A high-fidelity simulated ice-containing lunar regolith preparation system and method

Abstract

A highly realistic system and method for preparing simulated icy lunar soil, wherein a vacuum pressure gauge in the system is connected to a simulated icy lunar soil storage tank; the simulated icy lunar soil storage tank is used for sealed storage of simulated lunar soil, and a steam nozzle connection flange is preset at the bottom of the tank body of the simulated icy lunar soil storage tank, and a gas pipeline connection flange is also reserved on the side; a steam generator is used to convert deionized water into water vapor and connect it to a supercharger; the front end of the steam nozzle is connected to the supercharger, receives water vapor of a certain pressure delivered by the supercharger, and is used to spray water vapor onto the simulated lunar soil in the simulated icy lunar soil storage tank, so as to achieve uniform diffusion of water vapor into the pores of the simulated lunar soil; a vacuum pump is used to extract and discharge residual air in the simulated icy lunar soil storage tank, and a steam generator is used to evenly diffuse an appropriate amount of water vapor into the pores of the simulated lunar soil to replace the original air, thereby achieving highly realistic, highly uniform, and highly repeatable simulated icy lunar soil preparation with air discharge and uniform mixing of water and soil.

Description

Technical Field

[0001] The present invention relates to a preparation method of simulated ice-containing lunar regolith, in particular to a preparation method of highly simulated ice-containing lunar regolith, which can be used as an important supporting means for the ground principle test of volatile extraction in the lunar polar region and future water ice extraction in the lunar polar region in the fourth phase of China's lunar exploration project. At the same time, this method can also be used in the fields of gas displacement protection inside space stations, coal mines and underground closed facilities, etc. Background Art

[0002] As an important resource for space exploration, especially manned deep space exploration, water is a key carrier and important product for in-situ resource utilization, and its application runs through various links such as energy, propulsion and regenerative life support. It not only provides the necessities for maintaining life, but also provides the fuel (H2 and 02) required by modern rockets. By obtaining and converting and utilizing water resources in-situ extraterrestrially, the dependence of deep space exploration activities on materials and energy can be effectively solved, which is crucial for enhancing the capabilities of deep space exploration activities. Therefore, all major space powers regard lunar water ice exploration, especially the exploration of volatiles such as lunar south pole water ice, as an important development direction for future lunar exploration. The Artemis program of the United States will build a manned scientific research station at the lunar south pole and launch the Volatiles Investigating Polar Exploration Rover (VIPER) in the early stage to conduct in-situ detection of water ice resources at the lunar south pole; the European Union ESA jointly with Russia plans to carry the Prospect (Platform for Resource Observation and in-Situ Prospecting in support of Exploration, Commercial exploitation & Transportation) payload on Luna 27 to conduct water ice detection at the lunar south pole; Chang'e-7, the fourth-phase mission of China's lunar exploration project, will also conduct in-situ detection of volatiles such as water ice at the lunar south pole. It can be seen that the research on lunar south pole water ice detection and subsequent extraction technology will be the focus of lunar exploration in the near future.

[0003] The research on water ice detection and extraction technology involves how to prepare highly realistic simulated ice-containing lunar soil. The existing preparation of simulated ice-containing lunar soil mainly adopts the water-mixed soil freezing method. In this method, according to the water content of the simulated ice-containing lunar soil, a certain amount of water and soil are directly stirred and mixed, vibration-compacted, and cryogenically frozen to obtain simulated ice-containing lunar soil with a certain water content. However, there are mainly two deficiencies in the existing method: First, due to the low water content of the simulated ice-containing lunar soil (generally less than 6wt%), there is less water and more soil, and the viscosity is relatively large, resulting in phenomena such as agglomeration and caking of water and soil during the mixing process, making it difficult to mix evenly. The simulation degree of the simulated ice-containing lunar soil sample is poor and the repeatability is low. Second, the porosity of the simulated ice-containing lunar soil prepared by this method is relatively large (generally greater than 50%), and a large amount of air is filled and retained inside the pores. After cryogenic freezing, the air is sealed inside the above pores. Since the moon belongs to a high-vacuum environment and there is basically no residual gas in the lunar soil pores, the state of the simulated ice-containing lunar soil obtained by the above method is quite different from that of the real ice-containing lunar soil. In addition, for the high-air-filled simulated ice-containing lunar soil obtained by the above method, during the water ice thermal extraction process, the formed water vapor will be mixed with a large amount of air, which has a great impact on the low-pressure condensation of water vapor. It is necessary to continuously release non-condensable air to improve the condensation efficiency of water vapor, greatly increasing the difficulty and extraction efficiency of water ice extraction from ice-containing lunar soil.

