Variable-pressure plate-fin heat exchanger thermal fatigue experiment device

Abstract

The utility model provides a variable-pressure thermal fatigue experiment device for a plate-fin heat exchanger, and aims to solve the problems that most of traditional thermal fatigue experiment devices for plate-fin heat exchangers in the prior art are designed based on normal pressure, and the superimposed influence of pressure stress load on thermal fatigue of a plate-fin structure is not considered; therefore, the thermal fatigue experiment and the actual working condition have great access to each other. The device mainly comprises a workbench, a heating box, a clamp, a normal-pressure air system, a high-pressure air system, a camera and a control system, a plate-fin sample is uniformly and quickly heated to a high temperature through the electromagnetic induction coil group, and cold and hot alternation of the plate-fin heat exchanger can be more accurately simulated in a pressure stress state through the normal-pressure and high-pressure air systems, so that an experimental result is more in line with an actual working condition, and two air cooling systems can be started at the same time, so that the experimental efficiency is improved. Rapid cooling of the sample is achieved, the thermal fatigue test period is shortened, and universality can be achieved within the permissible range of the internal and external pressure difference of the sample.

Description

Technical Field

[0001] The utility model relates to the technical field of thermal fatigue experiments, in particular to a variable pressure plate-fin heat exchanger thermal fatigue experiment device. Background Art

[0002] A plate-fin heat exchanger is a highly efficient heat exchange device. Its structure includes components such as baffles, seals, and fins, and is manufactured through bonding processes such as brazing. It has the advantages of small size, light weight, high heat transfer efficiency, high strength, good durability, and the ability to handle two or more media. Therefore, it is widely used in industries such as petroleum, chemical industry, and natural gas processing. Plate-fin heat exchangers are particularly well-known in gas turbine systems. They can not only be used to reduce the inlet temperature of the gas turbine's high-pressure compressor and increase the gas turbine's output under high temperature conditions, but can also be used to recover gas turbine exhaust heat, increase the compressor outlet temperature, and thereby improve the gas turbine's operating efficiency, providing strong support for the safe and stable operation of the gas turbine.

[0003] Due to factors such as operating hours, alternating loads, seasons, and climate, the plate-fin heat exchangers of gas turbines often operate under alternating hot and cold conditions and high-pressure stress loads. In such an environment, the thermal stress generated by the deformation resistance within the heat exchanger material will also change repeatedly. Combined with the compressive stress, fatigue failure will occur after long-term and repeated cycles, ultimately leading to leakage in the heat exchanger. To address this issue, thermal fatigue tests on plate-fin heat exchangers are required to study their failure mechanisms.

[0004] The problem is: due to the complex structure of the plate-fin heat exchanger, many brazing points, narrow flow channels, and pressure differences between the partitions, it is difficult to effectively conduct a single thermal fatigue test. At the same time, commonly used heating methods such as microwaves, resistance furnaces, and circular induction coils are also difficult to uniformly heat the plate-fin structure. Therefore, there are few related device designs for thermal fatigue tests of plate-fin heat exchangers. In addition, most thermal fatigue tests are based on normal pressure designs and do not consider the superimposed effects of compressive stress loads on the thermal fatigue of the plate-fin structure, resulting in a large discrepancy between the thermal fatigue test and the actual working conditions. Utility Model Content

[0005] In response to the defects in the prior art, the present application provides a variable-pressure plate-fin heat exchanger thermal fatigue test device. Through two groups of electromagnetic induction coils parallel to the two sides of the plate fin in the heating box, the plate-fin sample can be heated to a high temperature evenly and quickly; through the normal pressure and high-pressure air systems, the hot and cold alternation of the plate-fin heat exchanger can be more accurately simulated under the compressive stress state, so that the experimental results are more in line with the actual working conditions, and the two air cooling systems can be started at the same time to achieve rapid cooling of the sample and shorten the thermal fatigue test cycle; at the same time, the experiment conducted by the utility model can be universal within the allowable range of the pressure difference between the inside and outside of the sample, and is suitable for different heating rates, maximum temperatures, cooling rates and minimum temperatures.

