A rubber expansion joint for nuclear power main pipeline

Abstract

This invention discloses a rubber expansion joint for nuclear power plant main pipelines, belonging to the technical field of pipeline joint accessories. It includes two connecting flanges and a connecting pipe section between the flanges. The connecting pipe section has a transversely arranged filling support cavity and an outer filling support cavity. A through hole is also provided inside the connecting pipe section, communicating with both the filling support cavity and the outer filling support cavity. A loop control mechanism is located between the flanges and on the outside of the connecting pipe section, communicating with the through hole. An oil supply and discharge mechanism is connected to the loop control mechanism. The loop control mechanism is used to control the supply and discharge of oil in the through hole. A control mechanism is provided on the oil supply and discharge mechanism. This design, through directional outward expansion deformation compensation, allows for more uniform distribution of stress within the connecting pipe section when it is subjected to frequent, long-term, lateral impacts, thus reducing internal fatigue.

Description

Technical Field

[0001] This invention belongs to the technical field of pipe joints and fittings, specifically relating to a rubber expansion joint for nuclear power plant main pipelines. Background Technology

[0002] Rubber expansion joints for nuclear power plant main pipelines are key flexible compensation devices that connect the main pipelines of the reactor coolant system (RCS) in nuclear power plants. They are mainly used to absorb the stress generated by the pipeline due to thermal expansion, mechanical vibration, seismic displacement, etc., and to ensure the safe operation of the system.

[0003] A typical nuclear power plant rubber expansion joint consists of three parts: an inner rubber layer, a reinforcing layer, and an outer rubber layer. The inner rubber layer is in direct contact with the coolant and must be resistant to high temperatures, corrosion (such as boric acid and sodium hydroxide), and have low permeability. It is commonly made of ethylene propylene diene monomer (EPDM) rubber or fluororubber (FKM). The reinforcing layer is the core structure that bears pressure and displacement. It is usually made of stainless steel wire braid or high-strength fiber (such as aramid) winding to ensure pressure resistance (typically meeting 1.5 times the design pressure). The outer rubber layer protects the reinforcing layer from environmental aging (such as ultraviolet radiation and ozone) and mechanical damage. It is commonly made of neoprene rubber (CR) or silicone rubber. The connecting parts are flanges or welded ends that are rigidly connected to the main pipeline to ensure sealing (usually using metal O-rings or graphite gaskets).

[0004] The invention patent application number 202211555566.1 discloses a seawater expansion joint for a nuclear power plant condenser, an expansion joint preparation mold, and a preparation method. The expansion joint includes a pressure ring, fixing bolts, a flange, and a rubber body. The pressure ring, flange, and rubber body are a one-time casting structure. The flange is connected to the pipeline. One end of the rubber body is located between the flange and the pressure ring. The two opposite sides of the flange and the pressure ring form a concave space, which matches the shape of the end of the rubber body. The flange and the pressure ring are connected and fixed by fixing bolts. The rubber body is connected to the pipeline by the connection and fixation of the flange and the pressure ring. The rubber body comprises an inner rubber layer, a middle rubber layer, an outer rubber layer, an inner fabric reinforcement layer, an outer fabric reinforcement layer, and metal O-rings. The inner rubber layer is located between the outer rubber layer and the middle rubber layer, the outer fabric reinforcement layer is located between the outer rubber layer and the inner rubber layer, and the inner fabric reinforcement layer is located between the inner rubber layer and the middle rubber layer. A pair of metal O-rings are located at both ends of the outer rubber layer, the outer fabric reinforcement layer, the inner rubber layer, the inner fabric reinforcement layer, and the middle rubber layer. The ends of the outer rubber layer, the outer fabric reinforcement layer, the inner rubber layer, the inner fabric reinforcement layer, and the middle rubber layer are folded back around the metal O-rings. The rubber body composed of the ends of the outer rubber layer, the outer fabric reinforcement layer, the inner rubber layer, the inner fabric reinforcement layer, the middle rubber layer, and the metal O-rings is integrally molded by casting a mixture of low-density polyurethane foam.

[0005] As can be seen, this type of expansion joint consists of an outer rubber layer, a fabric-reinforced outer layer, an inner rubber layer, a fabric-reinforced inner layer, and a middle rubber layer, with each end wrapped around a metal O-ring. This design ensures that the expansion joint is protected from frequent axial expansion and contraction and radial expansion and contraction processes caused by changes in pipeline pressure, reduces the displacement of the fabric-reinforced layer, lowers the intensity of stress failure, and effectively extends the service life of the expansion joint. It is suitable for high-temperature steam transportation environments in nuclear power facilities.

