A high vacuum performance test system for thermal protection materials

Abstract

The application discloses a kind of high vacuum performance test systems of heat protection material, belong to heat protection material performance test equipment technical field, solve the technical problem that the high vacuum heating device in prior art carries out high vacuum performance test, and heating is caused by clamping mode uneven heating of test sample.The test system of the application includes the high vacuum heating device and vacuum pumping unit connected;Vacuum pumping unit can be pumped to the high vacuum heating device to the vacuum degree ≤6.7×10 ‑6 Pa;High vacuum heating device is equipped with isothermal heating zone, and heat protection material sample is placed in isothermal heating zone by sample bracket.The application realizes the uniform heating when heat protection material carries out high vacuum performance test.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal protection material performance testing, and particularly relates to a thermal protection material high-vacuum performance testing system. BACKGROUND

[0002] Thermal protection material refers to a coating material coated on the surface of a substrate, which can isolate the substrate material from direct contact with an oxidizing atmosphere.

[0003] Thermal protection material plays an important role in modern energy industry and aerospace industry, and has been widely applied in gas turbine, spacecraft, rocket engine, nuclear reactor, submarine, thermal power generation and petroleum chemical equipment and the like.

[0004] Thermal protection material high-vacuum performance testing refers to heating a sample to a test temperature for a short time, maintaining the temperature, cooling to room temperature, performing a certain number of cycle tests, measuring the weight change of the sample and performing static air oxidation resistance performance testing to measure the damage time of the coating.

[0005] The existing high-vacuum heating device has complex results, and the measurement results have low reliability. SUMMARY

[0006] In view of the above analysis, the present application aims to provide a thermal protection material high-vacuum performance testing system to solve the problem of complex structure of the high-vacuum heating device in the prior art and low reliability of the measurement results.

[0007] The main purpose of the present application is achieved by the following technical solutions:

[0008] The present application provides a thermal protection material high-vacuum performance testing system, which comprises a high-vacuum heating device, a vacuum pumping unit and a temperature measuring device.

[0009] The high-vacuum heating device comprises a horizontal vacuum heating furnace; a hollow tubular graphite heating body is arranged in the horizontal vacuum heating furnace; a first graphite sleeve and a second graphite sleeve which are identical in structure are attached to the outer surfaces of the left end and the right end of the tubular graphite heating body, and the middle part of the outer surface of the tubular graphite heating body corresponds to an isothermal heating zone in the internal cavity; a thermal protection material sample is placed in the isothermal heating zone by a sample holder;

[0010] The vacuum pumping unit is used to pump the high-vacuum heating device to a vacuum degree of less than or equal to 6.7x10 -6 Pa;

[0011] The temperature measuring device is arranged outside the high-vacuum heating device and is used to measure the real-time temperature of the thermal protection material in the isothermal heating zone.

[0012] In a possible design, the testing system further comprises a sample moving and weighing unit;

[0013] The sample moving and weighing unit comprises a pull rod, a counterweight, a 7-shaped support frame, a first lifting belt, a balance tray, an electronic balance, a balance hook, a second lifting belt and a clamp for clamping the thermal protection material sample;

[0014] The counterweight is arranged at the first end of the pull rod, the 7-shaped support frame is fixed at the second end of the pull rod, the support frame is arranged in the vertical direction, the first lifting belt is arranged at the top end of the 7-shaped support frame, the balance tray is fixed below the first lifting belt, the electronic balance is placed on the balance tray, the balance hook is arranged at the bottom of the balance tray, the balance hook is fixedly connected with the clamp through the second lifting belt, and the clamp is used for clamping the thermal protection material sample.

[0015] In a possible design, the pull rod is columnar, and the counterweight is provided with a cavity for clamping on the pull rod.

[0016] In a possible design, the outer surface of the second graphite sleeve is sleeved with a third graphite sleeve, and the outer surface of the third graphite sleeve is sleeved with a fourth graphite sleeve; the third graphite sleeve and the fourth graphite sleeve have the same structure and the lengths of the third graphite sleeve and the fourth graphite sleeve are less than those of the first graphite sleeve and the second graphite sleeve.

[0017] The left end portions of the tubular graphite heating body, the first graphite sleeve and the third graphite sleeve are arranged in alignment; the right end portions of the tubular graphite heating body, the second graphite sleeve and the fourth graphite sleeve are arranged in alignment; the upper portion of the third graphite sleeve is connected with the input electrode, and the upper portion of the fourth graphite sleeve is connected with the output electrode.

[0018] The tubular graphite heating body is sleeved with a tubular heat insulation layer, the length of the tubular heat insulation layer is less than that of the tubular graphite heating body, and the left end portion and the right end portion of the tubular heat insulation layer correspondingly cover part of the first graphite sleeve and part of the second graphite sleeve.

