Gradient pressure reduction type lunar soil sample gas explosion suppression device and suppression method thereof

Abstract

The invention provides a gradient pressure reduction type lunar soil sample gas explosion suppression device and a suppression method thereof, and belongs to the field of deep space exploration. The problem of severe sample disturbance in the vacuum environment preparation process is solved. The device comprises a lunar soil barrel and a central release hole former, an upper flange cover is mounted above the lunar soil barrel, a lower flange cover is mounted below the lunar soil barrel, the bottom end of the central release hole former is inserted into an annular groove of the lower flange cover, the central release hole former comprises a plurality of wedge-shaped petals and wedge-shaped blocks, and the wedge-shaped petals and the wedge-shaped blocks are spliced into a cylinder. According to the method, the vacuum gas outlet characteristic of the lunar soil is considered in the lunar soil preparation stage, the central gas release hole of the lunar soil is constructed, and the proposed staged pressure reduction method is combined, so that the gas explosion phenomenon generated by simulating the end face of the lunar soil in the vacuum environment preparation process is effectively solved, and an environment is provided for the subsequent characteristics of the lunar soil.

Description

Technical Field

[0001] The present invention belongs to the field of deep space exploration, and particularly relates to a ground simulation device and method, and more particularly to a gradient decompression type lunar soil sample gas explosion suppression device and its suppression method. Background Technique

[0002] With the continuous deepening of lunar exploration activities, the demand for simulating the lunar surface environment on the ground is becoming increasingly strong. The lunar surface vacuum environment will significantly change the thermal conductivity, particle charging characteristics, and gas adsorption / desorption kinetics of lunar soil, thereby affecting the sampling efficiency, mobility of the detector, and measurement accuracy of scientific payloads. Therefore, preparing a simulated lunar soil sample equivalent to the vacuum environment is an important prerequisite for carrying out performance evaluation of lunar surface sampling mechanisms, sample disturbance analysis, and in-situ detection instrument calibration.

[0003] Currently, domestic and foreign research institutions mainly achieve vacuum environment simulation by preparing simulated lunar soil samples under normal pressure conditions and then transferring them to a vacuum chamber for evacuation. However, this method has obvious technical defects. Kleinhenz et al. at the NASA Glenn Research Center in the United States found in experiments that when the environmental pressure drops from 10 4 Pa to 10 2 Pa, there will be a violent gas release phenomenon on the surface of the simulated lunar soil, manifested as local "fountain effect" and "wave-like eruption". The generation mechanism of this "gas explosion" phenomenon mainly stems from the rapid desorption of adsorbed gas between lunar soil particles and the sudden release of internal pore gas. The "gas explosion" will not only destroy the original stacking structure of the simulated lunar soil, resulting in irreversible changes in key parameters such as porosity and density, but also bring fine-grained lunar soil into the vacuum pump group, causing pump body contamination and performance degradation, seriously affecting the reliability and service life of the experimental system.

[0004] To address this technical bottleneck, it is urgent to develop a new type of gas explosion suppression device to achieve controllable release of gas inside the lunar soil and ensure the integrity of the sample structure and the reliability of the experimental system. Summary of the Invention

[0005] In view of this, in order to solve the problem of severe sample disturbance during the preparation of the vacuum environment, the present invention proposes a gradient decompression type lunar soil sample gas explosion suppression device and its suppression method to achieve the simulation of the lunar soil vacuum environment on the ground. It includes the design of sample preparation equipment and a staged decompression method, which can effectively avoid the "gas explosion" phenomenon of the simulated lunar soil sample during the vacuum extraction process, realize the subsequent experimental process, and provide new scheme support for lunar soil research.

[0006] To achieve the above object, the present invention adopts the following technical solutions: A gradient decompression type lunar soil sample gas explosion suppression device, comprising a lunar soil bucket and a central release hole former. An upper flange cover is installed above the lunar soil bucket, and a lower flange cover is installed below. The bottom end of the central release hole former is inserted into the annular groove of the lower flange cover.

[0007] The central release hole former includes a number of wedge-shaped petals and a wedge-shaped block, and the number of wedge-shaped petals and the wedge-shaped block are assembled into a cylindrical shape.

