A device and method for efficiently measuring interface contact thermal resistance under multi-temperature conditions and multi-gas environments

Abstract

The present invention discloses a device and method for efficiently measuring interface contact thermal resistance under multi-temperature working conditions and multi-gas environments, and belongs to the field of contact thermal resistance testing technology. The device consists of five parts, including an insulation box, a specimen assembly, a cooling system, a heating system and a pressurizing system. The insulation box consists of two parts: a cylindrical cavity and an annular closed cylinder, and the specimen assembly is placed in the cylindrical cavity; the main body of the specimen assembly is composed of a plurality of cylindrical independent specimens with the same diameter stacked layer by layer through end face contact; the part of the cooling system located in the cylindrical cavity is composed of a plurality of independent cooling ring assemblies, and the cooling ring body is sleeved on the specimen assembly, and two large cooling rings are connected at the upper and lower ends of the specimen assembly; the heating system is composed of a plurality of independent heating wires and a temperature control box, and the heating wires are directly wound on the specimen assembly; the pressurizing system is composed of a pressurizing part and a control part, and the pressurizing part transfers the load to the specimen assembly. The device of the present invention is easy to operate, has small temperature fluctuation and high measurement accuracy, and can efficiently complete contact thermal resistance tests of test pieces of different materials and different surface roughness under multiple different temperature conditions and different gas environments at one time.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal resistance testing, and in particular relates to a device and method for efficiently measuring interface contact thermal resistance under multi-temperature conditions and multi-gas environments. Background Art

[0002] With the development of science and technology, contact thermal resistance has been paid more and more attention in both scientific research and engineering practice. Aerospace, nuclear power and other engineering projects are faced with the need to reduce contact thermal resistance to increase heat flux and establish a good heat conduction path. In the field of space nuclear power, vacuum, high and low temperature and microgravity are the working environment of space nuclear power. In such an extreme environment, the main heat exchange method is not heat convection, but heat conduction and radiation. The conduction thermal resistance is mainly composed of the thermal conductivity resistance inside the solid and the contact thermal resistance between the solid interfaces. The contact thermal resistance is an important parameter for determining the temperature distribution of multi-layer solid combinations and is one of the key issues that must be solved in the study of contact heat transfer between solids.

[0003] Surface roughness Ra is one of the key factors affecting the interface contact thermal resistance. However, because Ra is a one-dimensional quantity, it cannot fully characterize the surface morphology of the contact surface. When Ra is the same, the contact thermal resistance measured by specimens processed in different orders under the same experimental conditions may not be the same. When multiple specimens are tested under different Ra, different temperature conditions, and different gas environments, in order to ensure that the Ra of a single specimen is the same when measured under different experimental conditions, the contact surface of the specimen needs to be reprocessed before each experiment. However, Ra processing is not only affected by human factors, processing tools, and processing types, but also by the metal properties of the specimen itself. The metal properties of the specimen are mainly affected by the experimental conditions, especially for experiments under high temperature conditions. The hardness of the specimen will change significantly before and after the experiment. These factors that affect Ra processing lead to deviations in the surface morphology of specimens with the same Ra processed at different times and in different spaces. This deviation seriously reduces the accuracy of the contact thermal resistance measurement results. In order to improve the measurement accuracy of the interface contact thermal resistance and effectively avoid the influence of the secondary processing of the specimen contact surface in different time and space on the measurement results, it is necessary to process all the specimens required for the experiment in the same time and space. In order to avoid the contact surface of the processed specimens from being damaged during the storage process before the experiment and to save the manpower, material resources and time required for multiple experiments, it is necessary to design a device that can efficiently measure the contact thermal resistance of a large number of specimens with multiple independently adjustable temperature conditions and gas environment functions in a single experiment.

[0004] Patent Nos. ZL202110348478.3, ZL202011230625.9, ZL202010965520.1 and ZL201811522277.5 disclose contact thermal resistance measuring devices, which place the test piece between the heating system and the cooling system. Only the interface thermal resistance of a pair of test pieces can be measured in one test experiment, and the temperature conditions and gas environment in a single experiment are single and fixed, which makes it difficult to meet the needs of efficiently measuring the contact thermal resistance of a large number of test pieces. Moreover, this arrangement places the key part of the heating system (heating body) at the end of the test piece, so that the heating body is subjected to pressure load during the experiment, resulting in a reduction in the service life of the heating body. Especially for experiments under high-pressure conditions, the heating body is very likely to be damaged due to the huge pressure load, causing the heating system to fail to work properly, which limits the pressure range in which the contact thermal resistance measuring device can work. The several contact thermal resistance measurement devices disclosed in the papers "Contact Thermal Resistance Experiment and Numerical Simulation", "Experimental Study on Factors Affecting Interface Contact Thermal Resistance", "Interface Contact Thermal Resistance Experimental Analysis and Parameter Optimization Design", and "Influence of Temperature on Contact Thermal Resistance" all have the above shortcomings. In addition to the above shortcomings, the contact thermal resistance measurement device disclosed in Patent No. ZL201811522277.5 also arranges the pressure sensor on the top of the heating body. This arrangement will inevitably bring about the problem of high temperature leakage from the axial direction of the heating body damaging the pressure sensor. In order to make the pressurization system work normally, the upper temperature limit of the contact thermal resistance measurement device will inevitably be limited.

