Low-temperature refrigerating system with gas branch and liquid branch separated in vacuum environment

Abstract

The invention discloses a low-temperature refrigerating system with separated gas and liquid branches in a vacuum environment, and belongs to the technical field of vacuum low-temperature lunar soil simulation tests. The device comprises a liquid nitrogen supply pipeline and a nitrogen heating supply pipeline, the starting end of the liquid nitrogen supply pipeline is connected with a first liquid nitrogen source, the terminal end of the liquid nitrogen supply pipeline is connected to a cold barrel in a vacuum cabin, the cold barrel is filled with simulated lunar loam for testing, the starting end of the nitrogen heating supply pipeline is connected with a second liquid nitrogen source, and the terminal end of the nitrogen heating supply pipeline is connected with the second liquid nitrogen source. The terminal end of the nitrogen heating supply pipeline is connected to a temperature control barrel in the vacuum cabin body, a simulation test projectile body is arranged in the temperature control barrel, and a liquid nitrogen gasifier, a gas buffer tank, a pressure reducing valve and a heat tracing band heating device are sequentially arranged on the nitrogen heating supply pipeline from the starting end to the terminal end. According to the invention, independent and accurate control of liquid nitrogen ultralow temperature and specific constant temperature gaseous nitrogen is realized at the same time, meanwhile, the precision and reliability of a lunar soil equipment ground test are improved, and the test cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the field of vacuum low-temperature lunar soil simulation test refrigeration technology, and specifically relates to a low-temperature refrigeration system with gas-liquid two-branch separation in a vacuum environment. Background Art

[0002] With the in-depth development of lunar soil research, ground simulation tests are of key significance for obtaining the characteristic data of lunar soil in the low-temperature environment of the moon and evaluating the performance of lunar soil equipment. However, traditional low-temperature refrigeration technology has many limitations in meeting the needs of ground tests of lunar soil equipment. Traditional systems are difficult to achieve independent and precise control of liquid nitrogen ultra-low temperature and specific constant temperature gaseous nitrogen at the same time, and cannot effectively simulate the complex temperature field of lunar soil. In terms of the safety and stability of the system, there is a lack of a perfect pressure and flow control mechanism, which is prone to safety hazards such as leakage due to pressure fluctuations, and there are deficiencies in the sealing and thermal insulation of component connections and protective measures for special situations of lunar soil (such as gas explosions). In addition, the traditional refrigeration system has low efficiency in recycling refrigerants, which increases the test cost and waste of resources. These problems seriously restrict the accuracy and reliability of ground tests of lunar soil equipment. Summary of the invention

[0003] The present invention aims to solve the above-mentioned problems, remedy the deficiencies of the prior art, and provide a low-temperature refrigeration system with separated gas-liquid branches under a vacuum environment; the present invention can achieve independent and precise control of ultra-low temperature liquid nitrogen and specific constant temperature gaseous nitrogen, while improving the accuracy and reliability of ground tests of lunar soil equipment and reducing test costs.

[0004] To achieve the above purpose, the present invention adopts the following technical solution.

[0005] The present invention provides a low-temperature refrigeration system with gas-liquid two-branch separation under a vacuum environment, characterized in that it comprises a liquid nitrogen supply pipeline and a nitrogen heating supply pipeline, wherein the starting end of the liquid nitrogen supply pipeline is connected to a first liquid nitrogen source, and the terminal end of the liquid nitrogen supply pipeline is connected to a cold barrel in a vacuum cabin, wherein the cold barrel contains simulated lunar soil for a test, the starting end of the nitrogen heating supply pipeline is connected to a second liquid nitrogen source, and the terminal end of the nitrogen heating supply pipeline is connected to a temperature control barrel in the vacuum cabin, wherein the temperature control barrel contains a simulated test bomb, and a liquid nitrogen vaporizer, a gas buffer tank, a pressure reducing valve and a heating belt heating device are sequentially arranged on the nitrogen heating supply pipeline from the starting end to the terminal end, the outlet ends of the cold barrel and the temperature control barrel are respectively connected from two outlets of the vacuum cabin, and are connected to a nitrogen recovery processing device through a recovery pipeline from the outside of the vacuum cabin outlet, and the recovery pipeline coming out of the nitrogen recovery processing device returns to the first liquid nitrogen source and the second liquid nitrogen source respectively.

[0006] Furthermore, the cold barrel is provided with a cold barrel inner wall and a cold barrel outer wall, a liquid nitrogen chamber is formed between the cold barrel inner wall and the cold barrel outer wall, and an inlet and an outlet of the cold barrel are both connected to the liquid nitrogen chamber.

