A device for testing thermal stress of a structural member

Abstract

The application discloses a kind of structural member thermal stress test devices, belong to aerospace technical field.The device includes sealed environment box, cold water machine, air temperature and air pressure adjusting mechanism, inductive heating mechanism and heat exchanger;Inductive heating mechanism includes alternating current power supply and hollow copper pipe wound around the test piece in sealed environment box;Alternating current power supply is connected in hollow copper pipe;Two ends of hollow copper pipe are connected with the first water inlet and the first water outlet of cold water machine respectively;The second water inlet and the second water outlet of cold water machine are connected with the water outlet and the water inlet of heat exchanger respectively;The air inlet of heat exchanger is connected with the exhaust hole of sealed environment box;The air outlet of heat exchanger is connected with sealed environment box by air temperature and air pressure adjusting mechanism, to adjust the air temperature and air pressure in sealed environment box.The application can realize the application of non-uniform temperature distribution on test piece, exclude the oxidation of external air, meet the needs of structural member steady thermal stress test and thermal fatigue test.

Description

Technical Field

[0001] This invention belongs to the field of aerospace technology, and in particular relates to a thermal stress testing device for structural components. Background Technology

[0002] The aerospace industry places high demands on the heat resistance of structures, with some structures operating at temperatures exceeding 1000 degrees Celsius. This not only requires the materials used in the structure to withstand such temperatures, but also, because heating is generally uneven, this uneven temperature distribution can generate thermal stress, a significant factor leading to structural failure.

[0003] Before actual use, it is necessary to conduct experimental evaluations of the structure's performance under uneven heating conditions. Currently, the main heating methods include gas heating and induction heating. Gas heating suffers from difficulties in precise temperature control, and the exhaust gases produced after combustion directly impact the test structure, causing chemical reactions that affect its mechanical properties. Furthermore, gas heating consumes fuel and generates waste gases, which is environmentally unfriendly. In contrast, induction heating offers easier temperature control and minimizes the impact of chemical reactions, resulting in less environmental pollution and making it an ideal heating solution.

[0004] During ground testing, the air contains oxygen, and oxidation is unavoidable during high-temperature testing. Therefore, if it is necessary to examine thermal stress separately and exclude the influence of chemical reactions, the heating environment must be carefully designed. Using an inert gas atmosphere in an environmental chamber is an effective and cost-effective method.

[0005] Induction heating can control the heating temperature, but the oxidation problem in the air environment cannot be completely ignored. Existing environmental chambers are generally designed to maintain temperature and can apply uniform high temperatures to the test specimen, but they cannot achieve the application of non-uniform temperature distribution. However, thermal stress can only be generated under non-uniform temperatures. Summary of the Invention

[0006] The purpose of this invention is to provide a thermal stress testing device for structural components. This device can apply non-uniform temperature distribution to the test component, eliminate oxidation from external air, and has high reliability and economy for long-term testing, thus meeting the needs of steady-state thermal stress testing and thermal fatigue testing of structural components.

[0007] To achieve the above objectives, the present invention employs the following technical solution:

[0008] A structural component thermal stress testing device, comprising a sealed environment chamber 1, a chiller 2, an air temperature and pressure regulating mechanism 3, an induction heating mechanism 4, and a heat exchanger 6;

[0009] The induction heating mechanism 4 includes an AC power supply 4-1 for generating high-frequency current and a hollow copper tube 4-2 wound around the test piece 5 located inside the sealed environment chamber 1. The two electrodes of the AC power supply 4-1 are respectively connected to the two ends of the hollow copper tube 4-2, and the temperature distribution on the test piece 5 is uneven through induction heating. The two ends of the hollow copper tube 4-2 are respectively connected to the first water inlet 2-1 and the first water outlet 2-2 of the chiller 2, so that the water inside the hollow copper tube 4-2 circulates to prevent the hollow copper tube 4-2 from overheating.