[0008] Furthermore, the number of wedge-shaped petals includes wedge-shaped petal one, wedge-shaped petal two, and wedge-shaped petal three. Wedge-shaped petal one, wedge-shaped petal two, and wedge-shaped petal three have the same structure and are connected to the central wedge-shaped block through dovetail grooves.

[0009] Furthermore, a lunar soil bucket inner cylinder is also provided inside the lunar soil bucket.

[0010] Furthermore, a refrigerant is injected between the lunar soil bucket inner cylinder and the lunar soil bucket.

[0011] Furthermore, a first hole protection screen is installed on the lunar soil bucket inner cylinder.

[0012] Furthermore, the central release hole former also includes a second hole protection screen, and a second hole protection screen is sleeved outside the cylindrical shape assembled by the number of wedge-shaped petals and the wedge-shaped block.

[0013] Furthermore, threaded holes are provided both above and below the wedge-shaped block.

[0014] Furthermore, the adjusting screw is matched with the threaded hole of the wedge-shaped block, and the height adjustment and removal of the wedge-shaped block can be realized.

[0015] A suppression method for the above-mentioned gradient decompression type lunar soil sample gas explosion suppression device specifically includes the following steps:

[0016] Step 1: Place the lunar soil bucket into the central release hole former, insert the bottom end of the central release hole former into the annular groove of the lower flange cover, screw in the adjusting screw from the bottom of the lower flange cover to move the wedge-shaped block downward, forcing the three wedge-shaped petals to move radially and tighten the hole protection screen and the lower flange cover, so as to realize the fixation of the central release hole former and the lower flange cover;

[0017] Step 2: After filling the lunar soil bucket inner cylinder with the simulated lunar soil prefabricated sample, inject liquid nitrogen for refrigeration between the lunar soil bucket inner cylinder and the lunar soil bucket. After the refrigeration is completed, loosen the adjusting screw, screw the adjusting screw into the threaded hole at the top of the wedge-shaped block, and use the spiral lifting force to pull out the wedge-shaped block and remove the central release hole former to complete the sample preparation;

[0018] Step 3: After preparing the lunar soil sample with the lunar soil bucket, transfer the sample into the vacuum experimental device for pressure reduction along the pressure reduction curve. The specific implementation method is as follows: Construct a vacuum environment, turn on the vacuum pump for simulating the vacuum environment. After turning on the vacuum pump, first open the pressure relief valve to the maximum. When it reaches 1.6×10 4 Pa, close the pressure relief valve and maintain the pressure for 1 hour and 30 seconds. Then open the pressure relief valve. After reaching 10 4 Pa, adjust the pressure relief valve for gradient pressure reduction until the predetermined vacuum value is reached and then close the pressure relief valve.

[0019] Step 4: After reaching the pressure required for the vacuum environment, conduct subsequent simulated lunar soil vacuum experiments.

[0020] Furthermore, it is characterized in that: in Step 3, after reaching 10 4 Pa, the frequency of pressure reduction is to close the pressure relief valve for 100 seconds of pressure maintenance after each 1000 Pa of pressure reduction.

[0021] Compared with the prior art, the beneficial effects of the gradient pressure reduction type lunar soil sample gas explosion suppression device of the present invention are as follows:

[0022] In the stage of preparing lunar soil, the present invention takes into account the vacuum outgassing characteristics of lunar soil, constructs a central release hole for lunar soil, and combines with the proposed staged pressure reduction method, effectively solving the "gas explosion" phenomenon occurring at the end face of simulated lunar soil during the process of preparing the vacuum environment, and providing an environment for the subsequent characteristics of lunar soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0024] Figure 1 is a sectional view of the gradient pressure reduction type lunar soil sample gas explosion suppression device;

[0025] Figure 2 is a top view of the central release hole former;

[0026] Figure 3 is a structural schematic diagram of the central release hole former;

[0027] Figure 4 is a full process pressure reduction curve graph;

[0028] Figure 5 is a specific description curve graph of the stepped pressure reduction from C to D;

[0029] Figure 6 is a comparison graph of the gas explosion prevention device effects, where (a) is the drilling effect diagram of a normal experiment and (b) is the drilling experiment effect diagram using the gas explosion prevention device.