[0006] The technical solution adopted by the present invention to solve the above technical problems is:

[0007] A variable pressure plate-fin heat exchanger thermal fatigue test device, comprising:

[0008] Workbench, serving as a sample thermal fatigue test platform;

[0009] A heating box 14 is rotatably mounted on the workbench 1 , and electromagnetic induction heating devices are provided on both sides of the interior of the heating box 14 , and is connected to a heating power supply 141 for heating the plate-fin cell sample 144 ;

[0010] A pair of symmetrical fixtures are provided on the heating box 14. The fixtures are provided with two first joints 142. The box also includes two second joints 143 provided at a 90° angle to the first joints 142.

[0011] an atmospheric pressure air system capable of being connected to one of the first connector or the second connector;

[0012] a high-pressure air system connectable to one of the first connector and the second connector;

[0013] A camera is installed on the heating box to monitor the shape changes and surface thermal fatigue damage of the plate-fin cell sample caused by heating and cooling in real time;

[0014] The control system is connected to the normal pressure air system, high pressure air system and the temperature and pressure detection parts on the heating box, and is used to set parameters and control the operation of each component.

[0015] Furthermore, a built-in thermocouple is provided inside the workbench, the first joint and the second joint both include an inlet joint and an outlet joint, and the heating box is rotatably arranged on the workbench via a rotatable chassis.

[0016] Furthermore, the atmospheric pressure air system includes a blower, and the atmospheric pressure mass flow meter, the first atmospheric pressure regulating valve, the atmospheric pressure cooler, the second atmospheric pressure regulating valve, the atmospheric pressure inlet pressure gauge, the atmospheric pressure inlet thermocouple, the atmospheric pressure outlet thermocouple and the atmospheric pressure outlet pressure gauge are sequentially arranged on the sample path from the blower to the plate-fin cell.

[0017] Furthermore, the high-pressure air system includes an air compressor, and the air storage tank, high-pressure mass flow meter, first high-pressure regulating valve, high-pressure cooler, second high-pressure regulating valve, high-pressure inlet pressure gauge, high-pressure inlet thermocouple, high-pressure outlet thermocouple, and high-pressure outlet pressure gauge are sequentially arranged on the path from the air compressor to the plate-fin cell sample.

[0018] Furthermore, it also includes a high-pressure bypass system arranged on the high-pressure air system path, the high-pressure bypass system includes a bypass regulating valve arranged on the air storage tank and the high-pressure mass flowmeter path, and a bypass valve connected to a branch is arranged between the bypass regulating valve and the high-pressure mass flowmeter.

[0019] Furthermore, a normal pressure system back pressure valve is provided at the end of the path of the normal pressure air system.

[0020] Furthermore, a high-pressure system back-pressure valve is provided at the end of the path of the high-pressure air system.

[0021] Furthermore, the control system dynamically adjusts the opening of the back pressure valve of the normal pressure system according to the monitoring values ​​of the normal pressure inlet pressure gauge and the normal pressure outlet pressure gauge.

[0022] Furthermore, the control system dynamically adjusts the opening of the high-pressure system back-pressure valve according to the monitoring values ​​of the high-pressure inlet pressure gauge and the high-pressure outlet pressure gauge.

[0023] Furthermore, the control system dynamically adjusts the power of the heating source according to the monitoring value of the built-in thermocouple.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The utility model can heat the plate-fin type sample evenly and quickly to a high temperature through two sets of electromagnetic induction coil groups parallel to the two sides of the plate fin in the heating box; through the normal pressure and high-pressure air systems, it can more accurately simulate the hot and cold alternation of the plate-fin type heat exchanger under the compressive stress state, so that the experimental results are more in line with the actual working conditions, and the two air cooling systems can be started at the same time to achieve rapid cooling of the sample and shorten the thermal fatigue test cycle; at the same time, the experiment conducted by the utility model can be universally applicable within the allowable range of the pressure difference between the inside and outside of the sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a system block diagram of the utility model;

[0027] Figure 2 It is a structural schematic diagram of the workbench in the utility model.