[0006] In contrast, besides the main pipelines for boiling water reactors (BWR), heavy water reactors (CANDU), and sodium-cooled block reactors, the main pipelines for pressurized water reactors (PWR) have the largest amount of pipelines. They are used to transport high-temperature, high-pressure (approximately 327°C, 15.5 MPa) deionized water (containing boric acid as a neutron absorber) to remove heat from the reactor core. This heat is then transferred to the secondary loop water via a steam generator to generate steam to drive the turbine and generate electricity.

[0007] Therefore, the expansion joints used in the main pipeline of this nuclear power plant will withstand extremely short-term conditions of high temperature and high pressure (approximately 327℃, 15.5MPa), strong corrosion (boron water environment), and radiation aging. Especially in the deionized water pressurization section, they also face the pressure of instantaneous pressurization by the nuclear power plant-grade pressurization pump, requiring radial displacement compensation. Therefore, the fluororubber expansion joints used in the main body are widely used in this area. Besides absorbing the vibration generated by the operation of the nuclear power plant-grade pressurization pump, they are adaptable to high temperature and high pressure (approximately 327℃, 15.5MPa), strong corrosion (boron water environment), and have strong resistance to radiation aging. Especially in the deionized water pressurization section, facing the pressure of instantaneous pressurization by the nuclear power plant-grade pressurization pump, they provide better radial displacement compensation compared to special metal telescopic expansion joints.

[0008] However, this instantaneous water pressure is compensated for by the radial displacement of the fluororubber expansion joint. But due to the pressurization effect in this section, it is not modulated by a pressure regulator. The high-pressure deionized water entering the expansion joint is not axially balanced, but rather impacts laterally to a certain side of the inner wall before converging. In this situation, the inner wall of the expansion joint experiences significant outward deformation due to the instantaneous pressure impact, while other areas, unaffected by the impact, experience less outward deformation. Long-term, frequent exposure to this environment leads to uneven outward deformation of the fluororubber, causing stress within the fluororubber to be unevenly distributed, concentrating in weak bond areas, forming cracks, thus increasing fluororubber fatigue and visibly reducing its service life and long-term safe operation. To ensure uniform internal stress in the fluororubber expansion joints used in this area and reduce internal fatigue, it is necessary to install a nuclear power plant main pipeline rubber expansion joint that meets the actual requirements. Summary of the Invention

[0009] The purpose of this invention is to provide a rubber expansion joint for nuclear power plant main pipelines to solve the problems existing in the prior art.

[0010] To achieve the above objectives, the present invention provides the following technical solution: a rubber expansion joint for a nuclear power main pipeline, comprising two connecting flanges and a joint tube connecting the connecting flanges, wherein a filling support cavity and an outer filling support cavity are respectively arranged transversely inside the joint tube, and a through hole is also provided inside the joint tube and the through hole communicates with the filling support cavity and the outer filling support cavity, and an elastic outer support mechanism is uniformly arranged circumferentially on the outside of the joint tube, the elastic outer support mechanism being used to circumferentially support the outer wall of the joint tube, and a pressure sensing plate is provided between the elastic outer support mechanism and the joint tube;

[0011] A loop control mechanism is installed between the connecting flanges and at an external location on the pipe section, and the loop control mechanism is connected to the pipe section through hole. An oil supply and discharge mechanism is connected to the loop control mechanism. The oil supply and discharge mechanism is used to pump and discharge oil in the filling support cavity and the outer filling support cavity through the loop control mechanism, and to monitor the oil pressure data. The loop control mechanism is used to control the on / off process of oil supply and discharge in the through hole.

[0012] The oil supply and discharge mechanism is equipped with a control mechanism, which is used to obtain pressure information in real time through a pressure sensor and control the operation of the oil supply and discharge mechanism and the circulation control mechanism.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] In the nuclear power main pipeline rubber expansion joint of this invention, when a momentary high pressure occurs on a certain side wall of the joint, the pressure sensor in that area provides feedback on the pressure. After the pressure sensor acquires the pressure signal of that area in real time, the control mechanism analyzes and processes the dynamic pressure change data to control the hydraulic oil supply and discharge mechanism to pressurize hydraulic oil into the filling and outer filling cavities of other areas until the pressure data acquired by the pressure sensor in other areas is balanced with the pressure data acquired by the pressure sensor in this area. At this point, the hydraulic oil supply stops, and an equal amount of pressure relief is performed after a delay. Throughout the process, when the joint is subjected to momentary impacts on a certain side position for a long time, this directional outward expansion deformation compensation setting makes the stress generated inside the joint more evenly distributed, reducing internal fatigue of the joint. Attached Figure Description