[0010] The second inlet 2-3 and the second outlet 2-4 of the chiller 2 are respectively connected to the outlet 6-3 and the inlet 6-4 of the heat exchanger 6; the air inlet 6-1 of the heat exchanger 6 is connected to the exhaust port 1-1 of the sealed environment box 1; the air outlet 6-2 of the heat exchanger 6 is connected to the environmental air inlet pipe 1-2 of the sealed environment box 1 through the air temperature and pressure regulating mechanism 3, so as to regulate the air temperature and pressure inside the sealed environment box 1.

[0011] Furthermore, the temperature and pressure regulating mechanism 3 includes an exhaust valve 3-1, a return valve 3-2, an air source 3-3, an air pump 3-4, and a first flow regulating valve 3-5; the exhaust valve 3-1, the return valve 3-2, the air pump 3-4, and the first flow regulating valve 3-5 are connected in sequence; the air source 3-3 is connected to the air outlet of the return valve 3-2;

[0012] The air inlet of the exhaust valve 3-1 is connected to the air outlet 6-2 of the heat exchanger 6; the first flow regulating valve 3-5 is connected to the environmental air inlet pipe 1-2 of the sealed environment box 1 to regulate the air temperature and pressure inside the sealed environment box 1.

[0013] Furthermore, the temperature and pressure regulating mechanism 3 also includes a second flow regulating valve 3-6;

[0014] One end of the second flow regulating valve 3-6 is connected to the air pump 3-4; the other end of the second flow regulating valve 3-6 is connected to the sealed environment chamber 1 to control the cooling rate of the test piece 5.

[0015] Furthermore, the sealed environment chamber 1 includes a base 1-3, an upper cover 1-4, and a glass tube 1-5; the bottom end and the upper end of the glass tube 1-5 are respectively sealed to the base 1-3 and the upper cover 1-4.

[0016] The upper end cover 1-4 is provided with an exhaust hole 1-1 that is connected to the air inlet 6-1 of the heat exchanger 6;

[0017] The base 1-3 is provided with a first air intake channel 1-14 and a plurality of environmental air intake pipes 1-2 communicating with the first air intake channel 1-14; the plurality of environmental air intake pipes 1-2 are connected to the first flow regulating valve 3-5 to introduce airflow into the glass tube 1-5.

[0018] Furthermore, the base 1-3 is also provided with a second air intake channel 1-16 and a cooling air intake pipe 1-6 communicating with the second air intake channel;

[0019] One end of the second air intake channel 1-16 is connected to the second flow regulating valve 3-6; the other end of the second air intake channel 1-16 is connected to the pipeline 1-7 installed in the sealed environment chamber 1; the outlet of the pipeline 1-7 faces the test piece 5 to control the cooling rate of the test piece 5.

[0020] Furthermore, the upper end cover 1-4 and the base 1-3 are clamped together by the positioning pin 1-8 to prevent the air pressure inside the glass tube 1-5 from opening the upper end cover 1-4.

[0021] Furthermore, a lower sealing ring 1-9 and an upper sealing ring 1-19 are respectively provided between the contact surfaces of the glass tube 1-5 and the base 1-3 and the glass tube 1-5;

[0022] The inner cylindrical surfaces of the lower sealing ring 1-9 and the upper sealing ring 1-19 are in contact with the glass tube 1-5; the outer conical surfaces of the lower sealing ring 1-9 and the upper sealing ring 1-19 are respectively in contact with the base 1-3 and the upper end cap 1-4.

[0023] The lower sealing ring 1-9 and the upper sealing ring 1-19 are pressed together by a semi-circular annular pressure plate 1-10 and a locking component 1-20.

[0024] Furthermore, the upper cover 1-4 is provided with a measuring port 1-11 for installing a pressure gauge 1-12 and a thermometer 1-13 to detect the air pressure and temperature inside the sealed environment box 1 in real time.

[0025] Furthermore, an insulating ring 1-18 is provided between the contact surfaces of the upper end cover 1-4 and the hollow copper tube 4-2 to prevent the hollow copper tube 4-2 from short-circuiting.

[0026] Furthermore, the glass tubes 1-5 are made of quartz glass.

