spring fixing sleeve 9, a baffle side spring fixing sleeve 10, a spring baffle 11, a second fixing nut 12 and a positioning ring 13.
[0028] One end of the coil 1 is arranged in the flange cover 5 and pressed against the boss in the flange cover 5. A through hole is reserved at one end of the flange cover 5 for installing an aviation plug 7. The aviation plug 7 can seal the through hole of the flange cover 5, thereby realizing the overall sealing of the device. The aviation plug 7 also has a sealing hole for leading the signal cable at one end of the coil 1 out from the inside of the flange cover 5.
[0029] The other end of the coil 1 is fixedly connected to the coil side spring fixing sleeve 9, and the flange cover 5 is installed on the pressure relief valve measuring module 14 by means of fixing screws 6. One end of the measuring rod 2 is a core package, which is located in the through hole in the center of the coil side spring fixing sleeve 9 and can move axially relative to the coil 1. The other end of the measuring rod 2 is connected to the auxiliary measuring rod 3, and the spring 8 surrounds the outer side of the measuring rod 2 and the auxiliary measuring rod 3. One end of the spring 8 is fixedly connected to the coil side spring fixing sleeve 9, and the other end of the spring 8 is fixedly connected between the two ends of the auxiliary measuring rod 3. The other end of the auxiliary measuring rod 3 passes through the positioning ring 13 and directly reaches the valve core of the pressure relief valve 16 installed on the pressure relief valve control module 15. The measuring rod 2 and the auxiliary measuring rod 3 can move with the axial movement of the valve core. The device disclosed in the present invention is based on the LVDT principle. The coil 1 includes a primary coil and two secondary coils, which can react to the position change of the measuring rod 2 according to the differential electromotive force induced by the two secondary coils, output a measurement information number, and thereby realize accurate measurement of the action of the pressure relief valve.
[0030] In a possible implementation, a baffle side spring fixing sleeve 10, a spring baffle 11 and a second fixing nut 12 are arranged between the two ends of the auxiliary measuring rod 3 in an order away from the coil 1 one by one. The baffle side spring fixing sleeve 10 is clamped with the other end of the spring 8, and the end of the baffle side spring fixing sleeve 10 is embedded in the groove of the spring baffle 11. The baffle side spring fixing sleeve 10 and the spring baffle 11 can move relative to the auxiliary measuring rod 3. The second fixing nut 12 is threadedly connected to the auxiliary measuring rod 3 to block the spring baffle 11. The extension and contraction amount of the spring 8 can be adjusted by rotating the second fixing nut 12, so that the measuring rod 2 and the auxiliary measuring rod 3 have better follow-up performance, thereby further improving the measurement accuracy.
[0031] In a possible implementation, the measuring rod 2 and the auxiliary measuring rod 3 may be made of stainless steel.
[0032] In one possible implementation, the outer side of the measuring rod 2 is threadedly connected to the first fixing nut 4, which is used to adjust the thread engagement length of the measuring rod 2 and the auxiliary measuring rod 3, thereby controlling the total length of the measuring rod 2 and the auxiliary measuring rod 3, facilitating the subsequent zero point calibration of the LVDT displacement sensor.
[0033] The spring 8 is used to overcome the jamming caused by the additional hydraulic static force generated by the LVDT movement, and ensure that the measuring rod 2 and the auxiliary measuring rod 3 can closely follow the action of the pressure relief valve 16 to open. The main action conditions are as follows: when the pressure relief valve 16 is opened, the measuring rod 2 and the auxiliary measuring rod 3 closely follow the action of the pressure relief valve 16 to open under the action of the spring 8; when the pressure relief valve 16 is in the initial stage of closing, the pressure difference between the two ends of the valve core of the pressure relief valve 16 caused by the throttle hole 17 is mainly used to make the measuring rod 2 and the auxiliary measuring rod 3 follow the action of the pressure relief valve 16 to close; when the pressure relief valve 16 is at the critical point of closing, the pressure difference between the two ends of the valve core of the pressure relief valve 16 is zero, and at this time, the force difference between the built-in spring 18 of the pressure relief valve and the spring 8 in the device is mainly used to make the measuring rod 2 and the auxiliary measuring rod 3 follow the action of the pressure relief valve 16 to close completely.
[0034] In a possible implementation, bosses are axially arranged on the edges of both side end surfaces of the coil side spring fixing sleeve 9, one side end surface of the coil side spring fixing sleeve 9 can be clamped on the edge of the end of the coil 1, and the other side end surface of the coil side spring fixing sleeve 9 can fix the end of the spring 8 to prevent the coil 1 and the spring 8 from relative radial movement.