[0028] Including: 1. Workbench; 2. Blower; 3. Atmospheric pressure mass flowmeter; 4. First atmospheric pressure regulating valve; 5. Atmospheric pressure cooler; 6. Second atmospheric pressure regulating valve; 7. Atmospheric pressure inlet pressure gauge; 8. Atmospheric pressure inlet thermocouple; 9. Atmospheric pressure outlet thermocouple; 10. Built-in thermocouple; 11. Camera; 12. Atmospheric pressure outlet pressure gauge; 13. Atmospheric pressure system back pressure valve; 14. Heating box; 141. Heating power supply; 142. First connector; 143. Second connector; 1 44. Plate-fin cell sample; 145. Rotatable chassis; 15. Air compressor; 16. Air storage tank; 17. Bypass regulating valve; 18. Bypass valve; 19. High-pressure mass flowmeter; 20. First high-pressure regulating valve; 21. High-pressure cooler; 22. Second high-pressure regulating valve; 23. High-pressure inlet pressure gauge; 24. High-pressure inlet thermocouple; 25. High-pressure outlet thermocouple; 26. High-pressure outlet pressure gauge; 27. High-pressure system back-pressure valve; 28. Control system. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] This embodiment proposes a variable-pressure plate-fin heat exchanger thermal fatigue test device, which aims to solve the problem that traditional plate-fin heat exchanger thermal fatigue test devices in the prior art are mostly based on normal pressure design and do not consider the superimposed effect of compressive stress load on the thermal fatigue of the plate-fin structure, resulting in a large discrepancy between the thermal fatigue test and the actual working conditions.

[0031] like Figure 1 and Figure 2 As shown, the main structure of the variable pressure plate-fin heat exchanger thermal fatigue test device provided by the present invention includes a workbench 1, which serves as a sample thermal fatigue test platform;

[0032] A heating box 14 is rotatably mounted on the workbench 1 , and electromagnetic induction heating devices are provided on both sides of the interior of the heating box 14 , and is connected to a heating power supply 141 for heating the plate-fin cell sample 144 ;

[0033] A pair of symmetrical fixtures are provided on the heating box 14. The fixtures are provided with two first joints 142. The box also includes two second joints 143 provided at a 90° angle to the first joints 142.

[0034] an atmospheric pressure air system capable of being connected to one of the first connector or the second connector;

[0035] a high-pressure air system connectable to one of the first connector and the second connector;

[0036] The camera 11 is provided on the housing of the heating box 14 and is used to monitor in real time the shape changes and surface thermal fatigue damage of the plate-fin cell sample 144 caused by heating and cooling;

[0037] The control system 28 is connected to the atmospheric pressure air system, the high pressure air system and the temperature and pressure detection components on the heating box 14, and is used to set parameters and control the operation of each component.

[0038] In one embodiment of the present invention, a built-in thermocouple 10 is provided inside the workbench 1 for monitoring the temperature changes of the plate-fin cell sample 144 inside the workbench, thereby providing data basis for the next operation of the control system. The first joint and the second joint both include an inlet joint and an outlet joint, and the heating box 14 is rotatably set on the workbench 1 through a rotatable chassis 145.

[0039] In one embodiment of the present invention, the atmospheric pressure air system includes a blower 2, which serves as a source of atmospheric pressure cooling airflow and can adjust the air supply volume according to the cooling speed indication signal; the path from the blower 2 to the plate-fin cell sample 144 is sequentially provided with an atmospheric pressure mass flowmeter 3 for monitoring the atmospheric pressure cooling gas flow, a first atmospheric pressure regulating valve 4 (the valve opening and closing amplitude can be computer-controlled to thereby control the atmospheric pressure cooling airflow flow), an atmospheric pressure cooler 5 (the atmospheric pressure cooling airflow temperature can be adjusted according to experimental requirements), a second atmospheric pressure regulating valve 6, an atmospheric pressure inlet pressure gauge 7 for monitoring the pressure value of the atmospheric pressure cooling airflow before entering the workbench, an atmospheric pressure inlet thermocouple 8 for monitoring the temperature value of the atmospheric pressure cooling airflow before entering the workbench, an atmospheric pressure outlet thermocouple 9 for monitoring the temperature value of the atmospheric pressure cooling airflow after flowing out of the workbench, and an atmospheric pressure outlet pressure gauge for monitoring the pressure value of the atmospheric pressure cooling airflow after flowing out of the workbench.

