Thermal stress test device for structural member

Abstract

The invention discloses a structural member thermal stress test device, and belongs to the technical field of aerospace. The device comprises a sealed environment box, a cooling-water machine, an air temperature and air pressure adjusting mechanism, an induction heating mechanism and a heat exchanger. The induction heating mechanism comprises an alternating current power supply and a hollow copper pipe wound around a test piece positioned in the sealed environment box; the AC power supply is connected to the hollow copper pipe; two ends of the hollow copper pipe are respectively connected with a first water inlet and a first water outlet of the cooling-water machine; a second water inlet and a second water outlet of the cooling-water machine are respectively connected with a water outlet and a water inlet of the heat exchanger; an air inlet of the heat exchanger is connected with an exhaust hole of the sealed environment box; an air outlet of the heat exchanger is connected with the sealed environment box through an air temperature and air pressure adjusting mechanism to adjust air temperature and air pressure in the sealed environment box. According to the invention, non-uniform temperature distribution can be applied to a test piece, oxidation of external air is eliminated, and the requirements of a steady-state thermal stress test and a thermal fatigue test of a structural member are met.

Description

Technical Field

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

[0002] The aerospace industry has very high requirements for the heat resistance of structures, and some structures have an operating temperature higher than 1000 degrees Celsius. This requires not only that the material used in the structure itself can withstand the temperature, but also that the structure is generally heated unevenly, and the uneven temperature distribution will cause thermal stress in the structure. Thermal stress is also an important factor leading to structural damage.

[0003] Before the structure is actually used, it is necessary to test and evaluate the performance of the structure under uneven heating conditions. The main heating methods currently include gas heating and induction heating. Among them, the use of gas heating method has the problem that the temperature is difficult to accurately control, and the exhaust gas generated after the gas combustion will directly impact the test structure, causing chemical reactions that affect the mechanical properties of the structure. At the same time, gas heating consumes fuel and produces exhaust gas, which is not conducive to environmental protection. Relatively speaking, the induction heating temperature is easy to control, and the impact of chemical reactions can be eliminated to the greatest extent, resulting in less environmental pollution, which is an ideal heating solution.

[0004] During ground tests, the air contains oxygen, and oxidation problems are inevitable when conducting high-temperature tests. Therefore, if it is necessary to examine thermal stress alone and exclude the influence of chemical reactions, the heating environment needs to be carefully designed. Using an inert gas atmosphere environment in an environmental chamber is an effective and low-cost method.

[0005] The use of induction heating can achieve control of the heating temperature, but the oxidation problem in the air environment cannot be completely ignored. Existing environmental chambers are generally designed for the purpose of maintaining temperature. They can apply uniform high temperature to the test piece, but cannot achieve the application of non-uniform temperature distribution. However, thermal stress can only be generated under non-uniform temperature. Summary of the invention

[0006] The purpose of the present invention is to provide a thermal stress testing device for structural parts, which can realize the application of non-uniform temperature distribution on the test piece, eliminate oxidation by external air, and has high reliability and economy in long-term testing, thus meeting the needs of steady-state thermal stress testing and thermal fatigue testing of structural parts.

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

[0008] A structural component thermal stress test device, the structural component thermal stress test device comprising a sealed environmental 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 in the sealed environment box 1; 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 made 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 in the hollow copper tube 4-2 circulates to prevent the hollow copper tube 4-2 from overheating;

[0010] The second water inlet 2-3 and the second water outlet 2-4 of the chiller 2 are respectively connected to the water outlet 6-3 and the water inlet 6-4 of the heat exchanger 6; the air inlet 6-1 of the heat exchanger 6 is connected to the exhaust hole 1-1 of the sealed environmental 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 environmental box 1 through the air temperature and pressure regulating mechanism 3 to regulate the air temperature and pressure in the sealed environmental box 1.

[0011] Further, the air temperature and pressure regulating mechanism 3 comprises an exhaust valve 3-1, a reflux 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 reflux 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 reflux valve 3-2;

[0012] The 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 regulating valve 3-5 is connected to the environmental air inlet pipe 1-2 of the sealed environmental box 1 to adjust the air temperature and pressure in the sealed environmental box 1.

