Structural design method of multidirectional gradient aperture reaction carrier

Abstract

The invention provides a structural design method of a multidirectional gradient aperture reaction carrier, which comprises the following steps of: firstly, designing a porous reaction carrier on the basis of an implicit trigonometric function, and constructing a porous structural body of a porous reaction carrier model by describing all points on an equivalent curved surface of the carrier; then, by adjusting parameters in an implicit trigonometric function, association between porous structure aperture regulation and control parameters and space coordinate positions is established, so that a gradient aperture reaction carrier of the carrier model is constructed, and then by changing modeling parameters, the gradient aperture reaction carrier is constructed; the porosity and gradient rate of the gradient aperture reaction carrier under different parameters are recorded to analyze the influence relationship between the geometric attributes of the model and the modeling parameters, and the construction of the gradient aperture reaction carrier is realized by modifying the parameters of the implicit trigonometric function; according to the invention, the designed gradient porous structure has high specific surface area and controllable reactant flow direction, and can be better applied as a hydrogen production catalytic reaction carrier.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogen production, in particular to a structural design method of a multi-directional gradient aperture reaction carrier. Background Art

[0002] As an efficient and clean secondary energy source, hydrogen energy plays an important role in the future development of the energy industry.

[0003] In the microreactor hydrogen production technology, the microreactor has the advantages of strong heat and mass transfer capacity, rapid integration and amplification, and high safety, making it an important development direction for hydrogen production technology research. In the design of the catalytic reaction carrier of the hydrogen production microreactor, the traditional catalytic reaction carrier with high specific surface area can have a higher porosity under the same volume, so as to load more catalysts and achieve good hydrogen production performance, but the complex and disordered flow channels inside make it impossible to control the flow direction of the reactants, which will lead to the situation that the catalyst cannot be fully utilized.

[0004] In order to solve the above problems, it is necessary to involve a gradient pore size hydrogen production reaction carrier with both high specific surface area and controllable reactant flow direction. Summary of the invention

[0005] The present invention proposes a structural design method for a multi-directional gradient pore size reaction carrier, which can enable the designed gradient porous structure to have the performance of high specific surface area and controllable reactant flow direction, and can be better used as a hydrogen production catalytic reaction carrier.

[0006] The present invention adopts the following technical solutions.

[0007] A method for structural design of a multi-directional gradient aperture reaction carrier, the method first designs a porous reaction carrier based on an implicit trigonometric function, the implicit trigonometric function constructs a porous structure of a porous reaction carrier model by describing all points on an isovalue surface of the carrier, the porous structure has the characteristics of being smooth, fully closed and having a high porosity, then by adjusting the parameters in the implicit trigonometric function, an association between the aperture control parameters of the porous structure and the spatial coordinate position is established, thereby constructing a gradient aperture reaction carrier of the carrier model, then by changing the modeling parameters and recording the porosity and gradient rate of the gradient aperture reaction carrier under different parameters, the influence relationship between the model geometric properties and the modeling parameters is analyzed, and the construction of the gradient aperture reaction carrier is realized by modifying the parameters of the implicit trigonometric function, that is, a reaction carrier with different aperture gradients is obtained by changing the parameters.

[0008] The average curvature of all points on the surface of the porous reaction carrier model is 0.

[0009] The porous reaction carrier is a hydrogen production reaction carrier, which has the characteristics of high specific surface area and the performance of controllable reactant flow direction.

[0010] The implicit trigonometric function is implemented in a program module based on Rhino software.

[0011] The structural design method comprises the following steps:

[0012] Step S1: constructing program modules based on implicit trigonometric function modeling in Rhino software, testing the functions of each module and setting parameters;

[0013] Step S2: Generate four porous structure models of Gyroid, Diamond, Primitive and I-WP based on implicit trigonometric functions in Rhino software, and calculate the specific surface areas of the four porous structure models under the same constraint conditions;

[0014] Step S3: Perform subsequent structural design of the gradient pore size reaction carrier on the porous structure model with the largest specific surface area among the four porous structure models generated by implicit trigonometric functions.

