Rapid modeling method of neutron physical calculation model

Abstract

The invention discloses a rapid modeling method of a neutron physical calculation model. The rapid modeling method comprises the following steps: 1, determining a material of a neutron physical calculation area; 2, constructing a geometric structure of a neutron physical calculation area; 3, correlating geometric structures and materials of neutron physical calculation areas; 4, constructing a special model of a neutron physical calculation area; and 5, neutron physical parameters are set, and neutron physical calculation is carried out. According to the method, the geometric structure of the neutron physical calculation area is directly constructed through geometric modeling software and is associated with the material of the neutron physical calculation area, a general three-dimensional image data file is generated, the associated three-dimensional image data file is converted into a neutron physical calculation model file through data conversion software, and then a special model of the neutron physical calculation area is constructed. And performing neutron physical calculation. The method solves the problems that traditional neutron physical calculation consumes a large amount of time and resources for complex geometry, and influences of structural changes in multi-physics coupling on neutron physics are difficult to analyze, and provides method support for advanced reactor design analysis.

Description

Technical Field

[0001] The invention relates to the technical field of reactor neutron physics calculation, and in particular to a rapid modeling method for a neutron physics calculation model. Background Art

[0002] In the design and operation of nuclear reactors, neutron physics calculation is the first step to ensure the safety and reliability of reactors. Traditional neutron physics calculation usually uses constructive solid geometry (CSG) to generate calculation models. CSG is a computer graphics technology that constructs complex three-dimensional geometric models through Boolean operations (such as union, intersection, and difference) of basic geometric bodies (such as cubes, spheres, cylinders, etc.). It is suitable for generating neutron physics calculation models with simple geometry and high linearization. With the development of nuclear energy technology, especially the research and application needs of fourth-generation reactors, small modular reactors, and fusion reactors, the structures of various research reactors and zero-power reactors tend to be complex, characterized by a significant increase in the number of structural geometric bodies, an increase in nonlinear surfaces, an increase in the number of vacuum gaps in the structure and a variety of shapes, and an increase in the number of neutron physics materials. In addition, advanced reactor design requires models to be able to cope with more complex working conditions and physical phenomena, such as multi-physics coupling effects. Using CSG technology to generate such complex geometries will result in a lot of time and resource consumption, and it is difficult to analyze the impact of structural changes in multi-physics coupling on neutron physics. Therefore, developing a fast modeling method that can significantly shorten the modeling time has become an important direction for the current application of nuclear reactor neutron physics calculations. Summary of the invention

[0003] In order to solve the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a rapid modeling method for a neutron physics calculation model. For the complex geometry of the neutron physics calculation area, the geometric structure is directly constructed through geometric modeling software, the geometric structure is associated with the material of the neutron physics calculation area, and a general three-dimensional image data file is generated. Through data conversion software, the associated three-dimensional image data file is converted into a neutron physics calculation model file, and then a special model of the neutron physics calculation area is constructed to perform neutron physics calculations. The present invention solves the problem that the construction solid geometry technology used in traditional neutron physics calculations consumes a lot of time and resources for complex geometry, and it is difficult to analyze the impact of structural changes on neutron physics in multi-physical field coupling, and provides method support for advanced reactor design analysis.

[0004] In order to achieve the above object, the present invention adopts the following technical scheme:

[0005] A rapid modeling method for a neutron physics calculation model, for the complex geometry of a neutron physics calculation area, directly constructs its geometric structure through geometric modeling software, associates the geometric structure with the material of the neutron physics calculation area, generates a general three-dimensional image data file, converts the associated three-dimensional image data file into a neutron physics calculation model file through data conversion software, and then constructs a special model of the neutron physics calculation area to perform neutron physics calculation;

[0006] The specific steps include:

[0007] Step 1: Determine the materials in the neutron physics calculation area: Determine all the materials used in the entire neutron physics calculation area, establish the corresponding neutron physics cross section of each material according to the atomic composition of each material, and name and number each material;