[0013] Furthermore, the air 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 box 1 to control the cooling speed of the test piece 5 .

[0015] Furthermore, the sealed environment box 1 comprises a base 1-3, an upper end cover 1-4 and a glass round tube 1-5; the bottom end and the upper end of the glass round tube 1-5 are sealedly connected to the base 1-3 and the upper end cover 1-4 respectively;

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

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

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

[0019] 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 the pipeline 1-7 arranged in the sealed environment box 1; the outlet of the pipeline 1-7 faces the test piece 5 to control the cooling speed of the test piece 5.

[0020] Furthermore, the upper end cover 1-4 and the base 1-3 cooperate to clamp the glass tube 1-5 through the positioning column 1-8 to prevent the air pressure in the glass tube 1-5 from pushing open 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 glass tube 1-5 and the contact surface between 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 matched with the base 1-3 and the upper end cover 1-4;

[0023] The lower sealing ring 1-9 and the upper sealing ring 1-19 are pressed together by the semicircular ring pressing piece 1-10 and the locking component 1-20.

[0024] Furthermore, 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 so as to detect the air pressure and temperature in the sealed environment box 1 in real time.

[0025] Furthermore, an insulating ring 1-18 is provided between the contact surface between 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 material of the glass round tube 1-5 is quartz glass.

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

[0028] The present invention realizes the application of non-uniform temperature distribution by winding the hollow copper tube in the induction heating mechanism around the test piece; prevents the copper tube from overheating by a chiller; isolates the outside air by a sealed environmental box to eliminate the possible influence of oxidation on the test piece and equipment; regulates the gas temperature inside the sealed environmental box by an air temperature and pressure regulating mechanism to maintain a low-temperature environment, which is conducive to realizing non-uniform temperature distribution and protecting the environmental box, which is conducive to long-term testing, reduces testing costs, and ensures the reliability and economy of long-term testing. The present invention is suitable for steady-state thermal stress testing and thermal fatigue testing of structural parts to verify the thermal stress bearing capacity and thermal fatigue bearing capacity of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

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

[0031] Figure 2 A schematic diagram of a pipeline of a thermal stress testing device for a structural component according to an embodiment of the present invention;

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

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

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

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

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

[0037] Figure 8 Schematic diagram of an environmental chamber air pressure control method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0039] This embodiment provides a thermal stress test device for structural parts. Figure 1 and 2 The structural component thermal stress test device includes a sealed environment box 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 box 1 by an air path, the chiller 2 is connected to the air temperature and pressure regulating mechanism 3 by a water path, and the chiller 2 is also connected to the induction heating mechanism 4 by a water path. The air copper pipe 4-2 of the induction heating mechanism 4 extends into the sealed environment box 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 wrapped around a test piece 5 located in a sealed environment box 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 in the hollow copper tube 4-2 circulates, adjusts the heating temperature of the hollow copper tube 4-2, and prevents the copper tube from overheating. The power of the AC power supply 4-1 can be adjusted to meet different heating requirements.

[0041] The second water inlet 2-3 and the second water outlet 2-4 of the chiller 2 are respectively connected to the water outlet 6-3 and the water inlet 6-4 of the heat exchanger 6. The air inlet 6-1 of the heat exchanger 6 is connected to the exhaust hole 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 to adjust the air temperature and pressure in the sealed environment box 1. The water discharged from the heat exchanger 6 and the hollow copper tube 4-2 in this embodiment is cooled by the same chiller.

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

[0043] The air temperature and pressure regulating mechanism 3 in this embodiment includes an exhaust valve 3-1, a reflux 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 reflux valve 3-2, the air pump 3-4 and the first flow regulating valve 3-5 are connected in sequence, and the air source 3-3 is connected to the air outlet of the reflux valve 3-2. The air inlet end of the exhaust valve 3-1 is connected to the air outlet 6-2 of the heat exchanger 6, and the first flow regulating valve 3-5 is connected to the environmental air inlet pipe 1-2 of the sealed environmental box 1 to control the flow of the environmental air inlet channel (i.e., the first air inlet channel 1-14) to adjust the air temperature and pressure in the sealed environmental box 1.

