High-temperature under-pressure fatigue test system device for expansion joint

Abstract

The invention discloses a high-temperature under-pressure fatigue test system device for an expansion joint, and relates to the technical field of expansion joints, the high-temperature under-pressure fatigue test system device comprises a main body, the main body is provided with a stable loading mechanism for applying a load to the expansion joint, the main body is also provided with a high-temperature heating mechanism and a boosting mechanism, and the high-temperature heating mechanism is used for heating the expansion joint; the boosting mechanism is used for increasing the internal pressure of the expansion joint. According to the high-temperature under-pressure fatigue test system device for the expansion joint provided by the invention, the stable loading mechanism can apply a load to the expansion joint, the high-temperature heating mechanism can heat the expansion joint, and the boosting mechanism can improve the internal pressure of the expansion joint, so that a high-temperature and under-pressure environment is provided in the process of applying the load to the expansion joint; therefore, the actual working conditions of an expansion joint for a high-temperature gas cooled reactor, an expansion joint for a sodium cooled fast reactor, an expansion joint for a thorium-based molten salt reactor or an expansion joint for a petrochemical pipeline are simulated, and the fatigue life of the expansion joint product in different use working conditions is verified.

Description

Technical Field

[0001] The invention relates to the technical field of expansion joints, and in particular to a high-temperature pressure fatigue test system device for expansion joints. Background Art

[0002] The bellows expansion joint is a flexible connector used in piping systems, mainly used to absorb the expansion and contraction displacement of the pipeline caused by temperature changes or vibrations.

[0003] New structural expansion joints in the nuclear power industry's high-temperature gas-cooled reactor, sodium-cooled fast reactor, molten salt experimental reactor, lead-based fast reactor, high-end petrochemical industry, etc. must be verified by fatigue test equipment before they can be implemented.

[0004] For example, the patent document with application publication number CN115326376A and application publication date November 11, 2022, and titled "A high-cycle fatigue test device and test method for metal bellows expansion joints", includes a vertical support assembly, a horizontal mounting plate, a servo electric cylinder, a threaded joint, a connecting plate, a tooling pull plate, a pressure plate assembly, a fixing plate, a pressure detection element, a test device base, an operating panel, a communication cable and a PLC controller. The high-cycle fatigue test device for metal bellows expansion joints provided by the patent has low construction cost, is easy to maintain, flexible to install and easy to operate, reducing labor costs.

[0005] In the prior art, expansion joints for high-temperature gas-cooled reactors, expansion joints for sodium-cooled fast reactors, expansion joints for thorium-based molten salt reactors and expansion joints for petrochemical pipelines are one of the key components in the system equipment. In the process of simulating actual working conditions, they not only need to provide a high-temperature environment, but also a pressurized environment. Summary of the invention

[0006] The object of the present invention is to provide a high temperature pressure fatigue test system device for expansion joints to solve the above-mentioned deficiencies in the prior art.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A high temperature and pressure fatigue test system device for an expansion joint comprises a main body, on which a stable loading mechanism for applying a load to the expansion joint is arranged, and on which:

[0009] A high temperature heating mechanism, which is used to heat the expansion joint;

[0010] A booster mechanism is used to increase the internal pressure of the expansion joint.

[0011] In the above-mentioned high-temperature pressure fatigue test system device for expansion joints, the stable loading mechanism includes an upper connecting flange and a lower connecting flange respectively connected to the two ends of the expansion joint.

[0012] In the above-mentioned high-temperature pressure fatigue test system device for expansion joints, an actuator and a force sensor are arranged between the main body and the upper connecting flange.

[0013] In the above-mentioned high-temperature pressure fatigue test system device for expansion joints, a connecting ring is sleeved on the expansion joint, and an upper high-temperature pull rod is arranged between the connecting ring and the upper connecting flange.

[0014] In the above-mentioned high-temperature pressure fatigue test system device for expansion joints, a lower high-temperature pull rod is arranged between the lower connecting flange and the main body.

[0015] In the above-mentioned high-temperature pressure fatigue test system device for expansion joints, the high-temperature heating mechanism comprises a high-temperature box, the expansion joint is located in the high-temperature box, and a heating component and a temperature measuring component are arranged in the high-temperature box.

[0016] In the above-mentioned high-temperature pressure fatigue test system device for expansion joints, the upper high-temperature tie rod and the lower high-temperature tie rod both penetrate the high-temperature box.

