Method for measuring heat conductivity coefficient of lunar soil brick

Abstract

The invention provides a lunar soil brick heat conductivity coefficient measuring method which comprises the following steps: constructing a measuring sample plate which comprises a lunar soil brick, transition layers located on the upper surface and the lower surface of the lunar soil brick, and an auxiliary plate filled around the lunar soil brick; measuring the thickness delta < total >, the area A < total > and the heat conductivity coefficient k < total > of the measuring sample plate by using measuring equipment; establishing a thermal resistance model based on a one-dimensional steady-state Fourier heat conduction law; and calculating the heat conductivity coefficient of the lunar soil brick according to the thermal resistance model. According to the invention, by establishing the equivalent thermal resistance model of the lunar soil brick, the steady-state thermal conductivity measurement of the thermal conductivity of the lunar soil brick is realized, and the problems of small size and rough surface of the lunar soil brick in the steady-state thermal conductivity measurement process can be effectively solved, so that the steady-state measurement of the thermal conductivity of the lunar soil bricks with various sizes is met.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of space resource development and utilization, and particularly relates to a lunar soil brick thermal conductivity measurement method. BACKGROUND

[0002] The goal of future manned lunar exploration missions is to achieve long-term and sustainable human residence on the lunar surface, and lunar in-situ resource utilization technology is an important technology to achieve the goal. The lunar soil brick, which is made of lunar soil as raw material through printing and sintering, can be used for the construction of lunar landing sites, manned lunar bases and the like. The thermal conductivity of the lunar soil brick is an important performance parameter, which is closely related to the manufacturing process of the lunar soil brick. At the same time, the thermal conductivity of the lunar soil brick is also an input parameter for the design of subsequent lunar soil brick application systems, so it is necessary to measure and obtain the thermal conductivity of the lunar soil brick.

[0003] In the prior art, for example, the Chinese patent with the publication number CN102288641A proposes a transient thermal bridge method, but it is only applicable to homogeneous high-temperature materials and cannot solve the problem of local heat flow distortion caused by the porous structure of lunar soil. For another example, the Chinese patent with the publication number CN111443106A simulates the thermal conductivity of heterogeneous materials based on finite elements, but the disadvantage is that it is too dependent on prior parameters of the materials.

[0004] Further, the thermal conductivity measurement method based on the one-dimensional steady-state Fourier heat conduction law is also a commonly used method for measuring the thermal conductivity of solid materials, which has the advantages of high measurement accuracy and good repeatability. For example, the absolute accuracy of the TA-FOX-200 thermal conductivity instrument is ±1%, and the repeatability is ±0.5%. However, this measurement method requires that the size of the sample to be measured meets the size of the hot plate of the instrument, otherwise it is difficult to obtain accurate measurement data.

[0005] At the same time, the size of the lunar soil brick made by the in-situ manufacturing method is usually difficult to meet the size of the thermal conductivity instrument, and cannot meet the size requirements of the thermal conductivity instrument for the sample to be measured. In addition, the lunar soil brick has a large surface roughness, and it is difficult to form a good surface contact with the instrument hot plate during the measurement of its thermal conductivity, which further affects the measurement accuracy of the thermal conductivity of the sample. SUMMARY

[0006] To solve the technical problems existing in the prior art, the purpose of the present application is to provide a lunar soil brick thermal conductivity measurement method, which realizes the steady-state heat conduction measurement of the thermal conductivity of the lunar soil brick by establishing an equivalent thermal resistance model of the lunar soil brick, and can effectively solve the problems of small size and rough surface of the lunar soil brick during the steady-state heat conduction measurement, thereby meeting the steady-state measurement of the thermal conductivity of lunar soil bricks of various sizes.

