Simulated lunar soil preparation method based on electromagnetic heating characteristics

Abstract

The invention provides a simulated lunar soil preparation method based on electromagnetic heating characteristics, and belongs to the technical field of in-situ utilization of lunar resources. Selecting lunar soil electromagnetic heating characteristic evaluation indexes and lunar soil electromagnetic heating characteristic influence factors; preparing a simulated lunar soil initial material according to the real lunar soil basic parameters; a real lunar soil electromagnetic heating characteristic evaluation index data set is constructed, and simulated lunar soil electromagnetic heating characteristic influence factor constraints are established; constructing a lunar soil electromagnetic heating characteristic influence factor-evaluation index parameter prediction model in combination with simulated lunar soil electromagnetic heating characteristic influence factor constraints; and by using the lunar soil electromagnetic heating characteristic influence factor prediction model and presetting electromagnetic heating characteristic evaluation index parameters, obtaining predicted values of the simulated lunar soil electromagnetic heating characteristic influence factors, and combining the predicted values with the simulated lunar soil initial material to obtain simulated lunar soil with expected electromagnetic heating characteristics. According to the method, the accuracy and the efficiency are balanced, and the simulated lunar soil with expected electromagnetic heating characteristics can be obtained without a large number of experiments.

Description

Technical Field

[0001] The present invention relates to the technical field of in-situ utilization of lunar resources and in-situ intelligent construction on the lunar surface, and particularly to a method for preparing simulated lunar soil based on electromagnetic heating characteristics. Background Art

[0002] The moon is the natural celestial body closest to the earth, and it is the outpost and transfer station for deep space exploration. Building a permanent lunar base is the first goal for humanity to develop into outer space. Using lunar soil as a building material for in-situ construction is the most feasible technical solution for future large-scale lunar surface projects. Based on the idea of in-situ resource utilization, the lunar soil sintering / fusion forming technology has been developed currently. The lunar soil sintering / fusion forming technology directly uses external energy to heat the lunar soil to achieve solidification, with a high in-situ resource utilization rate and reduced earth-moon transportation costs. The current energy form for lunar soil sintering / fusion forming is mainly the microwave fusion forming method, which utilizes the electromagnetic loss generated by the lunar soil in an alternating electromagnetic field to achieve the temperature rise and solidification of the lunar soil. The heating process has significant advantages such as selectivity, integrity, and instantaneity.

[0003] However, since real lunar soil is extremely precious and limited in quantity, laboratory systematic scientific research requires simulated lunar soil for support. The formation environment and evolutionary history of real lunar soil are significantly different from those of earth materials. In the process of simulating lunar soil, it is impossible to pursue the consistency of all properties. The current research and development of simulated lunar soil mostly focus on the similarity of mineral chemical composition, particle size distribution, and conventional physical and mechanical properties, without considering the electromagnetic parameters of the lunar soil that control microwave fusion forming.

[0004] Therefore, there is an urgent need to develop a simulated lunar soil with similar electromagnetic heating characteristics as the raw material for microwave fusion of lunar soil experiments. Summary of the Invention

[0005] In view of this, the present invention provides a method for preparing simulated lunar soil based on electromagnetic heating characteristics. By combining the constraints of the influencing factors of the electromagnetic heating characteristics of simulated lunar soil, a prediction model of the influencing factors-evaluation index parameters of the electromagnetic heating characteristics of lunar soil is constructed; and the predicted values are input into the prediction model of the influencing factors-evaluation index parameters of the electromagnetic heating characteristics of lunar soil to prepare simulated lunar soil with expected electromagnetic heating characteristics; realizing the efficient and accurate preparation of lunar soil.