[0005] Patent No. ZL201910243647.X discloses a high-precision method for determining the interface contact thermal resistance by the bidirectional heat flow method. The invention focuses on the protection of radial heat dissipation of the high-temperature heating body, and arranges the heating body in the center of the test body. Although this arrangement allows the interface thermal resistance of two pairs of specimens to be measured in one experiment, it does not fundamentally solve the problem of the existing measurement device measuring less interface thermal resistance in a single experiment, and the temperature conditions and gas environment of a single experiment are still single; the heating body arrangement of the invention completely ignores the problem of the heating body being subjected to pressure loads during the experiment, and this arrangement greatly reduces the service life of the heating body; the invention sets a light guide near the contact interface and uses non-contact thermal imaging technology for temperature collection. The interface contact thermal resistance R is equal to ΔT to q, ΔT is the temperature difference of the contact interface, and q is the one-dimensional heat flow at the contact interface. Obviously, stable and good one-dimensional heat conduction is the key to achieving high-precision measurement of interface contact thermal resistance. The light guide tube provided in the invention will disturb the temperature of the contact interface. The heat radiation loss through the light guide tube will cause a reduction in the heat flow through the contact interface, making the contact interface of the specimen no longer one-dimensionally conductive. Moreover, there are some problems with temperature measurement using thermal imaging technology. The images taken by thermal imagers have low contrast and poor detail resolution capabilities. It is difficult to extract accurate temperature distribution data from the captured temperature field images. In addition, thermal imagers are expensive and costly. Patent No. ZL201510954538.0 discloses a contact thermal resistance test device with a compensating heating and thermal insulation system, which arranges the specimen between the heating system and the cooling system, and designs a compensating heating device. Although the designed compensating heating device cooperates with the heating system to enable the invention to have good one-dimensional heat conduction in the axial direction, thereby making it possible for the invention to measure the thermal resistance of multiple pairs of specimen interfaces in one experiment, the main heat flow comes from the heating system at the bottom of the specimen. When there are multiple test pieces between the heating system and the cooling system, the temperature of the test piece close to the heating system is extremely different from the temperature of the test piece close to the cooling system, and the temperature of each test piece cannot be independently adjusted according to the test requirements. The independent adjustability of the temperature of the contact interface between the test pieces is extremely poor, which makes the temperature of each contact interface in the experimental test full of randomness and cannot be independently controlled; in addition, since the multiple test pieces of the invention are in the same enclosed space and the gas environment of each contact interface is the same, the test device of the invention does not have the ability to perform measurements in multiple gas environments in a single experiment; the heating system designed by the invention has a furnace table, and the test piece heater is located in the furnace cavity of the furnace table. The furnace table is made of high-temperature mullite bricks and high-alumina bricks, and has a stacked bottom pedestal, side walls stacked circumferentially on the outer edge of the upper surface of the bottom pedestal, and the top of the furnace table is sealed by an overlapping top plate. The outer circumference of the bottom pedestal is the non-main load-bearing part. The non-main load-bearing part adopts high-temperature mullite bricks with excellent thermal insulation performance but not resistant to high stress. The top plate and the upper bricks of the bottom pedestal, except for the bricks connected to the side walls, the rest of the bricks are used as direct load-bearing parts. The direct load-bearing parts adopt high-alumina bricks with poor thermal insulation effect but high stress resistance.Although the furnace can solve the pressure problem of the heating system, the construction of the furnace itself is too complicated and requires extremely high structural integrity. In summary, the existing contact thermal resistance test device does not have the ability to independently adjust multiple temperature conditions and multiple gas environments in a single experiment, and it is difficult to meet the needs of efficiently measuring the contact thermal resistance of a large number of specimens, and there is no good method for arranging the heating body. Summary of the invention

[0006] The object of the present invention is to provide a device and method for efficiently measuring interface contact thermal resistance under multi-temperature conditions and multi-gas environments.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] A device for efficiently measuring interface contact thermal resistance under multiple temperature conditions and multiple gas environments, comprising a heat preservation box, a test piece assembly, a cooling system, a heating system and a pressurizing system;

[0009] The heat preservation box comprises a cylindrical cavity and an annular closed cylinder, and the test piece assembly is located in the cylindrical cavity;

[0010] The main body of the test piece assembly includes at least three cylindrical independent test pieces with the same diameter, which are connected by end face contact and stacking;

[0011] The cooling system body is located outside the heat preservation box, and the cooling system part located in the cylindrical cavity includes at least 3 independent cooling ring assemblies; the cooling ring assembly includes at least 2 small cooling rings and 2 large cooling rings, the small cooling rings are sleeved on the specimen assembly, and the upper and lower ends of the specimen assembly are connected to the 2 large cooling rings;

[0012] The heating system includes at least one independent heating wire. When there are multiple heating wires, the heating wires are located at different axial positions of the specimen assembly and away from each contact interface, and the heating wires and small cooling rings are alternately arranged on adjacent independent specimens;

[0013] The pressurizing system includes a pressurizing part and a control part. The specimen assembly is fixed on the center line of the pressurizing system. The pressurizing part is a rigid test frame. The insulation box is located in the rigid test frame. The pressurizing part transfers the load to the specimen assembly, and the control part controls the pressure.

[0014] Furthermore, the insulation box body consists of two layers, the inner layer is a cylindrical cavity with a diameter of 200 mm, the specimen assembly is located in the middle of the cavity, the space between the specimen assembly and the cylindrical cavity is filled with aerogel insulation felt, and the gap between the insulation felt and the specimen assembly is filled with perlite powder; the outer layer is an annular closed cylinder, the interior of which is filled with aerogel insulation felt; bosses are provided at equal intervals along the height direction between the inner wall of the annular closed cylinder and the specimen assembly, and bolt holes are provided at equal intervals on the bosses; an air vent is provided at the upper and lower diagonal positions of the annular closed cylinder between adjacent bosses, and the cylindrical cavity is evacuated or the experimental gas is replaced through the air vent.