[0044] The gas source 3-3 in this embodiment can be a gas cylinder, which contains inert gas to prevent oxidation of the test piece, and 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 environmental box under different test conditions.

[0045] The air temperature and pressure regulating mechanism 3 in this embodiment further 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 of the second flow regulating valve 3-6 is connected to the sealed environment box 1 to control the cooling speed of the test piece 5. The second flow regulating valve 3-6 controls the flow of the cooling air intake channel (i.e., the second air intake channel 1-16).

[0046] In order to prevent the gas circuit from backflowing, the exhaust valve 3-1, the first flow regulating valve 3-5 and the second flow regulating valve 3-6 provided in the connecting pipeline of the present embodiment are all one-way valves.

[0047] The structure of the sealed environment box 1 in this embodiment is as follows: Figures 3 to 6 As shown, it includes a base 1-3, an upper end cover 1-4 and a glass tube 1-5. The bottom end and the upper end of the glass tube 1-5 are sealed and connected to the base 1-3 and the upper end cover 1-4 respectively. This embodiment adopts a bevel seal. The upper end cover 1-4 and the base 1-3 are tightened by the positioning column 1-8 with a nut to clamp the glass tube 1-5 to prevent the air pressure in the glass tube 1-5 from pushing open the upper end cover 1-4. A lower sealing ring 1-9 and an upper sealing ring 1-19 with a right-angle trapezoidal cross-section are respectively arranged between the contact surfaces of the glass tube 1-5 and the base 1-3 and the glass tube 1-5. 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 matched with the base 1-3 and the upper end cover 1-4. The lower sealing ring 1-9 and the upper sealing ring 1-19 are pressed together by a semicircular ring pressing sheet 1-10 and a locking component 1-20 (such as an M20 nut). The sealing rings in this embodiment (such as the lower sealing ring 1-9 and the upper sealing ring 1-19) are made of high temperature resistant materials, and the sealing ring material is preferably made of graphite material.

[0048] The upper end cover 1-4 in this embodiment is provided with an exhaust hole 1-1 connected to the air inlet 6-1 of the heat exchanger 6. 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, so as to detect the air pressure and temperature (i.e., gas pressure and ambient temperature) in the sealed environment box 1 in real time, which serves as a basis for adjusting the gas flow, which is safe and reliable. The measuring port 1-11 can also be installed with an electric sensor, which can be a thermocouple. 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 the hollow copper tube 4-2 from short-circuiting.

[0049] In this embodiment, the base 1-3 is provided with a first air inlet channel 1-14 and a plurality of environmental air inlet pipes 1-2 communicating with the first air inlet channel 1-14 to increase the air inlet area. The plurality of environmental air inlet pipes 1-2 are connected to a first flow regulating valve 3-5 to introduce air flow into the glass round tube 1-5 to adjust the temperature in the sealed environmental box 1.

[0050] In this embodiment, the base 1-3 is further provided with a second air inlet channel 1-16 and a cooling air inlet pipe 1-6 communicating with 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, and the other end of the second air inlet channel 1-16 is connected to a pipeline 1-7 provided in the sealed environment box 1. The outlet of the pipeline 1-7 faces the test piece 5 to control the cooling speed of the test piece 5 and help the test piece 5 to 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 hole 1-1 is 90 mm. The diameter of the columnar space inside the sealed environmental box 1 is 480 mm and the height is 500 mm, which can be used for testing.

[0052] The base 1-3 and the upper end cover 1-4 in this embodiment are made of high temperature alloy. The glass tube 1-5 is made of high temperature resistant quartz glass, and the state of the test piece can be observed in real time from the outside.

[0053] When conducting tests on insulating materials, since insulating materials cannot generate large induced currents and cannot be directly heated, this embodiment uses a metal material close to its surface, heats the metal material through induced current, and then heats the insulating material through convection and radiation heat exchange. The metal material is preferably tungsten, which has a high melting point and will not oxidize in an inert gas environment, as the metal material to be inductively heated.

[0054] Before starting the test, press Figure 3 and Figure 4 Set the test piece position as shown, and assemble the sealed environmental chamber 1. Figure 2After the pipeline is connected, make sure that all parts are sealed properly and then start the test.

