Vacuum experimental device and system for planetary atmospheric sound detection research

Abstract

The present invention discloses a vacuum experimental device for planetary atmospheric sound detection research, including a vacuum tank and a wind tunnel structure, the vacuum tank includes a tank body and an end cover, the inner side of the tank body and the end cover is provided with a heat preservation layer, the inner side of the heat preservation layer of the tank body is provided with a first heat shielding layer, the inner side of the heat preservation layer of the end cover is provided with a second heat shielding layer, the second heat shielding layer is buckled on the end of the first heat shielding layer, a heat sink is provided inside the first heat shielding layer, the wind tunnel structure is arranged in the tank body, including an air intake contraction section, a test chamber section and a fan section connected in sequence, a circulating return air duct is formed between the outer side and the heat sink, the inlet of the air intake contraction section is provided with a front guide cover for introducing the airflow of the circulating return air duct, the outlet of the fan section is provided with a rear guide cover, and an annular fin heat exchanger is provided at the junction of the front guide cover and the circulating return air duct, the annular fin heat exchanger includes a plurality of medium ring tubes, and fins are provided on the surface of the medium ring tube. The present invention achieves a wind tunnel airflow environment temperature of ‑173°C under positive and negative pressure environments.

Description

Technical Field

[0001] The invention relates to a wind tunnel device, in particular to a vacuum experimental device and system for planetary atmospheric sound detection research. Background Art

[0002] Planetary atmospheric acoustic detection research is to carry out the detection and analysis of acoustic signals in the exploration of space science planets. By simulating the pressure, temperature, gas composition, wind speed, and acoustic environmental conditions of the planetary atmosphere, it deeply explores the atmospheric environment, studies the laws of planetary climate, and explores life activities. The existing vacuum tank with a wind tunnel structure, such as the technical solution in the Chinese patent with publication number CN110567668A, is equipped with a low-pressure icing wind tunnel, a water spray nozzle array, a honeycomb, an evaporator, etc. in the vacuum tank, the purpose of which is to simulate the low temperature and low pressure environment within 100km of the high altitude. In the planetary atmospheric acoustic detection research, the ambient temperature is required to be as low as -173℃ or below, and the air pressure varies in the range of 100Pa to 2atm. Obviously, the airflow generated by the wind tunnel of the vacuum tank wind tunnel structure in the above-mentioned prior art forms heat conduction with the vacuum tank body, so the internal environment cannot meet the above requirements. Summary of the invention

[0003] In view of the defects of the above-mentioned prior art, the present invention provides a vacuum experimental device for planetary atmospheric sound detection research, which solves the problem that the airflow formed by the wind tunnel in the vacuum tank causes heat conduction with the vacuum tank body and it is difficult to make the temperature reach below -173°C. The present invention also provides a vacuum experimental system for planetary atmospheric sound detection research.

[0004] The technical solution of the present invention is as follows: A vacuum experimental device for planetary atmospheric sound detection research comprises a vacuum tank and a wind tunnel structure, wherein the vacuum tank comprises a tank body and an end cover, the inner sides of the tank body and the end cover are provided with a thermal insulation layer, the inner side of the thermal insulation layer of the tank body is provided with a first heat shielding layer, the inner side of the thermal insulation layer of the end cover is provided with a second heat shielding layer, the circumference of the second heat shielding layer is provided with a flange, the diameter of the flange is larger than the diameter of the first heat shielding layer, the second heat shielding layer is buckled on the end of the first heat shielding layer, the inner side of the first heat shielding layer is provided with a heat sink, and the wind tunnel structure is arranged in the Inside the tank body, the wind tunnel structure includes an air inlet contraction section, a test chamber section and a fan section which are connected in sequence, a circulating return air duct is formed between the outer side of the wind tunnel structure and the heat sink, the inlet of the air inlet contraction section is provided with a front guide cover for guiding the airflow of the circulating return air duct into the air inlet contraction section, the outlet of the fan section is provided with a rear guide cover for guiding the airflow into the circulating return air duct, an annular fin heat exchanger is provided at the junction of the front guide cover and the circulating return air duct, the annular fin heat exchanger includes a plurality of medium ring tubes arranged around the air inlet contraction section, and fins are provided on the surface of the medium ring tube.