[0007] To achieve the above object, the application provides a method for measuring the thermal conductivity of lunar soil bricks, comprising the following steps:

[0008] Constructing a measurement sample plate, which comprises a lunar soil brick, a transition layer on the upper and lower surfaces of the lunar soil brick, and an auxiliary plate filled around the lunar soil brick;

[0009] Measuring the thickness δ of the measurement sample plate using a measurement device total , the area A total , and the thermal conductivity κ total ;

[0010] Establishing a thermal resistance model based on a one-dimensional steady-state Fourier heat conduction law:

[0011]

[0012] Wherein, R total is the thermal resistance of the measurement sample plate, R1 is the thermal resistance of the lunar soil brick, R2 is the thermal resistance of the transition layer, and R3 is the thermal resistance of the auxiliary plate;

[0013] Calculating the thermal conductivity of the lunar soil brick according to the thermal resistance model.

[0014] According to one technical solution of the application, the construction of the measurement sample plate comprises:

[0015] Measuring the size of the lunar soil brick, including the length x, the width y, and the thickness z, which satisfies 20mm≤x,y≤200mm and 10mm≤z≤50mm;

[0016] Calculating the size of the auxiliary plate according to the sample size requirement of the thermal conductivity instrument;

[0017] Manufacturing the auxiliary plate and the transition layer;

[0018] Assembling the lunar soil brick, the transition layer, and the auxiliary plate into a measurement sample plate.

[0019] According to one technical solution of the application, the auxiliary plate comprises two first auxiliary plates consistent with the width y of the lunar soil brick, and two second auxiliary plates consistent with the length of the lunar soil brick and the two first auxiliary plates.

[0020] The two first auxiliary plates are oppositely arranged based on the lunar soil brick, and the two second auxiliary plates are oppositely arranged based on the lunar soil brick.

[0021] According to one technical solution of the application, the transition layer is a silica gel sheet or lunar soil powder with known thermal conductivity.

[0022] According to one technical solution of the application, the auxiliary plate is a polystyrene foam plate or a polyimide foam plate.

[0023] According to one of the technical solutions of the present application, the measuring device is a TA-FOX-200 thermal conductivity instrument, and the measuring sample plate is arranged between the cold plate and the hot plate of the thermal conductivity instrument.

[0024] According to one of the technical solutions of the present application, the thermal resistance of the measuring sample plate is the total thermal resistance of the thermal resistance of the lunar soil brick and the thermal resistance of the transition layer and the thermal resistance of the auxiliary plate in series and parallel.

[0025] According to one of the technical solutions of the present application, the calculation process of the thermal conductivity κ1 of the lunar soil brick is as follows:

[0026] The thermal resistance R1 of the lunar soil brick and the thermal resistance R2 of the transition layer are in series, and the thermal resistance of the lunar soil brick and the transition layer is represented as:

[0027]

[0028] The thermal resistance of the lunar soil brick and the transition layer and the thermal resistance R3 of the auxiliary plate are in parallel, and the total thermal resistance R total is:

[0029]

[0030] The measured thermal conductivity is the thermal conductivity κ total of the measuring sample plate including the lunar soil brick, the transition layer and the auxiliary plate, and the relationship with the total thermal resistance R total is:

[0031]

[0032] The total thermal resistance R total is calculated, and the known parameters are brought into the relationship of the total thermal resistance to calculate the thermal conductivity κ1 of the lunar soil brick.

[0033] Compared with the prior art, the present application has the following beneficial effects:

[0034] The present application provides a lunar soil brick thermal conductivity measurement method, which realizes the steady-state thermal conductivity measurement of the lunar soil brick by establishing an equivalent thermal resistance model of the lunar soil brick, can effectively solve the problems of small size and rough surface of the lunar soil brick in the steady-state thermal conductivity measurement process, and thus meets the steady-state measurement of the thermal conductivity of lunar soil bricks of various sizes.

[0035] The measurement method provided by the present application can be used for the steady-state measurement of the thermal conductivity of lunar soil bricks of various sizes, and the length and width size range is 20-200mm, and the thickness size range is 10-50mm.