[0017] In the above-mentioned high-temperature pressure fatigue test system device for expansion joints, the pressure-increasing mechanism comprises sealing plates fixed at both ends of the expansion joint and an air inlet pipe extending into the expansion joint.

[0018] In the above-mentioned high-temperature pressure fatigue test system device for expansion joints, the boosting mechanism also includes a pressure-maintaining component. When the high-temperature heating mechanism is in operation, the pressure-maintaining component is used to maintain the pressure in the expansion joint.

[0019] In the above-mentioned high-temperature pressure fatigue test system device for expansion joints, the pressure-maintaining component includes a pressure-maintaining valve in the prior art.

[0020] In the above technical scheme, the present invention provides a high-temperature pressurized fatigue test system device for expansion joints, in which a stable loading mechanism can apply a load to the expansion joint, a high-temperature heating mechanism can heat the expansion joint, and a boosting mechanism can increase the internal pressure of the expansion joint, thereby providing a high-temperature and pressurized environment in the process of applying a load to the expansion joint, thereby simulating the actual working conditions of expansion joints for high-temperature gas-cooled reactors, expansion joints for sodium-cooled fast reactors, expansion joints for thorium-based molten salt reactors, or expansion joints for petrochemical pipelines, and further verifying the fatigue life of the expansion joint product in different usage conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0022] Figure 1A schematic diagram of the overall structure provided by an embodiment of the present invention;

[0023] Figure 2 A schematic diagram of the expansion joint structure provided by an embodiment of the present invention;

[0024] Figure 3 A schematic diagram of a pressure-maintaining assembly provided in an embodiment of the present invention.

[0025] Description of reference numerals:

[0026] 1. Solenoid switch valve; 2. Pneumatic triplex; 3. Solenoid reversing valve; 4. Supercharger; 5. Check valve; 6. Pressure maintaining valve; 7. Pressure sensor; 8. Expansion joint; 9. Main body; 10. Upper connecting flange; 11. Lower connecting flange; 12. Actuator; 13. Force sensor; 14. Connecting ring; 15. Upper high-temperature pull rod; 16. Lower high-temperature pull rod; 17. High-temperature box; 18. Sealing plate; 19. Inlet pipe. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0028] Reference Figure 1-3 An embodiment of the present invention provides a high-temperature pressure fatigue test system device for an expansion joint, including a main body 9, on which a stable loading mechanism for applying a load to the expansion joint 8 is provided, and a high-temperature heating mechanism and a boosting mechanism are also provided on the main body 9. The high-temperature heating mechanism is used to heat the expansion joint 8; the boosting mechanism is used to increase the internal pressure of the expansion joint 8.

[0029] Specifically, the expansion joint 8 (bellows) is a flexible connector used in a pipeline system, which is mainly used to absorb the expansion or contraction displacement of the pipeline due to temperature changes or vibrations; the expansion joint 8 itself has good elasticity and pressure resistance, which can effectively alleviate the stress concentration caused by temperature changes, thereby protecting the pipeline and its connecting parts; the fatigue test system device is used to test the fatigue life of the expansion joint 8 product under different working conditions, and it can apply a load to the expansion joint 8 at a certain frequency to verify the performance and fatigue life of the expansion joint 8. The above are all existing technologies and will not be repeated here. The innovation of the embodiment of the present invention is that the main body 9 is constructed as a frame structure, and a high-temperature heating mechanism and a boosting mechanism are arranged on the main body 9 to cooperate with the stable loading mechanism to simulate the operating condition of the expansion joint 8. The high-temperature heating mechanism can select the closed chamber heating structure in the prior art, and the boosting mechanism can select the boosting pump in the prior art. Through the cooperation of multiple mechanisms, a high temperature and pressurized environment can be provided in the process of applying load to the expansion joint 8. For the expansion joint 8 for high-temperature gas-cooled reactor, the expansion joint 8 for sodium-cooled fast reactor, the expansion joint 8 for thorium-based molten salt reactor or the expansion joint 8 for petrochemical pipeline, this simulation method is more in line with the actual working conditions and can accurately verify the fatigue life of the expansion joint 8 in different operating conditions.