[0005] Furthermore, sealing rings are provided between the outer edge of the front air guide cover and the heat sink, and between the outer edge of the rear air guide cover and the heat sink. The provision of sealing rings can further reduce the air circulation formed by the wind tunnel structure and the gas convection between other parts in the vacuum tank, thereby improving the temperature control effect.

[0006] Furthermore, the front guide cover and the rear guide cover are provided with a plurality of stacked guide vanes, and the adjacent guide vanes form an air flow channel. The arrangement of the guide vanes reduces the generation of turbulence when the airflow after heat exchange by the heat sink and the airflow discharged by the fan section turns, thereby reducing the heat exchange generated from the guide end cover.

[0007] Furthermore, a medium ring tube of an annular fin heat exchanger is provided at the inlet of each airflow channel formed by the front guide cover. The medium ring tube provided at the inlet of each airflow channel is more conducive to quickly cooling the airflow flowing into the air inlet contraction section, so that the airflow temperature in each airflow channel is more uniform.

[0008] Furthermore, the insulation layer is a polytetrafluoroethylene foam board, which can achieve low-temperature insulation performance, reduce heat exchange through the tube wall of the vacuum tank, and meet the oil-free requirement of the vacuum environment.

[0009] Furthermore, liquid nitrogen or nitrogen gas is introduced into the heat sink and the medium ring tube to control the temperature.

[0010] Another technical solution of the present invention is:

[0011] A vacuum experiment system for planetary atmospheric sound detection research comprises the above-mentioned vacuum experiment device for planetary atmospheric sound detection research, an exhaust system and an inflation system, wherein the exhaust system is connected to the vacuum tank body to exhaust air from the vacuum tank, and the inflation system is connected to the vacuum tank body to inflate air into the vacuum tank.

[0012] The advantages of the technical solution provided by the present invention are:

[0013] The heat sink forms one side of the circulating return air duct, so that the return airflow directly exchanges heat with the heat sink through convection and radiation to achieve the purpose of rapid cooling. An annular fin heat exchanger is set at the front guide end cover to further control the temperature of the airflow to meet the requirements when it enters the wind tunnel. The present invention combines the heat shield buckle structure and the front and rear guide end cover structures to minimize the airflow flow in the non-wind tunnel structure part of the vacuum tank and reduce the heat exchange through the vacuum tank body. Without using a vacuum insulation jacket, the wind tunnel airflow environment temperature of -173°C is achieved while ensuring a low manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of a vacuum experimental system for planetary atmospheric sound detection research according to an embodiment.

[0015] Figure 2 Schematic diagram of a vacuum experimental device for planetary atmospheric sound detection research according to an embodiment.

[0016] Figure 3 It is a partial schematic diagram of the junction of the first heat shielding layer and the second heat shielding layer.

[0017] Figure 4 It is a schematic diagram of the structure of annular fin heat exchanger. DETAILED DESCRIPTION

[0018] The present invention is further described below in conjunction with examples. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading this description, various equivalent modifications to this description by those skilled in the art fall within the scope defined by the claims attached to this application.

[0019] Example, please combine Figure 1 As shown, the vacuum experimental system for planetary atmospheric sound detection research of this embodiment includes a vacuum experimental device for planetary atmospheric sound detection research, an exhaust system 1 and an inflation system 2. The vacuum experimental device for planetary atmospheric sound detection research mainly includes a vacuum tank 3 and a wind tunnel structure arranged in the vacuum tank 3. The exhaust system 1 is configured with a plurality of parallel cryogenic pumps 101, a molecular pump 102 and a Roots pump 103, and then connected with a front-stage exhaust unit 104 and a rough exhaust unit 105. The exhaust system 1 is connected to the tank body 301 of the vacuum tank 3 to extract air from the tank of the vacuum tank 3. The specific pipeline connection structure of the exhaust system 1 is the same as that of the prior art and will not be repeated. The inflation system 2 generally includes a plurality of inflation valves connected to the vacuum tank 3, and various required gas sources are connected to the inflation valves to inflate the vacuum tank 3.