[0019] In a possible design, the test system further comprises a water cooling unit, and the water cooling unit comprises a water cooling sandwich structure, an input electrode water cooling structure and an output electrode water cooling structure.

[0020] The water cooling sandwich structure is sleeved on the tubular heat insulation layer, and a cavity is arranged between the water cooling sandwich structure and the tubular heat insulation layer; the input electrode water cooling structure is arranged outside the input electrode, and the output electrode water cooling structure is arranged outside the output electrode.

[0021] The first cooling water pipeline is arranged in the water cooling sandwich structure; the second cooling water pipeline is arranged in the input electrode water cooling structure and the output electrode water cooling structure; and the first cooling water pipeline and the second cooling water pipeline are in communication.

[0022] A cooling water inlet is arranged at the top of the horizontal vacuum heating furnace, and a cooling water outlet is arranged at the bottom of the horizontal vacuum heating furnace; and the first cooling water pipeline is in communication with the cooling water inlet and the cooling water outlet.

[0023] In a possible design, the test system further comprises a water cooling supply unit, the water cooling supply unit comprising a water storage tank, a refrigerating machine, a water supply pump and a purification filter;

[0024] The water storage tank is provided with a water supplementing opening and a water returning opening, the water returning opening is connected with the cooling water outlet through a water returning pipeline, and the water introduced through the water supplementing opening and the water returning opening is injected into the water storage tank after being purified by the purification filter;

[0025] The refrigerating machine is used for cooling the cooling water in the water storage tank, and the water supply pump pressurizes the cooling water after cooling and supplies the cooling water to the cooling water inlet of the horizontal vacuum heating furnace through a water supply pipeline.

[0026] In a possible design, the left end of the furnace body of the horizontal vacuum heating furnace is provided with an optical window, the temperature measuring device is arranged outside the optical window, and the temperature measuring device can measure the temperature of the thermal protection material sample on the sample holder through the optical window to obtain the real-time temperature of the thermal protection material sample.

[0027] The right end of the furnace body of the horizontal vacuum heating furnace is provided with a furnace cover, the thermal protection material sample is placed in the isothermal heating zone by using the sample holder after the furnace cover is opened.

[0028] In a possible design, the vacuum pumping unit comprises a vacuum pipeline, a vacuum measuring device, a first-stage vacuum equipment and a second-stage vacuum equipment, the first-stage vacuum equipment and the second-stage vacuum equipment are arranged in series.

[0029] The upper end of the vacuum pipeline penetrates through the bottom of the horizontal vacuum heating furnace and is communicated with the isothermal heating zone, the lower end of the vacuum pipeline is provided with a tee joint, one end of the tee joint is connected with the vacuum measuring device, and the other end is connected with the first-stage vacuum equipment and the second-stage vacuum equipment in sequence.

[0030] In a possible design, the first-stage vacuum equipment adopts a mechanical vacuum pump, and the second-stage vacuum equipment adopts a turbo molecular pump.

[0031] In a possible design, the test system further comprises a double-layer test platform, the double-layer test platform comprising an upper layer platform and a lower layer platform, the high-vacuum heating device is arranged on the upper layer platform, and the vacuum pumping unit is arranged on the lower layer platform.

[0032] Compared with the prior art, the present application can at least realize one of the following beneficial effects:

[0033] (1) the prior art uses a direct clamping heating method to heat the thermal protection material sample, although the structure of the setting method is relatively simple, but the heating method is directly clamped on the sample, which will cause the thermal protection material sample to be heated unevenly.

[0034] (2) the first graphite sleeve and the second graphite sleeve are arranged at both ends of the outer surface of the tubular graphite heating body, so that the heat dissipation of the left end region and the right end region of the tubular graphite heating body can be reduced.

[0035] (3) the third graphite sleeve is arranged outside the first graphite sleeve, and the fourth graphite sleeve is arranged outside the second graphite sleeve, so that the heat dissipation of the left end and the right end of the tubular graphite heating body can be further reduced, thereby further reducing the heat loss of the two ends of the tubular graphite heating body. In addition, the third graphite sleeve and the fourth graphite sleeve can also fix and support the tubular graphite heating body, so that it is fixed at the middle position of the horizontal vacuum heating furnace.

[0036] (4) the high vacuum heating device provided by the present application can perform vacuum environment performance test, the test temperature is 600-2200 DEG C, the limit vacuum reached by the vacuum pumping assembly is ≤6.7*10-6Pa, the temperature control unit can set the heating, holding and cooling time, the temperature control precision is ±10 DEG C, and the multiple cycle test can be performed.