[0030] An embodiment of the present invention provides a high-temperature pressurized fatigue test system device for an expansion joint 8, wherein a stable loading mechanism can apply a load to the expansion joint 8, a high-temperature heating mechanism can heat the expansion joint 8, and a boosting mechanism can increase the internal pressure of the expansion joint 8, thereby providing a high-temperature and pressurized environment in the process of applying a load to the expansion joint 8, thereby simulating the actual operating conditions of the expansion joint 8 for a high-temperature gas-cooled reactor, the expansion joint 8 for a sodium-cooled fast reactor, the expansion joint 8 for a thorium-based molten salt reactor, or the expansion joint 8 for a petrochemical pipeline, and further verifying the fatigue life of the expansion joint 8 product in different operating conditions.

[0031] In another embodiment provided by the present invention, further, the stable loading mechanism comprises an upper connecting flange 10 and a lower connecting flange 11 respectively connected to both ends of the expansion joint 8. An actuator 12 and a force sensor 13 are arranged between the main body 9 and the upper connecting flange 10. Specifically, a flange is generally provided at the end of the expansion joint 8 to connect the pipeline. In the present embodiment, the upper connecting flange 10 and the lower connecting flange 11 are respectively connected to the two ends of the expansion joint 8 (can be connected by bolts), and then the upper connecting flange 10 and the lower connecting flange 11 are driven to move relative to each other (relative movement along the axial direction of the expansion joint 8) to apply a load to the expansion joint 8; the actuator 12 can use a linear drive structure in the prior art, such as a cylinder or a hydraulic cylinder, one end of which is fixed on the main body 9 and the other end is fixed on the upper connecting flange 10, so as to drive the upper connecting flange 10 to move relative to the lower connecting flange 11 through the actuator 12 (a corresponding actuator 12 structure can be provided between the lower connecting flange 11 and the main body 9); the force sensor 13 can use a pressure sensor 7 in the prior art, which is located between the actuator 12 and the upper connecting flange 10. When the actuator 12 applies a load to the expansion joint 8, the load applied to the expansion joint 8 by the actuator 12 can be detected in real time through the force sensor 13.

[0032] Furthermore, a connecting ring 14 is sleeved on the expansion joint 8, and an upper high-temperature tie rod 15 is arranged between the connecting ring 14 and the upper connecting flange 10. Specifically, in the above embodiment, the upper connecting flange 10 can be directly fixed at the end of the expansion joint 8. In this embodiment, a connecting ring 14 is sleeved on the outer wall of the expansion joint 8 away from the lower connecting flange 11. The connecting ring 14 is tightly attached to the recessed part of the outer wall of the expansion joint 8 (the recessed structure of the outer wall of the bellows), so that the connecting ring 14 can apply a load to the expansion joint 8 when it is close to or away from the lower connecting flange 11; the upper high-temperature tie rod 15 is arranged along the axial direction of the expansion joint 8, one end of which is fixed on the outer wall of the connecting ring 14, and the other end is fixed on the upper connecting flange 10; four upper high-temperature tie rods 15 are arranged, and the four upper high-temperature tie rods 15 are evenly arranged along the circumference of the expansion joint 8. The advantage of such a configuration is that, due to its own structure, it is difficult to achieve consistent circumferential stiffness of the expansion joint 8 (especially in a high temperature environment, it is even more difficult to ensure consistency). During the high temperature fatigue test, the expansion joint 8 is very likely to tilt in the direction of lower pipe wall strength. If the tilt is too large, the test will fail. For this reason, four upper high temperature tie rods 15 are arranged. When the actuator 12 is running, the upper connecting flange 10 and the four upper high temperature tie rods 15 can drive the connecting ring 14 to rise or fall smoothly as a whole, so that the expansion joint 8 is subjected to uniform load in the circumferential direction during the fatigue test, and the expansion joint 8 is prevented from tilting during the experiment as much as possible.

[0033] Preferably, a lower high-temperature tie rod 16 is provided between the lower connecting flange 11 and the main body 9. Specifically, in the above embodiment, a corresponding actuator 12 structure may be provided between the lower connecting flange 11 and the main body 9. In this embodiment, both ends of the lower high-temperature tie rod 16 are respectively fixed to the lower connecting flange 11 and the main body 9, thereby limiting the position of the lower end of the expansion joint 8, so that the actuator 12 can drive the connecting ring 14 away from the lower connecting flange 11 when in operation, thereby applying a load to the expansion joint 8.