[0020] Please combine Figures 2 to 4As shown, the vacuum experimental device for planetary atmospheric sound detection research includes a vacuum tank 3 and a wind tunnel structure. The vacuum tank 3 includes a tank body 301 and an end cover 302. A thermal insulation layer 4 is applied on the inner side of the tank body 301 and the end cover 302. The thermal insulation layer 4 is made of polytetrafluoroethylene foam board, and the material can achieve both low-temperature thermal insulation performance and meet the requirements of vacuum oil-free. A first heat shielding layer 5 is provided on the inner side of the thermal insulation layer 4 of the tank body 301. The first heat shielding layer 5 is cylindrical. A second heat shielding layer 6 is provided on the inner side of the thermal insulation layer 4 of the end cover 302. The second heat shielding layer 6 is generally set to be a slightly curved disc shape, leaving a space between the second heat shielding layer 6 and the end cover 302. The first heat shielding layer 5 and the second heat shielding layer 6 are made of mirror-polished stainless steel plates. A flange 601 is provided in the circumferential direction of the second heat shielding layer 6, and the diameter of the flange 601 is greater than the diameter of the first heat shielding layer 5. When the end cover 302 of the vacuum tank 3 is covered with the tank body 301, the second heat shielding layer 6 is buckled on the end of the first heat shielding layer 5, and a small gap is formed at the connection between the two. On the one hand, when the vacuum tank 3 is evacuated or inflated, the connection of various places in the vacuum tank 3 is ensured. On the other hand, the airflow generated by the wind tunnel structure in the tank body 301 is not easy to disturb the gas between the heat shielding layers 5, 6 and the tank body 301 at this connection, which can reduce the heat exchange between the internal airflow and the tank wall of the vacuum tank 3 to ensure that the internal airflow can reach a lower temperature.

[0021] In the tank 301, a heat sink 7 is provided inside the first heat shielding layer 5. The heat sink 7 is also cylindrical. It should be noted that Figure 2In order to show the airflow channel of the wind tunnel structure, only the upper half of the heat sink 7 is shown. The wind tunnel structure is arranged in a cylindrical structure formed by the tank body 301 and the heat sink 7. The wind tunnel structure includes an air inlet contraction section 8, a test chamber section 9 and a fan section 10 connected in sequence, and a circulating return air duct 11 is formed between the outer side of the wind tunnel structure and the heat sink 7. That is to say, the airflow led out by the fan section 10 in the wind tunnel structure returns from the circulating return air duct 11 between the outer side of the wind tunnel structure and the heat sink 7 to the outer side of the air inlet contraction section 8, and then enters the air inlet contraction section 8, passes through the test chamber section 9, and is then led out from the fan section 10 to form a circulating flow. The inlet of the air inlet contraction section 8 is provided with a front guide cover 12 for guiding the airflow of the circulating return air duct 11 into the air inlet contraction section 8, and the outlet of the fan section 10 is provided with a rear guide cover 13 for guiding the airflow into the circulating return air duct 11. A plurality of stacked guide vanes 14 are provided in the front guide cover 12 and the rear guide cover 13. Each guide vane 14 is an annular groove structure, and an airflow channel is formed between adjacent guide vanes 14. Through the guidance of the airflow by the front guide cover 12 and the rear guide cover 13, in the circulating return air duct 11, the airflow close to the heat sink 7 is more guided to the center of the air inlet contraction section 8, and the airflow close to the wind tunnel structure is more guided to the edge of the air inlet contraction section 8. A sealing ring 15 is provided between the outer edge of the front guide cover 12 and the heat sink 7, and between the outer edge of the rear guide cover 13 and the heat sink 7. This creates a certain degree of isolation between the internal space of the wind tunnel structure and the space inside the vacuum tank 3. It should be noted that this isolation cannot form a vacuum seal in the strict sense, that is, it will not affect the overall vacuuming or inflation of the vacuum tank 3, but it can prevent most of the airflow generated by the wind tunnel from leaking into the vacuum tank 3, thereby causing more heat exchange and destroying the low-temperature environment. The provision of the guide vane 14 reduces the generation of turbulence when the airflow after heat exchange with the heat sink 7 and the airflow discharged from the fan section 10 turns, thereby reducing the heat exchange generated from the guide end covers 12 and 13. In order to ensure that the temperature of the airflow entering the air inlet contraction section 8 can reach the lowest level and the airflow temperature is uniform, an annular fin heat exchanger 16 is provided at the junction of the front guide cover 12 and the circulating return air duct 11. Please refer to the following for details. Figure 4 As shown, the annular fin heat exchanger 16 includes a plurality of medium annular tubes 1601 arranged around the air inlet contraction section 8, and fins 1602 are arranged on the surface of the medium annular tubes 1601. These medium annular tubes 1601 are distributed in concentric circles, so that the inlet of each air flow channel formed by the front guide cover 12 is provided with a medium annular tube 1601 of the annular fin heat exchanger 16. One end of the diameter end of all the medium annular tubes 1601 is connected to form an inlet 1603, and the other end forms an outlet 1604. Low-temperature liquid nitrogen or high-temperature nitrogen is introduced into the heat sink 7 and the medium annular tubes 1601 to adjust the temperature in the vacuum tank 3.