[0036] The present application, based on the thermal resistance model established by one-dimensional steady-state Fourier heat conduction law, clearly reflects the series-parallel connection of the thermal resistance of each part in the total sample plate, provides a rigorous theoretical basis for the calculation of the lunar soil brick thermal conductivity, ensures the reliability of the measurement data, and can accurately deduce the thermal conductivity of the lunar soil brick by combining the known parameters and the measured parameters.

[0037] Further, the present application reduces the implementation cost of the measurement scheme while ensuring the measurement effect, and is convenient for popularization and application. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description only represent some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0039] Figure 1 The structural schematic diagram of the measurement sample plate in an embodiment of the present application;

[0040] Figure 2 The schematic diagram of the position relationship between the lunar soil brick and the transition layer in an embodiment of the present application;

[0041] Figure 3 The equivalent circuit diagram of the thermal resistance of the lunar soil brick thermal conductivity measurement method in an embodiment of the present application.

[0042] In the drawings, the correspondence between the reference signs and the component names is as follows:

[0043] 1, measurement sample plate; 2, lunar soil brick; 3, transition layer; 4, first auxiliary plate; 5, second auxiliary plate. DETAILED DESCRIPTION

[0044] The description of the embodiments of the present application should be combined with the corresponding drawings, and the drawings should be regarded as a part of the complete description. In the drawings, the shape or thickness of the embodiments can be enlarged, and simplified or convenient indications are used. Furthermore, the parts of the structures in the drawings will be described separately, and it should be noted that the elements not shown in the drawings or not described by words are in the form known by those skilled in the art.

[0045] The description of the embodiments herein, any reference to direction and orientation, is only for the convenience of description, and cannot be understood as any limitation on the scope of protection of the present application. The following description of the preferred embodiments will involve combinations of features, which can exist independently or in combination, and the present application is not particularly limited to the preferred embodiments. The scope of the present application is defined by the claims.

[0046] As Figures 1 to 3 shown, the application provides a method for measuring the thermal conductivity of lunar soil bricks, comprising the following steps:

[0047] Constructing a measurement template 1, which includes a lunar soil brick 2, a transition layer 3 located on the upper and lower surfaces of the lunar soil brick 2, and an auxiliary plate filled around the lunar soil brick 2;

[0048] Using a measurement device to measure the thickness δ total , area A total , and thermal conductivity κ total of the measurement template 1;

[0049] Based on the one-dimensional steady-state Fourier heat conduction law, a thermal resistance model is established:

[0050]

[0051] where R total is the thermal resistance of the measurement template 1, R1 is the thermal resistance of the lunar soil brick 2, R2 is the thermal resistance of the transition layer 3, and R3 is the thermal resistance of the auxiliary plate;

[0052] According to the thermal resistance model, the thermal conductivity of the lunar soil brick 2 is calculated.

[0053] By establishing an equivalent thermal resistance model of the lunar soil brick 2, the steady-state heat conduction measurement of the thermal conductivity of the lunar soil brick 2 is realized, which effectively solves the problem of small size and rough surface of the lunar soil brick 2 in the steady-state heat conduction measurement process, thereby meeting the steady-state measurement of the thermal conductivity of lunar soil bricks 2 of various sizes.

[0054] In some embodiments of the application, the construction of the measurement template 1 includes:

[0055] Measuring the size of the lunar soil brick 2, including length x, width y, and thickness z, satisfying 20mm≤x,y≤200mm and 10mm≤z≤50mm;

[0056] Calculating the size of the auxiliary plate according to the sample size requirements of the thermal conductivity instrument;

[0057] Making the auxiliary plate and the transition layer 3;

[0058] Assembling the lunar soil brick 2, the transition layer 3, and the auxiliary plate into the measurement template 1.

[0059] The construction steps of the measuring template 1 (measuring the size of the lunar soil brick 2, calculating the size of the auxiliary plate, making and assembling each component) ensure that the size of the total template strictly meets the sample requirements of the measuring equipment. Among them, the accurate size design of the auxiliary plate can fill the space between the cold and hot plates of the instrument, eliminate the interference of air convection and conduction on the measurement; the addition of the transition layer 3 improves the surface contact of the lunar soil brick 2 and the cold and hot plates of the instrument, and reduces the thermal contact resistance. The construction process lays a foundation for the accurate measurement of the thermal conductivity of the total template and the derivation of the thermal conductivity of the lunar soil brick 2, and improves the standardization and reliability of the measurement process.