[0008] Step 2: Construct the geometric structure of the neutron physics calculation area: Use geometric modeling software to establish the geometric structure of the neutron physics calculation area and convert the geometric structure into general three-dimensional image data. The specific steps are as follows:

[0009] Step 2-1: Use geometric modeling software to establish the geometric structure of the neutron physics calculation area, and each area of ​​the geometric structure is divided according to the material determined in step 1;

[0010] Step 2-2: Create a solid geometric body with the same outer contour as the geometric structure obtained in step 2-1, and use the Boolean operation function of the geometric modeling software to cut out the geometric structure obtained in step 2-1 in the solid geometric body to obtain a vacuum area within the geometric structure;

[0011] Step 2-3: adding the vacuum region obtained in step 2-2 to the geometric structure obtained in step 2-1, and using geometric modeling software to save the geometric structure with the vacuum region added as a general three-dimensional image data file;

[0012] Step 3: Associating the geometric structure and material of the neutron physics calculation area: Use geometric modeling software to open the three-dimensional image data file obtained in steps 2-3, name each part of the geometric structure according to the material, and the name is the same as the material name described in step 1, so as to associate the geometric structure and material of the neutron physics calculation area and obtain the associated three-dimensional image data file;

[0013] Step 4: Construct a dedicated model of the neutron physics calculation area: Use data conversion software to convert the associated three-dimensional image data file obtained in step 3 into a neutron physics calculation model file, and then construct a dedicated model of the neutron physics calculation area, which is specifically divided into the following steps:

[0014] Step 4-1: using data conversion software to convert the associated three-dimensional image data file obtained in step 3 into a neutron physics calculation model file according to the data format of the neutron physics calculation model used in the neutron physics calculation software;

[0015] Step 4-2: Import the neutron physics calculation area materials determined in step 1 and their names, numbers, and neutron physics cross sections into the neutron physics calculation software;

[0016] Step 4-3: Import the neutron physics calculation model file into the neutron physics calculation software, set boundary conditions, and build a dedicated model for the neutron physics calculation area;

[0017] Step 5: Import the dedicated model of the neutron physics calculation area constructed in step 4 into the neutron physics calculation software, set the neutron physics parameters, and perform neutron physics calculations.

[0018] The present invention has the following advantages and effects:

[0019] 1. In the process of constructing the geometric structure of the neutron physics calculation area in step 2, the geometric structure of the neutron physics calculation area is directly established through geometric modeling software, avoiding the tedious Boolean operation of basic geometric bodies in the traditional modeling process to construct the geometric structure, and no geometric simplification is required;

[0020] 2. In step 2, the geometric structure of the neutron physics calculation area is converted into a general three-dimensional image data file, whose data structure and reading and writing methods have a standard form and can be modified by modifying the script file.

[0021] This enables analysis of the impact of structural changes on neutron physics in multi-physics field coupling;

[0022] It has been proved through experiments that the method of the present invention can quickly model and calculate advanced small reactors, and has the characteristics of simple modeling process and no need for geometric simplification. The method of the present invention is simple to operate and has a wide range of applications. It can realize neutron physics calculations for reactors of any geometric shape, which helps users to choose according to their own needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The figure is a flow chart of the method of the present invention.

[0024] Figure 2 Schematic diagram of the geometry and materials of the neutron physics calculation area of ​​the present invention.

[0025] Figure 3 It is a schematic diagram of the longitudinal section of the geometric structure of the neutron physics calculation area of ​​the present invention.

[0026] Figure 4It is a schematic longitudinal section diagram of the neutron physics calculation model of the neutron physics calculation area of ​​the present invention.

[0027] Figure 5 It is a schematic longitudinal section diagram of a special model of the neutron physics calculation area of ​​the present invention.

