Experimental device and method for measuring heat conductivity of diamond enhanced aluminum heat expansion plate

Abstract

The invention discloses an experimental device and method for measuring the heat conductivity of a diamond enhanced aluminum heat expansion plate, and relates to the field of heat conduction performance detection, the experimental device comprises a cold source device for cooling one end of a test piece and a heat source device for heating the other end of the test piece, the cold source device comprises a cold source clamp, and the cold source clamp is fixedly connected with a cold source fixing plate; the cold source device comprises a cold source clamp, the cold source clamp is slidably connected with a cold source sliding plate, the sliding direction of the cold source sliding plate is close to or far away from the cold source fixing plate, cooling layers are arranged on the opposite sides of the cold source sliding plate and the cold source fixing plate, and the heat source device comprises a heat source clamp, and a plurality of length-adjustable supporting adjusting rods are connected between the cold source clamp and the heat source clamp; the heat source clamp is fixedly connected with the heat source fixing plate and slidably connected with the heat source sliding plate, the sliding direction of the heat source sliding plate is close to or away from the heat source fixing plate, and heating layers are arranged on the opposite sides of the heat source fixing plate and the heat source sliding plate. And the overall heat conductivity of the heat expansion plate in the main heat flow direction is accurately obtained.

Description

Technical Field

[0001] The present application belongs to the technical field of thermal conductivity testing, and in particular relates to an experimental device and method for measuring the thermal conductivity of a diamond-reinforced aluminum heat diffusion plate. Background Art

[0002] Spacecraft electronic products must experience harsh thermal environments during the pre-research and on-orbit flight stages. In order to ensure the stability of spacecraft product operation and prevent thermal failure, the temperature of heat-generating components must be effectively controlled. Generally, it is required to meet the requirements of the first-level derating design. As onboard electronic equipment develops towards high-speed computing, large-scale storage, and efficient data transmission, the heat consumption of internal components of onboard large-scale integrated circuits is increasing, and the heat dissipation is becoming more and more difficult. As a payload system, analog integrated circuit products are often arranged in the cabin, and the main heat transfer method is heat conduction. In order to solve the heat dissipation problem of internal components of such products, a heat expansion plate can be installed on the top of the component. The heat generated by the component can be directly transferred to the heat sink by using a high thermal conductivity heat expansion plate, which can effectively reduce the operating temperature of the component and improve product reliability. Therefore, a high thermal conductivity heat expansion plate is an important measure to solve the heat dissipation of large-scale digital integrated circuit components in spacecraft.

[0003] Diamond reinforced aluminum material is a metal-based composite material with a complex production process. It requires a customized graphite mold based on the product drawing, 100-micron diamond particles are filled into the mold, and then aluminum is liquefied and poured into the mold under high temperature and high pressure conditions. After the diamond and aluminum are fully combined, the mold is formed and demolded. The thermal conductivity of diamond is very high (up to 2000W / (m·K)). After good contact with aluminum, the prepared diamond reinforced aluminum material has a high thermal conductivity (generally greater than 500W / (m·K)), and its density is less than 3.3g / cm 3 , which is comparable to aluminum, can be used to prepare high thermal conductivity heat expansion plates. Due to differences in the purity of raw materials and differences in the temperature field distribution during the preparation process, the thermal conductivity of the prepared diamond-reinforced aluminum heat expansion plate has a certain degree of discreteness, and there is a certain gap in the thermal conductivity of different heat expansion plates. Even when preparing diamond-reinforced aluminum heat expansion plates, thermal conductivity test specimens are prepared at the same time, there is a large difference in size between the specimens and the heat expansion plates, and they cannot fully represent the thermal conductivity of the heat expansion plates. The thermal conductivity of the entire heat expansion plate directly affects the heat dissipation performance of the heat expansion plate. It is a key parameter of the heat expansion plate and requires special attention.