[0015] In step S1, the implicit trigonometric function for constructing the porous reaction carrier is first selected; then the outer dimensions and the number of unit cells of the constructed model are determined, and the relevant parameters are set in the Grasshopper plug-in of the Rhinoceros 7.4 software.

[0016] In step S2, there are four implicit trigonometric functions, corresponding to the four porous structure models of Gyroid, Diamond, Primitive and I-WP;

[0017] The implicit trigonometric function corresponding to Gyroid is: The implicit trigonometric functions corresponding to Diamond are:

[0018] The implicit trigonometric functions corresponding to Primitive are:

[0019] The implicit trigonometric function corresponding to I-WP is: In the above implicit trigonometric function, the C value in the function represents a constant, and porous structures with different porosities can be obtained by changing the C value.

[0020] In step S2, a grid model of a gradient porous reaction carrier is generated by a built-in plug-in in the Grasshopper plug-in, and the outer dimensions of the model are controlled to be 2×2×2 mm, and the minimum pore size of each model is 0.5 mm. The four implicit trigonometric functions are respectively input into the modeling program to generate the corresponding models, and the specific surface area of ​​each model is calculated by measuring the surface area and volume of the model. The models and specific surface areas constructed by the four implicit trigonometric functions are shown in Table 2.

[0021] In step S3, if the porous structure model with the largest specific surface area among the four porous structure models comes from the I-WP type porous structure model, then a functional relationship between the C value and the coordinate axis corresponding to the corresponding gradient direction is established based on the implicit trigonometric function, and the gradient pore design is realized by changing the parameter value of the implicit trigonometric function; specifically: the C value is converted into a one-variable linear function, and in the function expression formed by the C value, the parameter A is used to control the pore size and pore gradient of the model, and the parameter T is used to assist in controlling the pore size of the model. By changing the above parameters A and T, the porous carrier structure design with a specific pore gradient is realized; a gradient pore reaction carrier model is formed;

[0022] The implicit trigonometric functions corresponding to the gradient aperture reaction carrier model in each direction are as follows:

[0023] When there is no gradient direction, the implicit trigonometric function is When the gradient direction is X, the implicit trigonometric function is

[0024]

[0025] When the gradient direction is in the Y direction, the implicit trigonometric function is

[0026]

[0027] When the gradient direction is in the Z direction, the implicit trigonometric function is

[0028]

[0029] When the gradient direction is bidirectional xy, the implicit trigonometric function is

[0030]

[0031] When the gradient direction is xz bidirectional, the implicit trigonometric function is

[0032]

[0033] When the gradient direction is bidirectional, the implicit trigonometric function is

[0034]

[0035] When the gradient direction is three-way, the implicit trigonometric function is

[0036]

[0037] In step S3, if the porous structure model with the largest specific surface area among the four porous structure models comes from the I-WP type porous structure model, and the multi-directional gradient pore size reaction carrier is used for microreactor hydrogen production, then, when preparing the designed multi-directional gradient pore size reaction carrier, CuSn10 material is used to make a reaction carrier with a size of 16×16×16 mm, which is assembled with the hydrogen production reaction chamber through gap fitting. In the hydrogen production reaction, the gradient pore size structure is used so that the reactants first flow through the large pores to achieve sufficient diffusion during the hydrogen production process, and then flow out through the small pores to increase the contact probability of the reactants.

[0038] During the modeling, the gradient rate of the constructed isotropic gradient pore size reaction carrier model was ensured to be 1.5%, the total porosity of the model was 68.50%, and the model size was 16×16×16mm. Due to the reaction requirements of the porous structure, in the designed gradient pore size reaction carrier model, the pore size gradient in the X direction is a single-sided gradient, and the pore size gradients in the Y and Z directions are double-sided gradients. In the functions of each gradient direction, the function parameters involving the pore size in the Y and Z directions are assigned absolute values.