[0015] Furthermore, the main body of the specimen assembly is composed of independent cylindrical specimens; the diameters of each independent cylindrical specimen are the same; the specimens at both ends of the specimen assembly are connected to a large cooling ring, and the connections are sealed with high-temperature sealing gaskets and fastened with sealing clamps; in the middle of some specimens located in the large cooling ring, holes are opened along the flow direction of the small cooling ring to enhance the cooling of the ends; each independent cylindrical specimen is provided with a temperature measuring point at an axial position, and a thermocouple is provided at each temperature measuring point, and the other end of the thermocouple is connected to a temperature acquisition system.

[0016] Furthermore, the cooling system also includes an air compressor, a constant temperature water tank, a recovery water tank, a water pump, a flow meter and a flow regulating valve; small cooling rings are placed at different axial positions of the specimen assembly and away from the positions of each contact interface; two large cooling rings are connected to both ends of the specimen assembly to enable double cooling of independent specimens at both ends of the specimen assembly to protect the pressurization system; independent flow regulating valves are provided on the inlet pipes of the small cooling ring and the large cooling ring, and the flow regulating valves are located outside the insulation box.

[0017] Furthermore, the at least three independent cooling ring assemblies also include at least three independent detachable cooling ring brackets and at least three insulating thin plates; the inner diameter of the small cooling ring and the large cooling ring is equal to the outer diameter of the specimen assembly, and a sealing edge is provided on the inner diameter, and a high-temperature sealing gasket is used to seal the sealing edge and the specimen assembly and a sealing clamp is used to fasten the sealing edge and the specimen assembly; the inlet and outlet metal pipes of the small cooling ring and the large cooling ring are fixed on the detachable cooling ring bracket; the detachable cooling ring brackets are connected to each other through the connecting buckles on the brackets; the height of each cooling ring bracket can be adjusted according to the position of the cooling ring on the specimen assembly; the complete cooling ring bracket is assembled to enable the small cooling ring and The center of the large cooling ring is located on the same straight line; the insulating plate is circular, with a circular notch in the center for the specimen assembly to pass through, and the circular notch has a sealing edge; the insulating plate is fixed on the cooling ring bracket, and the height of the bracket is adjusted so that the outer edge of the sealing plate is located on the boss, and the cooling ring bracket and the boss support the insulating plate; there is at least one contact interface between adjacent insulating plates; the insulating plate and the boss are sealed with a high-temperature sealing gasket and fastened with a sealing bolt, the high-temperature sealing gasket is located between the sealing edge and the specimen assembly, and the sealing edge is fastened by a sealing clamp; the air vents on the insulating plate and the annular closed cylinder provide different experimental gas environments for each contact interface.

[0018] Furthermore, the heating system also includes at least one temperature control box; the heating wire is wound around the specimen assembly and is located in the middle of a relatively long independent specimen without a small cooling ring, and the area where the heating wire is arranged is called the heating zone; the temperature control box is connected to the heating wire, and the power of each heating wire and the preset upper limit heating temperature are regulated by the temperature control box; the heating system can heat the temperature near the heating zone of the specimen assembly to above 1000°C; the heating wire and the small cooling ring enable the temperature of each interface to be independently regulated.

[0019] Furthermore, the overall structure of the pressurizing part of the pressurizing system is a floor-to-ceiling door structure, including a table panel and a movable beam, which is a rigid test frame; the control part includes a high-precision pressure sensor and a pressure control host connected thereto, and the high-precision pressure sensor is located above the specimen assembly.

[0020] A method for efficiently measuring interface contact thermal resistance under multiple temperature conditions and multiple gas environments, the steps of the measurement method are as follows:

[0021] Step 1). According to the test conditions required by the experiment, stack the cylindrical independent specimens into a specimen assembly in sequence;

[0022] Step 2). Fix the lower end of the specimen assembly in the channel of the large cooling ring so that the specimen assembly is located on the center line of the pressurized system, and install the cooling ring bracket around the specimen assembly;

[0023] Step 3). Install the first insulation sheet to the lower middle part of the independent specimen 2011 at the lower end of the specimen assembly;

[0024] Step 4). Install the first small cooling ring on the cooling ring bracket, install the first small cooling ring to the middle of the part of the independent specimen 2011 at the bottom of the specimen assembly that does not enter the large cooling ring, and be located above the first insulation sheet. The small cooling ring is connected to the inlet and outlet metal pipes, and an independent flow throttle valve is installed on the metal pipe. After the installation is completed, check whether the first small cooling ring is leaking. If it is leaking, reinstall the first small cooling ring. If it is not leaking, proceed to the next step;

[0025] Step 5). Connect a thermocouple at the temperature measuring point near the contact interface between the independent specimen 2011 and the independent specimen 2010, and record the number of the thermocouple corresponding to each temperature measuring point. The other end of the thermocouple is connected to the temperature acquisition system;

[0026] Step 6). Wrap the first heating wire around the middle of the specimen 2010, and connect the other end of the heating wire to the temperature control box;

[0027] Step 7). Fill the first insulation sheet with aerogel insulation felt and perlite powder to a position slightly higher than the heating wire on the independent test piece 2010;

[0028] Step 8). Install the second insulation sheet to the middle and upper part of the independent test piece 2010, compact the insulation filler on the first insulation sheet through the second insulation sheet, and check whether the sealed space between the first and second insulation sheets is leaking. If there is a leak, reseal the leaking place. If there is no leak, proceed to the next step;