[0007] Furthermore, the temperature control barrel is provided with a temperature control barrel inner wall and a temperature control barrel outer wall, a nitrogen cavity is formed between the temperature control barrel inner wall and the temperature control barrel outer wall, and a spirally wound coil is provided in the nitrogen cavity.

[0008] Furthermore, a first manual stop valve is provided on the liquid nitrogen supply pipeline at the rear end close to the first liquid nitrogen source, a second manual stop valve is provided on the nitrogen heating supply pipeline at the rear end close to the second liquid nitrogen source, and a third manual stop valve is provided on the nitrogen heating supply pipeline at the rear end close to the gas buffer tank.

[0009] Furthermore, an emergency pipeline is connected between the rear end pipeline of the first manual stop valve and the front end pipeline of the second manual stop valve, and a discharge valve and a fourth manual stop valve are arranged on the emergency pipeline.

[0010] Furthermore, a first spring safety valve is provided on the liquid nitrogen supply pipeline, and a second spring safety valve is provided on the gas buffer tank.

[0011] Furthermore, a first pressure gauge is connected to the gas buffer tank, and a fifth manual stop valve is arranged on the pipeline connected to the first pressure gauge, and a second pressure gauge is arranged on the nitrogen heating supply pipeline between the pressure reducing valve and the vacuum chamber.

[0012] Furthermore, a first solenoid valve is provided on the liquid nitrogen supply pipeline, and a second solenoid valve is provided on the nitrogen heating supply pipeline between the gas buffer tank and the pressure reducing valve, and both the first solenoid valve and the second solenoid valve are electrically connected to an externally arranged temperature control component.

[0013] Furthermore, a first temperature sensor is arranged in the cold barrel, a second temperature sensor is arranged in the temperature control barrel, and the first temperature sensor, the second temperature sensor and the heating belt heating device are all electrically connected to the temperature control component.

[0014] Furthermore, the liquid nitrogen supply pipeline and the vacuum chamber body, the nitrogen heating supply pipeline and the vacuum chamber body, and the vacuum chamber body and the recovery pipeline are all connected through vacuum flanges, and a multi-layer sealing gasket is arranged at each vacuum flange, and an insulating sleeve is wrapped around the outside of each vacuum flange.

[0015] Beneficial effects of the present invention.

[0016] The present invention conducts tests by placing simulated lunar soil for experiments and simulated test projectiles in a cold tank and a temperature control tank in a vacuum cabin under a vacuum environment, respectively. A liquid nitrogen supply pipeline and a nitrogen heating supply pipeline are used to provide an extremely cold environment for the simulated lunar soil for experiments and a stable constant temperature and low temperature environment for the simulated test projectile, respectively. The present invention can more effectively simulate the complex temperature field of the lunar soil, and avoid safety hazards such as leakage caused by pressure fluctuations through a perfect pressure and flow control mechanism. At the same time, a recovery pipeline for nitrogen after use is provided, which improves the recovery rate of liquid nitrogen, reduces the test cost and is more environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the specific implementation methods described herein are only used to explain the present invention and are not used to limit the present invention.

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0019] Figure 2 It is a schematic diagram of the side sectional structure of the cold barrel of the present invention.

[0020] Figure 3 It is a schematic diagram of the side section structure of the temperature control barrel of the present invention.

[0021] Figure 4 It is a principle block diagram of the temperature control system of the present invention.

[0022] Markings in the figure: 1 is a liquid nitrogen supply pipeline, 2 is a nitrogen heating supply pipeline, 3 is a first liquid nitrogen source, 4 is a second liquid nitrogen source, 5 is a vacuum chamber, 6 is a cold barrel, 7 is a temperature control barrel, 8 is a liquid nitrogen vaporizer, 9 is a gas buffer tank, 10 is a pressure reducing valve, 11 is a heating device for heating the heating belt, 12 is a recovery pipeline, 13 is a nitrogen recovery and processing device, 14 is the inner wall of the cold barrel, 15 is the outer wall of the cold barrel, 16 is a liquid nitrogen cavity, 17 is the inner wall of the temperature control barrel, 18 is the outer wall of the temperature control barrel, 19 is a nitrogen cavity, 20 2 is the coil, 21 is the first manual stop valve, 22 is the second manual stop valve, 23 is the third manual stop valve, 24 is the emergency pipeline, 25 is the discharge valve, 26 is the fourth manual stop valve, 27 is the first spring safety valve, 28 is the second spring safety valve, 29 is the first pressure gauge, 30 is the fifth manual stop valve, 31 is the second pressure gauge, 32 is the first solenoid valve, 33 is the second solenoid valve, 34 is the temperature control component, 35 is the vacuum flange, and 36 is the temperature sensor. DETAILED DESCRIPTION

[0023] Combined with Figure 1As shown, this embodiment provides a low-temperature refrigeration system with separated gas-liquid branches under a vacuum environment, including a liquid nitrogen supply pipeline 1 and a nitrogen heating supply pipeline 2, wherein the liquid nitrogen supply pipeline 1 is used to provide an extremely cold environment for the simulated lunar soil used in the test, and the nitrogen heating supply pipeline 2 is used to provide a stable constant temperature and low temperature environment for the simulated test projectile.