[0060] Specifically, the contour size of the lunar soil brick 2 is measured by a vernier caliper, which is recorded as x*y*z mm, and the length, width and height are all less than 200*200*50mm required by the instrument.

[0061] Then, according to the sample size requirement 200*200*50mm of the thermal conductivity instrument, the auxiliary plate is made by a laser beam cutting machine or a mechanical cutting machine to meet the sample size of the instrument. According to Figure 1 The auxiliary plate and the lunar soil brick 2 are combined as shown in FIG. 4 to construct the measuring template 1. The auxiliary plate can fill the space between the cold and hot plates of the instrument, eliminating the influence of air convection and conduction on the measurement of the thermal conductivity of the sample. The auxiliary plate is made of commercial polystyrene foam plate, polyimide foam plate and other materials, the thermal conductivity of which is known, and the price is low and easy to process.

[0062] In some embodiments of the present application, the auxiliary plate includes two first auxiliary plates 4 consistent with the width y of the lunar soil brick 2, and two second auxiliary plates 5 consistent with the length of the lunar soil brick 2 and the two first auxiliary plates 4;

[0063] The two first auxiliary plates 4 are arranged opposite to the lunar soil brick 2; the two second auxiliary plates 5 are arranged opposite to the lunar soil brick 2.

[0064] By designing the size of the auxiliary plate in the above manner, the gap around the lunar soil brick 2 can be accurately filled, so that the length and width of the total template strictly match the requirements of 200*200mm of the instrument. The symmetrical filling structure not only avoids the stagnation of air in the gap, reduces the influence of air convection and conduction on the thermal resistance measurement, but also ensures the uniformity of the heat flow distribution of the total template, and improves the applicability and calculation accuracy of the thermal resistance model.

[0065] As shown in Table 1 below, the size of the sample and the auxiliary plate is shown.

[0066] Name Long / mm Wide / mm Height / mm Lunar soil brick 2 x y z First auxiliary plate 4 (200-x) / 2 y z Second auxiliary plate 5 200 (200-y) / 2 z

[0067] Table 1

[0068] The transition layer 3 is provided with silica gel sheet or lunar soil powder with known thermal conductivity, which can fill the rough gaps on the surface of the lunar soil brick 2, improve the surface contact between the lunar soil brick 2 and the cold and hot plates of the instrument, and significantly reduce the contact thermal resistance. On the other hand, the thermal conductivity of the transition layer 3 is known, which can be used as a determined parameter in the thermal resistance model to reduce the measurement error caused by the uncertainty of the transition layer 3 itself, and further improve the accuracy of the calculation of the thermal conductivity of the lunar soil brick 2.

[0069] Further, the auxiliary plate is provided with polystyrene foam or polyimide foam with known thermal conductivity, which can be used as a determined parameter in the thermal resistance model to ensure the accuracy of the calculation of the thermal resistance of the auxiliary plate. Meanwhile, the easy processability of the material can accurately match the size requirements of the total sample plate, effectively fill the space around the lunar soil brick 2 to eliminate air interference, and the low cost can reduce the implementation cost of the measurement scheme, which is suitable for popularization and application in the thermal conductivity measurement of various lunar soil bricks 2 and similar porous materials.

[0070] In some embodiments of the present application, the measurement device is a TA-FOX-200 thermal conductivity instrument, and the measurement sample plate 1 is arranged between the cold plate and the hot plate of the thermal conductivity instrument.