[0004] Therefore, it is necessary to establish a more efficient, realistic and reliable method for preparing simulated ice-containing lunar soil according to the characteristics of the lunar environment and the occurrence characteristics of lunar soil water ice, combined with ground simulation conditions, so as to provide highly realistic simulated ice-containing lunar soil specimens for the research on key technologies for the detection and extraction of simulated ice-containing lunar soil. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: to overcome the deficiencies of the prior art and propose a method for preparing highly realistic simulated ice-containing lunar soil, so that the mixing uniformity of water and soil in the simulated ice-containing lunar soil is better, and at the same time, the air retained in the pores of the simulated ice-containing lunar soil is discharged as much as possible, and a simulated ice-containing lunar soil sample with a high simulation degree of the occurrence state of real ice-containing lunar soil is prepared, providing technical support for the detection and extraction of water ice in the lunar polar region.

[0006] The technical solution of the present invention is: a system for preparing highly realistic simulated ice-containing lunar soil, including a simulated ice-containing lunar soil storage tank, simulated lunar soil, a steam nozzle, deionized water, a steam generator, a supercharger, a vacuum pump, a drying and condensation device, and a filtering device;

[0007] The vacuum pressure gauge is connected to the simulated icy lunar soil storage tank and is used to measure the vacuum degree in the simulated icy lunar soil storage tank; the simulated icy lunar soil storage tank is used to seal and store simulated lunar soil, and a steam nozzle vent connection flange is preset at the bottom of the tank body of the simulated icy lunar soil storage tank, and a gas pipeline vent flange is also reserved on the side; the steam generator is used to convert deionized water into water vapor and connect it to the supercharger; the front end of the steam nozzle is connected to the supercharger, receives water vapor of a certain pressure delivered by the supercharger, and is used to spray water vapor into the simulated lunar soil in the simulated icy lunar soil storage tank, so as to achieve uniform diffusion of water vapor into the pores of the simulated lunar soil;

[0008] The vacuum pump is connected to the gas pipeline breaker flange through a pipeline. The drying and condensing device is arranged at the front end of the vacuum pump, which is used to dry and cool the mixed gas of air and water vapor extracted from the simulated ice-containing lunar soil storage tank, and is used to calibrate the mass of water vapor in the simulated ice-containing lunar soil storage tank; the filtering device is arranged at the air outlet end of the simulated ice-containing lunar soil storage tank, which is used to filter the simulated lunar soil particles entrained in the air in the pores of the simulated lunar soil when the vacuum pump is extracted. This prevents damage to the vacuum pump.

[0009] Preferably, a flow meter and a pressure gauge are installed on the gas pipeline to monitor the flow rate and steam pressure of the water vapor, thereby controlling the adjustment of the steam generator and the supercharger.

[0010] Preferably, the vacuum pump is a commercial mechanical pump; the simulated ice-containing lunar soil storage tank is a commercial product.

[0011] Preferably, the simulated icy lunar soil storage tank uses a stainless steel tank body, and the tank body uses a sealing rubber ring to achieve vacuum sealing.