[0037] In the present application, the above technical solutions can be combined with each other to realize more preferred combination schemes. Other features and advantages of the present application will be described in the subsequent specification, and some advantages will become apparent from the specification, or will be understood by implementing the present application. The purpose and other advantages of the present application can be realized and obtained through the contents specifically pointed out in the specification, examples and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0038] The drawings are only used for the purpose of illustrating specific embodiments and are not considered as limiting the present application, and the same reference signs represent the same parts throughout the drawings.

[0039] Figure 1Structure diagram of horizontal heating furnace provided by the present application; wherein, a - inner diameter of tubular graphite heating body; b - outer diameter of tubular graphite heating body; c - outer diameter of water-cooling clamping structure; d - diameter of two end covers of horizontal heating furnace; e - length of isothermal heating zone; f - furnace body length; g - length between two end covers of horizontal heating furnace.

[0040] Figure 2 Structure diagram of sample holder provided by the present application;

[0041] Figure 3 Structure diagram of water-cooling supply unit provided by the present application;

[0042] Figure 4 Structure diagram of sample moving and weighing unit.

[0043] Reference signs:

[0044] 1 - tubular graphite heating body; 2 - first graphite sleeve; 3 - second graphite sleeve; 4 - third graphite sleeve; 5 - fourth graphite sleeve; 6 - isothermal heating zone; 7 - tubular heat insulation layer; 8 - water-cooling clamping structure; 9 - water-cooling structure of leading-in electrode; 10 - water-cooling structure of leading-out electrode; 11 - leading-in electrode; 12 - leading-out electrode; 13 - cooling water inlet; 14 - cooling water outlet; 15 - temperature measuring device; 16 - optical window; 17 - furnace cover; 18 - sample holder; 19 - heat insulation layer support block; 20 - annular support frame; 21 - support rib; 22 - refrigerating machine; 23 - water supply pump; 24 - water storage tank; 25 - water supplement inlet; 26 - water return inlet; 27 - filter; 28 - vacuum measuring device; 29 - molecular vacuum pump; 30 - mechanical vacuum pump; 31 - counterweight; 32 - pull rod; 33 - 7-shaped support frame; 34 - first lifting belt; 35 - electronic balance; 36 - balance tray; 37 - balance hook; 38 - second lifting belt; 39 - clamp; 40 - thermal protection material sample. DETAILED DESCRIPTION

[0045] The preferred embodiments of the present application will be described in detail below with reference to the drawings, wherein the drawings constitute a part of the present application and serve to explain the principles of the embodiments of the present application, but are not used to limit the scope of the present application.

[0046] The high vacuum performance test of thermal protection material, i.e. thermal shock test under vacuum condition, refers to that the sample is heated to test temperature for a short time under high vacuum, then cooled to room temperature, and the cycle test is performed for a certain number of times, the weight change of the sample is measured, and the oxidation resistance performance test in static air is performed to measure the damage time of the coating.

[0047] Test temperature: 600-2200℃, temperature control accuracy: ±10℃, ultimate vacuum degree: ≤6.7×10-6Pa.

[0048] The application provides a high-vacuum performance testing system for heat protection materials, which comprises a high-vacuum heating device, a vacuumizing unit and a temperature measuring device 15. Figure 1 The high-vacuum heating device comprises a horizontal vacuum heating furnace, and a hollow tubular graphite heating body 1 is arranged in the horizontal vacuum heating furnace; a first graphite sleeve 2 and a second graphite sleeve 3 which are of the same structure are attached to the outer surfaces of the left end and the right end of the tubular graphite heating body 1; the middle part of the outer surface of the tubular graphite heating body 1 corresponds to an isothermal heating zone 6; a heat protection material sample 40 is placed in the isothermal heating zone 6 through a sample bracket 18; the vacuumizing unit can vacuumize the high-vacuum heating device to a vacuum degree of less than or equal to 6.7*10 -6 Pa; the temperature measuring device 15 is arranged outside the high-vacuum heating device and is used for measuring the real-time temperature of the heat protection material in the isothermal heating zone 6.

[0049] Specifically, the high-vacuum heating device of the application adopts a horizontal high-vacuum heating furnace, a hollow tubular graphite heating body 1 is arranged horizontally at the central position of the furnace body of the horizontal high-vacuum heating furnace, a first graphite sleeve 2 is arranged on the outer surface of the left end of the tubular graphite heating body 1, a second graphite sleeve 3 is arranged on the outer surface of the right end of the tubular graphite heating body 1, the first graphite sleeve 2 and the second graphite sleeve 3 are attached to the tubular graphite heating body 1, the first graphite sleeve 2 and the second graphite sleeve 3 correspond to left end region and right end region in the inner cavity of the tubular graphite heating body 1, and the middle part of the outer surface of the tubular graphite heating body 1 (i.e. the region not covered by the first graphite sleeve 2 and the second graphite sleeve 3) is the isothermal heating zone 6; when the first graphite sleeve 2 and the second graphite sleeve 3 are electrified, the tubular graphite heating body 1 is also electrified and starts to heat; after heating for a certain time, the temperature in the isothermal heating zone 6 is more uniform relative to the temperatures of the left end region and the right end region, so that the heat protection material sample 40 can be uniformly heated.