[0039] In view of the problems existing in the existing hydrogen production catalytic reaction carrier structure, the present invention proposes a gradient porous structure design method based on implicit trigonometric functions, which can enable the designed gradient porous structure to have the performance of high specific surface area and controllable reactant flow direction, and can be better used as a hydrogen production catalytic reaction carrier.

[0040] The present invention is a porous structure for hydrogen production, which is used to ensure multi-directional regulation of the flow distribution of reactants in the hydrogen production reaction and achieve efficient utilization of the catalyst for the hydrogen production reaction.

[0041] The present invention discloses a structural design method for a multi-directional gradient aperture hydrogen production reaction carrier, which adopts CuSn10 material to make a reaction carrier with a size of 16×16×16mm, and assembles it with a hydrogen production reaction chamber through clearance fit. The carrier is designed with a gradient aperture structure, so that the reactants first flow through the large pores to achieve sufficient diffusion during the hydrogen production process, and then flow out through the small pores to increase the contact probability of the reactants. This gradient morphology design is intended to regulate the flow distribution of the reactants in multiple directions and effectively improve the utilization rate of the hydrogen production reaction catalyst. It includes: 1. Building program modules based on implicit trigonometric function modeling in Rhino software, introducing the functions and parameter setting results of each module. 2. Four porous structure models of Gyroid, Diamond, Primitive and I-WP based on implicit trigonometric functions are carried out in Rhino software, and the specific surface areas of the four porous structure models are respectively counted under the same constraints. 3. The I-WP type with the largest specific surface area among the four porous structure models is selected for gradient structure design. On the basis of implicit trigonometric functions, a functional relationship between its C value and the coordinate axis corresponding to the corresponding gradient direction is established, and the gradient structure design of the model is realized by changing the parameter value of the implicit trigonometric function. The present invention proves that the structural design of the gradient aperture hydrogen production reaction carrier based on implicit trigonometric functions can be realized by modifying the implicit trigonometric functions, which can provide new ideas for subsequent gradient modeling.

[0042] Compared with the existing technology, the present invention provides a new gradient aperture reaction carrier structure design method suitable for hydrogen production, which has the following beneficial effects: the present invention designs a porous reaction carrier based on an implicit trigonometric function, which can describe all points on a certain isovalue surface, so that a porous structure can be constructed. The implicit trigonometric function can be used to generate a porous reaction carrier model with smooth, fully closed and high porosity characteristics. The average curvature of all points on the surface is 0. On the basis of the implicit trigonometric function, by adjusting the parameters in the implicit trigonometric function, the relationship between the aperture control parameter and the spatial coordinate position is established, so as to construct a gradient aperture reaction carrier. By changing the modeling parameters and recording the porosity and gradient rate of the gradient aperture reaction carrier under different parameters, the influence relationship between the model geometric properties and the modeling parameters is explored. The results show that the construction of the gradient aperture reaction carrier can be realized by modifying the parameters of the implicit function, and the reaction carrier with different aperture gradients can be obtained by changing the parameters, so that it can have the performance of high specific surface area and controllable reactant flow direction when used as a hydrogen production reaction carrier. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0044] Attached Figure 1It is a schematic diagram of the overall visual programming of the Grasshopper plug-in in the operation process of the Rhino software (Rhino software) according to the embodiment of the present invention;

[0045] Attached Figure 2 is a schematic diagram of a basic structural control module of a model of an embodiment;

[0046] Attached Figure 3 is a schematic diagram of a data processing module of an embodiment;

[0047] Attached Figure 4 is a schematic diagram of a space point generation and coordinate conversion module of an embodiment;

[0048] Attached Figure 5 is a schematic diagram of a grid generation module of an embodiment;

[0049] Attached Figure 6 is a schematic diagram of a mesh softening module of an embodiment;

[0050] Attached Figure 7 is a schematic diagram of a grid thickening module of an embodiment;

[0051] Attached Figure 8 is a schematic diagram of a grid scaling module of an embodiment;

[0052] Attached Fig. 9 Schematic diagram of an output module of an embodiment. DETAILED DESCRIPTION

[0053] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. The embodiments described are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, other embodiments obtained by ordinary technicians in this field without creative work are all within the scope of protection of the present invention.