[0015] Figure 1 This is a front view schematic diagram of the present invention;

[0016] Figure 2 for Figure 1 A partial cross-sectional diagram;

[0017] Figure 3 for Figure 2 A magnified structural diagram at point a;

[0018] Figure 4 for Figure 2A magnified structural diagram at point b;

[0019] Figure 5 for Figure 1 A top-down view;

[0020] Figure 6 This is a schematic diagram of a transverse section of the tube in the present invention;

[0021] Figure 7 for Figure 6 A magnified structural diagram at point c;

[0022] Figure 8 This is a schematic diagram showing the connections of the modules in the development board of this invention.

[0023] In the diagram: 1. Connecting flange, 2. Pipe section, 3. Inner reinforcing pipe, 4. Lateral traction rope, 5. Longitudinal traction rope, 6. Filling support cavity, 7. Outer support edging, 8. Through hole, 9. Pipe row, 10. Pipe, 11. Solenoid valve one, 12. Bellows compensator, 13. Connecting ring pipe, 14. Elastic support plate, 19. Pressure plate, 20. Pressure sensor plate, 21. Inlet pipe, 22. Solenoid valve two, 23. Pipe one, 24. Electronic oil pressure gauge, 25. Pipe two, 26. Oil pump, 27. Pipe three, 28. Oil tank, 29. Pipe row one, 30. Electronic pressure relief valve, 31. Pipe row two, 101. Side support rod, 281. Control box, 282. Development board, 283. Integrated relay, 601. Elastic support edge, 602. Outer filling support cavity, 603. Tension ring. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0025] See Figure 1 , Figure 2 and Figure 5A rubber expansion joint for nuclear power plant main pipeline includes two connecting flanges 1 and a connecting pipe 2 connecting the connecting flanges 1. The two ends of the connecting pipe 2 are tightly clamped to the inner edge of the connecting flanges 1 through annular grooves. The material of the connecting pipe 2 is fluororubber, with a minimum sidewall thickness of 20 cm and a maximum sidewall thickness of 38 cm. When the connecting pipe 2 is not filled with hydraulic oil, its size and thickness are sufficient to prevent radial deformation under normal deionized water pressure. The connecting pipe 2 is provided with a filling support cavity 6 and an outer filling support cavity 602 in the transverse direction. The cross-section of the filling support cavity 6 and the outer filling support cavity 602 is elliptical. The inner wall of the filling support cavity 6 and the outer filling support cavity 602 is bonded with aramid fiber mesh. With this configuration, in addition to ensuring the expansion and deformation capacity of the filling support cavity 6 and the outer filling support cavity 602, it can also ensure the long-term tear resistance of the filling support cavity 6 and the outer filling support cavity 602. The middle section of the tube 2 has uniformly arranged through holes 8, which are connected to the filling support cavity 6 and the outer filling support cavity 602. Therefore, hydraulic oil can be injected into the filling support cavity 6 and the outer filling support cavity 602 through the through holes 8, and hydraulic oil can also be released outward through the filling support cavity 6 and the outer filling support cavity 602 through the through holes 8. The outer side of the tube 2 has uniformly arranged elastic external support mechanisms, which are used to provide circumferential support to the outer wall of the tube 2. A pressure sensing plate 20 is arranged between the elastic external support mechanism and the tube 2.

[0026] The pressure sensor 20 is a sheet-like structure with pressure-sensitive pressure sensing contacts on both sides, used to sense the pressure of the joint tube 2 against the elastic external support mechanism.

[0027] A loop control mechanism is installed between the connecting flanges 1 and at the external location of the pipe section 2, and the loop control mechanism is connected to the through hole 8 of the pipe section 2. An oil supply and discharge mechanism is connected to the loop control mechanism. The oil supply and discharge mechanism is used to pump and discharge the oil in the filling support cavity 6 and the outer filling support cavity 602 through the loop control mechanism, and to monitor the oil pressure data. The loop control mechanism is used to control the on / off process of oil supply and discharge in the through hole 8.

[0028] A control mechanism is installed on the oil supply and discharge mechanism. The control mechanism is used to obtain pressure information in real time through the pressure sensor 20 and control the operation of the oil supply and discharge mechanism and the circulation control mechanism.