[0012] A method for preparing simulated icy lunar soil using the highly realistic simulated icy lunar soil preparation system comprises:

[0013] S1. Place a predetermined amount of simulated lunar soil into a simulated icy lunar soil storage tank, vibrate and compact the simulated lunar soil, and then tightly seal the simulated icy lunar soil storage tank.

[0014] S2. Turn on the vacuum pump to evacuate the simulated icy lunar soil storage tank;

[0015] S3. When the preset vacuum level is reached inside the tank, close the exhaust pipe and keep the simulated icy lunar soil tank sealed and stationary for approximately 1 to 2 hours. When the vacuum level inside the simulated icy lunar soil tank rises to the preset value due to the discharge of air from the simulated lunar soil voids, return to S2 and repeat the cycle 2 to 4 times, closing the exhaust pipe to maintain the vacuum environment inside the simulated icy lunar soil tank.

[0016] S4. Turn on the steam generator and the supercharger, adjust the flow rate and pressure of the steam, and start the process of steam diffusing into the simulated lunar soil; when the internal vacuum degree of the simulated ice-containing lunar soil storage tank rises to the preset value due to the discharge of the residual air in the voids of the simulated lunar soil, evacuate the simulated ice-containing lunar soil storage tank; when the difference between the water loss in the steam generator and the cooling water volume in the dry condenser reaches the initial set ratio of water volume, stop the vacuum pump and the steam generator, close the solenoid valve, and make the simulated ice-containing lunar soil storage tank in a sealed state; transfer the simulated ice-containing lunar soil storage tank to a cryogenic storage tank for cryogenic freezing, that is, prepare the high-fidelity simulated ice-containing lunar soil.

[0017] Preferably, the process of starting the steam to diffuse into the simulated lunar soil includes:

[0018] At the beginning, control the steam flow rate at 0.5 g / min to 1 g / min under normal pressure; as the amount of steam mixed in continuously increases, reduce the steam flow rate to 0 to 0.5 g / min and increase the steam pressure, that is, from normal pressure to 1 MPa, so as to overcome the gas resistance and improve the homogenization degree.

[0019] Preferably, the preset vacuum degree is 0.1 to 1 Pa.

[0020] Preferably, the preset value is 1 to 2 kPa.

[0021] Preferably, the uniform diffusion of water vapor is achieved by the dual actions of the steam generator and the vacuum pump, that is, by the dual actions of the diffusion of water vapor and the suction of the vacuum pump, the uniform diffusion of water vapor in the simulated lunar soil is realized.

[0022] Preferably, when the difference between the water loss in the steam generator and the cooling water volume in the dry condenser reaches the initial set ratio of water volume, that is, 6 wt% ± 1 wt%, stop the steam from diffusing into the simulated lunar soil.

[0023] The beneficial effects of the present invention compared with the prior art are as follows:

[0024] (1) The method for preparing the high-fidelity simulated ice-containing lunar soil proposed by the present invention can achieve uniform mixing of water and soil, avoid phenomena such as caking and clustering, and has a high degree of mixing uniformity.

[0025] (2) The method for preparing the high-fidelity simulated ice-containing lunar soil proposed by the present invention can effectively evacuate the air enclosed in the pores of the simulated lunar soil, and prepare a simulated lunar soil stacking and filling state closer to the real lunar environment, with a high degree of simulation.

[0026] (3) The ground-simulated ice-containing lunar soil sample prepared by the method for preparing the high-fidelity simulated ice-containing lunar soil proposed by the present invention has high uniformity and strong repeatability, and has good guidance for ground tests. Description of the Drawings

[0027] Figure 1 Structural schematic diagram of the present invention;

[0028] Figure 2 Flow chart of the preparation method of the present invention. Detailed implementation manners

[0029] The present invention will be described in detail below with reference to the accompanying drawings and examples, as follows:

[0030] As Figure 1 shown, the high-fidelity simulated ice-containing lunar soil preparation system mainly includes a vacuum pressure gauge 1, a simulated ice-containing lunar soil storage tank 2, simulated lunar soil 3, a steam nozzle 4, electromagnetic valves 5-1, 5-2, deionized water 6, a steam generator 7, a supercharger 8, a flowmeter 9, a pressure gauge 10, a vacuum pump 11, a drying and condensing device 12, a filtering device 13, and a breaking vacuum flange 14.