[0006] For this purpose, the present invention provides the following technical solutions:

[0007] A method for preparing simulated lunar soil based on electromagnetic heating characteristics, comprising:

[0008] Selecting the evaluation indexes of the electromagnetic heating characteristics of lunar soil and the influencing factors of the electromagnetic heating characteristics of lunar soil;

[0009] Preparing an initial material of simulated lunar soil according to the basic parameters of real lunar soil;

[0010] Construct a dataset of evaluation index for the electromagnetic heating characteristics of real lunar soil;

[0011] According to the dataset of evaluation index for the electromagnetic heating characteristics of real lunar soil, establish the constraints on the influencing factors of the electromagnetic heating characteristics of simulated lunar soil;

[0012] Combined with the constraints on the influencing factors of the electromagnetic heating characteristics of simulated lunar soil, construct a prediction model for the influencing factors - evaluation index parameters of the electromagnetic heating characteristics of lunar soil;

[0013] Based on the prediction model for the influencing factors - evaluation index parameters of the electromagnetic heating characteristics of lunar soil, preset the evaluation index parameters of the electromagnetic heating characteristics, and obtain the predicted values of the influencing factors of the electromagnetic heating characteristics of simulated lunar soil;

[0014] Using the initial material of simulated lunar soil and the predicted values of the influencing factors of the electromagnetic heating characteristics of simulated lunar soil, obtain simulated lunar soil with expected electromagnetic heating characteristics.

[0015] Furthermore, the influencing factors of the electromagnetic heating characteristics of lunar soil include: the content of FeTiO3 and the density value.

[0016] Furthermore, the basic parameters of the real lunar soil include: mineral composition, chemical composition, and different particle size ratios.

[0017] Furthermore, the preparation of the initial material of simulated lunar soil based on the basic parameters of real lunar soil includes:

[0018] Select the raw materials of simulated lunar soil based on the basic parameters of real lunar soil;

[0019] Perform pretreatment on the raw materials of simulated lunar soil to obtain the initial material of simulated lunar soil.

[0020] Furthermore, the constraints on the influencing factors of the electromagnetic heating characteristics of simulated lunar soil include:

[0021] Dielectric constant and dielectric loss.

[0022] Furthermore, select the evaluation index of the electromagnetic heating characteristics of lunar soil based on the theory of electromagnetic conversion into heat energy;

[0023] The evaluation index of the electromagnetic heating characteristics of lunar soil includes: electromagnetic reflection loss and attenuation loss.

[0024] Furthermore, the prediction model for the influencing factors - evaluation index parameters of the electromagnetic heating characteristics of lunar soil includes:

[0025] The correlation prediction model of the percentage of FeTiO3 in the mass of simulated lunar soil - electromagnetic reflection loss and attenuation loss;

[0026] The correlation prediction model of density - electromagnetic reflection loss and attenuation loss.

[0027] Furthermore, the correlation prediction model of the percentage of FeTiO3 in the simulated lunar soil - electromagnetic reflection loss and attenuation loss:

[0028] RL lower =-179.2i 3 -13.09

[0029] RL upper =-20i 2 +6.1i - 1.01

[0030] α lower =1.5e 2.8i +10.2i 2 -5.1i + 1.0

[0031] α upper =1.8e 3.2i +15.0i 3 -10.5i 2 +8.2i + 2.0

[0032] s.t. 10 ≤ i ≤ 50

[0033] Wherein, i represents the percentage of FeTiO3 in the simulated lunar soil, RL represents the electromagnetic reflection loss / dB, and α represents the attenuation loss.

[0034] Furthermore, the correlation prediction model of density - electromagnetic reflection loss and attenuation loss:

[0035] RL lower =-41.333ρ 2 +71.95ρ - 26.445

[0036] RL upper =-2.314ρ + 2.498

[0037] α lower =-1.266ρ 2 +15.807ρ - 16.726

[0038]

[0039] s.t. 1.3 ≤ ρ ≤ 1.65

[0040] Wherein: ρ represents the density value, α represents the attenuation loss, and RL represents the electromagnetic reflection loss.