[0024] In order to ensure the sealing and thermal insulation performance of each joint, the liquid nitrogen supply pipeline 1 and the vacuum chamber 5, the nitrogen heating supply pipeline 2 and the vacuum chamber 5, and the vacuum chamber 5 and the recovery pipeline 12 are all connected through vacuum flanges 35, and multiple layers of sealing gaskets are arranged at each vacuum flange 35, and an insulating sleeve is wrapped around the outside of each vacuum flange 35 to reduce heat conduction.

[0025] The starting end of the liquid nitrogen supply pipeline 1 is connected to the first liquid nitrogen source 3, and the terminal end of the liquid nitrogen supply pipeline 1 is connected to the cold barrel 6 in the vacuum chamber 5, and the cold barrel 6 is filled with simulated lunar soil for the test. The starting end of the nitrogen heating supply pipeline 2 is connected to the second liquid nitrogen source 4, and the terminal end of the nitrogen heating supply pipeline 2 is connected to the temperature control barrel 7 in the vacuum chamber 5, and the temperature control barrel 7 is filled with a simulated test bomb.

[0026] The first liquid nitrogen source 3 and the second liquid nitrogen source 4 store a large amount of liquid nitrogen, which serves as the foundation of the liquid nitrogen supply of the entire refrigeration system and provides a sufficient source of cold for subsequent ultra-low temperature refrigeration. The vacuum chamber 5 is used to maintain a vacuum environment for testing, and the cold barrel 6 and the temperature control barrel 7 are placed in the vacuum chamber 5 respectively.

[0027] like Figure 2 As shown, the cold barrel 6 is provided with a cold barrel inner wall 14 and a cold barrel outer wall 15, and a liquid nitrogen chamber 16 is formed between the cold barrel inner wall 14 and the cold barrel outer wall 15. The inlet and outlet of the cold barrel 6 are both connected to the liquid nitrogen chamber 16, and the liquid nitrogen is introduced into the liquid nitrogen chamber 16 after passing through the liquid nitrogen supply pipeline 1.

[0028] like Figure 3 As shown, the temperature control barrel 7 is provided with a temperature control barrel inner wall 17 and a temperature control barrel outer wall 18, between which is a nitrogen chamber 19, in which a spirally wound coil 20 is provided. Nitrogen circulates in the nitrogen chamber 19 through the coil 20, and the gas flows from bottom to top. The nitrogen chamber 19 receives constant temperature nitrogen, providing a stable and precise specific constant temperature low temperature environment for other components of the lunar soil equipment, so as to adapt to the differentiated temperature requirements of different test scenarios, and ensure that the simulated test projectile is fully and accurately tested in a simulated low temperature environment.

[0029] A liquid nitrogen vaporizer 8, a gas buffer tank 9, a pressure reducing valve 10 and a heating belt heating device 11 are sequentially arranged on the nitrogen heating supply pipeline 2 from the starting end to the end end.

[0030] Among them, the liquid nitrogen vaporizer 8 efficiently converts liquid nitrogen into gaseous nitrogen. It has an optimized heat exchange structure inside, which can quickly and fully vaporize the liquid nitrogen, providing a stable gaseous nitrogen flow basis for subsequent gas buffering and temperature control.

[0031] The gas buffer tank 9 is used to store vaporized nitrogen and plays an important role in buffering pressure fluctuations and stabilizing gas flow. It effectively reduces the pressure changes caused by the instability of the gasification process or the changes in the working conditions of the downstream gas-using equipment, ensures the stability and continuity of the nitrogen supply, and provides strong support for the stable operation of the entire nitrogen heating supply pipeline 2.

[0032] A second spring safety valve 28 is provided on the gas buffer tank 9, and the second spring safety valve 28 is fixed to the top interface of the gas buffer tank 9 by means of a threaded connection. If the pressure in the gas buffer tank 9 exceeds the pressure value set by the second spring safety valve 28, the second spring safety valve 28 will automatically open to release part of the refrigerant into the atmosphere or other safe areas, thereby preventing the gas buffer tank 9 from exploding or being damaged due to excessive pressure, and ensuring the safety of the entire refrigeration system.