[0029] Therefore, after the pressure sensor 20 acquires the pressure signal of the area in real time, the control mechanism analyzes and processes the signal to obtain dynamic pressure change data and controls the hydraulic oil supply and discharge mechanism to press hydraulic oil into the filling support cavity 6 and the outer filling support cavity 602 of other areas until the pressure data acquired by the pressure sensor 20 of other areas is balanced with the pressure data acquired by the pressure sensor 20 of the area. Then, the hydraulic oil supply is stopped. When the pressure data of the area returns to normal, the hydraulic oil supply and discharge mechanism is controlled to release the hydraulic oil.

[0030] This process ensures uniform stress inside section 2, thereby reducing internal fatigue during long-term use.

[0031] See Figure 2 , Figure 3 , Figure 6 and Figure 7 In the section tube 2, and near the inner wall of the section tube 2, inner rib tubes 3 are uniformly arranged in a circumferential direction. The inner rib tubes 3 are arc-shaped tube structures made of tungsten vanadium alloy. The outer diameter of the cross section of the inner rib tube 3 is 1 cm. The inner rib tubes 3 have good bending resilience. The inner rib tubes 3 are arranged vertically corresponding to each elastic external support mechanism. The distance between vertically adjacent inner rib tubes 3 is 1 cm. The transverse expansion traction ropes 4 are tightly inserted in each layer of circumferentially arranged inner rib tubes 3. The cross section diameter of the transverse expansion traction ropes 4 is 2 mm. The transverse expansion traction ropes 4 are carbon fiber woven mesh rope structures and have a ring configuration. The longitudinal tension traction ropes 5 are tightly wound on the vertically arranged inner rib tubes 3 and transverse expansion traction ropes 4. The longitudinal tension traction ropes 5 are carbon fiber woven mesh rope structures. The stretchable length of the transverse expansion traction ropes 4 and the longitudinal tension traction ropes 5 is set to meet the deformation requirements of normal radial transverse expansion and axial longitudinal expansion of the section tube 2.

[0032] Each layer of circumferentially arranged inner ribs 3 is connected to a transverse expansion traction rope 4. This ensures that the section pipe 2 can expand and contract laterally, resulting in higher angular and transverse tear resistance. With the help of the inner ribs 3, the section pipe 2 has a stronger high-temperature recovery ability when the ion water pressure in the main pipe decreases. When the longitudinal traction rope 5 is tightly wrapped around the vertically arranged inner ribs 3 and transverse expansion traction rope 4, the section pipe 2 has higher axial tear resistance. With the help of the longitudinal traction rope 5, each vertical row of inner ribs 3 forms a whole. Therefore, when instantaneous high pressure occurs on the side wall of the section pipe 2, it is more conducive to elastic support from the elastic external support mechanism on each side, so that the pressure feedback to the pressure sensor 20 is more uniform, providing a more effective reference for subsequent radial expansion deformation compensation.

[0033] See Figure 2 , Figure 3 , Figure 4 and Figure 6A tension ring 603 is installed inside the tube 2, located between the filling support cavity 6 and the outer filling support cavity 602. The tension ring 603 is a ring-shaped structure with a 3D-printed polyurethane negative Poisson's ratio structure. It is distributed in the upper and lower parts of the tube 2, and the cross-section of the tension ring 603 in the upper and lower parts is a double-triangular structure with the tip pointing towards the middle and the sides pointing outward. Since the cross-sections of the filling support cavity 6 and the outer filling support cavity 602 gradually narrow from the middle to the upper and lower parts, the amount of deformation is relatively small when hydraulic oil is filled. The thickness of the tension ring 603 in the narrow area corresponding to the filling support cavity 6 and the outer filling support cavity 602 is larger, while the thickness in the wide area corresponding to the filling support cavity 6 and the outer filling support cavity 602 is thinner. Therefore, when stretching occurs on a certain side of the tube 2, the tension ring 603 is stretched, causing its inner and outer walls to expand laterally. This provides outward expansion compensation for the thickness areas of the filling support cavity 6 and the outer filling support cavity 602, thereby making the deformation of other sides of the tube 2 more uniform.

[0034] An elastic support edge 601 is provided inside the tube segment 2 and located between the filling support cavities 6. The elastic support edge 601 is made of tungsten vanadium alloy and has a thickness of 3 mm. The elastic support edge 601 mainly provides elastic support and protection for the areas inside the tube segment 2 that do not cover the filling support cavities 6 and the outer filling support cavities 602. When the tube segment 2 expands radially outward, it can effectively cooperate with its bending deformation. When the pressure inside the tube segment 2 is reduced and restored, it can accelerate the recovery of the tube segment 2 itself. Especially when hydraulic oil is released through the oil supply and discharge mechanism, during the process of the filling support cavities 6 and the outer filling support cavities 602 gradually recovering to a slender elliptical state due to the release of hydraulic oil, its bending resilience provides effective auxiliary power for the release of hydraulic oil, thereby accelerating the release of hydraulic oil in the filling support cavities 6 and the outer filling support cavities 602.