[0031] The vacuum gauge 1 is connected to the simulated ice-containing lunar soil storage tank 2 for breaking vacuum, mainly used to measure the vacuum degree inside the simulated ice-containing lunar soil storage tank 2. Since the vacuum degree inside the simulated ice-containing lunar soil storage tank 2 in the present invention is not high, commercial products can be used; the simulated ice-containing lunar soil storage tank 2 is mainly used to store simulated lunar soil and meet the sealing requirements of a certain vacuum degree. Generally, a stainless steel tank body is used, and the tank body uses a sealing rubber ring to achieve vacuum sealing. A steam nozzle 4 is preset at the bottom of the tank body for breaking vacuum connection to the flange, and a gas pipeline breaking vacuum flange is also reserved on the side; the simulated lunar soil 3 is mainly used to prepare the simulated ice-containing lunar soil. According to experimental needs, simulated lunar soil materials of different models, different particle size grading relationships, and different weights are selected; the steam nozzle 4 is mainly used to spray water vapor into the simulated lunar soil 3 inside the simulated ice-containing lunar soil storage tank 2 to achieve uniform dispersion of water vapor into the pores of the simulated lunar soil 3. Its front end is connected to the booster 8 and receives the water vapor with a certain pressure conveyed from the booster 8; the solenoid valves 5-1 and 5-2 are mainly used to control the opening and closing of the gas pipeline, and commercial normally open or normally closed solenoid valves can be selected; the deionized water 6 mainly serves to be uniformly mixed with the simulated lunar soil 3 and form ice-containing simulated lunar soil after freezing; the steam generator 7 is mainly used to form water vapor from the deionized water, which is pressurized by the booster 8 at the rear end and filled with water vapor into the simulated ice-containing lunar soil storage tank 2 through the steam nozzle 4. The steam generator 7 can adjust the temperature, pressure, and generation rate of the water vapor to facilitate the adjustment of the water vapor inlet state; the booster 8 mainly serves to pressurize the water vapor generated by the steam generator 7 to improve the diffusion speed and ability of the water vapor; the flow meter 9 and the pressure gauge 10 are mainly used to monitor the flow rate and steam pressure of the water vapor and play a control role in adjusting the steam generator 7 and the booster 8; the vacuum pump 11 is connected to the simulated ice-containing lunar soil storage tank 2 through a pipeline and is mainly used to obtain the internal vacuum degree of the simulated ice-containing lunar soil storage tank 2. Since the vacuum degree requirement inside the simulated ice-containing lunar soil storage tank 2 in the present invention is not high, a commercial mechanical pump can be selected; the drying and condensing device 12 is arranged at the front end of the vacuum pump 11 and is mainly used to dry and cool the mixed gas of air and water vapor extracted from the simulated ice-containing lunar soil storage tank 2 for calibrating the mass of water vapor inside the simulated ice-containing lunar soil storage tank 2; the filtering device 13 is arranged at the air outlet end of the simulated ice-containing lunar soil storage tank 2 and is mainly used to filter the simulated lunar soil particles mixed when the air in the pores of the simulated lunar soil 3 is extracted by the vacuum pump 11 to prevent damage to the vacuum pump 11.