[0030] In the figure: lunar soil bucket 2-1, upper fixing plate 2-2, upper flange cover 2-3, simulated lunar soil prefabricated sample 2-4, wedge flap 2-5, wedge block 2-6, adjusting screw 2-7, first hole protecting screen 2-8, gasket 2-9, inner cylinder of lunar soil bucket 2-10, lower flange cover 2-11, wedge flap one 2-12, wedge flap two 2-13, second hole protecting screen 2-14, wedge flap three 2-15, central hole former 2-16. Specific implementation mode

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0032] See Figure 1-6 In this implementation mode, a lunar soil sample air explosion suppression device with gradient decompression includes a lunar soil bucket 2-1 and a central release hole former 2-16. An upper flange cover 2-3 is installed above the lunar soil bucket 2-1, and a lower flange cover 2-11 is installed below. The bottom end of the central release hole former 2-16 is inserted into the annular groove of the lower flange cover 2-11.

[0033] The central release hole former 2-16 includes a number of wedge flaps 2-5, wedge blocks 2-6 and a second hole protecting screen 2-14. The number of wedge flaps 2-5 and wedge blocks 2-6 are assembled into a cylinder, and a second hole protecting screen 2-14 is sleeved outside the cylinder.

[0034] The number of wedge flaps 2-5 includes wedge flap one 2-12, wedge flap two 2-13 and wedge flap three 2-15. The wedge flap one 2-12, wedge flap two 2-13 and wedge flap three 2-15 have the same structure and are connected to the central wedge block 2-6 through dovetail grooves.

[0035] The present invention uses a wedge block and wedge flaps to facilitate the removal of the central release hole former 2-16. Here, the central release hole former 2-16 is understood as a cylindrical mold, which can build a cylindrical gas release channel in the center of the lunar soil sample.

[0036] The assembly of the central release hole former 2-16 is to first combine the wedge block 2-6 and the wedge flaps 2-5 into a cylinder through dovetail grooves, and then sleeve on the second hole protecting screen 2-14.

[0037] An inner cylinder of lunar soil bucket 2-10 is also arranged inside the lunar soil bucket 2-1.

[0038] A refrigerant is injected between the inner cylinder of lunar soil bucket 2-10 and the lunar soil bucket 2-1.

[0039] A first protective hole screen 2-8 is installed inside the inner cylinder 2-10 of the lunar soil bucket.

[0040] Threaded holes are provided both above and below the wedge block 2-6.

[0041] The adjustment screw 2-7 is engaged with the threaded hole of the wedge block 2-6, enabling the height adjustment and removal of the wedge block 2-6.

[0042] The usage method of the gradient decompression type lunar soil sample gas explosion suppression device:

[0043] Place the lunar soil bucket 2-1 into the central release hole former 2-16. Combine the wedge block 2-6 and the wedge flap 2-5 into a cylinder through the dovetail groove, put on the second protective hole screen 2-14, insert the bottom end of the central release hole former 2-16 into the annular groove of the lower flange cover 2-11, and screw the adjustment screw 2-7 into the bottom of the lower flange cover 2-11 to move the wedge block 2-6 downward, forcing the three wedge flaps 2-5 to move radially and tighten the protective hole screen 2-14 and the lower flange cover 2-11, thereby fixing the central release hole former 2-16 and the lower flange cover 2-11.

[0044] After filling the simulated lunar soil prefabricated sample 2-4, inject liquid nitrogen for refrigeration between the inner cylinder 2-10 of the lunar soil bucket and the lunar soil bucket 2-1. After the refrigeration is completed, loosen the adjustment screw 2-7, screw the adjustment screw 2-7 into the threaded hole at the top of the wedge block 2-6, and use the spiral lifting force to pull out the wedge block 2-6 and remove the central release hole former 2-16 to complete the sample preparation.