[0035] See Figure 1 , Figure 2 and Figure 4The elastic external support mechanism includes an outer support edging 7 that is circumferentially bolted to the outer wall of the tube section 2. Under natural filling conditions, the gap between adjacent outer support edgings 7 in the lateral direction is 0.1 mm. The outer support edging 7 is an arc-shaped spherical concave plate structure with a thickness of 1 cm and bent double ears. The material is tungsten vanadium alloy. The bent double ear area of ​​the outer support edging 7 is fixed to the docking flange 1 by bolts. The bent double ear area presses the tube section 2 and the docking flange 1 fitting area. Therefore, in addition to providing external elastic support and protection for the tube section 2, the outer support edging 7 can also naturally provide auxiliary elastic recovery capability for the tube section 2 after axial or radial deformation. Elastic support plate 14 is fixed to the flange 1 with uniform circumferential bolts. The thickness of elastic support plate 14 is 2 cm and the material is tungsten vanadium alloy. The initial bending rebound force of elastic support plate 14 is 1.9 times that of outer support edging 7. One end of elastic support plate 14 is fixed to pressure plate 19 with bolts. The non-sensing surface of pressure sensor 20 is glued to pressure plate 19 with resin adhesive and pressure sensor 20 is pressed against the upper and lower parts of each outer support edging 7. A drain pipe 9 is provided on the joint pipe 2 and the drain pipe 9 is connected to the through hole 8. A pipe 10 is provided on the outer support edging 7 and the drain pipe 9 is inserted into the pipe 10.

[0036] Under the elastic support of each elastic support plate 14, each pressure plate 19 presses the pressure sensing plate 20 mounted on its surface onto the outer wall of each outer support edge 7. Thus, during the radial or axial deformation of the joint tube 2, the two pressure-sensitive pressure sensing contacts on each pressure sensing plate 20 output signals to the outside. The transmission lines of the four pressure-sensitive pressure sensing contacts on two adjacent pressure sensing plates 20 are all connected to the signal input terminal of a signal connector.

[0037] Furthermore, during the release of hydraulic oil from the filling support cavity 6 and the outer filling support cavity 602, the deformation and recovery of the joint pipe 2 causes the outer support edge 7 to recover accordingly, and the elastic support plate 14 to bend and recover accordingly. Therefore, under the elastic pressure of the outer support edge 7 and the elastic support plate 14, the filling support cavity 6 and the outer filling support cavity 602 release hydraulic oil more quickly, thereby improving operating efficiency.

[0038] See Figure 1 , Figure 2 and Figure 5 The loop control mechanism includes a solenoid valve 11 connected to the flange of the connecting pipe 10. One end flange of the solenoid valve 11 is connected to one end of the bellows compensator 12, and the other end flange of the bellows compensator 12 is connected to the connecting loop pipe 13. Side support rods 101 are bolted to the connecting flange 1, and one end of the side support rods 101 is bolted to the connecting loop pipe 13.

[0039] In addition, the hydraulic oil volume in the connecting ring pipe 13 is sufficient to fill all the filling support cavities 6 and the outer filling support cavity 602 to the maximum extent.

[0040] When a solenoid valve 11 on a certain side opens and the oil pump 26 operates open, and the electronic pressure relief valve 30 closes, the hydraulic oil in the connecting ring pipe 13 will be discharged through the through hole 8 to the filling support cavity 6 and the outer filling support cavity 602 on that side. If a solenoid valve 11 on a certain side opens and the oil pump 26 stops and closes, the electronic pressure relief valve 30 opens, and the hydraulic oil in the filling support cavity 6 and the outer filling support cavity 602 is discharged through the through hole 8 to the connecting ring pipe 13, and then flows back to the oil tank 28 through the electronic pressure relief valve 30. With the assistance of the elastic support edge 601 and the outer support edge 7 and the elastic support plate 14, the speed at which the hydraulic oil is discharged back to the oil tank 28 is accelerated.

[0041] The size of the oil pump 26 is selected to ensure that all filling support cavities 6 and external filling support cavities 602 are filled to their maximum shape within 2.5 seconds.