[0040] The function of the second normal pressure regulating valve 6 is: when the workbench sample is heated, the computer can control the valve to close to prevent the high temperature air from affecting the cooling equipment; when the workbench sample enters the cooling cycle, the valve opens to let in normal pressure cooling air.

[0041] In one embodiment of the present invention, the high-pressure air system includes an air compressor 15 as a high-pressure cooling air flow source, which can replenish high-pressure air according to the pressure feedback of the air tank, and an air tank 16 is sequentially arranged on the path from the air compressor 15 to the sample (which can store high-pressure air from the air compressor according to the set pressure and provide a stable high-pressure cooling air flow inside the workbench), a high-pressure mass flowmeter 19 for monitoring the flow of high-pressure cooling gas, a first high-pressure regulating valve 20 that can control the valve opening and closing amplitude by computer to control the flow and pressure of the high-pressure cooling gas, a high-pressure cooler 21 that can adjust the temperature of the high-pressure cooling air flow according to experimental requirements, a second high-pressure regulating valve 22, a high-pressure inlet pressure gauge 23 for monitoring the pressure value of the high-pressure cooling air flow before entering the workbench, a high-pressure inlet thermocouple 24 for monitoring the temperature value of the high-pressure cooling air flow before entering the workbench, a high-pressure outlet thermocouple 25 for monitoring the temperature value of the high-pressure cooling air flow after flowing out of the workbench, and a high-pressure outlet pressure gauge 26 for monitoring the pressure value of the high-pressure cooling air flow after flowing out of the workbench.

[0042] The function of the second high-pressure regulating valve is to close the valve under computer control when the sample on the workbench is heated, preventing the high-temperature and high-pressure air from affecting the cooling equipment. When the sample on the workbench enters the cooling cycle, the valve opens to allow high-pressure cooling air to flow in.

[0043] In one embodiment of the present invention, it also includes a high-pressure bypass system arranged on the path of the high-pressure air system, and the high-pressure bypass system includes a bypass regulating valve 17 arranged on the path of the air storage tank 16 and the high-pressure mass flowmeter 19. The bypass regulating valve 17 can control the valve opening and closing amplitude according to the computer to control the flow and pressure of the high-pressure cooling airflow; a bypass valve 18 with a branch connection is provided between the bypass regulating valve 17 and the high-pressure mass flowmeter 19. After the bypass regulating valve 17 is opened, the bypass valve 18 can control the valve opening and closing amplitude by the computer to adjust the flow and pressure of the high-pressure pipeline and protect the safe operation of the high-pressure pipeline.

[0044] In one embodiment of the present invention, a back pressure valve 13 of the atmospheric pressure system is provided at the end of the path of the atmospheric pressure air system, and the opening and closing amplitude of the valve can be controlled by a computer, thereby regulating the internal air flow pressure of the sample to be stable.

[0045] In one embodiment of the present invention, a high-pressure system back pressure valve 27 is provided at the end of the path of the high-pressure air system, which can control the valve opening and closing amplitude according to a computer, thereby adjusting the internal air flow pressure of the workbench to stabilize.

[0046] In one embodiment of the present utility model, the control system 28 dynamically adjusts the opening of the atmospheric pressure system back pressure valve 13 according to the monitoring values ​​of the atmospheric pressure inlet pressure gauge 7 and the atmospheric pressure outlet pressure gauge 12; the control system 28 dynamically adjusts the opening of the high-pressure system back pressure valve 27 according to the monitoring values ​​of the high-pressure inlet pressure gauge 23 and the high-pressure outlet pressure gauge 26; the control system 28 dynamically adjusts the stable operation of each device according to the feedback data of each valve meter, and performs hot and cold cycle experiments according to design standards such as temperature, pressure, and time, and collects the temperature of the plate sample through the temperature acquisition system and outputs the test hot and cold cycle program.