[0027] In summary, the technical solution of the present invention has the following technical effects:

[0028] This invention achieves non-uniform temperature distribution by using a hollow copper tube in an induction heating mechanism to wrap around the test specimen; a chiller prevents the copper tube from overheating; a sealed environmental chamber isolates the test specimen and equipment from external air, eliminating the potential effects of oxidation; and a temperature and pressure regulating mechanism adjusts the gas temperature inside the sealed environmental chamber, maintaining a low-temperature environment. This facilitates non-uniform temperature distribution, protects the environmental chamber, allows for long-term testing, reduces testing costs, and ensures the reliability and economy of long-term testing. It is suitable for steady-state thermal stress testing and thermal fatigue testing of structural components to verify the thermal stress bearing capacity and thermal fatigue bearing capacity of structures. Attached Figure Description

[0029] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structural thermal stress testing device for structural components according to an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the piping of the thermal stress testing device for structural components according to an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the external assembly of the thermal stress testing device for structural components according to an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of the internal assembly of the thermal stress testing device for structural components according to an embodiment of the present invention;

[0034] Figure 5 This is a cross-sectional view of the thermal stress testing device for structural components according to an embodiment of the present invention;

[0035] Figure 6 This is a cross-sectional view of the base of the thermal stress testing device for structural components according to an embodiment of the present invention;

[0036] Figure 7 This is a schematic diagram of the environmental chamber temperature control method according to an embodiment of the present invention;

[0037] Figure 8 This is a schematic diagram of the environmental chamber air pressure control method according to an embodiment of the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] This embodiment provides a structural component thermal stress testing device, referencing... Figure 1 and 2 The thermal stress testing device for this structural component includes a sealed environment chamber 1, a chiller 2, an air temperature and pressure regulating mechanism 3, an induction heating mechanism 4, and a heat exchanger 6. The air temperature and pressure regulating mechanism 3 is connected to the sealed environment chamber 1 via an air circuit, the chiller 2 is connected to the air temperature and pressure regulating mechanism 3 via a water circuit, and the chiller 2 is also connected to the induction heating mechanism 4 via a water circuit. The air copper pipe 4-2 of the induction heating mechanism 4 extends into the sealed environment chamber 1 for heating.

[0040] The induction heating mechanism 4 in this embodiment includes an AC power supply 4-1 for generating high-frequency current and a hollow copper tube 4-2 wound around the test piece 5 located inside the sealed environmental chamber 1. The two electrodes of the AC power supply 4-1 are respectively connected to the two ends of the hollow copper tube 4-2, causing uneven temperature distribution on the test piece 5 through induction heating. The two ends of the hollow copper tube 4-2 are respectively connected to the first inlet 2-1 and the first outlet 2-2 of the chiller 2, allowing water to circulate within the hollow copper tube 4-2, regulating its heating temperature and preventing overheating. The power output of the AC power supply 4-1 is adjustable to meet different heating requirements.

[0041] The second inlet 2-3 and the second outlet 2-4 of the chiller 2 are connected to the outlet 6-3 and the inlet 6-4 of the heat exchanger 6, respectively. The air inlet 6-1 of the heat exchanger 6 is connected to the exhaust port 1-1 of the sealed environment chamber 1. The air outlet 6-2 of the heat exchanger 6 is connected to the environmental air inlet pipe 1-2 of the sealed environment chamber 1 through the air temperature and pressure regulating mechanism 3 to regulate the air temperature and pressure inside the sealed environment chamber 1. In this embodiment, the water discharged from the heat exchanger 6 and the hollow copper tube 4-2 is cooled by the same chiller.

[0042] In this embodiment, the heat exchanger 6 is used to cool the gas, and water is used as the cooling medium. The cooling water is connected to the chiller 2 through a pipeline. In order to purify the cooling gas of impurities (such as dust), a filter 7 is installed at the output end of the gas outlet 6-2 of the heat exchanger 6 in this embodiment.