[0032] The method for preparing highly realistic simulated ice-containing lunar soil mainly includes: using the vacuum pump 11 to extract and discharge the residual air inside the simulated ice-containing lunar soil storage tank 2, and using the steam generator 7 to uniformly disperse an appropriate amount of water vapor into the pores of the simulated lunar soil to replace the original air, realizing the preparation of highly realistic, highly uniform, and highly repeatable simulated ice-containing lunar soil with air discharge and uniform water-soil mixing. As Figure 2 shown, the specific steps are as follows:

[0033] First, place the quantified simulated lunar soil into the simulated ice-containing lunar soil storage tank, vibrate and compact the simulated lunar soil on a standard shaking table, and fasten and seal the simulated ice-containing lunar soil storage tank. Then, turn on the vacuum pump to evacuate the simulated ice-containing lunar soil storage tank. When the internal pressure of the tank reaches a certain vacuum degree (initially set to 0.1 - 1 Pa), close the solenoid valve, and let the storage tank stand still for about 1 - 2 hours. The air trapped in the pores of the simulated lunar soil will gradually be discharged, and the internal pressure of the storage tank will slowly rise. When the internal vacuum degree rises to a certain value (set to 1 - 2 kPa, this pressure can ensure that water can exist in a gaseous state under normal temperature conditions), since the pressure difference between the air in the pores and the surrounding atmosphere is small at this time, it is necessary to restart the vacuum pump for evacuation to reduce the vacuum degree in the storage tank, thereby enhancing the release and discharge of air in the simulated lunar soil. This cycle is carried out three times, and most of the air in the pores of the simulated lunar soil can be basically discharged. Then, close the vacuum pump and the solenoid valve of its connecting pipeline to maintain the internal vacuum environment of the storage tank. Turn on the steam generator and the supercharger, adjust the water vapor flow rate and pressure (initially, the water vapor flow rate is large and the pressure is small), and start the process of water vapor diffusing into the simulated lunar soil. As the amount of mixed water vapor continuously increases, reduce the water vapor flow rate and increase the water vapor pressure to overcome the gas resistance and improve the homogenization degree. As the water vapor continuously enters, the residual air will be continuously discharged, and the internal pressure of the storage tank will slowly increase. When the reading of the vacuum pressure gauge rises to a certain value (set to 10 kPa), turn on the vacuum pump and the pipeline solenoid valve to evacuate the storage tank. At this time, observe whether liquid water is generated in the drying and condensing device and record the volume (mass) of the liquid water. When the difference between the water loss in the steam generator and the cooling water volume in the drying and condensing device reaches the initially set ratio of water volume (6% ± 1%), the vacuum pump and the steam generator can be stopped, and the solenoid valve can be closed to make the simulated ice-containing lunar soil storage tank in a sealed state. Transfer the simulated ice-containing lunar soil storage tank to a low-temperature storage tank for cryogenic freezing, and then the highly realistic simulated ice-containing lunar soil can be prepared.

[0034] The parts not detailed in the present invention belong to the common general knowledge of those skilled in the art.

Claims

1. A method for preparing simulated ice-containing lunar regolith implemented by a high-fidelity simulation ice-containing lunar regolith preparation system, characterized in that Including: S1. Place the quantified simulated lunar soil into the simulated ice-containing lunar soil storage tank, vibrate and compact the simulated lunar soil, and tightly seal the simulated ice-containing lunar soil storage tank; S2. Open the vacuum pump to evacuate the simulated ice-containing lunar soil storage tank; S3. When the preset vacuum degree inside the tank body is reached, close the air extraction pipeline, and keep the simulated ice-containing lunar soil storage tank sealed and static for 1 - 2 h; when the internal vacuum degree of the simulated ice-containing lunar soil storage tank rises to the preset value due to the discharge of air inside the pores of the simulated lunar soil, return to S2 and execute it cyclically for 2 - 4 times, then close the air extraction pipeline to maintain the internal vacuum environment of the simulated ice-containing lunar soil storage tank; S4. Open the steam generator and the supercharger, adjust the water vapor flow rate and pressure, and start the process of water vapor diffusing into the simulated lunar soil; when the internal vacuum degree of the simulated ice-containing lunar soil storage tank rises to the preset value due to the discharge of residual air inside the pores of the simulated lunar soil, evacuate the simulated ice-containing lunar soil storage tank; when the difference between the water loss in the steam generator and the cooling water volume in the drying condenser reaches the initially set ratio of water volume, stop the vacuum pump and the steam generator, close the solenoid valve, and keep the simulated ice-containing lunar soil storage tank in a sealed state; transfer the simulated ice-containing lunar soil storage tank to a low-temperature storage tank for cryogenic freezing, thus preparing the highly realistic simulated ice-containing lunar soil; The process of starting the diffusion of water vapor into the simulated lunar soil includes: At the beginning, control the water vapor flow rate at 0.5 g / min - 1 g / min under normal pressure; As the amount of mixed water vapor continuously increases, reduce the water vapor flow rate to 0 - 0.5 g / min and increase the water vapor pressure, that is, from normal pressure to 1 MPa, to overcome the gas resistance and improve the homogenization degree.