[0029] Step 9). Repeat step 5) and install a thermocouple near the contact interface between the independent specimen 2010 and the independent specimen 209;

[0030] Step 10). Install a second small cooling ring on the cooling ring bracket, located in the middle of the independent test piece, and check the sealing of the second small cooling ring;

[0031] Step 11). Fill the second insulation sheet with aerogel insulation felt and perlite powder to a position slightly higher than the small cooling ring on the independent specimen 209;

[0032] Step 12). Repeat step 8) to install the third insulation sheet, repeat step 5) to install the thermocouple near the contact interface between the independent specimen 209 and the independent specimen 208, repeat step 6) to install the second heating wire in the middle of the independent specimen 208, repeat step 7) to fill the third insulation sheet, repeat step 8) to install the fourth insulation sheet;

[0033] Step 13). Repeat steps 9)-12) until the eleventh insulation sheet is installed;

[0034] Step 14). Fix the upper independent specimen 201 of the specimen assembly into the channel of the large cooling ring, and apply an initial force to the specimen assembly through the pressure control host;

[0035] Step 15). Connect the small cooling ring and the large cooling ring to the cooling system body outside the annular closed cylinder;

[0036] Step 16). According to the experimental needs, vacuum or replace the experimental gas environment of each independent sealed space where each contact interface is located through the vent;

[0037] Step 17). Load the pressure to the pressure point required for the first test and set it to automatic program control;

[0038] Step 18). Put the heating wire into use and slowly increase the power to prevent the heating wire from being burned by a sudden increase in power;

[0039] Step 19). When heated to a certain temperature, slowly adjust the heating power of a single or multiple heating wires through the temperature control box and adjust the cooling medium flow of the small cooling ring and the large cooling ring through the flow control valve, so that the temperature of each contact interface gradually reaches the temperature condition required for the test;

[0040] Step 20). When the temperature of the temperature measuring point near the interface is stable, record the temperature of the temperature measuring point;

[0041] Step 21). After recording the data, debug the next pressure condition and repeat steps 19) and 20).

[0042] The beneficial effects of the present invention are:

[0043] 1. The multi-stage heating and multi-stage cooling and specimen assembly of the present invention greatly improve the efficiency of measuring contact thermal resistance, and can efficiently complete the contact thermal resistance test of specimens of different materials and different surface roughness under multiple different temperature conditions and different gas environments at one time, saving a lot of manpower, material resources and time, so that the economy of contact thermal resistance test is significantly improved, and the contact surfaces of the loaded multiple specimens are processed in the same time and space and the same batch, which reduces the influence of the deviation of the specimen surface morphology on the measurement result, and improves the measurement accuracy of interface contact thermal resistance.

[0044] 2. The multi-stage heating wire of the present invention is directly wound around the test piece, and the heating wire is not affected by the pressurized load, so that the upper limit of the pressure that can be loaded by the pressurized system is higher, which effectively increases the working pressure range of the measuring device. In addition, this heating wire arrangement integrates the test piece and the heating body into one, which facilitates the protection of radial heat dissipation of the test piece and the heating body.

[0045] 3. The heating wires and cooling rings of the present invention are alternately arranged on the specimen assembly, so that the temperature of each contact interface can be adjusted independently. A single experiment can complete tests under multiple different temperature conditions, and the specimens at both ends of the specimen assembly are doubly cooled by a small cooling ring and a large cooling ring, ensuring that the pressure sensor and the table panel of the pressurization system are not affected by axial high temperature, thereby improving the upper temperature limit of the measuring device.

[0046] 4. The thermal insulation box of the present invention takes into account the function of the isolation cover, saving the material cost of manufacturing the isolation cover. The cylindrical cavity of the thermal insulation box leaves enough space for hand operation, which greatly facilitates the installation of test pieces, the fixation of the cooling ring assembly, the arrangement of temperature measurement points and the filling of multi-layer thermal insulation barriers. The boss on the annular closed cylinder of the thermal insulation box and the insulating sheet in the cooling ring assembly jointly construct a plurality of closed spaces centered on the contact interface. Different gases are filled into each closed space through corresponding air vents, so that the measuring device can complete tests under various gas environments in a single experiment.

[0047] 5. The multi-layer thermal insulation barrier of the present invention replaces the expensive thermal radiation shielding layer or the complex temperature compensation device, economically and effectively reduces the radial heat dissipation of the test piece, and further improves the measurement accuracy of the interface contact thermal resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a front view of the present invention;

[0049] Figure 2 It is the distribution diagram of the test piece assembly, cooling ring and heating wire of the present invention;

[0050] Figure 3 is an assembly diagram of the cooling ring and the test piece assembly of the present invention;

[0051] Figure 4 is an assembly diagram of the heat insulating sheet, the test piece assembly and the boss of the present invention;

[0052] Figure 5 It is a cooling system diagram of the present invention. DETAILED DESCRIPTION

[0053] In conjunction with the accompanying drawings, the technical solution of the present invention is further and more detailedly described below by taking five-level heat flow as an example.

[0054] according to Figures 1 to 5 A device for efficiently measuring interface contact thermal resistance under multi-temperature conditions and multi-gas environments includes an insulation box 1, a specimen assembly 2, a cooling system 3, a heating system 4, a pressurizing system 5, a thermocouple 7 and a temperature acquisition system 8.