[0045] After preparing the lunar soil sample with the lunar soil bucket 2-1, transfer the sample to the vacuum experimental device and perform pressure reduction according to the pressure reduction curve as shown in Figure 4 - Figure 5 The specific implementation method is as follows: Construct a vacuum environment and turn on the vacuum pump to simulate the vacuum environment. After turning on the vacuum pump, first open the pressure relief valve to the maximum. When it reaches 1.6×10 4 Pa, close the pressure relief valve and maintain the pressure for 1 h 30 s. Then open the pressure relief valve. After reaching 104 Pa, adjust the pressure relief valve for gradient pressure reduction, that is, close the pressure relief valve for 100 s of pressure maintenance after each pressure reduction of 1000 Pa until the predetermined vacuum value is reached and then close the pressure relief valve.

[0046] When the pressure required for the vacuum environment is reached, conduct subsequent simulated lunar soil vacuum experiments.

[0047] As shown in Figure 4 and Figure 5 Both are descriptions of the pressure curve during the pressure reduction process. As shown in Figure 4As shown, at point A, the vacuum pump is turned on and the throttle valve is adjusted. The pressure at point B1 reaches 16000 Pa. The stage from B₁ to B₂ is a constant pressure stage. At point B₂, the pressure relief valve is adjusted. The pressure at point C becomes 10000 Pa, and the diaphragm gauge shows a reading. The pressure at point D is 1000 Pa. The stage from C to D is a stepped pressure reduction. At point E, the pressure relief valve is completely closed. After staying for 10 minutes, at point F, the drill is turned on and the drilling stage lasts for 14 minutes. The test ends at point G.

[0048] Figure 5 For the specific description of the stepped pressure reduction from C to D, the diaphragm gauge at point C shows a reading; c₁ to c₈ are the adjustment points of the pressure relief valve. The pressure relief valve is adjusted, and each pressure drop is about 1000 Pa.

[0049] As Figure 6 shown, Figure 6 As shown in the figure, it is a comparison diagram of the effects of the anti - air - explosion device. Among them, (a) is the effect diagram of the ordinary experimental drilling. It is a process diagram of directly freezing and molding the lunar soil for the drilling experiment. It can be seen that during the experiment, there is a sudden increase in air pressure, and a serious "air - explosion" phenomenon occurs on the surface of the lunar soil bucket.

[0050] (b) is the effect diagram of the drilling experiment using the anti - air - explosion device. It is a lunar soil sample with a central air release hole constructed, and a staged pressure reduction method is used. The air pressure is stable during the experiment. It can be seen that the present invention effectively inhibits the occurrence of the "air - explosion" phenomenon.

[0051] The central release hole former 2 - 16 of the present application is to construct an air outlet channel (to analyze the vacuum outgassing characteristics of lunar soil), and at the same time cooperate with the staged pressure reduction. The combination of the two solves the "air - explosion problem".

[0052] The formation of the "air - explosion" phenomenon is due to the existence of air in the particle gaps of the lunar soil when it is put into the soil bucket. When vacuumizing, due to the internal and external pressure difference, the air between the particles surges out, driving the soil to eject.

[0053] The present invention constructs the central release hole former 2 - 16 to provide an exhaust channel for the air between the lunar soil particles.

[0054] The staged pressure reduction is to slowly release the vacuum pressure difference to prevent the soil from being carried out by the air due to too large a pressure difference.

[0055] The embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor limit the invention to the specific embodiments described. According to the content of this specification, many modifications and changes can be made. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the relevant technical field can well understand and utilize the present invention.

Claims

1. A gradient pressure reduction type lunar soil sample gas explosion suppression device, characterized in that: It includes a lunar soil bucket (2-1) and a central release hole former (2-16). An upper flange cover (2-3) is installed above the lunar soil bucket (2-1), and a lower flange cover (2-11) is installed below it. The bottom end of the central release hole former (2-16) is inserted into the annular groove of the lower flange cover (2-11). The central release hole former (2-16) includes a number of wedge-shaped petals (2-5) and a wedge-shaped block (2-6), and the number of wedge-shaped petals (2-5) and the wedge-shaped block (2-6) are assembled into a cylinder.