[0004] The traditional method of measuring thermal conductivity is the laser method. Its basic principle is to evenly heat the sample surface by emitting light pulses from a laser source. Subsequently, the temperature change on the sample surface is measured by an infrared detector to obtain a curve of temperature rise and time. Using this curve, the thermal diffusion coefficient of the material can be calculated. The thermal conductivity is further calculated by combining the specific heat and density of the material. When measuring thermal conductivity using the laser method, the test piece must be processed into a small disc of a specified size. However, the furnace samples during the processing of the diamond-reinforced aluminum heat expansion plate cannot fully represent its thermal conductivity. Therefore, the laser method is not suitable for testing the thermal conductivity of the diamond-reinforced aluminum heat expansion plate. Summary of the invention

[0005] The technical problem solved by this application is: to overcome the shortcomings of the prior art, this patent proposes an experimental device that can quickly measure the thermal conductivity of the diamond-enhanced aluminum heat expansion plate based on the principle of unidirectional heat conduction, which is used to accurately obtain the overall thermal conductivity of the heat expansion plate in the main heat flow direction. The experimental device can accurately obtain the heat passing through the diamond-enhanced aluminum heat expansion plate by controlling the power of the heat source heating resistor, and the temperature control system of the microchannel cold plate during the experiment allows the experimental system to quickly reach stability, making the system closer to actual working conditions.

[0006] The technical solutions provided by this application are as follows:

[0007] In a first aspect, an experimental device for measuring the thermal conductivity of a diamond-reinforced aluminum heat expansion plate is provided, comprising a cold source device for cooling one end of a specimen and a heat source device for heating the other end of the specimen, wherein the cold source device comprises a cold source clamp, wherein the cold source clamp is fixedly connected to a cold source fixing plate, wherein the cold source clamp is slidably connected to a cold source sliding plate, wherein the sliding direction of the cold source sliding plate approaches or moves away from the cold source fixing plate, and a cooling layer is arranged on opposite sides of the cold source sliding plate and the cold source fixing plate; and the heat source device comprises a heat source clamp, wherein a plurality of length-adjustable support adjustment rods are connected between the cold source clamp and the heat source clamp, wherein the heat source clamp is fixedly connected to the heat source fixing plate, wherein the heat source clamp is slidably connected to the heat source sliding plate, wherein the sliding direction of the heat source sliding plate approaches or moves away from the heat source fixing plate, and a heating layer is arranged on opposite sides of the heat source fixing plate and the heat source sliding plate.

[0008] The heating layer includes an insulating pressing component, a ceramic heating plate, a temperature equalizing plate and a heat source thermal conductive pad which are arranged in sequence. The insulating pressing component is connected to a heat source fixing plate or a heat source sliding plate, the heat source thermal conductive pad is in contact with the specimen, the ceramic heating plate is used for heating, and the temperature equalizing plate is used for evenly distributing the heat generated by the ceramic heating plate.

[0009] The cooling layer comprises a microchannel heat exchanger, and a cold source heat conduction pad is arranged on the opposite side of the microchannel heat exchanger.

[0010] The two ends of the two microchannel heat exchangers are respectively connected to the water inlet channel and the water outlet channel, one end of the water inlet channel is connected to the water inlet pipe, and the other end is connected to two water inlet bellows, the water inlet bellows is connected to a water inlet connection end for welding with the microchannel heat exchanger, one end of the water outlet channel is connected to the water outlet pipe, and the other end is connected to two water outlet bellows, the water outlet bellows is connected to a water outlet connection end for welding with the microchannel heat exchanger; a flow valve is provided on the water inlet pipe.

[0011] The microchannel heat exchanger is provided with a plurality of channels along the direction from the water inlet channel to the water outlet channel.

[0012] The heat source clamp is threadedly connected with a heat source adjusting screw, and the end of the heat source adjusting screw is rotatably connected to the heat source sliding plate; the cold source clamp is threadedly connected with a cold source adjusting screw, and the end of the cold source adjusting screw is rotatably connected to the cold source sliding plate.

[0013] The outer cover of the experimental device is equipped with a heat radiation resistant cover.

[0014] The inner side of the anti-thermal radiation outer cover is covered with multiple layers of aluminum-plated films.

[0015] In a second aspect, an experimental method for an experimental device for measuring thermal conductivity of a diamond-enhanced aluminum heat-expanding plate is provided, comprising:

[0016] Prepare the test piece and a pure copper heat expansion plate of the same size as the test piece;

[0017] The specimen is installed in the experimental device. Under vacuum conditions, a heat source is applied to one end of the specimen and a cold source is applied to the other end to obtain the heating amount Q0 and the temperature difference △t at both ends of the specimen.

[0018] The thermal conductivity of the pure copper heat expansion plate is measured using conventional standard methods to obtain the standard thermal conductivity λ2. The pure copper heat expansion plate is installed in the experimental device, and the calibration thermal conductivity λ1 is measured under the same experimental conditions as the test piece.