[0055] The heat preservation box 1 is divided into two layers, the inner layer is a cylindrical cavity 101 with a diameter of 200 mm, and the outer layer is an annular sealed cylinder 102, and an annular boss 103 is provided on the inner wall of the annular sealed cylinder 102. The specimen assembly 2 is located in the middle of the cylindrical cavity 101, and the remaining space of the cylindrical cavity 101 is filled with aerogel insulation felt, and the gap between the insulation felt and the specimen is filled with perlite powder. The multi-layer insulation effectively reduces the radial heat dissipation of the specimen, ensuring that the specimen is always in a one-dimensional heat conduction state during the experiment. The cooling system 3 includes an air compressor 301, a constant temperature water tank 302, a recovery water tank 303, a water pump 304, a flow meter 305, a flow regulating valve 306 and a cooling ring assembly 6. The cooling ring assembly 6 includes a small cooling ring 601, a large cooling ring 6011, a high temperature sealing gasket 602, a sealing clamp 603, a cooling ring bracket 604, an insulating sheet 605, a sealing edge 606, a cooling ring inlet and outlet metal pipe 607, a cooling ring bracket connecting buckle 608 and a sealing bolt 609. The heating system 4 includes a heating wire 401 and a temperature control box 402. The pressurizing system 5 mainly includes a table panel 501, a moving beam 502, a pressure sensor 503 and a pressure control host 504.

[0056] In this embodiment, the test piece assembly 2 is composed of 11 independent test pieces, and the outer diameter of the independent test pieces is 30 mm. Among them, the two end test pieces, namely, test piece 201 and test piece 2011, are 110 mm long at most, and the five longer test pieces, namely, test piece 202, test piece 204, test piece 206, test piece 208, and test piece 2010, are 100 mm long, and the remaining four are 80 mm long. The end test pieces of the test piece assembly 2, namely, test piece 201 and test piece 2011, are connected to the large cooling ring 6011. After the connection, a 30 mm long part of the end test piece enters the cooling ring channel. The test piece assembly 2 has a total of 10 contact interfaces. In this embodiment, temperature measuring points with radial depths of 5 mm and 15 mm are set at 5 mm, 15 mm, and 25 mm from each interface in the axial direction of the test piece. Each temperature measuring point corresponds to a thermocouple 7, and the other end of the thermocouple 7 is connected to the temperature acquisition system 8. In this embodiment, the five independent heating wires 401 are all 30 mm long. Each heating wire 401 is respectively wound around the middle of the five long specimens. The other end of the heating wire is connected to the temperature control box 402. The working state of each heating wire 401 is independently controlled by the corresponding temperature control box 402. In this embodiment, the six independent small cooling rings 601 have an inner diameter of 30 mm, an outer diameter of 50 mm, and a height of 10 mm. After the small cooling rings 601 are fixed on the cooling ring bracket 604, they are assembled in sequence to the two end specimens, i.e., the middle of the portion of the specimen 201 and the specimen 2011 that does not enter the large cooling ring 6011, and the four short specimens, i.e., the middle of the specimens 203, 205, 207, and 209. One end of the small cooling ring 601 is connected to the cooling system 3 body outside the heat preservation box through an inlet pipe, on which a flow meter 305 and a flow regulating valve 306 are provided, and the other end is connected to the recovery water tank 303 through an outlet pipe, on which a flow regulating valve 306 is also provided. The air compressor 301 and the water pump 304 are connected in parallel to the inlet pipe, and the water pump 304 and the constant temperature water tank 302 are connected in series to the inlet pipe.

[0057] The present invention can adopt air cooling, water cooling or air-water mixed cooling as needed. During air cooling, the air compressor 301 works and the water pump 304 stops. During water cooling, the water pump 304 works and the air compressor 301 does not start. During air-water mixed cooling, both the air compressor 301 and the water pump 304 are put into use.

[0058] The inner wall of the annular sealed cylinder 102 of the present invention is provided with bosses 103 at equal intervals along the height direction; an air vent is respectively provided at the upper and lower diagonal positions of the annular sealed cylinder 102 between adjacent bosses 103, and the cylindrical cavity 101 can be evacuated or replaced with other experimental gases through the air vent. For example, the upper air vent is connected to a He gas cylinder and the lower air vent is exhausted, so that the experimental gas environment can be replaced from air to He gas; the lower air vent is connected to a CO2 gas cylinder and the upper air vent is exhausted, so that the experimental gas environment can be replaced from air to CO2 gas. The insulating sheet 605 is circular, with a circular notch in the center for accommodating the specimen assembly 2 to pass through, and the circular notch has a sealing edge 606; the insulating sheet 605 is fixed on the cooling ring bracket 604, and the height of the cooling ring bracket 604 is adjusted so that the outer edge of the sheet 605 is located on the boss 103 on the inner wall of the annular closed cylinder; there is at least one contact interface between adjacent insulating sheets 605; the insulating sheet 605 and the specimen are sealed with a high-temperature sealing gasket 602, which is located between the sealing edge 606 and the specimen assembly 2, and the sealing edge 606 is fastened with a sealing clamp 603. The insulating sheet 605 and the boss 103 are also sealed with a high-temperature sealing gasket 602, and are fastened with a sealing bolt 609. According to the experimental needs, a number of insulating sheets 605 can be selected, and combined with the vents on the annular closed cylinder 102, each contact interface can have a different experimental gas environment. In this embodiment, 11 insulating sheets 605 are selected to create an independent gas environment for each contact interface.