[0054] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0055] As shown in the figure, a structural design method for a multi-directional gradient aperture reaction carrier is provided. The method first designs a porous reaction carrier based on implicit trigonometric functions. The implicit trigonometric functions construct a porous structure of a porous reaction carrier model by describing all points on the carrier isovalue surface. The porous structure has the characteristics of being smooth, fully closed and having a high porosity. Then, by adjusting the parameters in the implicit trigonometric functions, an association between the aperture control parameters of the porous structure and the spatial coordinate position is established, thereby constructing a gradient aperture reaction carrier of the carrier model. Then, by changing the modeling parameters and recording the porosity and gradient rate of the gradient aperture reaction carrier under different parameters, the influence relationship between the geometric properties of the model and the modeling parameters is analyzed. The construction of the gradient aperture reaction carrier is realized by modifying the parameters of the implicit trigonometric functions, that is, a reaction carrier with different aperture gradients is obtained by changing the parameters.

[0056] The average curvature of all points on the surface of the porous reaction carrier model is 0.

[0057] The porous reaction carrier is a hydrogen production reaction carrier, which has the characteristics of high specific surface area and the performance of controllable reactant flow direction.

[0058] The implicit trigonometric function is implemented in a program module based on Rhino software.

[0059] The structural design method comprises the following steps:

[0060] Step S1: constructing program modules based on implicit trigonometric function modeling in Rhino software, testing the functions of each module and setting parameters;

[0061] Step S2: Generate four porous structure models of Gyroid, Diamond, Primitive and I-WP based on implicit trigonometric functions in Rhino software, and calculate the specific surface areas of the four porous structure models under the same constraint conditions;

[0062] Step S3: Perform subsequent structural design of the gradient pore size reaction carrier on the porous structure model with the largest specific surface area among the four porous structure models generated by implicit trigonometric functions.

[0063] In step S1, the implicit trigonometric function for constructing the porous reaction carrier is first selected; then the outer dimensions and the number of unit cells of the constructed model are determined, and the relevant parameters are set in the Grasshopper plug-in of the Rhinoceros 7.4 software.

[0064] In step S2, there are four implicit trigonometric functions, corresponding to the four porous structure models of Gyroid, Diamond, Primitive and I-WP;

[0065] The implicit trigonometric function corresponding to Gyroid is: The implicit trigonometric functions corresponding to Diamond are:

[0066] The implicit trigonometric functions corresponding to Primitive are: The implicit trigonometric function corresponding to I-WP is: In the above implicit trigonometric function, the C value in the function represents a constant, and porous structures with different porosities can be obtained by changing the C value.

[0067] In step S2, a grid model of a gradient porous reaction carrier is generated by a built-in plug-in in the Grasshopper plug-in, and the outer dimensions of the model are controlled to be 2×2×2 mm, and the minimum pore size of each model is 0.5 mm. The four implicit trigonometric functions are respectively input into the modeling program to generate the corresponding models, and the specific surface area of ​​each model is calculated by measuring the surface area and volume of the model. The models and specific surface areas constructed by the four implicit trigonometric functions are shown in Table 2.