[0019] The heat leakage Q is obtained according to the standard thermal conductivity λ2 and the verified thermal conductivity λ1 L ;

[0020] According to the heating amount Q0 and the leakage heat Q L The corrected heating amount Q is obtained, and the thermal conductivity λ of the specimen is obtained according to the corrected heating amount Q and the temperature difference △t at both ends of the specimen.

[0021] Said Among them, δ is the length of the specimen and the pure copper heat expansion plate in the heat transfer direction, A is the cross-sectional area of ​​the specimen and the pure copper heat expansion plate in the heat transfer direction, △t1 is the temperature difference between the two ends of the pure copper heat expansion plate; the thermal conductivity of the specimen is

[0022] In summary, this application at least includes the following beneficial technical effects:

[0023] The heat source uses a ceramic heating plate with a temperature equalizing plate as a heat loading device, which can effectively ensure that the heating power is evenly loaded on both sides of the hot end of the heat expansion plate. The cold source uses a microchannel cold plate, which controls the consistency of the temperature on both sides of the cold end of the heat expansion plate by adjusting the flow of the water cooler, thereby ensuring the one-dimensional transfer of heat flow and improving the test effectiveness.

[0024] A comparison group was designed, and the copper heat expansion plate for measuring thermal conductivity was used as a comparison item to infer the amount of heat leakage and correct the measured value of thermal conductivity of the diamond-reinforced aluminum heat expansion plate.

[0025] The entire system is measured under vacuum conditions to block the influence of convection on the test. A heat-insulating cover is installed outside the system to reduce external radiation, further reducing the influence of heat leakage on the test accuracy. The extremely small heat leakage improves the accuracy of the group calibration.

[0026] This method can also be used to test the thermal conductivity of other isotropic high thermal conductivity materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The figure is a diagram of a thermal conductivity test device, wherein the left figure is a schematic diagram of the test device, and the right figure is a schematic diagram of the anti-thermal radiation cover;

[0028] Figure 2 This is a cross-sectional view of the flow channel of the microchannel heat exchanger.

[0029] Explanation of the accompanying drawings: 1. Heat source fixture; 2. Heat source thermal pad; 3. Temperature equalizer; 4. Ceramic heating plate; 5. Insulation clamping component; 6. Test piece; 7. Support adjustment rod; 8. Cold source thermal pad; 9. Microchannel heat exchanger; 10. Flow valve; 11. Water inlet channel; 12. Water outlet channel; 13. Cold source fixture; 14. Anti-thermal radiation cover. DETAILED DESCRIPTION

[0030] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0031] The embodiment of the present application discloses an experimental device for measuring the thermal conductivity of a diamond-reinforced aluminum heat expansion plate, which can be used to efficiently and accurately measure the thermal conductivity of a diamond-reinforced aluminum heat expansion plate. The heat expansion plate is generally rectangular, and the heat transfer on the heat expansion plate is generally along a specific edge direction of its width. The principle of thermal conductivity measurement is as follows: when there is a temperature difference on both sides of the heat expansion plate in one direction, heat will be transferred in this direction.

[0032] like Figure 1 The left picture and Figure 2As shown, the experimental device includes a heat source fixture 1, a heat source thermal pad 2, a temperature equalizing plate 3, a ceramic heating plate 4, an insulating pressing component 5, a support adjustment rod 7, a cold source thermal pad 8, a microchannel heat exchanger 9, a flow valve 10, an inlet channel 11, an outlet channel 12, a cold source fixture 13 and an anti-thermal radiation cover 14.

[0033] One side of the heat source fixture 1 is fixedly connected to a heat source fixed plate and slidably connected to a heat source sliding plate. The sliding direction of the heat source sliding plate is close to or away from the heat source fixed plate. The heat source fixture 1 is threadedly connected with a heat source adjustment screw, and the end of the heat source adjustment screw is rotatably connected to the heat source sliding plate. The opposite sides of the heat source fixed plate and the heat source sliding plate are sequentially connected to the heat insulation clamping component 5, the ceramic heating plate 4, the temperature equalizing plate 3 and the heat source thermal pad 2. The heat insulation clamping component 5 is used to reduce the heat transfer to the non-test piece side and reduce heat leakage. The ceramic heating plate 4 is used for heating. The temperature equalizing plate 3 is used to make the heat generated by the ceramic heating plate 4 more uniform and then transfer it to one end of the test piece 6 through the heat source thermal pad 2. The heat source thermal pad 2 has a certain compressibility and is flexible. The heat source thermal pad 2 can fit well with the surface of the test piece 6.