[0050] It should be noted that the thermal conductivity of graphite is just opposite to that of general metal materials, that is, graphite has a very high thermal conductivity coefficient at room temperature, but the thermal conductivity coefficient decreases when the temperature rises, and graphite even becomes a thermal insulator at very high temperature; according to the characteristics of graphite, the first graphite sleeve 2 and the second graphite sleeve 3 are arranged at the two ends of the outer surface of the tubular graphite heating body 1, so that the heat dissipation of the left end region and the right end region of the tubular graphite heating body 1 can be reduced.

[0051] In existing technologies, the thermal protection material sample 40 is heated by direct clamping. Although this method is relatively simple in structure, it results in uneven heating of the sample 40 due to the direct clamping. Compared with existing technologies, this invention, by setting an isothermal heating zone 6, ensures uniform heating of the thermal protection material sample 40, thereby improving the thermal shock test performance of the thermal protection material.

[0052] To further reduce heat dissipation at the first graphite sleeve 2 and the second graphite sleeve 3, a third graphite sleeve 4 is fitted on the outer surface of the second graphite sleeve 3, and a fourth graphite sleeve 5 is fitted on the outer surface of the third graphite sleeve 4. The third graphite sleeve 4 and the fourth graphite sleeve 5 have the same structure and their lengths are both shorter than those of the first graphite sleeve 2 and the second graphite sleeve 3. The left ends of the tubular graphite heating element 1, the first graphite sleeve 2, and the third graphite sleeve 4 are aligned. The right ends of the tubular graphite heating element 1, the second graphite sleeve 3, and the fourth graphite sleeve 5 are aligned. The upper part of the third graphite sleeve 4 is connected to the lead-in electrode 11, and the upper part of the fourth graphite sleeve 5 is connected to the lead-out electrode 12. A tubular heat insulation layer 7 is fitted over the tubular graphite heating element 1. The length of the tubular heat insulation layer 7 is shorter than the length of the tubular graphite heating element 1, and the left and right ends of the tubular heat insulation layer 7 cover a portion of the first graphite sleeve 2 and a portion of the second graphite sleeve 3, respectively.

[0053] Specifically, such as Figure 1 As shown, the present invention provides a third graphite sleeve 4 outside the first graphite sleeve 2 and a fourth graphite sleeve 5 outside the second graphite sleeve 3. The third graphite sleeve 4 is connected to the input electrode 11, and the fourth graphite sleeve 5 is connected to the output electrode 12. By setting the input electrode 11 and the output electrode 12, each graphite sleeve is energized, thereby heating the tubular graphite heating element 1 and ultimately forming an isothermal heating zone 6. In addition, a tubular heat insulation layer 7 is provided on the outer surface of the tubular graphite heating element 1. The length of the tubular heat insulation layer 7 is less than the length of the tubular graphite heating element 1, and a certain gap is provided between the tubular heat insulation layer 7 and the outer surface of the tubular graphite heating element 1. The provision of the tubular heat insulation layer 7 and the certain gap between the tubular heat insulation layer 7 and the tubular graphite heating element 1 can reduce the heat loss in the isothermal heating zone 6.

[0054] Compared with the prior art, the present invention, by providing a third graphite sleeve 4 outside the first graphite sleeve 2 and a fourth graphite sleeve 5 outside the second graphite sleeve 3, can further reduce heat dissipation at the left and right ends of the tubular graphite heating element 1, thereby further reducing heat loss at both ends of the tubular graphite heating element 1. In addition, the third graphite sleeve 4 and the fourth graphite sleeve 5 can also fix and support the tubular graphite heating element 1, ensuring it is fixed in the middle position of the horizontal vacuum heating furnace.