[0033] The gas buffer tank 9 is connected to a first pressure gauge 29 to monitor the pressure conditions in the gas buffer tank 9 and the surrounding pipelines in real time, providing an intuitive and critical pressure data basis for judging and regulating the system operation status, and ensuring that all links of the system operate within a safe pressure range.

[0034] The pressure reducing valve 10 reduces the pressure of the high-pressure nitrogen from the gas buffer tank 9 so that its pressure is adapted to the working requirements of the heating belt heating device 11 and the temperature control barrel 7, ensuring that all parts of the system operate under safe and appropriate pressure conditions to prevent damage to the equipment or affect the temperature control accuracy due to excessive pressure.

[0035] A second pressure gauge 31 is provided on the nitrogen heating supply pipeline 2 between the pressure reducing valve 10 and the vacuum chamber 5 to monitor the pressure of the nitrogen after decompression in real time so as to detect pressure anomalies in time and make adjustments to ensure the stability and safety of the nitrogen during subsequent heating and transportation.

[0036] The heating belt heating device 11 accurately heats the nitrogen passing through the pressure reducing valve 10 according to the temperature parameters set by the temperature control component 34. By intelligently adjusting the power of the heating belt, the nitrogen is heated to a specific constant temperature, meeting the precise temperature requirements of the temperature control barrel 7 for the low-temperature environment, and providing a stable constant temperature and low-temperature environment for the lunar soil equipment.

[0037] A first spring safety valve 27 is also provided on the liquid nitrogen supply pipeline 1 to perform real-time monitoring and overpressure protection on the pressure of the liquid nitrogen supply pipeline 1. Once the pipeline pressure exceeds the set safety threshold, the spring safety valve automatically opens to release the pressure, preventing pipeline rupture or other safety accidents caused by excessive pressure, thereby ensuring the safe operation of the system.

[0038] A first solenoid valve 32 is also provided on the liquid nitrogen supply pipeline 1, which accurately adjusts the flow of liquid nitrogen entering the cold barrel 6 according to the command signal of the temperature control component 34, thereby realizing automatic and precise control of the temperature in the cold barrel 6 to meet the strict requirements of the simulated lunar soil for the ultra-low temperature environment used in the experiment.

[0039] A second solenoid valve 33 is also provided on the nitrogen heating supply pipeline 2 between the gas buffer tank 9 and the pressure reducing valve 10. The second solenoid valve 33 can accurately adjust the nitrogen flow entering the temperature control barrel 7 according to the control signal of the temperature control component 34, and work in coordination with other components to achieve precise control of the temperature in the temperature control barrel 7 to meet the requirements of the simulated test projectile for a specific constant temperature and low temperature environment.

[0040] The first solenoid valve 32 and the second solenoid valve 33 are both electrically connected to an externally arranged temperature control assembly 34. A first temperature sensor 36 is arranged in the cold barrel 6, and a second temperature sensor 36 is arranged in the temperature control barrel 7. The first temperature sensor 36, the second temperature sensor 36 and the heating belt heating device 11 are all electrically connected to the temperature control assembly 34.

[0041] The temperature control component 34 serves as the core control unit of the entire refrigeration system. It receives temperature signals collected by temperature sensors 36 distributed in the cold barrel 6, the temperature control barrel 7 and key pipelines. After data processing and analysis, it sends control instructions to the solenoid valves, heating belt heating devices 11 and other executive components of the liquid nitrogen supply pipeline 1 and the nitrogen heating supply pipeline 2 according to the preset temperature control strategy, so as to achieve closed-loop precise control of the temperature in the cold barrel 6 and the temperature control barrel 7. See the principle block diagram of the temperature control system for details. Figure 4 As shown, the arrow direction indicates the flow direction of the temperature feedback signal.

[0042] For example, when the temperature in the cold barrel 6 is higher than the set ultra-low temperature threshold, the temperature control component 34 drives the first solenoid valve 32 to increase its opening, increasing the liquid nitrogen flow rate to enhance refrigeration; when the temperature in the temperature control barrel 7 deviates from the preset constant temperature, the temperature is returned to the set value by adjusting the power of the heating tape heating device 11 or the opening of the second solenoid valve 33, ensuring that the system always operates within the precise temperature control range, providing a stable and reliable low-temperature environment guarantee for ground tests of lunar soil equipment.