[0034] In another embodiment provided by the present invention, further, the high-temperature heating mechanism includes a high-temperature box 17, the expansion joint 8 is located in the high-temperature box 17, and a heating component and a temperature measuring component are arranged in the high-temperature box 17. Specifically, the high-temperature box 17 is arranged on the main body 9, and the two can be fixedly connected or detachably connected; the heating component can use the resistance wire heating structure (not shown) in the prior art, and the temperature measuring component can use the infrared temperature measuring structure (not shown) in the prior art, which is the prior art and will not be repeated here; when performing fatigue test, the expansion joint 8 in the high-temperature box 17 is heated by the heating component, and the temperature of the expansion joint 8 in the high-temperature box 17 is monitored by the temperature measuring component, so that the expansion joint 8 is subjected to stiffness fatigue test in a high temperature environment (below 1000°C, such as 500°C, 800°C or 1000°C).

[0035] Preferably, the upper high-temperature tie rod 15 and the lower high-temperature tie rod 16 both penetrate the high-temperature box 17. Specifically, in order to further improve the sealing performance of the high-temperature box 17, four upper sealing grooves adapted to the upper high-temperature tie rods 15 are constructed at the top of the high-temperature box 17, and a lower sealing groove adapted to the lower high-temperature tie rod 16 is constructed at the bottom of the high-temperature box 17. The upper high-temperature tie rod 15 is slidably connected in the upper sealing groove and a dynamic sealing structure is provided between the two. The lower high-temperature tie rod 16 is located in the lower sealing groove; such a configuration allows the actuator 12 to apply a load to the expansion joint 8 outside the high-temperature box 17, and avoids the actuator 12 and other structures being in a high-temperature environment together with the expansion joint 8 as much as possible.

[0036] In another embodiment provided by the present invention, further, the boosting mechanism includes a blocking plate 18 fixed at both ends of the expansion joint 8 and an air intake pipe 19 extending into the expansion joint 8 . Specifically, in the prior art, both ends of the expansion joint 8 are open structures (flange structures are generally provided at both ends of the expansion joint 8 to connect the pipeline), which does not affect the stable loading mechanism and the high-temperature heating mechanism. However, in order to simulate a pressurized environment, it is necessary to fill the expansion joint 8 with gas to simulate a constant pressure and high pressure state in the expansion joint 8. To this end, sealing plates 18 are fixed at both ends of the expansion joint 8 to make the interior of the expansion joint 8 in a closed state; accordingly, the temperature measuring component can be embedded in the sealing plate 18 and extend to the interior of the expansion joint 8; the air inlet pipe 19 can be embedded in the sealing plate 18, one end of the air inlet pipe 19 passes through the high-temperature box 17 and extends to the outside, and the other end passes through the sealing plate 18 and extends to the expansion joint 8. In this way, gas can be filled into the expansion joint 8 through structures such as a booster pump, so that the expansion joint 8 can be fatigue tested under a pressurized environment (below 2MPa, such as 1MPa, 1.5MPa or 2MPa).

[0037] When the high-temperature heating mechanism and the boosting mechanism are operating synchronously, the space inside the expansion joint 8 is fixed, so that the temperature and pressure inside the expansion joint 8 will affect each other, which will result in the inability to accurately control the temperature and pressure of the expansion joint 8 during the fatigue test.

[0038] Preferably, the boosting mechanism further includes a pressure-maintaining component, and when the high-temperature heating mechanism is in operation, the pressure-maintaining component is used to maintain the pressure in the expansion joint 8. Specifically, the pressure-maintaining component can use a one-way valve structure in the prior art, and preferably, the pressure-maintaining component includes a pressure-maintaining valve 6 in the prior art, which can start working when the pressure in the expansion joint 8 exceeds a set value to discharge the gas in the expansion joint 8, thereby controlling the pressure in the expansion joint 8 to a set value. In this embodiment, gas is first filled into the expansion joint 8 through the boosting mechanism to make the pressure in the expansion joint 8 reach a set value (below 2MPa, such as 1MPa, 1.5MPa or 2MPa), and then the boosting mechanism stops running; the expansion joint 8 is then heated by the high-temperature heating mechanism. As the temperature in the expansion joint 8 increases, the pressure in the expansion joint 8 also gradually increases. When the pressure in the expansion joint 8 reaches the set value, the pressure-maintaining valve 6 starts working to discharge excess gas, thereby controlling the pressure in the expansion joint 8 at the set value, until the temperature in the expansion joint 8 reaches the set value. The temperature and pressure inside the expansion joint 8 are both at the corresponding set values. At this time, the actuator 12 can be operated to perform fatigue testing on the expansion joint 8 in a high-temperature and pressurized environment.