[0042] See Figure 1 , Figure 2 and Figure 5 The oil supply and discharge mechanism includes a discharge pipe 21 connected to the rear side of the connecting ring pipe 13. One end of the discharge pipe 21 is flanged and connected to a solenoid valve 22. The inlet flange of the solenoid valve 22 is connected to a pipe 23. The right end flange of the pipe 23 is connected to an electronic oil pressure gauge 24. The right end flange of the electronic oil pressure gauge 24 is connected to a pipe 25. The right end flange of the pipe 25 is connected to the discharge end of the oil pump 26. The inlet flange of the oil pump 26 is connected to a pipe 3 27. The flange of the pipe 3 27 is connected to the lower rear access end of the oil tank 28.

[0043] Among them, the oil tank 28 is a closed oil tank, and the hydraulic oil used is silicone oil type hydraulic oil, which has good low thermal conductivity. When the solenoid valve 22 opens, the oil pump 26 senses the pressure and starts to operate. During this process, the electronic oil pressure gauge 24 can sense the oil pressure in the connecting ring pipe 13.

[0044] See Figure 1 and Figure 5 The oil supply and discharge mechanism also includes a second discharge pipe 31 connected to the front side of the connecting ring pipe 13. The front flange of the second discharge pipe 31 is connected to the electronic pressure relief valve 30. The discharge end flange of the electronic pressure relief valve 30 is connected to the first discharge pipe 29. The other end flange of the first discharge pipe 29 is connected to the front end of the oil tank 28.

[0045] After receiving the pressure relief command, the electronic pressure relief valve 30 opens. If the solenoid valve 11 in a certain area opens at this time, the hydraulic oil will be discharged through the through hole 8 to the connecting ring pipe 13, and then discharged to the oil tank 28 through the drain pipe 2 31, the electronic pressure relief valve 30 and the drain pipe 29.

[0046] See Figure 1 , Figure 2 and Figure 5The control mechanism includes a control box 281 screwed onto the oil tank 28. A heat-insulating pad is placed between the bottom of the control box 281 and the oil tank 28. An insulating pad and screws secure a development board 282 to the left side of the control box 281. The I / O power input of the development board 282 is connected to a 5V DC power supply via a cable. An integrated relay 283 is screwed onto the control box 281 near the development board 282. The various potential output terminals of the integrated relay 283 are connected to solenoid valve 11 and solenoid valve 22 via cables.

[0047] See Figure 8 The development board 282 contains a pressure signal receiving module and a hydraulic pressure signal receiving module. The signal output terminal of the signal cassette is connected to the signal input pin of the pressure signal receiving module. The pressure signal receiving module receives the real-time input signal from the pressure sensor 20 and converts the signal into pressure data. The transmission line of the electronic hydraulic pressure gauge 24 is connected to the signal input pin of the hydraulic pressure signal receiving module, which receives hydraulic pressure signals from the hydraulic supply and discharge mechanism. The pressure signal receiving module and the hydraulic pressure signal receiving module are connected to a pre-adjustment analysis module. The pre-adjustment analysis module is connected to relay control module one, relay control module two, and the pressure control information output module. The signal output pins of Module 1 and Relay Control Module 2 are connected to the various control signal input terminals of the integrated relay 283 via signal lines. The signal output pin of the pressure control information output module is connected to the signal input terminal of the electronic pressure relief valve 30 via signal lines. The pre-adjustment analysis module is used to analyze the pressure data converted from the pressure signal receiving module and make on / off judgments, and to issue a command to the relay control module 1 to control the opening and closing of the solenoid valve 11. It is also used to analyze the oil pressure signal from the oil pressure signal receiving module and make supply and discharge judgments, and to issue a command to the relay control module 2 to control the opening and closing of the solenoid valve 22. It also issues a command to the pressure control information output module to control the electronic pressure relief valve 30 to release and stop according to the set oil level.