[0022] The low temperature control process of the vacuum experimental system for planetary atmospheric sound detection research is as follows: the vacuum tank 3 is first evacuated through the exhaust system 1, and then liquid nitrogen is introduced into the heat sink 7 and the medium ring tube 1601 under vacuum conditions, and the heat sink 7 and the annular fin heat exchanger 16 are turned on to refrigerate, and the heat sink 7 and the annular fin heat exchanger 16 are quickly cooled to below -173°C, so that the wind tunnel structure is quickly precooled. Then, the planetary atmospheric component gas is filled into the required pressure by the inflation system 2, and the wind tunnel circulation is turned on again. Under the joint action of the heat sink 7 and the annular fin heat exchanger 16, the temperature requirement of -173°C in the internal test section of the wind tunnel is achieved.

Claims

1. A vacuum experimental device for planetary atmospheric sound detection research, comprising a vacuum tank and a wind tunnel structure, characterized in that: The vacuum tank comprises a tank body and an end cover, wherein the inner sides of the tank body and the end cover are provided with a heat-insulating layer, the inner side of the heat-insulating layer of the tank body is provided with a first heat-shielding layer, the inner side of the heat-insulating layer of the end cover is provided with a second heat-shielding layer, the circumference of the second heat-shielding layer is provided with a flange, the diameter of the flange is larger than the diameter of the first heat-shielding layer, the second heat-shielding layer is buckled on the end of the first heat-shielding layer, a gap is formed at the connection between the two, a heat sink is provided on the inner side of the first heat-shielding layer, the wind tunnel structure is arranged in the tank body, and the wind tunnel structure comprises The air inlet contraction section, the test chamber section and the fan section are connected, and a circulating return air duct is formed between the outer side of the wind tunnel structure and the heat sink. The inlet of the air inlet contraction section is provided with a front guide cover for guiding the airflow of the circulating return air duct into the air inlet contraction section, and the outlet of the fan section is provided with a rear guide cover for guiding the airflow into the circulating return air duct. An annular fin heat exchanger is provided at the junction of the front guide cover and the circulating return air duct, and the annular fin heat exchanger includes a plurality of medium annular tubes arranged around the air inlet contraction section, and fins are provided on the surface of the medium annular tube; A sealing ring is provided between the outer edge of the front air guide cover and the heat sink, and between the outer edge of the rear air guide cover and the heat sink; the sealing ring isolates the internal space of the wind tunnel structure from the internal space of the vacuum tank. Such isolation cannot form a vacuum seal in a strict sense and will not affect the overall vacuuming or inflation of the vacuum tank, but can prevent most of the airflow generated by the wind tunnel from leaking into the vacuum tank; The first heat shielding layer and the second heat shielding layer are made of mirror-polished stainless steel plates; The thermal insulation layer is a polytetrafluoroethylene foam board.

2. The vacuum experimental device for planetary atmospheric sound detection research according to claim 1, characterized in that: A plurality of stacked guide vanes are disposed inside the front guide cover and the rear guide cover, and air flow channels are formed between adjacent guide vanes.

3. The vacuum experimental device for planetary atmospheric sound detection research according to claim 2, characterized in that: A medium ring pipe of an annular fin heat exchanger is provided at the inlet of each air flow channel formed by the front guide cover.

4. The vacuum experimental device for planetary atmospheric sound detection research according to claim 1, characterized in that: Liquid nitrogen or nitrogen gas is introduced into the heat sink and the medium ring tube to control the temperature.

5. A vacuum experimental system for planetary atmospheric sound detection research, characterized in that: It comprises the vacuum experimental device, exhaust system and inflation system for planetary atmospheric sound detection research as described in any one of claims 1 to 4, wherein the exhaust system is connected to the tank body of the vacuum tank to exhaust air from the vacuum tank, and the inflation system is connected to the tank body of the vacuum tank to inflate air into the vacuum tank.

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