[0043] The outlet ends of the cold barrel 6 and the temperature control barrel 7 are connected to the two outlets of the vacuum chamber 5, respectively, and are connected to the nitrogen recovery and processing device 13 through the recovery pipeline 12 from the outlet of the vacuum chamber 5, and the recovery pipeline 12 coming out of the nitrogen recovery and processing device 13 returns to the first liquid nitrogen source 3 and the second liquid nitrogen source 4 respectively. The nitrogen recovery and processing device 13 adopts advanced low-temperature separation and purification technology to recycle the discharged gas and liquid nitrogen. After treatment, a part of it can continue to be recycled as a liquid nitrogen source, which effectively improves the utilization rate of liquid nitrogen, reduces the test cost and resource waste, and also conforms to the concept of environmental protection and sustainable development.

[0044] A first manual stop valve 21 is provided on the liquid nitrogen supply pipeline 1 at the rear end near the first liquid nitrogen source 3, so as to manually cut off the liquid nitrogen supply when the system is installed, debugged or shut down for a long time, thereby ensuring the flexibility and safety of operation.

[0045] A second manual stop valve 22 is provided on the nitrogen heating supply pipeline 2 at the rear end near the second liquid nitrogen source 4 to control the on-off of the liquid nitrogen from the liquid nitrogen source to the liquid nitrogen vaporizer 8, playing a key role when the system is started, stopped or partially overhauled, ensuring the operational controllability of the nitrogen generation link.

[0046] A third manual shut-off valve 23 is provided on the nitrogen heating supply pipeline 2 at the rear end near the gas buffer tank 9, which can manually cut off the nitrogen supply under specific circumstances, such as when maintaining, inspecting or troubleshooting downstream components, to facilitate operators to perform local operations and improve the maintainability and flexibility of the system.

[0047] A fifth manual stop valve 30 is provided on the pipeline connected to the first pressure gauge 29, which facilitates the maintenance and replacement of the first pressure gauge 29, protects the first pressure gauge 29, and can be isolated and cut off during maintenance. In some cases, the fifth manual stop valve 30 can be slightly opened or the opening degree adjusted to allow a small amount of refrigerant to pass through the pressure gauge to detect pressure changes for troubleshooting.

[0048] An emergency pipeline 24 is connected between the rear end pipeline of the first manual stop valve 21 and the front end pipeline of the second manual stop valve 22 , and a discharge valve 25 and a fourth manual stop valve 26 are arranged on the emergency pipeline 24 .

[0049] The main function of the emergency pipeline 24 is that when one liquid nitrogen source fails or needs maintenance, the fourth manual stop valve 26 can be manually operated to switch or connect the two liquid nitrogen sources to ensure the continuity of liquid nitrogen supply. The discharge valve 25 can be used to discharge liquid nitrogen or other gases in the pipeline when the system needs to be emptied or a specific maintenance operation is performed, thereby improving the flexibility and safety of system operation.

[0050] The working principle of this system is as follows: a path of liquid nitrogen from the first liquid nitrogen source 3 first passes through the first manual stop valve 21, which is open when the system is operating normally, and the liquid nitrogen continues to flow through the first spring safety valve 27. If the pressure is normal, it passes through the first solenoid valve 32, and its flow rate is regulated by the temperature control component 34. Then the liquid nitrogen enters the vacuum chamber 5 through the vacuum flange 35, and finally enters the liquid nitrogen chamber 16 of the cold barrel 6. With the low temperature characteristics of liquid nitrogen, the cold barrel 6 is quickly cooled to an ultra-low temperature state, providing an extremely cold environment for the simulated lunar soil used in the experiment.

[0051] At the same time, another liquid nitrogen enters the liquid nitrogen vaporizer 8 from the second liquid nitrogen source 4 through the second manual stop valve 22 and is converted into gaseous nitrogen. After flowing into the gas buffer tank 9 for pressure stabilization, it passes through the third manual stop valve 23, the second solenoid valve 33, the pressure reducing valve 10, and the second pressure gauge 31 in sequence and enters the heating belt heating device 11. The heating belt heating device 11 accurately adjusts the heating belt power according to the instructions of the temperature control component 34 to heat the nitrogen to a preset constant temperature. The heated constant temperature nitrogen enters the vacuum chamber 5 through the vacuum flange 35, and finally enters the nitrogen chamber 19 of the temperature control barrel 7, and circulates through the coil 20 to provide a stable constant temperature and low temperature environment for the simulated test bomb.

[0052] During the entire operation process, each temperature sensor 36 continuously monitors the temperature of key parts, and the temperature control component 34 automatically adjusts the working state of each component according to the temperature change, such as the opening of each solenoid valve, the power of the heating belt heating device 11, etc., to ensure that the system operates stably within the preset temperature range. In addition, the gaseous and liquid nitrogen in the cold barrel 6 and the temperature control barrel 7 are discharged and enter the nitrogen recovery and processing device 13. The processed part can be recycled, further improving the economy and resource utilization of the system.