[0048] Since the signal input from the pressure sensor 20 is converted by the pressure signal receiving module and returns multiple pressure data, the pre-adjustment analysis module will store the calibration equal pressure value. 均 Q 均 When the tube segment 2 has not undergone radial or axial expansion deformation, and the outer support edge 7 and elastic support plate 14 have not deformed, the average pressure data obtained by the two pressure sensors 20 at the upper and lower positions is the oil pressure value of the electronic oil pressure gauge 24 at this time; the pressure data obtained by any one of the upper pressure sensors 20 are the reference values ​​Q1 and Q2, and the pressure data obtained by any one of the lower pressure sensors 20 are the reference values ​​Q3 and Q4, respectively. In the pre-adjustment analysis module, the four pressure data of each side position are grouped and numbered, and (Q1+Q2+Q3+Q4) / 4>Q 均As an action threshold, in the natural state, (Q1+Q2+Q3+Q4) / 4=Q 均 When a momentary pressure impact occurs on one or more sides of the inner wall of section 2, the mean of all parameter values ​​is greater than Q. 均 The pre-adjustment analysis module sends opening commands to the solenoid valves 11 on other sides to the relay control module 1, and sends opening commands to the solenoid valve 22 on the relay control module 2. The oil pump 26 senses the pressure and opens the valve, drawing hydraulic oil from the oil tank 28 into the connecting ring pipe 13 through the oil pump 26, and discharging it into the filling support cavity 6 and the outer filling support cavity 602 through the solenoid valve 11 and the through hole 8. The pre-adjustment analysis module instantly calculates the average values ​​of Q1, Q2, Q3 and Q4 of other groups and sets the stop action threshold. The difference between similar parameter values ​​is ≤3 Newtons, and the average of the four parameter values ​​is the same as the average of the parameter values ​​corresponding to the side position where the inner wall of the tube 2 is subjected to instantaneous pressure from deionized water. The pre-adjustment analysis module sends a valve closing command to the solenoid valve 11 of that side position to the relay control input module until the average of all other numbered parameter values ​​reaches the stop action threshold. The oil pressure value F of the electronic oil pressure gauge 24 is instantaneously acquired. The pre-adjustment analysis module sends a valve closing command to the solenoid valve 22 through the relay control input module 2, and the oil pump 26 closes the valve based on the pressure. After a two-second delay, the pre-adjustment analysis module sends an opening command to all solenoid valves 11 in the deformation area to the relay control input module 1. The pre-adjustment analysis module uses the oil pressure change value of FG as the pressure relief endpoint value, inputs the pressure relief endpoint value into the electronic pressure relief valve 30 through the pressure control information output module, and controls the electronic pressure relief valve 30 to open and release pressure until the pressure relief amount reaches the pressure relief endpoint value. The electronic pressure relief valve 30 then automatically closes, completing the pressure relief.

[0049] The working principle of this embodiment is as follows: When a momentary high pressure occurs on a certain side wall of the tube 2, with the help of the longitudinal traction rope 5, each row of inner rib tubes 3 forms a whole, and the pressure sensor 20 in that area provides more uniform feedback of the pressure. With the elastic outer support mechanism and the radially expanding elastic support, the pressure sensor 20 inputs information to the control mechanism. After analysis and processing by the control mechanism, dynamic pressure change data is obtained, and the hydraulic oil supply and discharge mechanism is used to press hydraulic oil into the filling support cavity 6 and the outer filling support cavity 602 in other areas. When the pressure data obtained by the pressure sensor 20 in other areas is balanced with the pressure data obtained by the pressure sensor 20 in this area, the hydraulic oil supply is stopped, and an equal amount of pressure relief is performed after a delay. With the assistance of the elastic support edge 601 and the outer support edge 7 and the elastic support plate 14, the speed of hydraulic oil returning to the oil tank 28 is accelerated.

[0050] Under the above-mentioned operation and control method, when the tube 2 is subjected to instantaneous impacts in a certain side position for a long time, the stress generated inside the tube 2 is more evenly distributed through this directional outward expansion deformation compensation method, thereby reducing the internal fatigue of the tube 2.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention.

Claims

1. A rubber expansion joint for a nuclear power plant main pipeline, comprising two mating flanges (1) and a joint pipe (2) connecting the mating flanges (1), characterized in that, The section tube (2) is provided with a filling support cavity (6) and an outer filling support cavity (602) respectively in the transverse direction. The section tube (2) is also provided with a through hole (8) and the through hole (8) is connected to the filling support cavity (6) and the outer filling support cavity (602). The outer side of the section tube (2) is uniformly provided with an elastic outer support mechanism in the circumferential direction. The elastic outer support mechanism is used to provide circumferential support to the outer wall of the section tube (2). A pressure sensor plate (20) is provided between the elastic outer support mechanism and the section tube (2). An inner rib tube (3) is provided inside the section tube (2) and near the inner wall of the section tube (2). The inner rib tube (3) is arranged vertically in relation to each elastic external support mechanism. A horizontally expanding traction rope (4) is inserted inside each layer of the circumferentially arranged inner rib tube (3). A longitudinal pulling traction rope (5) is tightly wound on the vertically arranged inner rib tube (3) and the horizontally expanding traction rope (4). The elastic external support mechanism includes an external support edging (7) uniformly arranged around the outer wall of the section tube (2), with both ends of the external support edging (7) fixedly arranged on the docking flange (1), and an elastic support plate (14) uniformly arranged around the docking flange (1), with a pressure plate (19) connected to one end of the elastic support plate (14). A loop control mechanism is provided between the connecting flanges (1) and at the external position of the joint pipe (2), and the loop control mechanism is connected to the through hole (8) of the joint pipe (2). An oil supply and discharge mechanism is connected to the loop control mechanism. The oil supply and discharge mechanism is used to pump and discharge the oil in the filling support cavity (6) and the outer filling support cavity (602) through the loop control mechanism, and to monitor the oil pressure data. The loop control mechanism is used to control the on / off process of the oil supply and discharge in the through hole (8). The oil supply and discharge mechanism is equipped with a control mechanism, which is used to obtain pressure information in real time through the pressure sensor (20) and control the operation of the oil supply and discharge mechanism and the circulation control mechanism.