[0055] In order to cool the horizontal high-vacuum heating furnace and the lead-in electrode 11 and the lead-out electrode 12, the test system further comprises a water cooling unit, the water cooling unit comprising a water cooling sandwich structure 8, a lead-in electrode 11 water cooling structure 9 and a lead-out electrode 12 water cooling structure 10; the water cooling sandwich structure 8 is sleeved on the tubular heat insulation layer 7, and a cavity is arranged between the water cooling sandwich structure 8 and the tubular heat insulation layer 7; the lead-in electrode 11 water cooling structure 9 is arranged on the lead-in electrode 11, and the lead-out electrode 12 water cooling structure 10 is arranged on the lead-out electrode 12; the water cooling sandwich structure 8 is internally provided with a first cooling water pipeline; the lead-in electrode 11 water cooling structure 9 and the lead-out electrode 12 water cooling structure 10 are both internally provided with a second cooling water pipeline; the first cooling water pipeline and the second cooling water pipeline are in communication; a cooling water inlet is arranged at the top of the horizontal vacuum heating furnace, and a cooling water outlet 14 is arranged at the bottom of the horizontal vacuum heating furnace; the first cooling water pipeline is in communication with the cooling water inlet 13 and the cooling water outlet 14.

[0056] Specifically, the water cooling unit comprises the water cooling sandwich structure 8, the lead-in electrode 11 water cooling structure 9 and the lead-out electrode 12 water cooling structure 10, wherein the water cooling sandwich structure 8 is internally provided with the first cooling water pipeline, the lead-in electrode 11 water cooling structure 9 and the lead-out electrode 12 water cooling structure 10 are provided with the second cooling water pipeline, and the first cooling water pipeline and the second cooling water pipeline are in communication with each other and are in direct or indirect communication with the cooling water inlet and the cooling water outlet 14, so as to cool the horizontal vacuum heating furnace.

[0057] It should be noted that, as shown in the figure, Figure 3 The test system further comprises a water cooling supply unit, the water cooling supply unit comprising a water storage tank 24, a refrigerating machine 22, a water supply pump 23 and a purification filter 27; the water storage tank 24 is provided with a water supplementing opening 25 and a water returning opening 26, the water returning opening 26 is connected with the cooling water outlet 14 through a water returning pipeline; the water introduced through the water supplementing opening 25 and the water returning opening 26 is injected into the water storage tank 24 after passing through the purification filter 27; the refrigerating machine 22 is used for cooling the cooling water in the water storage tank 24, and the water supply pump 23 pressurizes the cooling water after cooling treatment and supplies the cooling water to the cooling water inlet 13 of the horizontal vacuum heating furnace through a water supply pipeline.

[0058] It should be noted that the left end of the furnace body of the horizontal vacuum heating furnace is provided with an optical window 16, and the temperature measuring device 15 is arranged outside the optical window 16; the temperature measuring device 15 can radiate and measure the temperature of the thermal protection material sample 40 on the sample holder 18 through the optical window 16, so as to obtain the real-time temperature of the thermal protection material sample 40; the right end of the furnace body of the horizontal vacuum heating furnace is provided with a furnace cover 17, the furnace cover 17 is opened, and the thermal protection material sample 40 is placed in the isothermal heating zone 6 by using the sample holder 18.

[0059] In order to facilitate the movement of the sample, as shown in the figure, Figure 2As shown, the sample holder 18 of the present application comprises a pull rod 32 and a sample tray, the sample tray comprises a ring-shaped support frame 20, and a plurality of support ribs 21 are arranged on the inner wall of the ring-shaped support frame 20 in the horizontal direction, and the support ribs 21 are used to support the thermal protection material sample 40; a plurality of limiting members are arranged on the ring-shaped support frame 20 in the vertical direction at equal intervals; and the plurality of limiting members are used to limit the movement of the thermal protection material sample 40.

[0060] Exemplarily, as shown, the inner wall of the ring-shaped support frame 20 of the present application is provided with three support ribs, the three support ribs are uniformly arranged on the inner wall of the ring-shaped support frame 20, and the length of the three support ribs is less than the radius of the ring-shaped support frame 20; by arranging the three support ribs 21, on one hand, the thermal protection material sample 40 can be supported, and on the other hand, the bottom of the thermal protection material sample 40 can be uniformly heated; in addition, three limiting members are uniformly arranged on the ring-shaped support frame 20 in the vertical direction, for example, the limiting member is a limiting strip, and by arranging the limiting strip, the relative displacement between the thermal protection material and the ribs can be avoided when the thermal protection material enters or moves out of the isothermal heating zone 6.

[0061] Alternatively, as an alternative to the sample holder 18, the test system of the present application further comprises a sample moving and weighing unit, the sample moving and weighing unit is arranged in the tubular graphite heating body 1, and the sample moving and weighing unit can place the clamped thermal protection material sample 40 in the isothermal heating zone 6.