[0041] Advantages and positive effects of the present invention:

[0042] The present invention prepares an initial material of simulated lunar soil based on the basic parameters of real lunar soil to ensure the accuracy of the initial material of simulated lunar soil; and according to the evaluation index dataset of the electromagnetic heating characteristics of real lunar soil, establishes constraints on the influencing factors of the electromagnetic heating characteristics of simulated lunar soil to ensure the accuracy of the subsequent prediction model; combines the constraints on the influencing factors of the electromagnetic heating characteristics of simulated lunar soil to construct a prediction model for the influencing factors-evaluation index parameters of the electromagnetic heating characteristics of lunar soil; based on the preset evaluation index parameters, the predicted values of the influencing factors of the electromagnetic heating characteristics can be obtained, and combined with the initial material of the simulated lunar soil, simulated lunar soil with expected electromagnetic heating characteristics can be obtained without a large number of experiments. The inventive method balances the accuracy and efficiency of preparing simulated lunar soil. Description of the Drawings

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0044] Figure 1 It is a flowchart of a method for preparing simulated lunar soil based on electromagnetic heating characteristics in an embodiment of the present invention;

[0045] Figure 2 It is a schematic diagram of the selection principle of lunar soil electromagnetic heating characteristic indexes in an embodiment of the present invention;

[0046] Figure 3 It is a comparison diagram of the predicted value (30%) of the influencing factors of the electromagnetic heating characteristics of simulated lunar soil and the evaluation of the initial material (0%) of simulated lunar soil in an embodiment of the present invention. Detailed Embodiments

[0047] In order to enable those skilled in the art to better understand the solution of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0048] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of the present invention are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0049] In summary, in the field of research and development of simulated lunar soil materials, at present, most are simulations of mineral chemical composition, particle size distribution, and conventional physical and mechanical properties. Some of the electromagnetic property studies carried out serve microwave remote sensing and lunar surface detection, rather than the study of the microwave absorption and heating characteristics of lunar soil. This may lead to errors in the ground simulation experiments of microwave-acting lunar soil.

[0050] Combined with Figure 1 As shown, the present invention provides a method for preparing simulated lunar soil with similar electromagnetic heating characteristics, comprising the following steps:

[0051] Step 1: Select the evaluation indexes of the electromagnetic heating characteristics of lunar soil and the influencing factors of the electromagnetic heating characteristics of lunar soil; by analyzing the physical process of lunar soil absorbing electromagnetic waves and referring to the theoretical background of the conversion of electromagnetic energy into thermal energy, the evaluation indexes of the electromagnetic heating characteristics of lunar soil are proposed.

[0052] Step 2: Prepare the initial material of the simulated lunar soil according to the basic parameters of the real lunar soil.

[0053] Step 3: Collect the parameters of the existing real lunar soil, and construct a data set of the evaluation indexes of the electromagnetic heating characteristics of the real lunar soil;

[0054] According to the data set of the evaluation indexes of the electromagnetic heating characteristics of the real lunar soil, establish the constraints of the influencing factors of the electromagnetic heating characteristics of the simulated lunar soil;

[0055] Step 4: Combine the constraints of the influencing factors of the electromagnetic heating characteristics of the simulated lunar soil to construct a prediction model of the influencing factors - evaluation index parameters of the electromagnetic heating characteristics of the lunar soil;

[0056] Step 5: Based on the prediction model of the influencing factors of the electromagnetic heating characteristics of the simulated lunar soil, preset the evaluation index parameters of the electromagnetic heating characteristics, and obtain the predicted values of the influencing factors of the electromagnetic heating characteristics of the simulated lunar soil;

[0057] Step 6: Use the initial material of the simulated lunar soil combined with the predicted values of the influencing factors of the electromagnetic heating characteristics of the simulated lunar soil to obtain the simulated lunar soil with the expected electromagnetic heating characteristics.