2. The rubber expansion joint for a nuclear power plant main pipeline according to claim 1, characterized in that: A tension ring (603) is provided inside the tube (2) and between the filling support cavity (6) and the outer filling support cavity (602), and an elastic support edge (601) is provided inside the tube (2) and between the filling support cavities (6).

3. A rubber expansion joint for a nuclear power plant main pipeline according to claim 2, characterized in that: The pressure sensor (20) is placed on the pressure plate (19) and the pressure sensor (20) is pressed against the outer support edge (7). The section pipe (2) is provided with a drain pipe (9) and the drain pipe (9) is connected to the through hole (8). The outer support edge (7) is provided with a pipe (10) and the drain pipe (9) is inserted into the pipe (10).

4. A rubber expansion joint for a nuclear power plant main pipeline according to claim 3, characterized in that: The loop control mechanism includes a solenoid valve (11) connected to the pipe (10). One end of the solenoid valve (11) is connected to the connecting loop pipe (13) through a bellows compensator (12). Each of the docking flanges (1) is connected to a side support rod (101), and one end of the side support rod (101) is connected to the connecting loop pipe (13).

5. A rubber expansion joint for a nuclear power plant main pipeline according to claim 4, characterized in that: The oil supply and discharge mechanism includes a discharge pipe (21) connected to one side of a connecting ring pipe (13). One end of the discharge pipe (21) is connected to a solenoid valve (22). One end of the solenoid valve (22) is connected to a pipe (23). One end of the pipe (23) is connected to an electronic oil pressure gauge (24). One end of the electronic oil pressure gauge (24) is connected to an oil pump (26) via a pipe (25). The inlet end of the oil pump (26) is connected to an oil tank (28) via a pipe (27).

6. A rubber expansion joint for a nuclear power plant main pipeline according to claim 5, characterized in that: The oil supply and discharge mechanism also includes a second discharge pipe (31) connected to the other side of the connecting ring pipe (13). One end of the second discharge pipe (31) is connected to an electronic pressure relief valve (30), and the discharge end of the electronic pressure relief valve (30) is connected to one end of the oil tank (28) through the first discharge pipe (29).

7. A rubber expansion joint for a nuclear power plant main pipeline according to any one of claims 1-6, characterized in that: The control mechanism includes a control box (281) installed on the oil tank (28), a development board (282) is installed on one side of the control box (281), and an integrated relay (283) is installed inside the control box (281) and near the development board (282).

8. A rubber expansion joint for a nuclear power plant main pipeline according to claim 7, characterized in that: The development board (282) is equipped with a pressure signal receiving module and an oil pressure signal receiving module. The pressure signal receiving module is used to receive the real-time input signal from the pressure sensor (20) and convert the signal into pressure data. The oil pressure signal receiving module is used to receive the oil pressure signal from the oil supply and discharge mechanism. The pressure signal receiving module and the oil pressure signal receiving module are connected to a pre-adjustment analysis module. The pre-adjustment analysis module is connected to a relay control module one, a relay control module two, and a pressure control information output module. The pre-adjustment analysis module is used to analyze the pressure data converted from the pressure signal receiving module and make on / off judgments. It also issues a command to the relay control module one to control the opening and closing of the solenoid valve one (11). It is also used to analyze the oil pressure signal from the oil pressure signal receiving module and make supply and discharge judgments. It issues a command to the relay control module two to control the opening and closing of the solenoid valve two (22). It issues a command to the pressure control information output module to control the electronic pressure relief valve (30) to release and stop according to the set oil.

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