[0068] In step S3, if the porous structure model with the largest specific surface area among the four porous structure models comes from the I-WP type porous structure model, then a functional relationship between the C value and the coordinate axis corresponding to the corresponding gradient direction is established based on the implicit trigonometric function, and the gradient pore design is realized by changing the parameter value of the implicit trigonometric function; specifically: the C value is converted into a one-variable linear function, and in the function expression formed by the C value, the parameter A is used to control the pore size and pore gradient of the model, and the parameter T is used to assist in controlling the pore size of the model. By changing the above parameters A and T, the porous carrier structure design with a specific pore gradient is realized; a gradient pore reaction carrier model is formed;

[0069] The implicit trigonometric functions corresponding to the gradient aperture reaction carrier model in each direction are as follows:

[0070] When there is no gradient direction, the implicit trigonometric function is When the gradient direction is X, the implicit trigonometric function is

[0071]

[0072] When the gradient direction is in the Y direction, the implicit trigonometric function is

[0073]

[0074] When the gradient direction is in the Z direction, the implicit trigonometric function is

[0075]

[0076] When the gradient direction is bidirectional xy, the implicit trigonometric function is

[0077]

[0078] When the gradient direction is xz bidirectional, the implicit trigonometric function is

[0079]

[0080] When the gradient direction is bidirectional, the implicit trigonometric function is

[0081]

[0082] When the gradient direction is three-way, the implicit trigonometric function is

[0083]

[0084] In step S3, if the porous structure model with the largest specific surface area among the four porous structure models comes from the I-WP type porous structure model, and the multi-directional gradient pore size reaction carrier is used for microreactor hydrogen production, then, when preparing the designed multi-directional gradient pore size reaction carrier, CuSn10 material is used to make a reaction carrier with a size of 16×16×16 mm, which is assembled with the hydrogen production reaction chamber through gap fitting. In the hydrogen production reaction, the gradient pore size structure is used so that the reactants first flow through the large pores to achieve sufficient diffusion during the hydrogen production process, and then flow out through the small pores to increase the contact probability of the reactants.

[0085] During the modeling, the gradient rate of the constructed isotropic gradient pore size reaction carrier model was ensured to be 1.5%, the total porosity of the model was 68.50%, and the model size was 16×16×16mm. Due to the reaction requirements of the porous structure, in the designed gradient pore size reaction carrier model, the pore size gradient in the X direction is a single-sided gradient, and the pore size gradients in the Y and Z directions are double-sided gradients. In the functions of each gradient direction, the function parameters involving the pore size in the Y and Z directions are assigned absolute values.

[0086] Example:

[0087] In this example, the following steps are included:

[0088] Step 1: Introduce implicit trigonometric functions into the Grasshopper plug-in in Rhinoceros 7.4 (Robert McNeel & Assoc, USA) software to build the modeling program module; the Grasshopper plug-in of Rhinoceros software has an overall visual programming diagram, as shown in Figure 1 As shown; Figure 2 It is the basic structure control module of the model, and controls the basic structure parameters of the model through the change of its parameters; Figure 2 (a) is the length, width and height of the control model; Figure 2(b) is the number of unit cells of the control model; Figure 3 is a data processing module; Figure 3 (a) is the Range operator, which is used to divide the numerical interval determined by the number of unit cells of the model into equal intervals. The more the number of divisions, the higher the final forming accuracy of the mesh model. Figure 3 (b) is a Cross Reference operator, which multiplies the divided numerical interval data with the modeling size data, and then uses its Holistic algorithm to perform cross operation; Figure 4 It is a space point generation and coordinate conversion module; among them, Figure 4 (a) X and Y coordinates are assigned to the data after the cross operation, and Z coordinates are assigned to the data after the equidistant division process. The assigned coordinates make the data after the cross operation form coordinate points in space. Figure 4 (b) is the coordinates of each point converted into the Cartesian coordinate system. Figure 5 It is a mesh generation module. The Cartesian coordinates of each point are input into the implicit trigonometric function, and the isosurface is extracted through the cube algorithm to finally generate the mesh of the porous structure. Figure 6 This is a mesh softening module that adjusts the softening level of the mesh by giving it the number of iterations. Figure 7 It is a mesh thickening module, which can thicken the generated porous structure mesh by assigning thickness. Figure 8 It is a mesh scaling module that assigns a scaling factor to obtain a porous structure mesh that meets the requirements. Fig. 9 This module is an output module that can assign colors to porous structure grids.