[0058] The method of the present invention is further described by specific embodiments:

[0059] Combined with Figure 2 As shown, in this embodiment, step 1 includes: The physical process of lunar soil absorbing electromagnetic waves mainly includes the incident electromagnetic waves entering the lunar soil interior, the attenuation and dissipation of electromagnetic wave energy inside the lunar soil. The lunar soil has relatively small electromagnetic reflection loss, reducing reflection to allow as much incident electromagnetic waves as possible to enter the lunar soil interior; and the electromagnetic waves entering the lunar soil interior are converted into heat energy, etc. through dissipation mechanisms, etc. Therefore, by reducing the reflection of the lunar soil to electromagnetic waves and increasing the loss of electromagnetic waves in the lunar soil, the absorption of electromagnetic waves by the lunar soil can be improved;

[0060] Referring to the theoretical background of the conversion of electromagnetic energy into heat energy, the conversion of electromagnetic energy into heat energy is the dissipation of electromagnetic waves inside the lunar soil, and the reference equation is:

[0061] P av =ωε0ε″ eff E 2 rms V + ωμ0μ″ eff H 2 rms V

[0062] Among them, P av represents the average power, E rms represents the effective value of the electric field, H rms represents the effective value of the magnetic field, ω represents the angular frequency, ε0 represents the permittivity of vacuum, μ0 represents the permeability of vacuum, ε"" eff represents the effective medium electric loss factor, μ″ eff represents the effective medium magnetic loss factor;

[0063] Regarding the electromagnetic heating characteristics of the simulated lunar soil, macroscopically, it is measured by the values of the permittivity ε′, dielectric loss ε″, dielectric loss tangent tanδ ε , permeability μ′, magnetic loss μ′", magnetic loss tangent tanδ μ . ε′ and μ′ are usually used to evaluate the electromagnetic energy storage ability, while ε″ and μ″ are used to evaluate the electromagnetic energy dissipation ability;

[0064] When microwaves are incident on the interface between vacuum and lunar soil, there is a certain reflection effect of the lunar soil boundary on microwaves. The loss of microwaves entering the lunar soil interior caused by the reflection of the lunar soil to microwaves can be evaluated by the electromagnetic reflection loss RL. The smaller the reflection loss, the more microwaves the lunar soil allows to enter; the attenuation loss characteristic of the lunar soil can convert the microwave energy entering the lunar soil interior into heat energy, and the attenuation loss characteristic is represented by the attenuation coefficient α; therefore, the higher the value of α, the stronger the response of the lunar soil to the alternating electromagnetic field, and the greater the proportion of electromagnetic wave energy converted into heat energy.

[0065] Therefore, the evaluation indexes for the electromagnetic heating characteristics of lunar soil are: electromagnetic reflection loss RL and attenuation loss α; and the dielectric constant and dielectric loss are used as constraints.

[0066] The influencing factors include: the content of FeTiO3 and the density value.

[0067] Step S2 in this embodiment includes:

[0068] 1) According to the basic parameters of real lunar soil, the basaltic volcanic ejecta in the Dayishan area of Huinan County, Jilin Province, which is highly consistent with the mineral composition and chemical composition of the real lunar soil obtained by the Apollo series, is selected as the raw material for the development of simulated lunar soil.

[0069] 2) Carry out a series of processing operations on the simulated lunar soil, including drying, crushing, grinding, and screening, to obtain the powder of the simulated lunar soil raw material. Preferably, the drying temperature is 103 °C and the drying time is 90 min.