[0071] The absolute accuracy of ±1% and the repeatability of ±0.5% of the TA-FOX-200 thermal conductivity instrument can be used to accurately measure the thermal conductivity of the total sample plate. Meanwhile, the measurement sample plate 1 is arranged between the cold plate and the hot plate of the instrument, and the total sample plate can completely fill the space between the cold and hot plates, which ensures the good surface contact between the cold and hot plates and the sample plate, and avoids the deviation of the thermal resistance measurement caused by poor contact. The combination of high-precision instrument and reasonable sample plate placement provides reliable data for the measurement of the thermal conductivity of the total sample plate, which is an important basis for the subsequent accurate derivation of the thermal conductivity of the lunar soil brick 2.

[0072] In some embodiments of the present application, the gap between the auxiliary plate and the lunar soil brick 2 is ignored, and the thermal resistance of the measurement sample plate 1 is the total thermal resistance of the thermal resistance of the lunar soil brick 2, the thermal resistance of the transition layer 3 and the thermal resistance of the auxiliary plate in series and parallel.

[0073] The calculation process of the thermal conductivity κ1 of the lunar soil brick 2 is as follows:

[0074] The thermal resistance R1 of the lunar soil brick 2 and the thermal resistance R2 of the transition layer 3 are in series, and the thermal resistance of the lunar soil brick 2 and the transition layer 3 is represented as:

[0075]

[0076] The thermal resistance of the lunar soil brick 2 and the transition layer 3 and the thermal resistance R3 of the auxiliary plate are in parallel, and the total thermal resistance R total is:

[0077]

[0078] The measured thermal conductivity is the thermal conductivity k of the measuring sample 1 including the lunar soil brick 2, the transition layer 3 and the auxiliary plate total , and the relationship with the total thermal resistance R total is expressed as:

[0079]

[0080] The total thermal resistance R total is calculated, and the known parameters are brought into the relationship of the total thermal resistance to calculate the thermal conductivity κ1 of the lunar soil brick 2.

[0081] The thermal conductivity of the lunar soil brick 2 can be directly solved by mathematical operation, which is not only logically rigorous, but also avoids errors caused by fuzzy calculation process, ensures the accuracy of the final result, and realizes the accurate measurement of the thermal conductivity of the lunar soil brick 2.

[0082] The parameters of each part of the measuring sample 1 are shown in Table 2.

[0083] Name Thermal conductivity Thickness Area Thermal resistance Lunar soil brick 2 K1 [delta 1] [A1] [R1] Transition layer 3 K2 [delta 2] [A2] [R2] Auxiliary plate K3 [delta] 3 [A3] [R3] Measurement template 1 k total ]]> delta total ]] A total ]]> [R total ]]>

[0084] Table 2

[0085] The measurement method of the thermal conductivity of the lunar soil brick 2 of the application is used to complete the following measurement experiments in the laboratory by simulating the lunar environment.

[0086] Example 1:

[0087] Firstly, the contour size of the lunar soil brick 2 is measured as 50*50*10mm.

[0088] Then, according to the sample size requirement 200*200*50mm of the thermal conductivity instrument, an auxiliary plate is made by using a laser cutting machine, the auxiliary plate is made of polystyrene foam plate, the thermal conductivity thereof is κ3, and the size is as follows

[0089] Table 3.

[0090] Name Long / mm Wide / mm Height / mm First auxiliary plate 4 75 50 10 Second auxiliary plate 5 200 75 10

[0091] Table 3

[0092] Then, according to the structure of the measuring sample 1 in the Figure 1 , the lunar soil brick 2 sample, the first auxiliary plate 4 and the second auxiliary plate 5 are assembled, and placed in the sample chamber of the thermal conductivity instrument, and the thermal conductivity of the measuring sample 1 is κ total =0.058W / (m.K).

[0093] Finally, according to the equivalent thermal resistance relationship of the measurement sample 1, the thermal conductivity of the measurement sample 1, and the known parameters (thickness, cross-sectional area, thermal conductivity) of the auxiliary plate and the lunar soil brick 2 sample are brought into the equivalent thermal resistance relationship, and the thermal conductivity κ1 of the lunar soil brick 2 is calculated to be 0.478 W / (m.K).