[0028] Figure 6 This is the neutron flux of the reactor longitudinal section calculated by the present invention. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] like Figure 1 As shown, a rapid modeling method for a neutron physics calculation model of the present invention comprises the following steps:

[0031] Step 1: Determine the materials used in the neutron physics calculation area: Determine all the materials used in the entire neutron physics calculation area, establish the corresponding neutron physics cross section of each material according to the atomic composition of each material, and name and number each material. There is no need to repeat the naming and numbering of the materials in the calculation area, such as Figure 2 As shown in the figure, taking the KRUSTY reactor as an example, there are 10 neutron physics calculation areas, namely fuel, axial shield, heat pipe hoop, pipe wall, wick, upper reflector, lower reflector, side reflector, side shield, and lifting platform. Only the neutron physics cross sections, naming and numbering of the six materials U8Mo, B4C, Hey230, BeO, SS316L, and Al2O3 used in the 10 neutron physics calculation areas need to be established;

[0032] Step 2: Construct the geometric structure of the neutron physics calculation area: Use geometric modeling software to establish the geometric structure of the neutron physics calculation area and convert the geometric structure into general three-dimensional image data. The specific steps are as follows:

[0033] Step 2-1: Use geometric modeling software to establish the geometric structure of the neutron physics calculation area, and each area of ​​the geometric structure is divided according to the material determined in step 1;

[0034] Step 2-2: Create a solid geometric body with the same outer contour as the geometric structure obtained in step 2-1, and use the Boolean operation function of the geometric modeling software to cut out the geometric structure obtained in step 2-1 in the solid geometric body to obtain a vacuum area within the geometric structure;

[0035] Step 2-3: Add the vacuum region obtained in step 2-2 to the geometric structure obtained in step 2-1, and use geometric modeling software to save the geometric structure with the vacuum region added as a general three-dimensional image data file, such as Figure 3As shown, the suffix of this type of file is generally .stp, .step, and needs to be saved in .step format;

[0036] Step 3: Associating the geometric structure and material of the neutron physics calculation area: Use geometric modeling software to open the three-dimensional image data file obtained in steps 2-3, name each part of the geometric structure according to the material, and the name is the same as the material name described in step 1, so as to associate the geometric structure and material of the neutron physics calculation area and obtain the associated three-dimensional image data file;

[0037] Step 4: Construct a dedicated model of the neutron physics calculation area: Use data conversion software to convert the associated three-dimensional image data file obtained in step 3 into a neutron physics calculation model file, and then construct a dedicated model of the neutron physics calculation area, which is specifically divided into the following steps:

[0038] Step 4-1: According to the data format of the neutron physics calculation model used in the neutron physics calculation software, use data conversion software to convert the associated three-dimensional image data file obtained in step 3 into a neutron physics calculation model file, such as Figure 4 As shown in the figure, in the geometric model, the structures above and to the side are far away from the neutron source, and the absorption and reflection cross sections of the materials are small, and the neutrons have been reflected by the reflection layer, which has almost no effect on the neutron physics calculation. Therefore, it is not necessary to geometrically model them in order to reduce the geometric scale of the dedicated model in the neutron physics calculation area, such as Figure 4 As shown, the neutron source position in step 5 needs to be determined from the coordinate origin position of the neutron physics calculation model file, and the neutron source position is located at the geometric center of the fuel;

[0039] Step 4-2: Import the neutron physics calculation area materials determined in step 1 and their names, numbers, and neutron physics cross sections into the neutron physics calculation software;

[0040] Step 4-3: Import the neutron physics calculation model file into the neutron physics calculation software, set the boundary conditions, and build a dedicated model for the neutron physics calculation area, such as Figure 5 As shown, the association between materials and geometries in the neutron physics calculation area has been realized in this dedicated model, and the colors of the geometric structures in the figure are distinguished by materials;

[0041] Step 5: Import the dedicated model of the neutron physics calculation area constructed in step 4 into the neutron physics calculation software, set neutron counters, calculation parameters, neutron source positions and other neutron physics parameters, and perform neutron physics calculations.