[0043] The temperature and pressure regulating mechanism 3 in this embodiment includes an exhaust valve 3-1, a return valve 3-2, an air source 3-3, an air pump 3-4, and a first flow regulating valve 3-5. The exhaust valve 3-1, return valve 3-2, air pump 3-4, and first flow regulating valve 3-5 are connected sequentially. The air source 3-3 is connected to the outlet of the return valve 3-2. The inlet of the exhaust valve 3-1 is connected to the outlet 6-2 of the heat exchanger 6. The first flow regulating valve 3-5 is connected to the environmental air inlet pipe 1-2 of the sealed environment chamber 1, controlling the flow rate of the environmental air inlet channel (i.e., the first air inlet channel 1-14) to regulate the temperature and pressure inside the sealed environment chamber 1.

[0044] In this embodiment, the gas source 3-3 can be a gas cylinder containing inert gas to prevent oxidation of the test specimens. The inert gas can be recycled. The flow rate of the gas pump 3-4 can be adjusted to meet the temperature requirements of the sealed environment chamber under different test conditions.

[0045] The air temperature and pressure regulating mechanism 3 in this embodiment also includes a second flow regulating valve 3-6. One end of the second flow regulating valve 3-6 is connected to the air pump 3-4, and the other end is connected to the sealed environment chamber 1 to control the cooling rate of the test piece 5. The second flow regulating valve 3-6 controls the flow rate of the cooling air intake channel (i.e., the second air intake channel 1-16).

[0046] To prevent backflow in the gas path, the exhaust valve 3-1, the first flow regulating valve 3-5, and the second flow regulating valve 3-6 in the connecting pipeline of this embodiment are all one-way valves.

[0047] The sealed environment box 1 structure in this embodiment is as follows: Figures 3-6 As shown, the device includes a base 1-3, an upper cover 1-4, and a glass tube 1-5. The bottom and top ends of the glass tube 1-5 are sealed to the base 1-3 and the upper cover 1-4, respectively. This embodiment uses a beveled seal. The upper cover 1-4 and the base 1-3 are tightened by positioning pins 1-8 and nuts to clamp the glass tube 1-5, preventing air pressure inside the glass tube 1-5 from opening the upper cover 1-4. A lower sealing ring 1-9 and an upper sealing ring 1-19 with right-angled trapezoidal cross-sections are respectively provided between the contact surfaces of the glass tube 1-5 and the base 1-3. The inner cylindrical surfaces of both the lower and upper sealing rings 1-9 and 1-19 are in contact with the glass tube 1-5. The outer conical surfaces of both the lower and upper sealing rings 1-9 and 1-19 are in contact with the base 1-3 and the upper cover 1-4, respectively. The lower sealing ring 1-9 and the upper sealing ring 1-19 are pressed together by a semi-circular annular pressure plate 1-10 and a locking component 1-20 (such as an M20 nut). In this embodiment, the sealing rings (lower sealing ring 1-9 and upper sealing ring 1-19) are made of high-temperature resistant materials, and the sealing ring material is preferably made of graphite.

[0048] In this embodiment, the upper end cover 1-4 is provided with an exhaust port 1-1 connected to the air inlet 6-1 of the heat exchanger 6. The upper end cover 1-4 is also provided with a measuring port 1-11 for mounting a pressure gauge 1-12 and a thermometer 1-13 to monitor the gas pressure and temperature (i.e., gas pressure and ambient temperature) inside the sealed environment chamber 1 in real time, serving as a basis for adjusting the gas flow rate, ensuring safety and reliability. An electrical sensor, such as a thermocouple, can also be installed at the measuring port 1-11. An insulating ring 1-18 is provided between the contact surface of the upper end cover 1-4 and the hollow copper tube 4-2 to prevent short circuits in the hollow copper tube 4-2.

[0049] In this embodiment, the base 1-3 is provided with a first air intake channel 1-14 and multiple environmental air intake pipes 1-2 communicating with the first air intake channel 1-14 to increase the air intake area. The multiple environmental air intake pipes 1-2 are connected to a first flow regulating valve 3-5 to introduce airflow into the glass tube 1-5 and regulate the temperature inside the sealed environmental chamber 1.