[0039] As a parallel solution of the above-mentioned pressure-maintaining valve 6, further, the pressure-maintaining assembly also includes an electromagnetic switch valve 1, a pneumatic triplet 2, an electromagnetic reversing valve 3, a booster 4, a check valve 5 and a pressure sensor 7. Specifically, as Figure 3The figure shows the schematic diagram of the pressure-maintaining component, which includes a boosting gas source and a test gas source. The special gas used for the test enters the expansion joint 8 through the electromagnetic switch valve 1, the pneumatic triplet 2, the one-way valve 5, and the high-pressure chamber of the booster 4. At this time, the pressure in the expansion joint 8 is relatively low. In order to reach the set value for the test (below 2MPa, such as 1MPa, 1.5MPa or 2MPa), it is necessary to perform pressurization; the boosting gas enters the boosting chamber of the booster 4 through the electromagnetic switch valve 1, the pneumatic triplet 2, and the electromagnetic reversing valve 3. The booster 4 will pressurize the test gas in the high-pressure chamber of the booster 4 and enter the expansion joint 8 to reach the set value for the test by boosting; when the pressure is constant, the electromagnetic switch valve 1 at the test gas source and the boosting gas source is closed.

[0040] During the heating process, the air pressure in the expansion joint 8 increases accordingly. In order to maintain a constant pressure, the pressure-maintaining valve 6 will discharge the high-pressure gas to keep the pressure in the expansion joint 8 constant. The pressure sensor 7 detects the pressure on a certain area of ​​the inner wall of the expansion joint 8 in real time during the entire test process. When the pressure is lower than the pressure corresponding to the pressure setting value, the sensor sends a signal to open the electromagnetic switch valve 1 at the test air source and the boost air source to increase the pressure in the expansion joint 8. When the pressure in the expansion joint 8 is lower than the set value for the test, the electromagnetic switch valve 1 at the test air source and the boost air source automatically opens.

[0041] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A high temperature and pressure fatigue test system for expansion joints, comprising a main body, on which a stable loading mechanism for applying a load to the expansion joint is provided, characterized in that: The main body is also provided with: A high temperature heating mechanism, which is used to heat the expansion joint; A booster mechanism is used to increase the internal pressure of the expansion joint.

2. A high temperature pressure fatigue test system for expansion joints according to claim 1, characterized in that: The stable loading mechanism comprises an upper connecting flange and a lower connecting flange respectively connected to two ends of the expansion joint.

3. A high temperature pressure fatigue test system for expansion joints according to claim 1, characterized in that: An actuator and a force sensor are arranged between the main body and the upper connecting flange.

4. A high temperature pressure fatigue test system for expansion joints according to claim 2, characterized in that: A connecting ring is sleeved on the expansion joint, and an upper high-temperature pull rod is arranged between the connecting ring and the upper connecting flange.

5. A high temperature pressure fatigue test system for expansion joints according to claim 4, characterized in that: A lower high-temperature pull rod is arranged between the lower connecting flange and the main body.

6. A high temperature pressure fatigue test system for expansion joints according to claim 5, characterized in that: The high-temperature heating mechanism comprises a high-temperature box, the expansion joint is located in the high-temperature box, and a heating component and a temperature measuring component are arranged in the high-temperature box.

7. A high temperature pressure fatigue test system for expansion joints according to claim 6, characterized in that: The upper high-temperature pull rod and the lower high-temperature pull rod both penetrate the high-temperature box.

8. The high temperature pressure fatigue test system for expansion joints according to claim 1, characterized in that: The boosting mechanism comprises blocking plates fixed at both ends of the expansion joint and an air inlet pipe extending into the expansion joint.

9. The high temperature pressure fatigue test system for expansion joints according to claim 1, characterized in that: The boosting mechanism also includes a pressure-maintaining component, which is used to maintain the pressure in the expansion joint when the high-temperature heating mechanism is in operation.

10. A high temperature pressure fatigue test system for expansion joints according to claim 9, characterized in that: The pressure maintaining component includes a pressure maintaining valve in the prior art.

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