[0042] The neutron flux of the reactor longitudinal section calculated by the neutron physics calculation model established by the present invention is as follows: Figure 6As shown, the neutron flux calculation results are consistent with reality, and the interface between the vacuum area and the material area is clear, which shows that the method of the present invention is feasible and proves that the present invention has advantages in solving the problem of rapid establishment of neutron physics calculation models.

[0043] The present invention aims at the complex geometry of the neutron physics calculation area, directly constructs its geometric structure through geometric modeling software, associates the geometric structure with the material of the neutron physics calculation area, generates a general three-dimensional image data file, and converts the associated three-dimensional image data file into a neutron physics calculation model file through data conversion software, thereby constructing a special model of the neutron physics calculation area to perform neutron physics calculation. The present invention solves the problem that the construction solid geometry technology used in traditional neutron physics calculations consumes a lot of time and resources for complex geometry, and it is difficult to analyze the impact of structural changes on neutron physics in multi-physical field coupling, and provides method support for advanced reactor design analysis.

Claims

1. A rapid modeling method for a neutron physics calculation model, characterized in that: For the complex geometry of the neutron physics calculation area, the geometric structure is directly constructed through geometric modeling software, and the geometric structure is associated with the material of the neutron physics calculation area to generate a general three-dimensional image data file. The associated three-dimensional image data file is converted into a neutron physics calculation model file through data conversion software, and then a special model of the neutron physics calculation area is constructed to perform neutron physics calculations; The specific steps include: Step 1: Determine the materials in the neutron physics calculation area: Determine all the materials used in the entire neutron physics calculation area, establish the corresponding neutron physics cross section of each material according to the atomic composition of each material, and name and number each material; Step 2: Construct the geometric structure of the neutron physics calculation area: Use geometric modeling software to establish the geometric structure of the neutron physics calculation area and convert the geometric structure into general three-dimensional image data. The specific steps are as follows: Step 2-1: Use geometric modeling software to establish the geometric structure of the neutron physics calculation area, and each area of ​​the geometric structure is divided according to the material determined in step 1; Step 2-2: Create a solid geometric body with the same outer contour as the geometric structure obtained in step 2-1, and use the Boolean operation function of the geometric modeling software to cut out the geometric structure obtained in step 2-1 in the solid geometric body to obtain a vacuum area within the geometric structure; Step 2-3: adding the vacuum region obtained in step 2-2 to the geometric structure obtained in step 2-1, and using geometric modeling software to save the geometric structure with the vacuum region added as a general three-dimensional image data file; Step 3: Associating the geometric structure and material of the neutron physics calculation area: Use geometric modeling software to open the three-dimensional image data file obtained in steps 2-3, name each part of the geometric structure according to the material, and the name is the same as the material name described in step 1, so as to associate the geometric structure and material of the neutron physics calculation area and obtain the associated three-dimensional image data file; Step 4: Construct a dedicated model of the neutron physics calculation area: Use data conversion software to convert the associated three-dimensional image data file obtained in step 3 into a neutron physics calculation model file, and then construct a dedicated model of the neutron physics calculation area, which is specifically divided into the following steps: Step 4-1: using data conversion software to convert the associated three-dimensional image data file obtained in step 3 into a neutron physics calculation model file according to the data format of the neutron physics calculation model used in the neutron physics calculation software; Step 4-2: Import the neutron physics calculation area materials determined in step 1 and their names, numbers, and neutron physics cross sections into the neutron physics calculation software; Step 4-3: Import the neutron physics calculation model file into the neutron physics calculation software, set boundary conditions, and build a dedicated model for the neutron physics calculation area; Step 5: Import the dedicated model of the neutron physics calculation area constructed in step 4 into the neutron physics calculation software, set the neutron physics parameters, and perform neutron physics calculations.

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