[0062] As shown, Figure 4 The above-mentioned sample moving and weighing unit comprises a columnar pull rod 32, a counterweight 31 is arranged on the first end of the pull rod 32 (i.e. the end close to the furnace cover 17); a 7-shaped support frame 33 perpendicular to the pull rod 32 is fixed on the second end of the pull rod 32, the 7-shaped support frame 33 is arranged in the vertical direction, a first lifting belt 34 is arranged on the top end of the 7-shaped support frame 33, a balance tray 36 is fixed below the first lifting belt 34, an electronic balance 35 is arranged on the balance tray 36, and a balance hook 37 is arranged on the bottom of the balance tray 36, the balance hook 37 is fixedly connected with a clamp 39 through a second lifting belt 38, and the clamp 39 is used to clamp the thermal protection material sample 40.

[0063] When the thermal shock resistance test of the thermal protection material is performed, the weight of the sample needs to be measured in real time for multiple times, and the sample moving and weighing unit of the present application does not need to move the sample to the outside of the horizontal heating furnace for weighing, and the real-time weight measurement of the sample can be completed in the furnace.

[0064] It should be noted that because the second end of the pull rod 32 is provided with components such as the electronic balance 35 and the balance tray 36, in order to prevent the pull rod 32 from shaking and affecting the accuracy of the test results, a counterweight is arranged at the first end of the pull rod 32, the counterweight is provided with a recess, the recess is engaged on the pull rod 32, and thus the pull rod 32 is fixed.

[0065] In order to reduce heat dissipation, the heat insulation coating comprises, from inside to outside, a first heat insulation layer, a low-density heat insulation layer and an aluminum silicate fiber layer; the first heat insulation layer adopts carbon fiber and aluminum silicate ceramic matrix composite material; the low-density heat insulation layer comprises a base material and a reinforcing material, the base material is phenolic resin added with hollow glass beads, and the reinforcing material is glass fiber.

[0066] Compared with the prior art, the first heat insulation layer can greatly reduce the heat transferred outward by the tubular graphite heating body 1, on the other hand, the low-density heat insulation layer arranged outside the first heat insulation layer can further reduce heat transfer, and on this basis, the aluminum silicate fiber layer arranged further can not only further reduce heat transfer and thus reduce heat loss, but also the aluminum silicate fiber is an insulator, which can reduce the arrangement of the insulation layer, thereby simplifying the structure of the device.

[0067] It should be noted that, in order to support the tubular heat insulation layer 7, two heat insulation layer support blocks 19 are arranged between the tubular heat insulation layer 7 and the water-cooled sandwich structure 8, and the two support blocks are the same in structure and are located at the bottom of the horizontal vacuum heating furnace.

[0068] In order to meet the vacuum degree requirement of the test system of the present application, the vacuum pumping unit of the present application comprises a vacuum pipeline, a vacuum measuring device 28, a first-stage vacuum equipment and a second-stage vacuum equipment; the first-stage vacuum equipment and the second-stage vacuum equipment are arranged in series; the upper end of the vacuum pipeline penetrates through the bottom of the horizontal vacuum heating furnace and communicates with the isothermal heating zone 6 (also communicates with other cavities, so that the whole furnace is in a vacuum state), and the lower end of the vacuum pipeline is provided with a tee pipe, one end of the tee pipe is connected with the vacuum measuring device 28, and the other end is connected with the first-stage vacuum equipment and the second-stage vacuum equipment in sequence. The first-stage vacuum equipment adopts a mechanical vacuum pump; and the second-stage vacuum equipment adopts a turbo molecular pump.

[0069] The advantage of adopting the turbo molecular pump in series with the mechanical vacuum pump lies in that the vacuum pumping unit can reach a vacuum degree of 10 -6 Pa without baking, and the vacuum degree can reach 10 -8 Pa after baking; in addition, the vacuum pumping assembly provided by the present application is relatively clean and can realize an oil-free ultra-high vacuum environment.

[0070] It should be noted that, in order to meet the vacuum degree requirement of the test system of the present application, the vacuum pumping unit of the present application comprises a vacuum pipeline, a vacuum measuring device 28, a first-stage vacuum equipment and a second-stage vacuum equipment; the first-stage vacuum equipment and the second-stage vacuum equipment are arranged in series; the upper end of the vacuum pipeline penetrates through the bottom of the horizontal vacuum heating furnace and communicates with the isothermal heating zone 6 (also communicates with other cavities, so that the whole furnace is in a vacuum state), and the lower end of the vacuum pipeline is provided with a tee pipe, one end of the tee pipe is connected with the vacuum measuring device 28, and the other end is connected with the first-stage vacuum equipment and the second-stage vacuum equipment in sequence. The first-stage vacuum equipment adopts a mechanical vacuum pump; and the second-stage vacuum equipment adopts a turbo molecular pump. 5 -1 Pa); and the B-A gauge is used to measure high vacuum degree (10 0 -7 Pa), and the two are connected in series to realize a vacuum degree of ≤6.7×10 -6 Pa in the furnace.​​

[0071] In order to save installation space, the test system of the application further comprises a double-layer test platform, the double-layer test platform comprising an upper layer platform and a lower layer platform, the high-vacuum heating device being arranged on the upper layer platform, and the vacuum pumping unit being arranged on the lower layer platform.