[0034] A plurality of length-adjustable support adjustment rods 7 are connected between one side of the cold source fixture 13 and the hot source fixture 1, so that the test device is suitable for test pieces 6 of different heights. The side of the cold source fixture 13 is also fixedly connected to a cold source fixed plate and slidably connected to a cold source sliding plate. The sliding direction of the cold source sliding plate is close to or away from the cold source fixed plate. The cold source fixture 13 is threadedly connected with a cold source adjusting screw, and the end of the cold source adjusting screw is rotatably connected to the cold source sliding plate. The opposite sides of the cold source fixed plate and the cold source sliding plate are connected with a microchannel heat exchanger 9 and a cold source thermal pad 8 at one time. The same end of the two microchannel heat exchangers 9 is connected to the water inlet channel 11, and the other end of the two microchannel heat exchangers 9 is connected to the water outlet channel 12. One end of the water inlet channel 11 is connected to the water inlet pipe, and the other end is connected to two bellows. The bellows are connected with a connection end for welding with the microchannel heat exchanger 9. The structure of the water outlet channel 12 is the same as that of the water inlet channel 11. The setting of the bellows makes the two microchannel heat exchangers 9 and the water inlet channel 11 and the water outlet channel 12 flexibly connected; a flow valve 10 is provided on the water inlet pipe to control the flow of the cooling medium. The microchannel heat exchanger 9 is provided with a plurality of channels along the direction from the water inlet channel 11 to the water outlet channel 12. In this embodiment, the channels of the microchannel heat exchanger 9 are arranged as follows: a row of channels with a square cross section and a row of channels with a semicircular cross section are alternately distributed.

[0035] like Figure 1 As shown in the right figure, the open end of the anti-thermal radiation outer cover 14 is provided with two notches, the shapes of the two notches match the water inlet channel 11 and the water outlet channel 12, and the inner side of the anti-thermal radiation outer cover 14 is covered with a multi-layer aluminum film, so that the anti-thermal radiation outer cover 14 is mounted on the outside of the experimental device to isolate the heat expansion plate from external heat radiation.

[0036] After placing the bottom end of the specimen 6 between the cold source fixed plate and the cold source sliding plate, and the top end of the specimen 6 between the heat source fixed plate and the heat source sliding plate, turn the cold source adjustment screw and the heat source adjustment screw, the cold source adjustment screw drives the cold source sliding plate to move until the cold source thermal pads 8 on both sides of the specimen 6 clamp the specimen 6, and the heat source adjustment screw drives the heat source sliding plate to move until the heat source thermal pads 2 on both sides of the specimen 6 clamp the specimen 6, and the assembled experimental device is obtained. Then, the assembled experimental device is placed in a vacuum tank, and the water inlet channel 11 and the water outlet channel 12 are connected to the external cooling medium through the access structure at the bottom of the vacuum tank. After the vacuum tank is evacuated, a heat source is applied to one end of the specimen 6 and a cold source is applied to the other end for testing.

[0037] The test method is:

[0038] During the test, the experimental device is located in a vacuum tank. The test of this patent is under vacuum conditions and there is no convection. In addition, a heat radiation protection cover covered with a multi-layer aluminum film is designed outside the experimental device to isolate the heat expansion plate from external heat radiation. It can be approximately assumed that the heat generated by the heater at one end of the heat expansion plate is all transmitted through the heat expansion plate along a certain edge of the heat expansion plate. In order to further reduce the impact of heat leakage on the thermal conductivity test, at the beginning of the test, a pure copper heat expansion plate of the same size was used for testing to obtain the calibration thermal conductivity λ1. Since the thermal conductivity of copper has been measured using conventional standard methods, that is, the standard thermal conductivity λ2 is measured by the laser method, the leakage heat Q can be calibrated through the heat dissipation simulation of the pure copper heat expansion plate. L , Further improve the accuracy of thermal conductivity testing of diamond-reinforced aluminum heat expansion plates. In order to ensure that the heat flow is transferred in one direction, a special design is adopted for the heat source and the cold source. The heat source adopts a loading method combining a ceramic heating plate and a temperature equalizing plate to ensure that the temperature of the heat expansion plate at the hot end is consistent. A small-sized microchannel plate heat exchanger is used at the cold end. By adjusting the flow rate of the chiller and the outlet water temperature, the temperature of the cold end of the heat expansion plate is controlled to make the temperature of the entire cold end of the heat expansion plate consistent. Since both the heat source and the cold source are controllable, the temperature difference between the hot and cold ends can be widened as much as possible to a certain extent, reducing the impact of temperature measurement errors on thermal conductivity.