[0047] In one embodiment of the present invention, the control system 28 dynamically adjusts the power of the heating power supply (141) according to the monitoring value of the built-in thermocouple 10.

[0048] Example 1, Experimental plan: Normal pressure gas inside the sample, high pressure gas outside

[0049] In this embodiment, the two symmetrical first joints 142 of the workbench 1 horizontally fix the two ends of the channel of the plate-fin cell detection sample 144, the joints on the clamps are connected to the normal pressure air system, and the other two second joints 143 are connected to the high pressure air system.

[0050] The internal and external pressures and initial temperature of the sample are set according to the experimental requirements. The control system 28 starts the blower 2 according to the setting, opens the first normal pressure regulating valve 4, the second normal pressure regulating valve 6, and the normal pressure system back pressure valve 13 in the normal pressure air system, opens the normal pressure cooler 5, monitors the normal pressure inlet thermocouple 8, the built-in thermocouple 10, and the normal pressure outlet thermocouple 9 to reach the specified temperature, and monitors the normal pressure inlet pressure gauge 7 and the normal pressure outlet pressure gauge 12 to reach the specified pressure.

[0051] At the same time, the control system 28 starts the air compressor 15 to make the air tank 16 reach the specified pressure and keep it stable, and opens the bypass regulating valve 17 and bypass valve 18 in the high-pressure air system to ensure that the high-pressure bypass system is normal.

[0052] The control system 28 closes the bypass valve 18, and at the same time opens the first high-pressure regulating valve 20, the second high-pressure regulating valve 22, the high-pressure system back-pressure valve 27, opens the high-pressure cooler 21, monitors the high-pressure inlet thermocouple 24, the built-in thermocouple 10, and the high-pressure outlet thermocouple 25 to reach the specified temperature, and monitors the high-pressure inlet pressure gauge 23 and the high-pressure outlet pressure gauge 26 to reach the specified pressure.

[0053] After the temperature feedback from the built-in thermocouple 10 stabilizes at the specified minimum temperature, the control system 28 turns off the blower 2, the first normal pressure regulating valve 4, the second normal pressure regulating valve 6, the normal pressure system back pressure valve 13, and the normal pressure cooler 5 of the normal pressure pipeline system; and turns off the first high pressure regulating valve 20, the second high pressure regulating valve 22, the high pressure system back pressure valve 27, and the high pressure cooler 21 of the high pressure pipeline system.

[0054] The sample heating rate and maximum temperature are set according to the experimental requirements. The control system 28 turns on the power of the heating box 14 and dynamically adjusts the power of the heating box 14 according to the monitoring value of the built-in thermocouple 10, so that the sample heats up at the preset rate and reaches the maximum temperature.

[0055] The control system 28 dynamically adjusts the opening of the atmospheric pressure system back pressure valve 13 according to the monitoring values ​​of the atmospheric pressure inlet pressure gauge 7 and the atmospheric pressure outlet pressure gauge 12 to keep the internal pressure of the sample stable; at the same time, according to the monitoring values ​​of the high-pressure inlet pressure gauge 23 and the high-pressure outlet pressure gauge 26, it dynamically adjusts the opening of the high-pressure system back pressure valve 27 to keep the external pressure of the sample stable.

[0056] After the temperature feedback from the built-in thermocouple 10 stabilizes at the specified maximum temperature, the sample cooling speed and minimum temperature are set according to the experimental requirements. The control system 28 turns off the heating power supply 141 of the heating box 14, and at the same time turns on the blower 2, the first normal pressure regulating valve 4, the second normal pressure regulating valve 6, the normal pressure system back pressure valve 13, and the normal pressure cooler 5 of the normal pressure pipeline system. According to the monitoring value of the built-in thermocouple 10, the air volume of the blower 2 and the power of the normal pressure cooler 5 are dynamically adjusted to allow the sample to cool at a preset speed and reach the lowest temperature.