[0059] When the present invention is used, the specimen assembly 2 is fixed on the center line of the pressurizing system 5, and an initial force is applied to the specimen assembly 2 through the pressure control host 504. After ensuring that the installation is correct, the pressure is slowly added to the working conditions required by the experiment through the pressure control host 504, and then the pressure control is set to program automatic control. The program automatic control of the pressurizing system 5 can make the pressure on the specimen assembly 2 constant during the experiment.

[0060] When the present invention uses five-level heat flow heating, the flow rate of the small cooling ring 601 and the large cooling ring 6011 near the interface and the power of the heating wire 401 should be reasonably adjusted according to the different required temperatures of different interfaces. During the initial temperature rise, each heating wire 401 is put into use with the same power. Because there is a difference between the heating temperature and the interface temperature, when the heating temperature approaches the required interface temperature condition, the power of the heating wire 401 near the interface can be reduced, and the flow rate of the cooling medium in the cooling ring 601 near the interface can be adjusted. When the interface temperature reaches stability, the data of each temperature measurement point is recorded.

[0061] The method for testing the contact thermal resistance using the above-mentioned device for measuring the interface contact thermal resistance comprises the following steps:

[0062] Step 1: According to the test conditions required by the experiment, stack the independent specimens in a reasonable order to form a specimen assembly 2;

[0063] Step 2: Fix the lower end of the specimen assembly 2 in the channel of the large cooling ring 6011, so that the specimen assembly 2 is located on the center line of the pressurized system, and install the cooling ring bracket 604 around the specimen assembly 2;

[0064] Step 3: Install the first thermal insulation sheet 605 to the lower middle part of the independent test piece 2011 at the lower end of the test piece assembly 2;

[0065] Step 4: Install the first small cooling ring 601 on the cooling ring bracket 604, install the first small cooling ring 601 to the middle of the part of the independent test piece 2011 at the bottom of the test piece assembly 2 that does not enter the large cooling ring 6011, and place it above the first insulation sheet 605. The cooling ring 601 is connected to the cooling ring inlet and outlet metal pipes 607, and an independent flow throttle valve 306 is installed on the pipe. After the installation is completed, check whether the cooling ring is leaking. If it is leaking, reinstall the cooling ring. If it is not leaking, proceed to the next step.

[0066] Step 5: Connect the thermocouple 7 at the temperature measuring point near the contact interface between the independent test piece 2011 and the independent test piece 2010, and record the number of the thermocouple 7 corresponding to each temperature measuring point. The other end of the thermocouple 7 is connected to the temperature acquisition system 8;

[0067] Step 6: Wrap the first heating wire 401 around the middle of the test piece 2010, and connect the other end of the heating wire 401 to the temperature control box 402;

[0068] Step 7: Fill the first insulation sheet 605 with aerogel insulation felt and perlite powder to a position slightly higher than the heating wire 401 on the test piece 2010;

[0069] Step 8: Install the second insulation sheet 605 to the middle and upper part of the independent test piece 2010, compact the thermal insulation filler on the first insulation sheet 605 through the second insulation sheet 605, and check whether the sealed space between the first and second insulation sheets is leaking. If there is leakage, reseal the leaking place. If there is no leakage, proceed to the next step.

[0070] Step 9: Repeat step 5 and install a thermocouple near the contact interface between the independent specimen 2010 and the independent specimen 209;

[0071] Step 10: Install a second small cooling ring 601 on the cooling ring support 604, located in the middle of the test piece 209, and check the sealing of the cooling ring;

[0072] Step 11: Fill the second insulation sheet 605 with aerogel insulation felt and perlite powder to a position slightly higher than the small cooling ring 601 on the test piece 209;

[0073] Step 12: Repeat step 8 to install the third insulation sheet 605, repeat step 5 to install the thermocouple near the contact interface between the test piece 209 and the test piece 208, repeat step 6 to install the second heating wire 401 in the middle of the test piece 208, repeat step 7 to fill the third insulation sheet 605, and repeat step 8 to install the fourth insulation sheet 605;

[0074] Step 13: Repeat steps 9, 10, 11, and 12 until the eleventh insulation partition is installed;

[0075] Step 14: Fix the upper independent specimen 201 of the specimen assembly 2 into the channel of the large cooling ring 6011, and apply an initial force to the specimen assembly 2 through the pressure control host 504;

[0076] Step 15: Connect the small cooling ring 601 and the large cooling ring 6011 to the cooling system 3 body outside the annular sealed cylinder 102;

[0077] Step 16: According to the experimental requirements, vacuum or replace the experimental gas environment of each independent sealed space where each contact interface is located through the vent;

[0078] Step 17: Load the pressure to the pressure point required for the first test and set it to automatic program control;

[0079] Step 18: Put the heating wire 401 into use and slowly increase the power to prevent the heating wire 401 from being burned by a sudden increase in power;

[0080] Step 19: When heated to a certain temperature, the heating power of a single or multiple heating wires 401 is slowly adjusted through the temperature control box 402, and the flow rate of the cooling medium of the small cooling ring 601 and the large cooling ring 6011 is adjusted through the flow regulating valve 306, so that the temperature of each contact interface gradually reaches the temperature condition required for the test;

[0081] Step 20: When the temperature of the temperature measuring point near the interface is stable, record the temperature of the temperature measuring point;

[0082] Step 21: After recording the data, debug the next pressure condition and repeat steps 19 and 20.

[0083] In short, this device can conveniently, quickly and accurately obtain the temperature of each temperature measuring point near the interface to be tested, and can efficiently complete the contact thermal resistance test of specimens of different materials and different surface roughness under multiple different temperature conditions and different gas environments in one experiment.