[0089] Step 2: The basic steps of the structural design of the four kinds of porous reaction carriers based on implicit trigonometric functions described in the present invention are as follows: ① Select the implicit trigonometric function for constructing the porous reaction carrier; ② Determine the dimensions of the constructed model and the number of unit cells contained, and set the relevant parameters in the Grasshopper plug-in of the Rhinoceros 7.4 software; ③ Generate the grid model of the gradient porous reaction carrier through the built-in plug-in in the Grasshopper plug-in; ④ Soften, thicken, and scale the generated gradient porous reaction carrier grid model; ⑤ Export the grid model, complete the conversion between the grid and the surface, and complete the modeling. The implicit trigonometric function modeling formulas of the four models are shown in Table 1.

[0090] Table 1 Four implicit trigonometric functions and their corresponding model names

[0091]

[0092] When constructing four basic implicit trigonometric function models, the C value in the function represents a constant, and porous structures with different porosities can be obtained by changing the C value. The outer dimensions of the control model are 2×2×2mm, and the minimum pore size of each model is 0.5mm. The four implicit trigonometric functions are input into the modeling program to generate the corresponding models. The surface area and volume of the model are measured to calculate the specific surface area of ​​each model. The models constructed by the four implicit trigonometric functions and the specific surface areas are shown in Table 2.

[0093]

[0094] Table 2 shows the models and specific surface areas constructed by the four implicit trigonometric functions. It can be seen from Table 2 that the porous structure model constructed by the I-WP implicit trigonometric function has a higher specific surface area than other implicit trigonometric functions. The porous structure has a high specific surface area, which can give it a higher catalyst loading area and higher mass and heat transfer capacity, and thus give it higher hydrogen production performance. Therefore, the I-WP implicit trigonometric function is used for the subsequent design study of the gradient pore size reaction carrier.

[0095] Step 3: Use the I-WP type to carry out the structural design of the subsequent gradient pore size reaction carrier. On the basis of the implicit trigonometric function, a functional relationship is established between the C value and the coordinate axis corresponding to the corresponding gradient direction, and the gradient pore size design scheme is realized by changing the parameter value of the implicit trigonometric function. As shown in Table 3, the C value is converted into a linear function. In the function expression composed of the C value, the parameter A is used to regulate the pore size and pore gradient of the model, and the parameter T is used to assist in regulating the pore size of the model. By changing the above parameters A and T, the design of a porous carrier structure with a specific pore size gradient is realized. The implicit trigonometric functions of the I-WP type reaction carrier in each gradient direction are shown in Table 3. Among them, the design ideas of the Y and Z unidirectional gradient models are consistent, so a common implicit trigonometric function is used for modeling.

[0096] Table 3 Implicit trigonometric functions corresponding to the isotropic gradient aperture reaction carrier model

[0097]

[0098] During the modeling, the gradient rate of the constructed isotropic gradient pore size reaction carrier model is ensured to be 1.5%, the total porosity of the model is 68.50%, and the model size is 16×16×16mm. Due to the reaction requirements of the porous structure, in the designed gradient pore size reaction carrier model, the pore size gradient in the X direction is a single-sided gradient, and the pore size gradient in the Y and Z directions is a double-sided gradient. Therefore, in the functions of each gradient direction, the function parameters involving the pore size in the Y and Z directions are assigned absolute values. The I-WP type isotropic gradient pore size reaction carrier model is shown in Table 3.