[0057] The control system 28 dynamically adjusts the opening of the atmospheric pressure system back pressure valve 13 according to the monitoring values ​​of the atmospheric pressure inlet pressure gauge 7 and the atmospheric pressure outlet pressure gauge 12 to keep the internal pressure of the sample stable; and dynamically opens the opening of the first high-pressure regulating valve 20, the second high-pressure regulating valve 22, and the high-pressure system back pressure valve 27 according to the monitoring values ​​of the high-pressure inlet pressure gauge 23 and the high-pressure outlet pressure gauge 26 to keep the external pressure of the sample stable.

[0058] The control system 28 dynamically turns on the air compressor 15 based on the pressure feedback of the air storage tank 16, so that the air storage tank 16 reaches the specified pressure and remains stable.

[0059] When the cooling speed of the atmospheric pressure cooling system cannot meet the experimental requirements, the control system 28 can dynamically open the opening of the first high-pressure regulating valve 20, the second high-pressure regulating valve 22, and the high-pressure system back-pressure valve 27 according to the monitoring value of the built-in thermocouple 10, and dynamically adjust the power of the high-pressure cooler 21 to speed up the cooling speed of the sample and reach the lowest temperature.

[0060] After the temperature feedback from the built-in thermocouple 10 stabilizes at the specified minimum temperature, the control system 28 completes one hot and cold alternating cycle, and completes subsequent hot and cold alternating cycles according to the above steps based on the set cycle time and number of cycles.

[0061] The high temperature resistant camera 11 is installed on the upper part of the heating box 14, which can monitor the morphological changes and surface fatigue damage of the sample placed inside the heating box 14 under the combined action of hot and cold cycles and internal and external pressure differences in real time, and transmit the information to the control system 28 for further analysis.

[0062] This experimental method is universally applicable within the allowable range of the pressure difference between the inside and outside of the sample, and is suitable for different heating rates, maximum temperatures, cooling rates and minimum temperatures.

[0063] Example 2, Experimental plan: high pressure gas inside the sample, normal pressure gas outside

[0064] In this embodiment, the two symmetrical clamps of the workbench 1 horizontally fix the two ends of the channel of the plate-fin cell detection sample, the first connector 142 on the clamp is connected to the high-pressure air system, and the other two second connectors 143 are connected to the normal-pressure air system.

[0065] The internal and external pressures and initial temperature of the sample are set according to the experimental requirements. The control system 28 starts the blower 2 according to the setting, opens the first normal pressure regulating valve 4, the second normal pressure regulating valve 6, and the normal pressure system back pressure valve 13 in the normal pressure air system, opens the normal pressure cooler 5, monitors the normal pressure inlet thermocouple 8, the built-in thermocouple 10, and the normal pressure outlet thermocouple 9 to reach the specified temperature, and monitors the normal pressure inlet pressure gauge 7 and the normal pressure outlet pressure gauge 12 to reach the specified pressure.

[0066] At the same time, the control system 28 starts the air compressor 15 to make the air tank 16 reach the specified pressure and keep it stable, and opens the bypass regulating valve 17 and bypass valve 18 in the high-pressure air system to ensure that the high-pressure bypass system is normal.

[0067] The control system 28 closes the bypass valve 18, and at the same time opens the first high-pressure regulating valve 20, the second high-pressure regulating valve 22, the high-pressure system back-pressure valve 27, opens the high-pressure cooler 21, monitors the high-pressure inlet thermocouple 24, the built-in thermocouple 10, and the high-pressure outlet thermocouple 25 to reach the specified temperature, and monitors the high-pressure inlet pressure gauge 23 and the high-pressure outlet pressure gauge 26 to reach the specified pressure.