[0053] Before use, assemble and initialize the system as follows.

[0054] The vacuum chamber 5 is thoroughly cleaned and pre-treated to remove internal impurities, oil stains and other pollutants. Subsequently, high vacuum exhaust equipment is installed to perform deep vacuum operation on the vacuum chamber 5 until the internal vacuum degree reaches the high vacuum standard required by the design, thereby creating an excellent insulation environment for the system.

[0055] According to the design layout, the cold barrel 6 and the temperature control barrel 7 are accurately installed at the designated positions in the vacuum chamber 5 through their corresponding vacuum flanges 35. During the installation process, the sealing of the flange connection is strictly checked and tested with professional sealing detection equipment to ensure that there is no leakage.

[0056] Connect the components and branch lines on the liquid nitrogen supply line 1 and the nitrogen heating supply line 2 in sequence. During the connection process, focus on the sealing performance and thermal insulation performance of each connection. For each vacuum flange 35 connection, a multi-layer sealing gasket is installed and tightened, and an insulating sleeve is wrapped to reduce heat conduction. The first pressure gauge 29 and the second pressure gauge 31 are installed at key positions on the liquid nitrogen supply line 1, the gas buffer tank 9 and the nitrogen pipeline connected thereto to monitor the pressure changes in real time. At the same time, connect the connecting pipeline between the liquid nitrogen sources to ensure that the fourth manual stop valve 26 and the discharge valve 25 are flexible and well sealed.

[0057] Temperature sensors 36 are installed at key locations in the cold barrel 6 and the temperature control barrel 7, and these temperature sensors 36 are accurately electrically connected and debugged with the temperature control component 34 to ensure that the temperature signal can be stably and accurately transmitted to the temperature control component 34, providing reliable data support for subsequent temperature control.

[0058] Initialize the first liquid nitrogen source 3 and the second liquid nitrogen source 4, and set the initial supply flow and pressure parameters of liquid nitrogen according to the test requirements; pre-debug the heating belt heating device 11, set the heating target temperature of nitrogen, and check whether its power regulation function is normal.

[0059] The system operates as follows.

[0060] The first liquid nitrogen source 3 is turned on, and the liquid nitrogen first flows through the first manual stop valve 21. When the system is operating normally, the first manual stop valve 21 remains open, and the liquid nitrogen then enters the first spring safety valve 27. If the pipeline pressure is within a safe range, the liquid nitrogen continues to enter the first solenoid valve 32. The first solenoid valve 32 accurately controls the flow of liquid nitrogen into the liquid nitrogen chamber 16 of the cold barrel 6 according to the instructions of the temperature control component 34. The liquid nitrogen absorbs heat in the chamber and evaporates rapidly, causing the temperature of the cold barrel 6 to drop rapidly to an ultra-low temperature range, providing an extremely cold test environment for the simulated lunar soil in the cold barrel 6. At this time, the temperature sensor 36 installed in the cold barrel 6 monitors the temperature change in real time and transmits the temperature signal to the temperature control component 34.

[0061] At the same time, the second liquid nitrogen source 4 and the second manual stop valve 22 are opened, and the liquid nitrogen enters the liquid nitrogen vaporizer 8 and is converted into gaseous nitrogen and then flows into the gas buffer tank 9. After the gas buffer tank 9 performs pressure stabilization on the gaseous nitrogen, it passes through the third manual stop valve 23, the second solenoid valve 33, the pressure reducing valve 10, and the second pressure gauge 31 in sequence and enters the heating belt heating device 11. The heating belt heating device 11 accurately adjusts the heating belt power according to the instructions of the temperature control component 34, and heats the nitrogen to a preset constant temperature. The heated constant temperature nitrogen enters the nitrogen chamber 19 of the temperature control barrel 7, circulates in the coil 20, and evenly provides a low temperature environment of a specific temperature for the simulated test bomb in the temperature control barrel 7. Similarly, the temperature sensor 36 in the temperature control barrel 7 also monitors the temperature in real time and feeds the signal back to the temperature control component 34.

[0062] The temperature control component 34 compares and analyzes the received temperature signal with the preset temperature range. If the temperature in the cold barrel 6 is higher than the set ultra-low temperature threshold, the temperature control component 34 controls the first solenoid valve 32 to increase the liquid nitrogen supply flow rate to enhance the refrigeration effect; if the temperature in the temperature control barrel 7 deviates from the preset constant temperature, the temperature control component 34 adjusts the power of the heating belt heating device 11 or the opening of the second solenoid valve 33 to restore the temperature to the set value, thereby realizing closed-loop precise control of the temperature in the cold barrel 6 and the temperature control barrel 7.