[0094]

[0095] The known parameters of the auxiliary plate and the lunar soil brick 2 sample are shown in Table 4 below.

[0096]

[0097] Table 4

[0098] Example 2:

[0099] First, the contour size of the lunar soil brick 2 is measured to be 50*50*20mm.

[0100] Then, according to the sample size requirement 200*200*50mm of the thermal conductivity instrument, an auxiliary plate is made by using a laser cutting machine, the auxiliary plate is made of polystyrene foam plate, the thermal conductivity of the auxiliary plate is κ3, and the size of the auxiliary plate is shown in Table 5 below.

[0101] Name Long / mm Wide / mm Height / mm First auxiliary plate 4 75 50 20 Second auxiliary plate 5 200 75 20

[0102] Table 5

[0103] After that, according to the structure of the measurement sample 1 in the Figure 1 , the lunar soil brick 2 sample, the first auxiliary plate 4 and the second auxiliary plate 5 are assembled, and placed in the sample chamber of the thermal conductivity instrument, and the thermal conductivity of the measurement sample 1 is measured to be κ total =0.059 W / (m.K).

[0104] Finally, according to the equivalent thermal resistance relationship of the measurement sample 1, the thermal conductivity of the measurement sample 1, and the known parameters (thickness, cross-sectional area, thermal conductivity) of the auxiliary plate and the lunar soil brick 2 sample are brought into the equivalent thermal resistance relationship, and the thermal conductivity κ1 of the lunar soil brick 2 is calculated to be 0.494 W / (m.K).

[0105]

[0106] The known parameters of the auxiliary plate and the lunar soil brick 2 sample are shown in Table 6 below.

[0107]

[0108] Table 6

[0109] Example 3:

[0110] Firstly, the outline size of the lunar soil brick 2 is measured as 100*100*10mm.

[0111] Then, according to the sample size requirement of the thermal conductivity instrument of 200*200*50mm, an auxiliary plate is made by using a laser cutting machine, the auxiliary plate is made of polystyrene foam plate, the thermal conductivity coefficient of the auxiliary plate is κ3, and the size of the auxiliary plate is shown in Table 7.

[0112] Name Long / mm Wide / mm Height / mm First auxiliary plate 4 50 50 10 Second auxiliary plate 5 200 50 10

[0113] Table 7

[0114] After that, according to the structure of the measurement sample plate 1 in the Figure 1 , the lunar soil brick 2 sample, the first auxiliary plate 4 and the second auxiliary plate 5 are assembled and placed in the sample chamber of the thermal conductivity instrument, and the thermal conductivity coefficient of the measurement sample plate 1 is measured as κ total =0.147W / (m.K).

[0115] Finally, according to the equivalent thermal resistance relationship of the measurement sample plate 1, the thermal conductivity coefficient of the measurement sample plate 1, and the known parameters (thickness, cross-sectional area, thermal conductivity coefficient) of the auxiliary plate and the lunar soil brick 2 sample are brought into the equivalent thermal resistance relationship, and the thermal conductivity coefficient of the lunar soil brick 2 is calculated as κ1=0.498W / (m.K).

[0116]

[0117] The known parameters of the auxiliary plate and the lunar soil brick 2 sample are shown in Table 8.

[0118]

[0119] Table 8

[0120] Example 4:

[0121] Firstly, the outline size of the lunar soil brick 2 is measured as 100*100*10mm.

[0122] Then, according to the sample size requirement of the thermal conductivity instrument of 200*200*50mm, an auxiliary plate is made by using a laser cutting machine, the auxiliary plate is made of polystyrene foam plate, the thermal conductivity coefficient of the auxiliary plate is κ3, and the size of the auxiliary plate is shown in Table 8.

[0123] Name Long / mm Wide / mm Height / mm First auxiliary plate 4 50 50 10 Second auxiliary plate 5 200 50 10

[0124] Table 8

[0125] After that, according to the structure of the measurement sample plate 1 in the Figure 1 , the lunar soil brick 2 sample, the first auxiliary plate 4 and the second auxiliary plate 5 are assembled and placed in the sample chamber of the thermal conductivity instrument, and the thermal conductivity coefficient of the measurement sample plate 1 is measured as κ total =0.145W / (m.K).