[0039] The heating amount Q0 plus the heat leakage Q of the diamond-reinforced aluminum material heat expansion plate after the patented device experiment L , obtain the corrected heating amount Q, and calculate the thermal conductivity λ based on Q.

[0040] According to the one-dimensional steady-state heat conduction law, the formula for calculating thermal conductivity is as follows:

[0041]

[0042] The meanings of the parameters in the formula are as follows:

[0043] Δt: temperature difference between the two ends of the heat expansion plate;

[0044] Q: heating amount;

[0045] δ: length in the direction of heat transfer;

[0046] A: Cross-sectional area of ​​heat expansion plate

[0047] λ: thermal conductivity of the heat expansion plate along the heat transfer direction;

[0048] The heat source of the thermal conductivity test device designed in this project adopts a ceramic heating plate combined with a temperature equalizing plate structure, and the cold source adopts a microchannel flat plate heat exchanger. The advantage of this is that the temperatures of the heat source and the cold source are consistent overall, which can effectively ensure that the heat flow flows in one direction and improve the accuracy of the test.

[0049] A test body suitable for thermal conductivity measurement was designed, in which the heat source uses a ceramic heating plate combined with a temperature plate to better control the consistency of the hot end temperature of the specimen, and the cold source uses a microchannel heat exchanger to ensure the uniformity of the cold end temperature of the specimen. The entire experimental body tests one-dimensional heat conduction, adjusts the heating amount and cold end flow, increases the temperature difference between the heat source and the cold source, and reduces the measurement error. Since the components in the entire test device are small in size and light in weight, the temperature is easier to stabilize, reducing the system stabilization time.

[0050] The main performance indicators of the entire experimental device are as follows: the maximum heat flux density of the flat heat pipe is 100W, and the isothermality is less than 1°C; the resistance range of the heating resistor is 50~100Ω; the temperature sensor used is an industrial-grade T-type (copper-constantan) thermocouple with a measurement temperature range of -200~300°C.

[0051] The main development process is as follows:

[0052] 1) Hot end loading method design;

[0053] 2) Cold end cooling method design;

[0054] 3) Reduce heat leakage and ensure one-dimensional thermal conductivity design;

[0055] 4) Temperature measurement and control scheme design;

[0056] 5) Experimental equipment integration.

[0057] Finally, the invention has been applied to the thermal conductivity measurement of diamond-reinforced aluminum heat expansion plates for aerospace many times, and a large number of thermal conductivity values ​​of diamond-reinforced aluminum heat expansion plates have been obtained. These thermal conductivity numerical data are used as input parameters in the thermal simulation of large-scale integrated circuits of massive data processing products, and the accuracy and effectiveness of thermal management measures are verified in a thermal vacuum environment. In addition, this achievement can also be extended to measure the thermal conductivity of other metal-based composite materials and comprehensively evaluate the heat dissipation effect of metal-based composite heat expansion plates for aerospace.

[0058] The contents not described in detail in this application specification belong to the common knowledge of those skilled in the art.

[0059] The present application is described in detail above in conjunction with specific implementation methods and exemplary examples, but these descriptions cannot be understood as limiting the present application. Those skilled in the art understand that, without departing from the spirit and scope of the present application, a variety of equivalent replacements, modifications or improvements can be made to the technical solution of the present application and its implementation methods, all of which fall within the scope of the present application. The scope of protection of the present application shall be subject to the attached claims.

Claims

1. An experimental device for measuring the thermal conductivity of a diamond-reinforced aluminum heat-expanding plate, characterized in that: The invention comprises a cold source device for cooling one end of a test piece (6) and a heat source device for heating the other end of the test piece (6), wherein the cold source device comprises a cold source clamp (13), the cold source clamp (13) is fixedly connected to a cold source fixing plate, the cold source clamp (13) is slidably connected to a cold source sliding plate, the sliding direction of the cold source sliding plate approaches or moves away from the cold source fixing plate, and a cooling layer is arranged on the opposite sides of the cold source sliding plate and the cold source fixing plate; the heat source device comprises a heat source clamp (1), a plurality of length-adjustable support adjustment rods (7) are connected between the cold source clamp (13) and the heat source clamp (1), the heat source clamp (1) is fixedly connected to the heat source fixing plate, the heat source clamp (1) is slidably connected to the heat source sliding plate, the sliding direction of the heat source sliding plate approaches or moves away from the heat source fixing plate, and a heating layer is arranged on the opposite sides of the heat source fixing plate and the heat source sliding plate.