[0063] During the operation of the entire system, the operator needs to regularly observe the readings of the first pressure gauge 29 and the second pressure gauge 31 to ensure that the pressure of each part is within the normal working range. If abnormal pressure fluctuations are found, the system's pipeline connections, valve status, and the operation of each component should be checked in time to eliminate potential faults. At the same time, the vacuum degree of the vacuum chamber 5 is continuously monitored. If the vacuum degree shows a downward trend, the vacuum pumping equipment should be immediately started for additional pumping to maintain the high vacuum insulation environment of the chamber and ensure the refrigeration efficiency and stability of the system. In addition, pay attention to the operating status of the nitrogen recovery and treatment device 13 to ensure that the gas-liquid nitrogen recovery and treatment process is carried out normally and improve the recycling rate of liquid nitrogen.

[0064] In addition, the system needs to be maintained and serviced regularly, the specific methods are as follows.

[0065] Regularly inspect the appearance of the vacuum chamber 5, cold barrel 6 and temperature control barrel 7 to check for frost, leakage or other abnormalities. If frost is found on the outer wall 15 of the cold barrel or the outer wall 18 of the temperature control barrel, it may mean that there is a problem with the internal insulation layer or a slight leakage at the pipe connection, which requires further inspection and repair. For the leaking part, the sealing gasket can be replaced or the pipeline can be repaired according to the specific situation.

[0066] Check whether the insulation layer of the vacuum flange 35 connecting pipeline is intact and whether the sealing performance of the vacuum flange 35 is reliable. If the insulation layer is damaged, it should be repaired or replaced in time to reduce the loss of cold; if there is leakage at the vacuum flange 35, the system should be stopped first, the internal gas should be emptied, and the flange should be re-sealed, such as tightening the bolts, replacing the sealing gasket, etc.

[0067] Perform regular maintenance and upkeep on the valves, pumps and other components of the first liquid nitrogen source 3 and the second liquid nitrogen source 4. Check the opening and closing flexibility of each valve to ensure that there is no sticking; perform regular lubrication and performance testing on the pumps of the first liquid nitrogen source 3 and the second liquid nitrogen source 4 to ensure that they stably provide liquid nitrogen with the set flow rate and pressure. For the liquid nitrogen vaporizer 8, clean the internal impurities and dirt regularly to prevent the liquid nitrogen vaporization effect from being affected by the decrease in heat exchange efficiency.

[0068] Perform regular pressure tests and safety valve inspections on the gas buffer tank 9 to ensure that it operates safely within the specified pressure range. Check the working performance of the first solenoid valve 32, the second solenoid valve 33 and the pressure reducing valve 10, such as whether the solenoid coils of each solenoid valve are working properly and whether the pressure regulation of the pressure reducing valve 10 is accurate. If there are any problems, repair or replace them in time.

[0069] The heating belt of the heating belt heating device 11 is regularly inspected to see if there is any damage or aging, and if any problem is found, it is replaced in time. At the same time, the temperature control system of the heating belt heating device 11 is calibrated to ensure that it accurately heats the nitrogen to a preset constant temperature.

[0070] Perform regular precision calibration and data backup on each temperature sensor 36 and temperature control component 34. The accuracy of the temperature sensor 36 directly affects the accuracy of temperature control and needs to be calibrated with a standard thermometer; the temperature control component 34 needs regular software upgrades and data backup to ensure its stable operation and accurate execution of the preset temperature control strategy.

[0071] It can be understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the protection scope of the present invention.

Claims

1. A low-temperature refrigeration system with gas-liquid separation under vacuum environment, characterized in that: The invention comprises a liquid nitrogen supply pipeline (1) and a nitrogen heating supply pipeline (2), wherein the liquid nitrogen supply pipeline (1) is connected at its starting end to a first liquid nitrogen source (3), and the terminal end of the liquid nitrogen supply pipeline (1) is connected to a cold barrel (6) in a vacuum chamber (5), wherein the cold barrel (6) contains simulated lunar soil for testing, the nitrogen heating supply pipeline (2) is connected at its starting end to a second liquid nitrogen source (4), and the terminal end of the nitrogen heating supply pipeline (2) is connected to a temperature control barrel (7) in the vacuum chamber (5), wherein the temperature control barrel (7) contains a simulated test bomb, and the nitrogen heating supply pipeline (2) is connected to a second liquid nitrogen source (4), and the terminal end of the nitrogen heating supply pipeline (2) is connected to a temperature control barrel (7) in the vacuum chamber (5), wherein the temperature control barrel (7) contains a simulated test bomb, and the nitrogen heating supply pipeline (2) is connected to a second liquid nitrogen source (4). A liquid nitrogen vaporizer (8), a gas buffer tank (9), a pressure reducing valve (10) and a heating belt heating device (11) are sequentially arranged on the pipeline (2) from the starting end to the terminal end. The outlet ends of the cold barrel (6) and the temperature control barrel (7) are respectively connected to the two outlets of the vacuum chamber (5), and are connected to the nitrogen recovery processing device (13) through a recovery pipeline (12) from the outlet of the vacuum chamber (5). The recovery pipeline (12) coming out of the nitrogen recovery processing device (13) returns to the first liquid nitrogen source (3) and the second liquid nitrogen source (4) respectively.