[0068] After the temperature feedback from the built-in thermocouple 10 stabilizes at the specified minimum temperature, the control system 28 turns off the blower 2, the first normal pressure regulating valve 4, the second normal pressure regulating valve 6, the normal pressure system back pressure valve 13, and the normal pressure cooler 5 of the normal pressure pipeline system; and turns off the first high pressure regulating valve 20, the second high pressure regulating valve 22, the high pressure system back pressure valve 27, and the high pressure cooler 21 of the high pressure pipeline system.

[0069] The sample heating rate and maximum temperature are set according to the experimental requirements. The control system 28 turns on the heating power supply 141 of the heating box 14 and dynamically adjusts the power of the heating box 14 according to the monitoring value of the built-in thermocouple 10, so that the sample heats up at the preset rate and reaches the maximum temperature.

[0070] The control system 28 dynamically adjusts the opening of the high-pressure system back-pressure valve 27 according to the monitoring values ​​of the high-pressure inlet pressure gauge 23 and the high-pressure outlet pressure gauge 26 to keep the internal pressure of the sample stable; at the same time, it dynamically adjusts the opening of the normal pressure system back-pressure valve 13 according to the monitoring values ​​of the normal pressure inlet pressure gauge 7 and the normal pressure outlet pressure gauge 12 to keep the external pressure of the sample stable.

[0071] After the temperature feedback from the built-in thermocouple 10 stabilizes at the specified maximum temperature, the sample cooling speed and minimum temperature are set according to the experimental requirements. The control system 28 turns off the heating power supply 141 of the heating box 14, and dynamically adjusts the opening of the first high-pressure regulating valve 20, the second high-pressure regulating valve 22, the high-pressure system back pressure valve 27 and the power of the high-pressure cooler 21 according to the monitoring value of the built-in thermocouple 10, so that the sample is cooled at a preset speed and reaches the minimum temperature.

[0072] The control system 28 dynamically opens the first high-pressure regulating valve 20, the second high-pressure regulating valve 22, and the high-pressure system back-pressure valve 27 according to the monitoring values ​​of the high-pressure inlet pressure gauge 23 and the high-pressure outlet pressure gauge 26 to keep the internal pressure of the sample stable; and opens the blower 2, the first normal pressure regulating valve 4, the second normal pressure regulating valve 6, and the normal pressure system back-pressure valve 13 according to the monitoring values ​​of the normal pressure inlet pressure gauge 7 and the normal pressure outlet pressure gauge 12 to keep the external pressure of the sample stable.

[0073] The control system 28 dynamically turns on the air compressor 15 based on the pressure feedback of the air storage tank 16, so that the air storage tank 16 reaches the specified pressure and remains stable.

[0074] When the cooling speed of the high-pressure cooling system cannot meet the experimental requirements, the control system 28 can dynamically adjust the power of the blower 2 and the atmospheric cooler 5 according to the monitoring value of the built-in thermocouple 10 to speed up the cooling speed of the sample and reach the lowest temperature.

[0075] After the temperature feedback from the built-in thermocouple 10 stabilizes at the specified minimum temperature, the control system 28 completes one hot and cold alternating cycle, and completes subsequent hot and cold alternating cycles according to the above steps based on the set cycle time and number of cycles.

[0076] The high temperature resistant camera 11 is installed on the upper part of the heating box 14, which can monitor the morphological changes and surface fatigue damage of the sample placed inside the heating box 14 under the combined action of hot and cold cycles and internal and external pressure differences in real time, and transmit the information to the control system 28 for further analysis.

[0077] This experimental method is universally applicable within the allowable range of the pressure difference between the inside and outside of the sample, and is suitable for different heating rates, maximum temperatures, cooling rates and minimum temperatures.

[0078] The above description is an explanation of the utility model, not a limitation of the utility model. The scope of the utility model is defined by the claims. Any form of modification can be made within the scope of protection of the utility model.