2. The gradient decompression type lunar soil sample gas explosion suppression device according to claim 1, characterized in that: The number of wedge-shaped petals (2-5) includes a first wedge-shaped petal (2-12), a second wedge-shaped petal (2-13) and a third wedge-shaped petal (2-15). The first wedge-shaped petal (2-12), the second wedge-shaped petal (2-13) and the third wedge-shaped petal (2-15) have the same structure and are connected to the central wedge-shaped block (2-6) through dovetail grooves.

3. The gradient pressure reduction type lunar soil sample gas explosion suppression device according to claim 1, characterized in that: A lunar soil bucket inner cylinder (2-10) is also arranged inside the lunar soil bucket (2-1).

4. The gradient pressure reduction type lunar soil sample gas explosion suppression device according to claim 3, wherein: A refrigerant is injected between the lunar soil bucket inner cylinder (2-10) and the lunar soil bucket (2-1).

5. The gradient pressure reduction type lunar soil sample gas explosion suppression device according to claim 3, wherein: The lunar soil bucket inner cylinder (2-10) is equipped with a first hole protection screen (2-8).

6. The gradient decompression type lunar soil sample gas explosion suppression device according to claim 1, wherein: The central release hole former (2-16) also includes a second hole protection screen (2-14). The number of wedge-shaped petals (2-5) and the wedge-shaped block (2-6) are assembled into a cylinder and are sleeved with the second hole protection screen (2-14).

7. The gradient decompression type lunar soil sample gas explosion suppression device according to claim 1, wherein: Threaded holes are provided both above and below the wedge-shaped block (2-6).

8. The gradient decompression type lunar soil sample gas explosion suppression device according to claim 7 is characterized by: The adjusting screw (2-7) cooperates with the threaded hole of the wedge-shaped block (2-6), and can realize the height adjustment and removal of the wedge-shaped block (2-6).

9. A suppression method for the gradient decompression type lunar soil sample gas explosion suppression device according to any one of claims 1-8, characterized in that: Specifically, it includes the following steps: Step 1: Place the lunar soil bucket (2-1) into the central release hole former (2-16), insert the bottom end of the central release hole former (2-16) into the annular groove of the lower flange cover (2-11), and screw the adjusting screw (2-7) into the bottom of the lower flange cover (2-11) to move the wedge-shaped block (2-6) downward, forcing the three wedge-shaped petals (2-5) to move radially and tighten the second hole protection screen (2-14) and the lower flange cover (2-11), so as to fix the central release hole former (2-16) and the lower flange cover (2-11). Step 2: After filling the lunar soil bucket inner cylinder (2-10) with the simulated lunar soil prefabricated sample (2-4), inject liquid nitrogen for refrigeration between the lunar soil bucket inner cylinder (2-10) and the lunar soil bucket (2-1). After the refrigeration is completed, loosen the adjusting screw (2-7), screw the adjusting screw (2-7) into the threaded hole at the top of the wedge-shaped block (2-6), and use the spiral lifting force to pull out the wedge-shaped block (2-6) and remove the central release hole former (2-16) to complete the sample preparation. Step 3: After the lunar soil sample is prepared using the lunar soil bucket (2-1), the sample is transferred to the vacuum experimental device for pressure reduction curve decompression. The specific implementation method is as follows: build a vacuum environment, turn on the vacuum pump to simulate the vacuum environment, and after turning on the vacuum pump, first open the pressure relief valve to the maximum to reach 1.6×10 4 Pa, close the pressure relief valve and maintain the pressure for 1h30s, then open the pressure relief valve and reach 10 4 After reaching the predetermined vacuum value, the pressure relief valve is adjusted to perform gradient pressure reduction until it is closed. Step 4: When the pressure required for the vacuum environment is reached, conduct subsequent simulated lunar soil vacuum experiments.

10. The suppression method of the gradient decompression type lunar soil sample gas explosion suppression device according to claim 9, characterized in that: In step 3, when it reaches 10 4 Pa, the frequency of gradient pressure reduction is to close the pressure relief valve after each 1000 Pa reduction and hold the pressure for 100 s.

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