[0035] In a possible implementation, the spring fixing sleeve 10 on the baffle side is provided with a concave platform in the middle of the end surface of the spring, and a circular hole is designed in the center, which can be used to fix the spring 8 and ensure that the auxiliary measuring rod 3 passes through it. The spring baffle 11 has a concave platform designed on one end surface, which is used to embed the spring fixing sleeve 9 on the coil side to further prevent the spring from moving radially.
[0036] In a possible implementation, the positioning ring 13 is fixed in the pressure relief valve measuring module 14 to ensure that the measuring rod 2, the auxiliary measuring rod 3 and the pressure relief valve core are always kept on a central axis, while increasing the convenience of on-site installation.
[0037] In one application example, a high-pressure sealing component is used, which can withstand a working pressure of 40 MPa in a short term and a working pressure of 35 MPa in a long term.
[0038] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.
Claims
1. A displacement measuring device for a main steam isolation valve and a pressure relief valve of a nuclear power plant, characterized in that: The device comprises: a coil, a measuring rod, an auxiliary measuring rod, a flange cover, fixing screws, an aviation plug, and a spring; One end of the coil is arranged in the flange cover and pressed against the boss in the flange cover. A through hole is reserved at one end of the flange cover for installing an aviation plug. The aviation plug can seal the through hole of the flange cover, thereby realizing the overall sealing of the device. The aviation plug also has a sealing hole for leading the signal cable at one end of the coil out from the inside of the flange cover. The other end of the coil is fixedly connected to the coil side spring fixing sleeve, and the flange cover is installed on the pressure relief valve measuring module by fixing screws. One end of the measuring rod is a core package, which is located in the through hole in the center of the coil side spring fixing sleeve and can move axially relative to the coil. The other end of the measuring rod is connected to the auxiliary measuring rod, and the spring is wrapped around the outside of the measuring rod and the auxiliary measuring rod. One end of the spring is fixedly connected to the coil side spring fixing sleeve, and the other end of the spring is fixedly connected between the two ends of the auxiliary measuring rod. The other end of the auxiliary measuring rod passes through the positioning ring and directly reaches the valve core of the pressure relief valve installed on the pressure relief valve control module. The measuring rod and the auxiliary measuring rod can move with the axial movement of the valve core. The coil includes a primary coil and two secondary coils, which can react to the position change of the measuring rod according to the differential electromotive force induced by the two secondary coils, and output a measurement information number.
2. The device according to claim 1, characterized in that The positions between the two ends of the auxiliary measuring rod are provided with a baffle side spring fixing sleeve, a spring baffle and a second fixing nut in the order of being away from the coil one by one. The baffle side spring fixing sleeve is clamped with the other end of the spring, and the end of the baffle side spring fixing sleeve is embedded in the groove of the spring baffle. The baffle side spring fixing sleeve and the spring baffle can move relative to the auxiliary measuring rod. The second fixing nut is threadedly connected to the auxiliary measuring rod to block the spring baffle. The expansion and contraction of the spring can be adjusted by rotating the second fixing nut.
3. The device according to claim 1, characterized in that The measuring rod and the auxiliary measuring rod are made of stainless steel.
4. The device according to claim 1, characterized in that The outer side of the measuring rod is threadedly connected to the first fixing nut, which is used to adjust the thread engagement length of the measuring rod and the auxiliary measuring rod.
5. The device according to claim 1, characterized in that The main actions of the spring are as follows: when the pressure relief valve is opened, the measuring rod and the auxiliary measuring rod closely follow the action of the pressure relief valve to open under the action of the spring; in the initial stage of closing the pressure relief valve, the pressure difference at both ends of the pressure relief valve core caused by the throttle hole is mainly used to make the measuring rod and the auxiliary measuring rod follow the action of the pressure relief valve to close; when the pressure relief valve is at the critical point of closing, the pressure difference at both ends of the pressure relief valve core is zero. At this time, the force difference between the built-in spring of the pressure relief valve and the spring in the device is mainly used to make the measuring rod and the auxiliary measuring rod follow the action of the pressure relief valve to close completely.
6. The device according to claim 1, characterized in that Bosses are axially arranged on the edges of both sides of the coil side spring fixing sleeve. One side end face of the coil side spring fixing sleeve can be stuck on the edge of the coil end, and the other side end face of the coil side spring fixing sleeve can fix the end of the spring to prevent the coil and the spring from relative radial movement.
7. The device according to claim 1, characterized in that The baffle side spring fixing sleeve is provided with a concave platform in the middle of the end surface facing the spring, a circular hole is designed in the center, and the spring baffle and one end surface are designed with a concave platform, which is used to embed the coil side spring fixing sleeve.
8. The device according to claim 1, characterized in that The positioning ring is fixed in the pressure relief valve measuring module and is used to keep the measuring rod, the auxiliary measuring rod and the pressure relief valve core on a central axis.