[0050] In this embodiment, the base 1-3 is further provided with a second air intake channel 1-16 and a cooling air intake pipe 1-6 communicating with the second air intake channel. One end of the second air intake channel 1-16 is connected to a second flow regulating valve 3-6, and the other end of the second air intake channel 1-16 is connected to a pipe 1-7 disposed in the sealed environment chamber 1. The outlet of the pipe 1-7 faces the test piece 5 to control the cooling rate of the test piece 5 and help the test piece 5 cool down quickly.

[0051] In this embodiment, the diameter of each environmental air intake pipe 1-2 and cooling air intake pipe 1-6 is 25 mm. The inner diameter of the exhaust port 1-1 is 90 mm, and the diameter of the cylindrical space inside the sealed environmental chamber 1 is 480 mm and the height is 500 mm, which is suitable for testing.

[0052] In this embodiment, the base 1-3 and the upper cover 1-4 are made of high-temperature alloy. The glass tube 1-5 is made of high-temperature resistant quartz glass, allowing for real-time external observation of the test specimen's condition.

[0053] When testing insulating materials, since they cannot generate a large induced current and therefore cannot be directly heated, this embodiment uses a metal material close to their surface. The metal material is heated by an induced current, and then the insulating material is heated through convection and radiation heat transfer. Tungsten is preferably used as the metal material because it has a high melting point and will not oxidize in an inert gas environment, making it suitable for induction heating.

[0054] Before starting the experiment, press Figure 3 and Figure 4 Set the test specimen position as shown, and assemble the sealed environment chamber 1. Then, proceed according to... Figure 2Connect the pipes as shown. After connecting the pipes, confirm that all parts are properly sealed before starting the test.

[0055] 1. The specific test steps for steady-state thermal stress testing include:

[0056] Step 1: Purge the air from the device. Close the first flow regulating valve 3-5 and the second flow regulating valve 3-6. Open the exhaust valve 3-1 and the return valve 3-2. Open the gas source 3-3 to allow the inert gas to purge the air from the gas source 3-3 to the return valve 3-2, and from the return valve 3-2 to the exhaust valve 3-1. After purging, close the gas source 3-3 and the return valve 3-2. Open the first flow regulating valve 3-5 and the second flow regulating valve 3-6, then open the gas source 3-3 again to purge the air from other gas paths and the sealed environment chamber 1. After purging, close the gas source 3-3 and the exhaust valve 3-1, and open the return valve 3-2. At this point, the inert gas circuit is complete.

[0057] Step 2: Allow gas and cooling water to flow. Close the second flow regulating valve 3-6 and turn on the air pump 3-4 to allow gas to flow in the gas path. Turn on the chiller 2 to allow the cooling water to start flowing, ensuring that the water flow fully wets the heat exchanger 6 and the hollow copper tubes 4-2.

[0058] Step 3: Turn on AC power supply 4-1 and start heating with appropriate power. Use an infrared thermal imager or thermocouple to detect the surface temperature of the test piece. When the predetermined temperature is reached, reduce the power of AC power supply 4-1 to maintain the surface temperature of test piece 5 at a steady state.

[0059] Step 4: End the test. First, turn off the AC power supply 4-1 and wait for the test piece 5 to cool naturally, or open the second flow regulating valve 3-6 to direct the airflow towards the test piece 5 to accelerate cooling. When the temperature inside the sealed environment chamber 1 is close to room temperature and the air pressure inside the sealed environment chamber 1 is close to atmospheric pressure, turn off the air pump 3-4, remove the pipes, nuts, pressure plates, and sealing rings from the upper cover 1-4, and then remove the upper cover and take out the test piece.

[0060] 2. The specific test steps for thermal fatigue testing include:

[0061] Step 1: Purge the air from the device. This is the same procedure as for a steady-state thermal stress test.

[0062] Step 2: Allow the gas and cooling water to flow. This is the same procedure as the steady-state thermal stress test.