[0072] It should be noted that the test system of the application further comprises a temperature control unit, the temperature control unit adopting a PID algorithm for temperature control, the temperature control unit being connected with the horizontal vacuum heating furnace, and being capable of ensuring the horizontal vacuum heating furnace to realize thermal shock test: after the sample is heated to a test set temperature under a vacuum environment, the sample is kept warm for a certain time, and then is cooled to a set temperature or room temperature, and the thermal shock test is repeated for multiple times, and the test number when the thermal protection material is damaged is determined.

[0073] The main technical indexes of the horizontal vacuum heating furnace of the application are as follows:

[0074] Overall size: 500mm (length) x 300mm (diameter); heating zone: 400mm (length) x 30mm (diameter); isothermal zone: 100mm (length) x 30mm (diameter); heating power: 5kW.

[0075] The main technical parameters of the vacuum pumping assembly of the application are shown in Table 1 and Table 2: technical parameters of the turbo molecular pump:

[0076] Table 1 Technical parameters of the turbo molecular pump

[0077] Model F250 / 1500 Suction rate (L / s) 1500 Limit pressure (Pa) <10 -7 ]] Inlet flange (mm) CF250 Exhaust flange (mm) KF50 Start-up time (min) <8 Vibration value (pm) ≤0.1 Cooling method Water cooling Pump body baking temperature (°C) <120 Mass (kg) 60

[0078] Technical parameters of the rotary vane vacuum pump:

[0079] Table 2 Technical parameters of the rotary vane vacuum pump

[0080] Model 2XZ-15D Suction rate (L / s) 18 Limit pressure (Pa) 2 x 10 -2 ]] Inlet flange (mm) 40 Rotational speed (r / min) 1400 Motor power (kW) 1.50 Operating temperature (°C) 90 Mass (kg) 90

[0081] Technical parameters of the resistance gauge:

[0082] Table 3 Technical parameters of the resistance gauge

[0083]

[0084] Technical parameters of the B-A gauge:

[0085] Table 4 Technical parameters of the B-A gauge

[0086]

[0087] It should be further noted that the sample size of the application is: 10mm x 1mm x 70mm; or 5mm x 3mm x 70mm square column; or Φ5mm x 70mm circular (elliptical) column. The sample weight is 10g.

[0088] It should be noted that the temperature measuring device 15 of the present application adopts a colorimetric pyrometer, and the specific parameters of the colorimetric pyrometer are shown in Table 5 below.

[0089] Table 5 Technical parameters of colorimetric pyrometer

[0090] Model HIT-3 Measurement temperature range 1000—2500℃ Temperature resolution 0.5℃ Temperature measurement accuracy 0.5％ Minimum test target 2mm 2 ]]> Minimum test distance 1000 mm Wavelength 0.9 pm