[0084] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A device for efficiently measuring interface contact thermal resistance under multi-temperature conditions and multi-gas environments, characterized in that: It comprises a heat preservation box (1), a test piece assembly (2), a cooling system (3), a heating system (4) and a pressurizing system (5); The thermal insulation box (1) comprises a cylindrical cavity (101) and an annular sealed cylinder (102), and the specimen assembly (2) is located in the cylindrical cavity (101); the thermal insulation box (1) comprises an inner and outer layer, the inner layer being a cylindrical cavity (101) with a diameter of 200 mm, the specimen assembly (2) being located in the middle thereof, the space between the specimen assembly (2) and the cylindrical cavity (101) being filled with aerogel thermal insulation felt, and perlite powder is used to fill the gap between the thermal insulation felt and the specimen assembly (2). The outer layer is an annular sealed cylinder (102), the interior of which is filled with aerogel insulation felt; bosses (103) are provided at equal intervals in the height direction between the inner wall of the annular sealed cylinder (102) and the specimen assembly (2), and bolt holes are provided at equal intervals on the bosses (103); an air vent is provided at the upper and lower diagonal positions of the annular sealed cylinder (102) between adjacent bosses (103), and the cylindrical cavity (101) is evacuated or the experimental gas is replaced through the air vent; The main body of the test piece assembly (2) comprises at least three cylindrical independent test pieces (201-2011) with the same diameter, which are connected by end face contact and stacking; The cooling system (3) is mainly located outside the heat preservation box (1), and the portion of the cooling system (3) located in the cylindrical cavity (101) includes at least three independent cooling ring assemblies (6); the cooling ring assembly (6) includes at least two small cooling rings (601) and two large cooling rings (6011), the small cooling rings (601) are sleeved on the specimen assembly (2), and the upper and lower ends of the specimen assembly (2) are connected to the two large cooling rings (6011); the cooling system (3) also includes an air compressor (301), a constant temperature water tank (302), a recovery water tank (303), and a water pump (304), a flow meter (305) and a flow regulating valve (306); a small cooling ring (601) is sleeved on different axial positions of the specimen assembly (2) and is away from the positions of each contact interface; two large cooling rings (6011) are connected to the two ends of the specimen assembly (2), so that the independent specimens (201, 2011) at the two ends of the specimen assembly (2) are doubly cooled to protect the pressurization system (5); independent flow regulating valves (306) are provided on the inlet pipes of the small cooling ring (601) and the large cooling ring (6011), and the flow regulating valve (306) is located outside the thermal insulation box (1); The at least three independent cooling ring assemblies (6) further include at least three independent detachable cooling ring brackets (604) and at least three insulating thin plates (605); the inner diameter of the small cooling ring (601) and the large cooling ring (6011) are equal to the outer diameter of the specimen assembly (2), and the inner diameter is provided with a sealing edge (606), and the sealing edge (606) and the specimen assembly (2) are sealed by a high-temperature sealing gasket (602) and fastened by a sealing clamp (603); the inlet and outlet metal pipes (607) of the small cooling ring (601) and the large cooling ring (6011) are fixed on the detachable cooling ring bracket (604); the detachable cooling ring brackets (604) are connected to each other via connecting buckles (608) on the brackets; the height of each cooling ring bracket (604) can be adjusted according to the position of the cooling ring (601) on the specimen assembly (2); the complete cooling ring bracket (604) is assembled so that the small cooling ring (601) and the large cooling ring (6011) are 011) are located on the same straight line; the insulating thin plate (605) is circular, and has a circular notch at the center for the specimen assembly (2) to pass through, and the circular notch has a sealing edge (606); the insulating thin plate (605) is fixed on the cooling ring bracket (604), and the height of the bracket is adjusted so that the outer edge of the sealing thin plate (605) is located on the boss (103), and the cooling ring bracket (604) and the boss (103) support the insulating thin plate (605); adjacent insulating thin plates (605) are There is at least one contact interface between the heat insulating sheet (605) and the boss (103); a high temperature sealing gasket (602) is used to seal and a sealing bolt (609) is used to fasten the heat insulating sheet (605) and the boss (103); the high temperature sealing gasket (602) is located between the sealing edge (606) and the specimen assembly (2); the sealing edge (606) is fastened by a sealing clamp (603); the vents on the heat insulating sheet (605) and the annular sealed cylinder (102) enable different experimental gas environments to be provided at each contact interface; The heating system (4) comprises at least one independent heating wire (401). When there are multiple heating wires (401), the heating wires (401) are located at different axial positions of the specimen assembly (2) and away from each contact interface, and the heating wires (401) and the small cooling rings (601) are alternately arranged on adjacent independent specimens (201-2011); the heating system (4) also comprises at least one temperature control box (402); the heating wires (401) are wound around the specimen assembly (2) and are located in the middle of a relatively long independent specimen without a small cooling ring (601), and the area where the heating wires are arranged is called a heating zone; the temperature control box (402) is connected to the heating wires (401), and the power and the preset upper limit heating temperature of each heating wire (401) are regulated by the temperature control box (402); the heating system (4) can heat the temperature near the heating zone of the specimen assembly (2) to above 1000°C; the heating wires (401) and the small cooling rings (601) enable the temperature of each interface to be independently regulated; The pressurizing system (5) comprises a pressurizing part and a control part. The specimen assembly (2) is fixed on the center line of the pressurizing system (5). The pressurizing part is a rigid test frame. The heat preservation box (1) is located in the rigid test frame. The pressurizing part transfers the load to the specimen assembly (2), and the control part controls the pressure.