[0063] Step 3: Turn on AC power supply 4-1 and begin heating at an appropriate power level. Use an infrared thermal imager or thermocouple to detect the surface temperature of test piece 5. When the predetermined temperature is reached, reduce the power of AC power supply 4-1 to maintain the surface temperature of test piece 5 at a high level for a certain period of time as required by the experiment. Afterward, cool test piece 5 by reducing the power of AC power supply 4-1, using natural cooling or forced cooling by opening the second flow regulating valve 3-6. After cooling to the predetermined temperature, maintain the temperature for a period of time as required by the experiment.

[0064] Step 4: Repeat step 3 until the required number of cycles is reached.

[0065] Step 5: End the test. The procedure is the same as for the steady-state thermal stress test.

[0066] For steady-state thermal stress and thermal fatigue tests, the pressure and temperature inside the sealed environment chamber 1 are monitored during the test. The air temperature control method is as follows: Figure 7 As shown, if the temperature inside the chamber exceeds 600 degrees Celsius, the power of the air pump 3-4 needs to be increased appropriately, and the first flow control valve 3-5 needs to be adjusted to promote gas flow and cooling. The air pressure control method is as follows: Figure 8 As shown, if the air pressure is lower than 90% of atmospheric pressure, the air source 3-3 needs to be turned on to replenish the air; if the air pressure is higher than 110% of atmospheric pressure, the exhaust valve 3-1 needs to be opened to exhaust the air.

[0067] In this embodiment, the air source 3-3, air pump 3-4, first flow control valve 3-5, second flow control valve 3-6, return valve 3-2, exhaust valve 3-1, and AC power supply 4-1 are controllable components, while the pressure gauge 1-12 and thermometer 1-13 are measuring components. The aforementioned controllable and measuring components can be configured according to… Figure 7 and Figure 8 The control method shown enables the monitoring and automatic control of air pressure and temperature inside the sealed environment chamber 1.

[0068] This embodiment achieves non-uniform temperature distribution by wrapping a hollow copper tube in the induction heating mechanism around the test specimen. A chiller prevents the copper tube from overheating. A sealed environmental chamber isolates the test specimen and eliminates the potential impact of oxidation on the equipment. A temperature and pressure regulating mechanism adjusts the gas temperature inside the sealed environmental chamber, maintaining a low-temperature environment. This facilitates non-uniform temperature distribution, protects the environmental chamber, and allows for long-term testing, reducing testing costs and ensuring the reliability and economy of long-term testing. It is suitable for steady-state thermal stress testing and thermal fatigue testing of structural components to verify the thermal stress bearing capacity and thermal fatigue bearing capacity of structures.

[0069] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A structural member thermal stress testing apparatus, characterized by comprising: The structural member thermal stress testing device comprises a sealed environment box (1), a cold water machine (2), an air temperature and pressure adjusting mechanism (3), an induction heating mechanism (4) and a heat exchanger (6); The induction heating mechanism (4) comprises an alternating current power supply (4-1) for generating high-frequency current and a hollow copper pipe (4-2) wound around a test piece (5) in the sealed environment box (1); two electrodes of the alternating current power supply (4-1) are connected to two ends of the hollow copper pipe (4-2) respectively, and the temperature distribution on the test piece (5) is made uneven through induction heating; the two ends of the hollow copper pipe (4-2) are connected to a first water inlet (2-1) and a first water outlet (2-2) of the cold water machine (2) respectively, so that the water in the hollow copper pipe (4-2) circulates to prevent overheating of the hollow copper pipe (4-2); The second water inlet (2-3) and the second water outlet (2-4) of the cold water machine (2) are connected to a water outlet (6-3) and a water inlet (6-4) of the heat exchanger (6) respectively; an air inlet (6-1) of the heat exchanger (6) is connected to an exhaust hole (1-1) of the sealed environment box (1); an air outlet (6-2) of the heat exchanger (6) is connected to an environment air inlet pipeline (1-2) of the sealed environment box (1) through the air temperature and pressure adjusting mechanism (3) to adjust the air temperature and pressure in the sealed environment box (1).