[0099] Table 3 I-WP type isotropic gradient pore size reaction carrier model

[0100]

[0101] In summary, based on the four classic implicit trigonometric functions, this example finally selected the I-WP type implicit trigonometric function model with a larger specific surface area for gradient pore modeling through the screening of specific surface area. By modifying the I-WP type implicit trigonometric function, the new implicit trigonometric function obtained can construct a reaction carrier with gradient pore size in one direction, two directions, and three directions. Its advantages of high specific surface area and controllable reactant flow direction make it suitable for use as a hydrogen production reaction carrier.

Claims

1. A method for designing a structure of a multi-directional gradient aperture reaction carrier, characterized in that: The method first designs a porous reaction carrier based on implicit trigonometric functions. The implicit trigonometric functions construct a porous structure of the porous reaction carrier model by describing all points on the carrier isovalue surface. The porous structure has the characteristics of smoothness, full closure and high porosity. Then, by adjusting the parameters in the implicit trigonometric functions, the association between the pore size control parameters of the porous structure and the spatial coordinate position is established, so as to construct a gradient pore size reaction carrier of the carrier model. Then, by changing the modeling parameters and recording the porosity and gradient rate of the gradient pore size reaction carrier under different parameters, the influence relationship between the model geometric properties and the modeling parameters is analyzed. The construction of the gradient pore size reaction carrier is realized by modifying the parameters of the implicit trigonometric functions, that is, the reaction carrier with different pore size gradients is obtained by changing the parameters.

2. The method for structural design of a multi-directional gradient pore size reaction carrier according to claim 1, characterized in that: The average curvature of all points on the surface of the porous reaction carrier model is 0.

3. The method for structural design of a multi-directional gradient pore size reaction carrier according to claim 2, characterized in that: The porous reaction carrier is a hydrogen production reaction carrier, which has the characteristics of high specific surface area and the performance of controllable reactant flow direction.

4. The method for structural design of a multi-directional gradient pore size reaction carrier according to claim 1, characterized in that: The implicit trigonometric function is implemented in a program module based on Rhino software.

5. The method for structural design of a multi-directional gradient pore size reaction carrier according to claim 4, characterized in that: The structural design method comprises the following steps: Step S1: constructing program modules based on implicit trigonometric function modeling in Rhino software, testing the functions of each module and setting parameters; Step S2: Generate four porous structure models of Gyroid, Diamond, Primitive and I-WP based on implicit trigonometric functions in Rhino software, and calculate the specific surface areas of the four porous structure models under the same constraint conditions; Step S3: Perform subsequent structural design of the gradient pore size reaction carrier on the porous structure model with the largest specific surface area among the four porous structure models generated by implicit trigonometric functions.

6. The method for structural design of a multi-directional gradient pore size reaction carrier according to claim 5, characterized in that: In step S1, the implicit trigonometric function for constructing the porous reaction carrier is first selected; then the outer dimensions of the constructed model and the number of unit cells contained therein are determined, and the relevant parameters are set in the Grasshopper plug-in of the Rhinoceros software.

7. The method for structural design of a multi-directional gradient pore size reaction carrier according to claim 6, characterized in that: In step S2, there are four implicit trigonometric functions, corresponding to the four porous structure models of Gyroid, Diamond, Primitive and I-WP; The implicit trigonometric functions corresponding to Gyroid are: φ(x,y,z)=sin(πx)cos(πy)+sin(πy)cos(πz)+sin(πz)cos(πx)+C; the implicit trigonometric functions corresponding to Diamond are: φ(x,y,z)=sin(πx)sin(πy)sin(πz)+sin(πx)cos(πy)cos(πz)+cos(πx)sin(πy)cos(πz)+cos(πx)cos(πy)sin(πz)+cos(πx)cos(πy)sin(πz)+C; The implicit trigonometric function corresponding to Primitive is: φ(x,y,z)=cos(πx)+cos(πy)+cos(πz)+C; The implicit trigonometric function corresponding to I-WP is: φ(x, y, z) = cos(πx)cos(πy)+cos(πy)cos(πz)+cos(πz)cos(πx)+C; in the above implicit trigonometric function, the C value in the function represents a constant, and porous structures with different porosities can be obtained by changing the C value.