[0070] S3 in this embodiment includes:

[0071] 1) Collect the existing real lunar soil parameters and establish a dataset for the evaluation indexes of the electromagnetic phase heating characteristics of real lunar soil, as shown in Table 1;

[0072] Table 1

[0073] sample Apollo 14 Apollo 15 Apollo 16 Apollo 17 dielectric constant 2.01-7.00 1.96-6.70 1.66-7.82 1.73-7.50 dielectric loss 0.0006-0.05 0.0008-0.0252 0.001-2 0.0029-0.123

[0074] 2) According to the dataset of the evaluation indexes of the electromagnetic phase heating characteristics of real lunar soil, obtain the constraints on the influencing factors of the electromagnetic heating characteristics of simulated lunar soil, as shown in Tables 2 and 3;

[0075] Table 2

[0076] <![CDATA[Mass percentage of FeTiO3 in the simulated lunar soil]]> dielectric constant dielectric loss 10％ 3.87～4.00 0.08～0.26 20％ 4.14～4.29 0.09～0.28 30％ 4.52～4.72 0.10～0.37 40％ 4.90～5.14 0.09～0.40 50％ 5.34～5.60 0.08～0.43

[0077] Table 3

[0078] density dielectric constant dielectric loss <![CDATA[1.30g / cm 3 > 3.18～3.34 0.02～0.17 <![CDATA[1.35g / cm 3 > 3.29～3.44 0.03～0.18 <![CDATA[1.40g / cm 3 > 3.44～3.58 0.04～0.20 <![CDATA[1.45g / cm 3 > 3.49～3.64 0.05～0.20 <![CDATA[1.50 g / cm 3 > 3.62～3.79 0.07～0.24 <![CDATA[1.55g / cm 3 > 3.71～3.89 0.08～0.25 <![CDATA[1.60g / cm 3 > 3.78～3.97 0.08～0.28 <![CDATA[1.65g / cm 3 > 3.85～4.06 0.09～0.30

[0079] Therefore, the constraints on the influencing factors of the electromagnetic heating characteristics of simulated lunar soil are: the value of the mass percentage of FeTiO3 in the simulated lunar soil ranges from 0% to 50%; the density ranges from 1.30 g / cm 3 - 1.65 g / cm 3 .

[0080] In step 4 of this embodiment, combined with the constraints on the influencing factors of the electromagnetic heating characteristics of simulated lunar soil, a prediction model for the influencing factors of the electromagnetic heating characteristics - electromagnetic heating characteristic parameters of lunar soil is constructed, including:

[0081] The correlation prediction model of the mass percentage of FeTiO3 in the simulated lunar soil - electromagnetic reflection loss and attenuation loss:

[0082] RL lower = -179.2i 3 -13.09

[0083] RL upper = -20i 2 +6.1i - 1.01

[0084] α lower = 1.5e 2.8i +10.2i 2 -5.1i + 1.0

[0085] α upper = 1.8e 3.2i +15.0i 3 -10.5i 2 +8.2i + 2.0

[0086] s.t. 10 ≤ i ≤ 50

[0087] Wherein, i represents the percentage (%) of FeTiO3 in the simulated lunar soil by mass, RL represents the electromagnetic reflection loss (dB), and α represents the attenuation loss;

[0088] Density - electromagnetic reflection loss and attenuation loss correlation prediction model:

[0089] RL lower = -41.333ρ 2 +71.95ρ - 26.445

[0090] RL upper = -2.314ρ + 2.498

[0091] α lower = -1.266ρ 2 +15.807ρ - 16.726

[0092]

[0093] s.t. 1.3 ≤ ρ ≤ 1.65

[0094] Where: ρ represents the density value, that is, the percentage of FeTiO3 in the simulated lunar soil by mass (g / cm 3 ), α represents the attenuation loss, and RL represents the electromagnetic reflection loss (dB).