Claims

1. A variable pressure plate-fin heat exchanger thermal fatigue test device, characterized by: include: A workbench (1) is used as a sample thermal fatigue test platform; A heating box (14) is rotatably arranged on the workbench (1), wherein an electromagnetic induction heating device is arranged inside the heating box (14) and is connected to a heating power supply (141) for heating the plate-fin cell sample (144); A pair of left-right symmetrical clamps are arranged on the box body of the heating box (14), the clamps are provided with two first joints (142), and the box body further includes two second joints (143) arranged at a 90° angle to the first joints (142); an atmospheric pressure air system capable of being connected to one of the first connector or the second connector; a high-pressure air system connectable to one of the first connector and the second connector; A camera (11) is provided on the housing of the heating box (14) and is used to monitor in real time the shape changes and surface thermal fatigue damage of the plate-fin cell sample (144) caused by heating and cooling; The control system (28) is connected to the normal pressure air system, the high pressure air system and the temperature and pressure detection components on the heating box (14) and is used to set parameters and control the operation of each component.

2. The variable pressure plate-fin heat exchanger thermal fatigue testing device according to claim 1, characterized in that: A built-in thermocouple (10) is provided inside the workbench (1), the first joint (142) and the second joint (143) both include an inlet joint and an outlet joint, and the heating box (14) is rotatably arranged on the workbench (1) via a rotatable chassis (145).

3. The variable pressure plate-fin heat exchanger thermal fatigue testing device according to claim 1, characterized in that: The atmospheric pressure air system comprises a blower (2), and a atmospheric pressure mass flow meter (3), a first atmospheric pressure regulating valve (4), a atmospheric pressure cooler (5), a second atmospheric pressure regulating valve (6), a atmospheric pressure inlet pressure gauge (7), a atmospheric pressure inlet thermocouple (8), a atmospheric pressure outlet thermocouple (9), and a atmospheric pressure outlet pressure gauge (12) are sequentially arranged on a path from the blower (2) to the plate-fin cell sample (144).

4. The variable pressure plate-fin heat exchanger thermal fatigue testing device according to claim 1, characterized in that: The high-pressure air system includes an air compressor (15), and an air storage tank (16), a high-pressure mass flow meter (19), a first high-pressure regulating valve (20), a high-pressure cooler (21), a second high-pressure regulating valve (22), a high-pressure inlet pressure gauge (23), a high-pressure inlet thermocouple (24), a high-pressure outlet thermocouple (25), and a high-pressure outlet pressure gauge (26) are sequentially arranged on the path from the air compressor (15) to the plate-fin cell sample (144).

5. The variable pressure plate-fin heat exchanger thermal fatigue testing device according to claim 4, characterized in that: The invention also includes a high-pressure bypass system arranged on the path of the high-pressure air system, wherein the high-pressure bypass system includes a bypass regulating valve (17) arranged on the path of the air storage tank (16) and the high-pressure mass flow meter (19), and a bypass valve (18) connected to a branch is arranged between the bypass regulating valve (17) and the high-pressure mass flow meter (19).

6. The variable pressure plate-fin heat exchanger thermal fatigue testing device according to claim 3, characterized in that: A normal pressure system back pressure valve (13) is provided at the end of the normal pressure air system path.

7. The variable pressure plate-fin heat exchanger thermal fatigue testing device according to claim 4, characterized in that: A high-pressure system back-pressure valve (27) is provided at the end of the path of the high-pressure air system.

8. The variable pressure plate-fin heat exchanger thermal fatigue testing device according to claim 6, characterized in that: The control system (28) dynamically adjusts the opening of the atmospheric pressure system back pressure valve (13) according to the monitoring values ​​of the atmospheric pressure inlet pressure gauge (7) and the atmospheric pressure outlet pressure gauge (12).

9. The variable pressure plate-fin heat exchanger thermal fatigue testing device according to claim 7, characterized in that: The control system (28) dynamically adjusts the opening of the high-pressure system back pressure valve (27) according to the monitoring values ​​of the high-pressure inlet pressure gauge (23) and the high-pressure outlet pressure gauge (26).

10. The variable pressure plate-fin heat exchanger thermal fatigue testing device according to claim 2, characterized in that: The control system (28) dynamically adjusts the power of the heating source according to the monitoring value of the built-in thermocouple (10).

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