2. The method according to claim 1, wherein: The preset vacuum degree is 0.1 - 1 Pa.

3. The method according to claim 1, wherein: The preset value is 1 - 2 kPa.

4. The method according to claim 1, characterized in that: The uniform diffusion of water vapor is achieved by the dual action of the steam generator and the vacuum pump, that is, by the dual action of the diffusion of water vapor and the suction of the vacuum pump, to achieve the uniform diffusion of water vapor inside the simulated lunar soil.

5. The method according to claim 1, wherein: When the difference between the water loss in the steam generator and the cooling water volume in the drying condenser reaches the initially set ratio of water volume, that is, 6 wt% ± 1 wt%, stop the diffusion of water vapor into the simulated lunar soil.

6. A high-fidelity simulated lunar regolith containing ice preparation system, characterized in that: Including a simulated ice-containing lunar soil storage tank, simulated lunar soil, a steam nozzle, deionized water, a steam generator, a supercharger, a vacuum pump, a drying and condensing device, and a filtering device; The vacuum pressure gauge is connected to the simulated ice-containing lunar soil storage tank for breaking the vacuum to measure the vacuum degree inside the simulated ice-containing lunar soil storage tank; the simulated ice-containing lunar soil storage tank is used for sealing and storing the simulated lunar soil, and a steam nozzle breaking vacuum connection flange is preset at the bottom of the tank body of the simulated ice-containing lunar soil storage tank, and a gas pipeline breaking vacuum flange is also reserved on the side; the steam generator is used to form water vapor from deionized water and is connected to the supercharger; the front end of the steam nozzle is connected to the supercharger, receives the water vapor transported from the supercharger, and is used to spray water vapor into the simulated lunar soil inside the simulated ice-containing lunar soil storage tank to achieve the uniform diffusion of water vapor into the pores of the simulated lunar soil; The vacuum pump is connected to the gas pipeline breaker flange through a pipeline. The drying and condensing device is arranged at the front end of the vacuum pump, which is used to dry and cool the mixed gas of air and water vapor extracted from the simulated ice-containing lunar soil storage tank, and is used to calibrate the mass of water vapor in the simulated ice-containing lunar soil storage tank; the filtering device is arranged at the air outlet end of the simulated ice-containing lunar soil storage tank, which is used to filter the simulated lunar soil particles entrained in the air in the pores of the simulated lunar soil when the vacuum pump is extracted. This prevents damage to the vacuum pump.

7. The system according to claim 6, wherein: By installing flow meters and pressure gauges on the gas pipeline, the flow rate and steam pressure of water vapor are monitored, which plays a control role in adjusting the steam generator and booster.

8. The system according to claim 6, characterized in that: The vacuum pump is a commercial mechanical pump; the simulated ice-containing lunar soil storage tank is a commercial product.

9. The system according to claim 8, wherein: The simulated icy lunar soil storage tank uses a stainless steel tank body, and the tank body uses a sealing rubber ring to achieve vacuum sealing.

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