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

[0056] Step 1: Exhaust the air in 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 reflux valve 3-2, open the gas source 3-3, and let the inert gas exhaust the air in the two sections of the pipeline from the gas source 3-3 to the reflux valve 3-2, and from the reflux valve 3-2 to the exhaust valve 3-1. After exhausting, close the gas source 3-3, close the reflux valve 3-2, open the first flow regulating valve 3-5 and the second flow regulating valve 3-6, and then open the gas source 3-3 to exhaust the air in other gas circuits and the sealed environment box 1. After exhausting, close the gas source 3-3, close the exhaust valve 3-1, and open the reflux valve 3-2. At this point, the inert gas circuit has been formed.

[0057] Step 2: Make the gas and cooling water flow. Close the second flow regulating valve 3-6, turn on the air pump 3-4, and let the gas in the gas path flow. Turn on the chiller 2 to make the cooling water flow, so that the water flow fully soaks the heat exchanger 6 and the hollow copper tube 4-2.

[0058] Step 3: Turn on the AC power supply 4-1 and start heating with appropriate power. Use an infrared thermal imager or a thermocouple to detect the surface temperature of the test piece. When the predetermined temperature is reached, reduce the power of the AC power supply 4-1 so that the surface temperature of the test piece 5 is maintained 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 to the test piece 5 to accelerate cooling. When the temperature in the sealed environment box 1 is close to room temperature and the air pressure in the sealed environment box 1 is close to atmospheric pressure, turn off the air pump 3-4, remove the pipes and nuts, pressing pieces, and sealing rings of the upper end cover 1-4, and then remove the upper end cover to take out the test piece.

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

[0061] Step 1: Exhaust the air in the device. The operation is the same as the steady-state thermal stress test.

[0062] Step 2: Make the gas and cooling water flow. The operation is the same as the steady-state thermal stress test.

[0063] Step 3: Turn on the AC power supply 4-1 and start heating with appropriate power. Use an infrared thermal imager or a thermocouple to detect the surface temperature of the test piece 5. When the predetermined temperature is reached, reduce the power of the AC power supply 4-1 so that the surface temperature of the test piece 5 is maintained at a high level for a certain period of time as required by the experiment. After that, cool the test piece 5, reduce the power of the AC power supply 4-1, use natural cooling or open the second flow regulating valve 3-6 for forced cooling, and keep warm for a period of time as required by the experiment after cooling to the predetermined temperature.

[0064] Step 4: Repeat step 3 until the number of cycles reaches the test requirement.

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

[0066] For steady-state thermal stress tests and thermal fatigue tests, attention is paid to the pressure and temperature in the sealed environmental chamber 1 during the test. The air temperature control method is as follows: Figure 7 As shown, if the temperature in the box is higher than 600 degrees Celsius, it is necessary to appropriately increase the power of the air pump 3-4 and adjust the first flow control valve 3-5 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 the atmospheric pressure, the air source 3-3 needs to be opened for air replenishment; if the air pressure is higher than 110% of the atmospheric pressure, the exhaust valve 3-1 needs to be opened for exhaust.

[0067] In this embodiment, the gas source 3-3, the air pump 3-4, the first flow control valve 3-5, the second flow control valve 3-6, the reflux valve 3-2, the exhaust valve 3-1 and the AC power supply 4-1 are controllable components, and the pressure gauge 1-12 and the thermometer 1-13 are measuring components. The above controllable components and measuring components can be Figure 7 and Figure 8 The control method shown realizes the monitoring and automatic control of the air pressure and temperature in the sealed environment box 1.

[0068] This embodiment achieves the application of non-uniform temperature distribution by wrapping the hollow copper tube in the induction heating mechanism around the test piece; prevents the copper tube from overheating by a chiller; isolates the outside air by a sealed environmental box to eliminate the possible effects of oxidation on the test piece and equipment; adjusts the gas temperature inside the sealed environmental box by an air temperature and pressure regulating mechanism to maintain a low temperature environment, which is conducive to achieving non-uniform temperature distribution and protects the environmental box, which is conducive to 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 parts to verify the thermal stress bearing capacity and thermal fatigue bearing capacity of the structure.