[0126] Finally, according to the equivalent thermal resistance relationship of the measurement sample 1, the thermal conductivity of the measurement sample 1, and the known parameters (thickness, cross-sectional area, thermal conductivity) of the auxiliary plate and the lunar soil brick 2 sample are brought into the equivalent thermal resistance relationship, and the thermal conductivity κ1 of the lunar soil brick 2 is calculated to be 0.49 W / (m.K).

[0127]

[0128] The known parameters of the auxiliary plate and the lunar soil brick 2 sample are shown in Table 9.

[0129]

[0130] Table 9

[0131] Example 5:

[0132] First, the profile size of the lunar soil brick 2 is measured to be 100*100*10mm.

[0133] Then, according to the sample size requirement of the thermal conductivity instrument of 200*200*50mm, an auxiliary plate is made by a laser cutting machine, the auxiliary plate is made of polystyrene foam plate, the thermal conductivity of which is κ3, and the size is as follows

[0134] Table 10.

[0135] Name Long / mm Wide / mm Height / mm First auxiliary plate 4 50 50 10 Second auxiliary plate 5 200 50 10

[0136] Table 10

[0137] After that, according to the structure of the measurement sample 1 in Figure 1 , the lunar soil brick 2 sample, the first auxiliary plate 4 and the second auxiliary plate 5 are assembled and placed in the sample chamber of the thermal conductivity instrument, and the thermal conductivity of the measurement sample 1 is measured to be k total =0.148 W / (m.K).

[0138] Finally, according to the equivalent thermal resistance relationship of the measurement sample 1, the thermal conductivity of the measurement sample 1, and the known parameters (thickness, cross-sectional area, thermal conductivity) of the auxiliary plate and the lunar soil brick 2 sample are brought into the equivalent thermal resistance relationship, and the thermal conductivity κ1 of the lunar soil brick 2 is calculated to be 0.502 W / (m.K).

[0139]

[0140] The known parameters of the auxiliary plate and the lunar soil brick 2 sample are shown in Table 11.

[0141]

[0142] Table 11

[0143] Example 6:

[0144] First, the outline size of the lunar soil brick 2 was measured to be 100*100*10mm.

[0145] Then, according to the sample size requirement of the thermal conductivity instrument of 200*200*50mm, an auxiliary plate was made using a laser cutting machine. The auxiliary plate was made of polystyrene foam board with a thermal conductivity of κ3. Its dimensions are shown in Table 12 below.

[0146] Name Long / mm Wide / mm Height / mm First auxiliary plate 4 50 50 10 Second auxiliary plate 5 200 50 10

[0147] Table 12

[0148] Afterwards, follow Figure 1 Name Long / mm Wide / mm Height / mm First auxiliary plate 4 Second auxiliary plate 5 Figure 1 The structure of the measurement sample 1 is assembled, and the lunar soil brick 2 sample, the first auxiliary plate 4 and the second auxiliary plate 5 are placed in the sample chamber of the thermal conductivity meter. The thermal conductivity coefficient of the measurement sample 1 is measured as κ total =0.146W / (mK).

[0149] Finally, according to the equivalent thermal resistance relationship of the measurement sample 1, the thermal conductivity of the measurement sample 1, the known parameters of the auxiliary plate and the lunar soil brick 2 sample (thickness, cross-sectional area, thermal conductivity) are substituted into the equivalent thermal resistance relationship, and the thermal conductivity of the lunar soil brick 2 is calculated to be κ1 = 0.494W / (mK).

[0150]

[0151] The known parameters of the auxiliary plate and lunar soil brick 2 samples are shown in Table 13 below.