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing simulated lunar soil based on electromagnetic heating characteristics, characterized in that, Including: Selecting the evaluation indexes of the electromagnetic heating characteristics of lunar soil and the influencing factors of the electromagnetic heating characteristics of lunar soil; Preparing the initial material of simulated lunar soil according to the basic parameters of real lunar soil; Constructing a dataset of evaluation indexes for the electromagnetic heating characteristics of real lunar soil; Establishing the constraints of the influencing factors of the electromagnetic heating characteristics of simulated lunar soil according to the dataset of evaluation indexes for the electromagnetic heating characteristics of real lunar soil; Combining the constraints of the influencing factors of the electromagnetic heating characteristics of simulated lunar soil to construct a prediction model of the influencing factors-evaluation index parameters of the electromagnetic heating characteristics of lunar soil; Based on the prediction model of the influencing factors-evaluation index parameters of the electromagnetic heating characteristics of lunar soil, presetting the evaluation index parameters of the electromagnetic heating characteristics to obtain the predicted values of the influencing factors of the electromagnetic heating characteristics of simulated lunar soil; Using the initial material of simulated lunar soil and combining the predicted values of the influencing factors of the electromagnetic heating characteristics of simulated lunar soil to obtain simulated lunar soil with expected electromagnetic heating characteristics.

2. The method for preparing simulated lunar soil based on electromagnetic heating characteristics according to claim 1, wherein, The influencing factors of the electromagnetic heating characteristics of lunar soil include: the content of FeTiO3 and the density value.

3. The method for preparing simulated lunar soil based on electromagnetic heating characteristics according to claim 1, characterized in that, The basic parameters of real lunar soil include: mineral composition, chemical composition, and the ratio of different particle sizes.

4. The method for preparing simulated lunar soil based on electromagnetic heating characteristics according to claim 3, wherein, The preparation of the initial material of simulated lunar soil according to the basic parameters of real lunar soil includes: Selecting the raw materials of simulated lunar soil based on the basic parameters of real lunar soil; Preprocessing the raw materials of simulated lunar soil to obtain the initial material of simulated lunar soil.

5. The method for preparing simulated lunar soil based on electromagnetic heating characteristics according to claim 1, wherein, The constraints of the influencing factors of the electromagnetic heating characteristics of simulated lunar soil include: Dielectric constant and dielectric loss.

6. The method for preparing simulated lunar soil based on electromagnetic heating characteristics according to claim 1, wherein, Selecting the evaluation indexes of the electromagnetic heating characteristics of lunar soil based on the theory of electromagnetic conversion into heat energy; The evaluation indexes of the electromagnetic heating characteristics of lunar soil include: electromagnetic reflection loss and attenuation loss.

7. The method for preparing simulated lunar soil based on electromagnetic heating characteristics according to claim 6, wherein, The prediction model of the influencing factors-evaluation index parameters of the electromagnetic heating characteristics of lunar soil includes: The correlation prediction model of the percentage of FeTiO3 in the mass of simulated lunar soil - electromagnetic reflection loss and attenuation loss; The correlation prediction model of density - electromagnetic reflection loss and attenuation loss.

8. The method for preparing simulated lunar soil based on electromagnetic heating characteristics according to claim 7, wherein The correlation prediction model of the percentage of FeTiO3 in the mass of simulated lunar soil - electromagnetic reflection loss and attenuation loss: RL lower = -179.2i 3 -13.09 RL upper = -20i 2 + 6.1i - 1.01 α lower = 1.5e 2.8i + 10.2i 2 - 5.1i + 1.0 α upper = 1.8e 3.2i + 15.0i 3 - 10.5i 2 + 8.2i + 2.0 s.t.10≤i≤50 Where, i represents the percentage of FeTiO3 in the mass of simulated lunar soil, RL represents the electromagnetic reflection loss / dB, and α represents the attenuation loss.

9. The method for preparing simulated lunar soil based on electromagnetic heating characteristics according to claim 7, wherein, The correlation prediction model of density - electromagnetic reflection loss and attenuation loss: RL lower = -41.333ρ 2 + 71.95ρ - 26.445 RL upper =-2.314ρ + 2.498 α lower = -1.266ρ 2 + 15.807ρ - 16.726 s.t.1.3≤ρ≤1.65 Where: ρ represents the density value, α represents the attenuation loss, and RL represents the electromagnetic reflection loss.

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