2. The apparatus according to claim 1, wherein The air temperature and pressure adjusting mechanism (3) comprises an exhaust valve (3-1), a backflow valve (3-2), an air source (3-3), an air pump (3-4) and a first flow adjusting valve (3-5); the exhaust valve (3-1), the backflow valve (3-2), the air pump (3-4) and the first flow adjusting valve (3-5) are connected in sequence; the air source (3-3) is connected to an air outlet of the backflow valve (3-2); An air inlet end of the exhaust valve (3-1) is connected to the air outlet (6-2) of the heat exchanger (6); the first flow adjusting valve (3-5) is connected to the environment air inlet pipeline (1-2) of the sealed environment box (1) to adjust the air temperature and pressure in the sealed environment box (1).

3. The apparatus of claim 2, wherein The air temperature and pressure adjusting mechanism (3) further comprises a second flow adjusting valve (3-6); One end of the second flow adjusting valve (3-6) is connected to the air pump (3-4); the other end of the second flow adjusting valve (3-6) is connected to the sealed environment box (1) to control the cooling speed of the test piece (5).

4. The apparatus of claim 3, wherein The sealed environment box (1) comprises a base (1-3), an upper end cover (1-4) and a glass round pipe (1-5); the bottom end and the upper end of the glass round pipe (1-5) are sealingly connected to the base (1-3) and the upper end cover (1-4) respectively; The upper end cover (1-4) is provided with the exhaust hole (1-1) connected to the air inlet (6-1) of the heat exchanger (6); The base (1-3) is provided with a first air inlet channel (1-14) and a plurality of ambient air inlets (1-2) connected to the first air inlet channel (1-14); the plurality of ambient air inlets (1-2) are connected to the first flow regulating valve (3-5) to introduce air flow into the glass round tube (1-5).

5. The apparatus of claim 4, wherein The base (1-3) is further provided with a second air inlet channel (1-16) and a cooling air inlet channel (1-6) connected to the second air inlet channel; One end of the second air inlet channel (1-16) is connected to the second flow regulating valve (3-6); the other end of the second air inlet channel (1-16) is connected to a pipe (1-7) provided in the sealed environment box (1); the outlet of the pipe (1-7) faces the test piece (5) to control the cooling speed of the test piece (5).

6. The apparatus of claim 5, wherein the structure is a structure of a vehicle. The upper end cover (1-4) and the base (1-3) clamp the glass round tube (1-5) through positioning columns (1-8) to prevent the air pressure in the glass round tube (1-5) from pushing open the upper end cover (1-4).

7. The apparatus of claim 6, wherein the structure is a structure of a vehicle. The glass round tube (1-5) is provided with a lower sealing ring (1-9) and an upper sealing ring (1-19) between the contact surfaces of the glass round tube (1-5) and the base (1-3) and the upper end cover (1-4), respectively; The inner ring cylindrical surface of the lower sealing ring (1-9) and the upper sealing ring (1-19) is in contact with the glass round tube (1-5); the outer ring conical surface of the lower sealing ring (1-9) and the upper sealing ring (1-19) is in contact with the base (1-3) and the upper end cover (1-4), respectively; The lower sealing ring (1-9) and the upper sealing ring (1-19) are compressed by a semicircular ring-shaped pressing piece (1-10) and a locking component (1-20).

8. The apparatus of claim 7, wherein the structure is a structure of a vehicle. The upper end cover (1-4) is provided with a measuring port (1-11) for installing a pressure gauge (1-12) and a thermometer (1-13) to detect the air pressure and temperature in the sealed environment box (1) in real time.

9. The apparatus of claim 8, wherein the structure is a structure of a vehicle. An insulating ring (1-18) is provided between the contact surface of the upper end cover (1-4) and the hollow copper pipe (4-2) to prevent short circuit of the hollow copper pipe (4-2).

10. The apparatus of claim 9, wherein the structure is a structure of a vehicle. The material of the glass round tube (1-5) is quartz glass.

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