[0152]

[0153] Table 13

[0154] According to Examples 1 to 6, the average thermal conductivity of lunar soil bricks of different sizes was 0.493 W / (mK), with a maximum relative deviation of 1.8%. According to Examples 3 to 6, the average thermal conductivity of lunar soil bricks of the same size was 0.496 W / (mK), with a maximum relative deviation of 1.2%. In summary, the lunar soil brick thermal conductivity measurement method of the present invention achieves steady-state thermal conductivity measurement of lunar soil bricks with high accuracy.

[0155] The above-described specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above-described specific embodiments are merely examples of the present application and are not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for measuring the thermal conductivity of lunar soil bricks, characterized in that: The following steps are involved: Constructing a measurement template, the measurement template comprising a lunar soil brick, transition layers located on the upper and lower surfaces of the lunar soil brick, and auxiliary plates filled around the lunar soil brick; Use a measuring device to measure the thickness δ of the measurement sample total 、Area A total and thermal conductivity κ total ; The thermal resistance model is established based on the one-dimensional steady-state Fourier heat conduction law: Among them, R total To measure the thermal resistance of the sample, R1 is the thermal resistance of the lunar soil brick, R2 is the thermal resistance of the transition layer, and R3 is the thermal resistance of the auxiliary plate; The thermal conductivity of lunar soil bricks is calculated based on the thermal resistance model.

2. The method for measuring thermal conductivity of lunar soil bricks according to claim 1, characterized in that: The construction of the measurement template includes: Measure the dimensions of the lunar soil bricks, including length x, width y, and thickness z, which must satisfy the following conditions: 20 mm ≤ x, y ≤ 200 mm and 10 mm ≤ z ≤ 50 mm. Calculate the auxiliary plate size according to the thermal conductivity meter sample size requirements; Make auxiliary plates and transition layers; The lunar soil bricks, transition layer and auxiliary plates are assembled into a measurement sample.

3. The method for measuring thermal conductivity of lunar soil bricks according to claim 2, characterized in that: The auxiliary plates include two first auxiliary plates that are consistent with the width y of the lunar soil brick, and two second auxiliary plates that are consistent with the sum of the lengths of the lunar soil brick and the two first auxiliary plates; Two first auxiliary plates are arranged opposite to each other based on the lunar soil bricks; two second auxiliary plates are arranged opposite to each other based on the lunar soil bricks.

4. The method for measuring thermal conductivity of lunar soil bricks according to claim 1, characterized in that: The transition layer is a silica gel sheet or lunar soil powder with a known thermal conductivity.

5. The method for measuring thermal conductivity of lunar soil bricks according to claim 1, characterized in that: The auxiliary board is a polystyrene foam board or a polyimide foam board.

6. The method for measuring thermal conductivity of lunar soil bricks according to claim 1, characterized in that: The measuring device is a TA-FOX-200 thermal conductivity meter, and the measuring sample is arranged between the cold plate and the hot plate of the thermal conductivity meter.

7. The method for measuring thermal conductivity of lunar soil bricks according to claim 6, characterized in that: The thermal resistance of the measurement sample is the total thermal resistance of the lunar soil brick, the thermal resistance of the transition layer, and the thermal resistance of the auxiliary plate connected in series and in parallel.

8. The method for measuring thermal conductivity of lunar soil bricks according to claim 7, characterized in that: The calculation process of the thermal conductivity coefficient κ1 of the lunar soil brick is: The thermal resistance R1 of the lunar soil brick is connected in series with the thermal resistance R2 of the transition layer. The thermal resistance of the lunar soil brick and the transition layer is expressed as: The thermal resistance of the lunar soil bricks and the transition layer is connected in parallel with the thermal resistance R3 of the auxiliary plate, so the total thermal resistance R total for: The measured thermal conductivity is the thermal conductivity k of the measurement sample including the lunar soil brick, transition layer and auxiliary plate. total , which is related to the total thermal resistance R total The relationship is expressed as: Calculate the total thermal resistance R total , substituting the known parameters into the total thermal resistance equation, the thermal conductivity coefficient κ1 of the lunar soil brick is calculated.

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