2. A low-temperature refrigeration system with gas-liquid separation under vacuum environment according to claim 1, characterized in that: The cold barrel (6) is provided with a cold barrel inner wall (14) and a cold barrel outer wall (15), a liquid nitrogen chamber (16) is formed between the cold barrel inner wall (14) and the cold barrel outer wall (15), and an inlet and an outlet of the cold barrel (6) are both connected to the liquid nitrogen chamber (16).

3. The low-temperature refrigeration system with gas-liquid separation under vacuum environment according to claim 1, characterized in that: The temperature control barrel (7) is provided with a temperature control barrel inner wall (17) and a temperature control barrel outer wall (18), a nitrogen chamber (19) is provided between the temperature control barrel inner wall (17) and the temperature control barrel outer wall (18), and a spirally wound coil (20) is provided in the nitrogen chamber (19).

4. A low-temperature refrigeration system with gas-liquid separation under vacuum environment according to claim 1, characterized in that: A first manual stop valve (21) is provided on the liquid nitrogen supply pipeline (1) at a rear end close to the first liquid nitrogen source (3), a second manual stop valve (22) is provided on the nitrogen heating supply pipeline (2) at a rear end close to the second liquid nitrogen source (4), and a third manual stop valve (23) is provided on the nitrogen heating supply pipeline (2) at a rear end close to the gas buffer tank (9).

5. A low-temperature refrigeration system with gas-liquid branch separation under vacuum environment according to claim 4, characterized in that: An emergency pipeline (24) is connected between the rear pipeline of the first manual stop valve (21) and the front pipeline of the second manual stop valve (22), and a discharge valve (25) and a fourth manual stop valve (26) are provided on the emergency pipeline (24).

6. A low-temperature refrigeration system with gas-liquid separation under vacuum environment according to claim 1, characterized in that: A first spring safety valve (27) is also provided on the liquid nitrogen supply pipeline (1), and a second spring safety valve (28) is provided on the gas buffer tank (9).

7. The low-temperature refrigeration system with gas-liquid separation under vacuum environment according to claim 1, characterized in that: The gas buffer tank (9) is connected to a first pressure gauge (29), and a fifth manual stop valve (30) is provided on the pipeline connected to the first pressure gauge (29), and a second pressure gauge (31) is provided on the nitrogen heating supply pipeline (2) between the pressure reducing valve (10) and the vacuum chamber (5).

8. The low-temperature refrigeration system with gas-liquid separation under vacuum environment according to claim 1, characterized in that: The liquid nitrogen supply pipeline (1) is also provided with a first solenoid valve (32), and the nitrogen heating supply pipeline (2) is also provided with a second solenoid valve (33) between the gas buffer tank (9) and the pressure reducing valve (10), and the first solenoid valve (32) and the second solenoid valve (33) are both electrically connected to an externally provided temperature control component (34).

9. A low-temperature refrigeration system with gas-liquid separation under vacuum environment according to claim 8, characterized in that: A first temperature sensor (36) is arranged in the cold barrel (6), a second temperature sensor (36) is arranged in the temperature control barrel (7), and the first temperature sensor (36), the second temperature sensor (36) and the heating belt heating device (11) are all electrically connected to the temperature control component (34).

10. The low-temperature refrigeration system with gas-liquid separation under vacuum environment according to claim 1, characterized in that: The liquid nitrogen supply pipeline (1) and the vacuum chamber (5), the nitrogen heating supply pipeline (2) and the vacuum chamber (5), and the vacuum chamber (5) and the recovery pipeline (12) are all connected via vacuum flanges (35), and a multi-layer sealing gasket is provided at each of the vacuum flanges (35), and a heat insulating sleeve is wrapped around the outside of each of the vacuum flanges (35).

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