[0091] The above description is only the preferred embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A high vacuum performance test system for thermal protection materials, characterized in that, The high-vacuum heating device comprises a horizontal vacuum heating furnace; the horizontal vacuum heating furnace is internally provided with a hollow tubular graphite heating body; the outer surfaces of the left end and the right end of the tubular graphite heating body are respectively provided with a first graphite sleeve and a second graphite sleeve which are of the same structure; the middle part of the outer surface of the tubular graphite heating body corresponds to an isothermal heating zone in the internal cavity; the thermal protection material sample is placed in the isothermal heating zone through a sample holder; The temperature measuring device is arranged outside the high-vacuum heating device and is used for measuring the real-time temperature of the thermal protection material in the isothermal heating zone; The vacuum pumping unit is used for pumping the high-vacuum heating device to a vacuum degree ≤ 6.7 × 10 -6 Pa. The outer surface of the second graphite sleeve is sleeved with a third graphite sleeve, and the outer surface of the third graphite sleeve is sleeved with a fourth graphite sleeve; the third graphite sleeve and the fourth graphite sleeve are of the same structure and the lengths of the third graphite sleeve and the fourth graphite sleeve are both smaller than those of the first graphite sleeve and the second graphite sleeve; The upper part of the third graphite sleeve is connected with an input electrode, and the upper part of the fourth graphite sleeve is connected with an output electrode; The test system further comprises a water cooling unit, and the water cooling unit comprises a water cooling sandwich structure, an input electrode water cooling structure and an output electrode water cooling structure; The water cooling sandwich structure is sleeved on the tubular heat insulation layer, and a cavity is arranged between the water cooling sandwich structure and the tubular heat insulation layer; the input electrode water cooling structure is arranged outside the input electrode, and the output electrode water cooling structure is arranged outside the output electrode; The water cooling sandwich structure is internally provided with a first cooling water pipeline; the input electrode water cooling structure and the output electrode water cooling structure are both internally provided with a second cooling water pipeline; the first cooling water pipeline and the second cooling water pipeline are connected in communication; A cooling water inlet is arranged at the top of the horizontal vacuum heating furnace, and a cooling water outlet is arranged at the bottom of the horizontal vacuum heating furnace; the first cooling water pipeline is connected in communication with the cooling water inlet and the cooling water outlet; The test system further comprises a sample moving and weighing unit; The sample moving and weighing unit comprises a pull rod, a counterweight, a 7-shaped support frame, a first lifting belt, a balance tray, an electronic balance, a balance hook, a second lifting belt and a clamp; the clamp is used for clamping the thermal protection material sample; The counterweight is arranged at the first end of the pull rod, the 7-shaped support frame is fixed at the second end of the pull rod, the support frame is arranged in the vertical direction, the first lifting belt is arranged at the top end of the 7-shaped support frame, the balance tray is fixed below the first lifting belt, the electronic balance is arranged on the balance tray, the balance hook is arranged at the bottom of the balance tray, the balance hook is fixedly connected with the clamp through the second lifting belt, and the clamp is used for clamping the thermal protection material sample. The pull rod is columnar, the counterweight is provided with a recess, and the counterweight is clamped on the pull rod by means of the recess.

2. The heat protection material high vacuum performance test system according to claim 1, wherein, The tubular graphite heating body is sleeved with a tubular heat insulation layer, the length of the tubular heat insulation layer is smaller than the length of the tubular graphite heating body, and the left end and the right end of the tubular heat insulation layer correspond to cover part of the first graphite sleeve and part of the second graphite sleeve; 3. The heat protection material high vacuum performance test system according to claim 2, wherein, The left ends of the tubular graphite heating body, the first graphite sleeve and the third graphite sleeve are arranged in alignment; the right ends of the tubular graphite heating body, the second graphite sleeve and the fourth graphite sleeve are arranged in alignment. The test system further comprises a water cooling supply unit, and the water cooling supply unit comprises a water storage tank, a refrigerating machine, a water supply pump and a purification filter; 4. The heat protection material high vacuum performance test system according to claim 3, characterized in that, ​ The water storage tank is provided with a water supplementing port and a water returning port, and the water returning port is connected with the cooling water outlet through a water returning pipeline; the water introduced through the water supplementing port and the water returning port is injected into the water storage tank after being filtered by a purifying filter; The refrigerating machine is used for cooling the cooling water in the water storage tank, and the feed water pump pressurizes and feeds the cooling water after cooling treatment to the cooling water inlet of the horizontal vacuum heating furnace through a water supply pipeline.

5. The heat protection material high vacuum performance test system according to claim 4, characterized in that, The left end of the furnace body of the horizontal vacuum heating furnace is provided with an optical window, the temperature measuring device is arranged outside the optical window, and the temperature measuring device can perform radiation temperature measurement on the thermal protection material sample on the sample holder through the optical window to obtain the real-time temperature of the thermal protection material sample. The right end of the furnace body of the horizontal vacuum heating furnace is provided with a furnace cover, and the thermal protection material sample is placed in the isothermal heating zone by using the sample holder after the furnace cover is opened.

6. The heat protection material high vacuum performance test system according to claim 1, wherein, The vacuum pumping unit comprises a vacuum pipeline, a vacuum measuring device, a first-stage vacuum equipment and a second-stage vacuum equipment; the first-stage vacuum equipment and the second-stage vacuum equipment are arranged in series. The upper end of the vacuum pipeline penetrates through the bottom of the horizontal vacuum heating furnace and communicates with the isothermal heating zone, the lower end of the vacuum pipeline is provided with a tee joint, one end of the tee joint is connected with the vacuum measuring device, and the other end is connected with the first-stage vacuum equipment and the second-stage vacuum equipment in sequence.

7. The heat protection material high vacuum performance test system according to claim 6, wherein, The first-stage vacuum equipment adopts a mechanical vacuum pump, and the second-stage vacuum equipment adopts a turbo molecular pump.

8. The system of any one of claims 1 to 7, wherein, The test system further comprises a double-layer test platform, the double-layer test platform comprises an upper layer platform and a lower layer platform, the high-vacuum heating device is arranged on the upper layer platform, and the vacuum pumping unit is arranged on the lower layer platform.

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