2. The device for efficiently measuring interface contact thermal resistance under multi-temperature conditions and multi-gas environments according to claim 1, characterized in that: The main body of the test piece assembly (2) is composed of independent cylindrical test pieces (201-2011); The diameters of the independent cylindrical test pieces (201-2011) are the same; the test pieces (201, 2011) at both ends of the test piece assembly (2) are connected to a large cooling ring (6011), and the connection is sealed with a high-temperature sealing gasket (602) and fastened with a sealing clamp (603); a through hole is opened in the middle of a portion of the test pieces located in the large cooling ring (6011) along the flow direction of the small cooling ring (601) to enhance cooling of the end portions; Each independent cylindrical test piece (201-2011) is provided with a temperature measuring point at an axial position, and each temperature measuring point is provided with a thermocouple (7), and the other end of the thermocouple (7) is connected to a temperature acquisition system (8).

3. The device for efficiently measuring interface contact thermal resistance under multi-temperature conditions and multi-gas environments according to claim 1, characterized in that: The overall structure of the pressurizing part of the pressurizing system (5) is a floor-standing door-type structure, comprising a table panel (501) and a movable beam (502), which is a rigid test frame; the control part comprises a high-precision pressure sensor (503) and a pressure control host (504) connected thereto, and the high-precision pressure sensor (503) is located above the test piece assembly (2).

4. The method for efficiently measuring the interface contact thermal resistance device under multi-temperature conditions and multi-gas environments according to claim 1 is characterized in that: Step 1). According to the test conditions required by the experiment, the cylindrical independent test pieces (201-2011) are stacked in sequence to form a test piece assembly (2); Step 2). Fix the lower end of the specimen assembly (2) in the channel of the large cooling ring (6011), so that the specimen assembly (2) is located on the center line of the pressurizing system (5), and install a cooling ring bracket (604) around the specimen assembly (2); Step 3). Install the first insulation sheet (605) to the lower middle part of the independent specimen (2011) at the lower end of the specimen assembly (2); Step 4). Install the first small cooling ring (601) on the cooling ring bracket (604), install the first small cooling ring (601) to the middle of the part of the independent test piece (2011) at the bottom of the test piece assembly (2) that does not enter the large cooling ring (6011), and is located above the first insulation sheet (605). The small cooling ring (601) is connected to the inlet and outlet metal pipes (607), and an independent flow throttle valve (306) is installed on the metal pipe (607). After the installation is completed, check whether the first small cooling ring (601) is leaking. If it is leaking, reinstall the first small cooling ring (601). If it is not leaking, proceed to the next step; Step 5). Connect a thermocouple (7) at a temperature measuring point near the contact interface between the independent specimen (2011) and the independent specimen (2010), and record the number of the thermocouple (7) corresponding to each temperature measuring point. The other end of the thermocouple (7) is connected to the temperature acquisition system (8); Step 6). Wrap the first heating wire (401) around the middle of the test piece (2010), and connect the other end of the heating wire (401) to the temperature control box (402); Step 7). Fill the first insulation sheet (605) with aerogel insulation felt and perlite powder to a position slightly higher than the heating wire (401) on the independent test piece (2010); Step 8). Install the second insulation sheet (605) to the middle and upper part of the independent test piece (2010), compact the thermal insulation filler on the first insulation sheet (605) through the second insulation sheet (605), and check whether the sealed space between the first and second insulation sheets is leaking. If there is a leak, reseal the leaking place. If there is no leak, proceed to the next step. Step 9). Repeat step 5) to install a thermocouple (7) near the contact interface between the independent specimen (2010) and the independent specimen (209); Step 10). Install a second small cooling ring (601) on the cooling ring support (604), located in the middle of the independent test piece (209), and check the sealing of the second small cooling ring (601); Step 11). Fill the second insulation sheet (605) with aerogel insulation felt and perlite powder to a position slightly higher than the small cooling ring (601) on the independent specimen (209); Step 12). Repeat step 8) to install the third thermal insulation sheet (605), repeat step 5) to install the thermocouple (7) near the contact interface between the independent specimen (209) and the independent specimen (208), repeat step 6) to install the second heating wire (401) in the middle of the independent specimen (208), repeat step 7) to fill the third thermal insulation sheet (605), and repeat step 8) to install the fourth thermal insulation sheet (605); Step 13). Repeat steps 9)-12) until the eleventh insulation sheet (605) is installed; Step 14). Fix the upper independent specimen (201) of the specimen assembly (2) into the channel of the large cooling ring (6011), and apply an initial force to the specimen assembly (2) through the pressure control host (504); Step 15). Connect the small cooling ring (601) and the large cooling ring (6011) to the cooling system (3) body outside the annular sealed cylinder (102); Step 16). According to the experimental needs, vacuum or replace the experimental gas environment of each independent sealed space where each contact interface is located through the vent; Step 17). Load the pressure to the pressure point required for the first test and set it to automatic program control; Step 18). Put the heating wire (401) into use and slowly increase the power to prevent the heating wire (401) from being burned by a sudden increase in power; Step 19). When heated to a certain temperature, the heating power of a single or multiple heating wires (401) is slowly adjusted through the temperature control box (402) and the cooling medium flow of the small cooling ring (601) and the large cooling ring (6011) is adjusted through the flow control valve (306), so that the temperature of each contact interface gradually reaches the temperature condition required for the test; Step 20). When the temperature of the temperature measuring point near the interface is stable, record the temperature of the temperature measuring point; Step 21). After recording the data, debug the next pressure condition and repeat steps 19) and 20).

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