[0069] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A structural component thermal stress testing device, characterized in that: The structural component thermal stress test device comprises a sealed environmental chamber (1), a chiller (2), an air temperature and pressure regulating 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 tube (4-2) wound around a test piece (5) located in the sealed environment box (1); two electrodes of the alternating current power supply (4-1) are respectively connected to two ends of the hollow copper tube (4-2), and the temperature distribution on the test piece (5) is made uneven through induction heating; the two ends of the hollow copper tube (4-2) are respectively connected to a first water inlet (2-1) and a first water outlet (2-2) of the chiller (2), so that water in the hollow copper tube (4-2) circulates to prevent the hollow copper tube (4-2) from overheating; The second water inlet (2-3) and the second water outlet (2-4) of the chiller (2) are respectively connected to the water outlet (6-3) and the water inlet (6-4) of the heat exchanger (6); the air inlet (6-1) of the heat exchanger (6) is connected to the exhaust hole (1-1) of the sealed environmental 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 environmental box (1) through the air temperature and pressure regulating mechanism (3) to regulate the air temperature and pressure in the sealed environmental box (1).

2. The structural component thermal stress testing device according to claim 1, characterized in that: The air temperature and pressure regulating mechanism (3) comprises an exhaust valve (3-1), a reflux 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 reflux 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 reflux valve (3-2); The 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 regulating valve (3-5) is connected to the environmental air inlet pipe (1-2) of the sealed environmental box (1) to adjust the air temperature and pressure in the sealed environmental box (1).

3. The structural component thermal stress testing device according to claim 2, characterized in that: The air temperature and pressure regulating mechanism (3) further comprises 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); the other end of the second flow regulating valve (3-6) is connected to the sealed environment box (1) to control the cooling speed of the test piece (5).

4. The structural component thermal stress testing device according to claim 3, characterized in that: The sealed environment box (1) comprises a base (1-3), an upper end cover (1-4) and a glass round tube (1-5); the bottom end and the upper end of the glass round tube (1-5) are respectively sealedly connected to the base (1-3) and the upper end cover (1-4); The upper end cover (1-4) is provided with an 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 environmental air inlet pipes (1-2) communicating with the first air inlet channel (1-14); the plurality of environmental air inlet pipes (1-2) are connected to the first flow regulating valve (3-5) to introduce airflow into the glass round tube (1-5).

5. The structural component thermal stress testing device according to claim 4, characterized in that: 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; 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 pipeline (1-7) arranged in the sealed environment box (1); the outlet of the pipeline (1-7) faces the test piece (5) to control the cooling speed of the test piece (5).

6. The structural component thermal stress testing device according to claim 5, characterized in that: The upper end cover (1-4) and the base (1-3) cooperate to clamp the glass round tube (1-5) via a positioning column (1-8), thereby preventing the air pressure in the glass round tube (1-5) from pushing open the upper end cover (1-4).

7. The structural component thermal stress testing device according to claim 6, characterized in that: A lower sealing ring (1-9) and an upper sealing ring (1-19) are respectively arranged between the glass round tube (1-5) and the contact surface between the base (1-3) and the glass round tube (1-5); The inner cylindrical surfaces of the lower sealing ring (1-9) and the upper sealing ring (1-19) are in contact with and matched 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 matched with the base (1-3) and the upper end cover (1-4); The lower sealing ring (1-9) and the upper sealing ring (1-19) are pressed together by means of a semicircular ring-shaped pressing sheet (1-10) and a locking component (1-20).

8. The structural component thermal stress testing device according to claim 7, characterized in that: 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) so as to detect the air pressure and temperature in the sealed environment box (1) in real time.

9. The structural component thermal stress testing device according to claim 8, characterized in that: An insulating ring (1-18) is provided between the contact surface between the upper end cover (1-4) and the hollow copper tube (4-2) to prevent the hollow copper tube (4-2) from short-circuiting.

10. The structural component thermal stress testing device according to claim 9, characterized in that: The material of the glass round tube (1-5) is quartz glass.

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