2. The experimental device for measuring thermal conductivity of diamond-reinforced aluminum heat expansion plate according to claim 1, characterized in that: The heating layer comprises a heat-insulating pressing component (5), a ceramic heating plate (4), a temperature-averaging plate (3) and a heat source thermal pad (2) which are arranged in sequence; the heat-insulating pressing component (5) is connected to a heat source fixing plate or a heat source sliding plate; the heat source thermal pad (2) is in contact with a test piece (6); the ceramic heating plate (4) is used for heating; and the temperature-averaging plate (3) is used for evenly distributing the heat generated by the ceramic heating plate (4).

3. The experimental device for measuring thermal conductivity of diamond-reinforced aluminum heat-expanding plate according to claim 1, characterized in that: The cooling layer comprises a microchannel heat exchanger (9), and a cold source heat conductive pad (8) is arranged on the opposite side of the microchannel heat exchanger (9).

4. The experimental device for measuring thermal conductivity of diamond-reinforced aluminum heat-expanding plate according to claim 3, characterized in that: The two ends of the two microchannel heat exchangers (9) are respectively connected to a water inlet channel (11) and a water outlet channel (12); one end of the water inlet channel (11) is connected to a water inlet pipe and the other end is connected to two water inlet bellows; the water inlet bellows is connected to a water inlet connection end for welding with the microchannel heat exchanger (9); one end of the water outlet channel (12) is connected to a water outlet pipe and the other end is connected to two water outlet bellows; the water outlet bellows is connected to a water outlet connection end for welding with the microchannel heat exchanger (9); and a flow valve (10) is provided on the water inlet pipe.

5. The experimental device for measuring thermal conductivity of diamond-reinforced aluminum heat-expanding plate according to claim 3, characterized in that: The microchannel heat exchanger (9) is provided with a plurality of channels along the direction from the water inlet channel (11) to the water outlet channel (12).

6. The experimental device for measuring thermal conductivity of diamond-reinforced aluminum heat-expanding plate according to claim 1, characterized in that: The heat source clamp (1) is threadedly connected with a heat source adjustment screw, and the end of the heat source adjustment screw is rotatably connected to the heat source sliding plate; the cold source clamp (13) is threadedly connected with a cold source adjustment screw, and the end of the cold source adjustment screw is rotatably connected to the cold source sliding plate.

7. The experimental device for measuring thermal conductivity of diamond-reinforced aluminum heat-expanding plate according to claim 1, characterized in that: The outer cover of the experimental device is provided with a heat radiation resistant outer cover (14).

8. The experimental device for measuring thermal conductivity of diamond-reinforced aluminum heat-expanding plate according to claim 7, characterized in that: The inner side surface of the anti-thermal radiation outer cover (14) is covered with multiple layers of aluminum-plated films.

9. The experimental method of the experimental device for measuring thermal conductivity of diamond-reinforced aluminum heat expansion plate according to any one of claims 1 to 8, characterized in that: include: Prepare a test piece (6) and a pure copper heat expansion plate having the same size as the test piece (6); The test piece (6) is installed in the experimental device, and under vacuum conditions, a heat source is applied to one end of the test piece (6) and a cold source is applied to the other end to obtain a heating amount Q0 and a temperature difference △t at both ends of the test piece (6); The thermal conductivity of the pure copper heat expansion plate is measured using a conventional standard method to obtain a standard thermal conductivity λ2. The pure copper heat expansion plate is installed in an experimental device, and the calibration thermal conductivity λ1 is measured under the same experimental conditions as the specimen (6); The heat leakage Q is obtained according to the standard thermal conductivity λ2 and the verified thermal conductivity λ1 L ; According to the heating amount Q0 and the leakage heat Q L The corrected heating amount Q is obtained, and the thermal conductivity λ of the test piece (6) is obtained according to the corrected heating amount Q and the temperature difference Δt at both ends of the test piece (6).

10. The experimental method according to claim 9, characterized in that: Said Wherein, δ is the length of the test piece (6) and the pure copper heat expansion plate in the heat transfer direction, A is the cross-sectional area of ​​the test piece (6) and the pure copper heat expansion plate in the heat transfer direction, and △t1 is the temperature difference between the two ends of the pure copper heat expansion plate; Thermal conductivity of specimen (6)

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