8. The method for structural design of a multi-directional gradient pore size reaction carrier according to claim 7, characterized in that: In step S2, a grid model of a gradient porous reaction carrier is generated by a built-in plug-in in the Grasshopper plug-in, and the outer dimensions of the model are controlled to be 2×2×2 mm, and the minimum pore size of each model is 0.5 mm. The four implicit trigonometric functions are respectively input into the modeling program to generate the corresponding models, and the specific surface area of ​​each model is calculated by measuring the surface area and volume of the model. The models and specific surface areas constructed by the four implicit trigonometric functions are shown in Table 2.

9. The method for structural design of a multi-directional gradient pore size reaction carrier according to claim 7, characterized in that: In step S3, if the porous structure model with the largest specific surface area among the four porous structure models comes from the I-WP type porous structure model, a functional relationship between the C value and the coordinate axis corresponding to the corresponding gradient direction is established on the basis of the implicit trigonometric function, and the gradient pore design scheme is realized by changing the parameter value of the implicit trigonometric function; specifically, the C value is converted into a one-variable linear function, in the function expression formed by the C value, the parameter A is used to regulate the pore size and pore gradient of the model, and the parameter T is used to assist in regulating the pore size of the model; by changing the above parameters A and T, a porous carrier structure design with a specific pore gradient is realized; and a gradient pore reaction carrier model is formed; The implicit trigonometric functions corresponding to the gradient aperture reaction carrier model in each direction are as follows: When there is no gradient direction, the implicit trigonometric function is φ(r)=cos(πx)cos(πy)+cos(πy)cos(πz)+cos(πz)cos(πx)+T; when the gradient direction is the X direction, the implicit trigonometric function is φ(r)=cos(πx)cos(πy)+cos(πy)cos(πz)+cos(πz)cos(πx)+A1x+T; When the gradient direction is in the Y direction, the implicit trigonometric function is φ(r)=cos(πx)cos(π|y|)+cos(π|y|)cos(πz)+cos(πz)cos(πx)+A1|y|+T; When the gradient direction is in the Z direction, the implicit trigonometric function is φ(r)=cos(πx)cos(πy)+cos(πy)cos(π|z|)+cos(π|z|)cos(πx)+A1|z|+T; When the gradient direction is bidirectional xy, the implicit trigonometric function is φ(r)=cos(πx)cos(π|y|)+cos(π|y|)cos(πz)+cos(πz)cos(πx)+A1x+A2|y|+T; When the gradient direction is bidirectional xz, the implicit trigonometric function is φ(r)=cos(πx)cos(π|z|)+cos(πy)cos(π|z|)+cos(π|z|)cos(πx)+A1x+A2|z|+T; When the gradient direction is bidirectional yz, the implicit trigonometric function is φ(r)=cos(πx)cos(π|y|)+cos(π|y|)cos(π|z|)+cos(π|z|)cos(πx)+A1|y|+A2|z|+T; When the gradient direction is three-directional, the implicit trigonometric function is φ(r)=cos(πx)cos(π|y|)+cos(π|y|)cos(π|z|)+cos(π|z|)cos(πx)+A1x+A2|y|+A3|z|+T.

10. The method for structural design of a multi-directional gradient pore size reaction carrier according to claim 9, characterized in that: In step S3, if the porous structure model with the largest specific surface area among the four porous structure models comes from the I-WP type porous structure model, and the multi-directional gradient pore size reaction carrier is used for hydrogen production in a microreactor, then the designed multi-directional gradient pore size reaction carrier is prepared by using CuSn10 material to make the reaction carrier, which is assembled with the hydrogen production reaction chamber through gap fitting. In the hydrogen production reaction, the gradient pore size structure allows the reactants to first flow through the large pores to achieve sufficient diffusion during the hydrogen production process, and then flow out through the small pores to increase the contact probability of the reactants.

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