CAD and CSG coupling modeling method and system for petal-shaped spiral fuel rod of reactor

Abstract

The invention discloses a CAD and CSG coupling modeling method and system for a petal-shaped spiral fuel rod of a reactor, and relates to the field of nuclear reactor physical calculation. The problems that more computing resources are occupied when the CAD model is subjected to Monte Carlo processing, so that the processing efficiency of the model is affected, and the CAD model is converted into a processable Monte Carlo file, and boundary conditions are few are solved. The method comprises the following steps: establishing a fuel rod geometric model and outputting a CAD geometric file; the CAD geometric file is processed, and a Monte Carlo file used for Monte Carlo method simulation is output; inputting the Monte Carlo file into a Monte Carlo neutronics calculation program, and constructing a petal-shaped helical fuel rod geometric entity based on a modeling method of CSG and CAD; and the Monte Carlo neutronics calculation result is repeatedly iterated until the precision of the calculation result meets the requirement, and the result is post-processed. The method is applied to the field of nuclear reactor design.

Description

Technical Field

[0001] The invention relates to the field of nuclear reactor physical calculation, and in particular to a CAD and CSG coupling modeling method for a reactor petal-shaped spiral fuel rod. Background Art

[0002] The basic construction of the CSG (Constructive Solid Geometry) model construction method is simple geometric bodies, such as cubes, spheres, cones, and cylinders. It provides a flexible and accurate way to construct geometric bodies for Monte Carlo neutronics calculations. However, with the development of Monte Carlo technology, the requirements for calculation accuracy have gradually increased. The traditional CSG model construction method has exposed the following shortcomings: 1) The CSG model construction method relies on Boolean operations (such as union, intersection, and difference) to combine geometric bodies. On the one hand, it limits the flexibility in the model creation process. On the other hand, the CSG model construction method is more suitable for simple and regular geometric shapes, so it cannot accurately construct petal-shaped spiral fuel rods with special-shaped geometric structures; 2) Generally, for a complex geometric model, it can correspond to multiple Boolean combinations of the CSG method. When performing numerical calculations, the CSG model may cause discontinuity or overlap of the model boundary due to different model construction methods, thereby causing calculation errors; 3) For complex CSG models, multiple Boolean operations are involved between the various components of the model, which have a strong correlation. Therefore, in the process of modifying the model, multiple operations will be involved, which increases the complexity of model modification.

[0003] Compared with the CSG method, the CAD (Computer-Aided Design) method has a more flexible way of creating geometry. A variety of geometric representation methods are usually used, such as β-splines, surfaces, and polyhedrons, which are suitable for complex, free-form designs. Therefore, in order to make up for the shortcomings of the traditional CSG model construction method in the Monte Carlo calculation process, accurate particle transport simulation is performed on the CAD model. It is necessary to achieve high-performance parallel computing for the CAD model, while enhancing the Monte Carlo method's ability to handle complex models. However, if only the CAD model is processed by Monte Carlo, there will be the following shortcomings: 1) For complex CAD models, which usually contain a large number of details and complex geometric features, directly processing such geometric files will require more computing resources, which will affect the processing efficiency of the model and increase the time cost of the processing process; on the other hand, when converting the CAD model into a processable Monte Carlo file, some structures of the model need to be simplified or approximated, resulting in reduced geometric accuracy of the model; 2) The traditional CSG model construction method has rich boundary conditions, but the CAD model has fewer boundary conditions that can be used after processing, such as reflective (total reflection boundary condition), vacuum (vacuum boundary condition), and transmission (transmission boundary condition). Summary of the invention

[0004] The present invention aims at the problem that the Monte Carlo processing of the CAD model occupies more computing resources, thereby affecting the processing efficiency of the model, and the problem that the CAD model is converted into a processable Monte Carlo file with few boundary conditions. A CAD and CSG coupling modeling method for a reactor petal-shaped spiral fuel rod is proposed. The method comprises:

[0005] Step 1: Establish the fuel rod geometry model and output the CAD geometry file;

[0006] Step 2: Process the CAD geometry file and output the Monte Carlo geometry file for Monte Carlo method simulation;

[0007] Step 3: Input the Monte Carlo file into the Monte Carlo neutronics calculation program, and construct the petal-shaped spiral fuel rod geometric entity based on the CSG and CAD modeling method;

[0008] Step 4: Repeat the iterative Monte Carlo neutronics calculation results until the calculation results meet the accuracy requirements, and then post-process the results.

[0009] Furthermore, a preferred method is proposed, wherein the fuel rod geometric model in step 1 includes: cylindrical fuel rods and petal-shaped spiral fuel rods, and the petal-shaped spiral fuel rods include petal fuel rods with 2 to 8 petals; the geometric characteristic parameters of the petal-shaped spiral fuel rods include: the radius r of the outer convex arc, the radius R of the inner concave arc, the connection length l between the outer convex arc and the inner concave arc, the height H of the fuel rod, and the pitch P of the fuel rod.

[0010] Furthermore, a preferred method is proposed, wherein the step 2 comprises:

[0011] Perform watertightness treatment on the petal-shaped spiral fuel rod to obtain a watertight CAD model;

[0012] Partition and mesh the watertight CAD model to obtain Monte Carlo geometry files and mesh files for simulation and post-processing.

[0013] Furthermore, a preferred method is proposed, wherein the partitioning process of the watertight CAD model comprises:

[0014] Group and name the watertightness CAD models;

[0015] Check the water tightness of the model. If the water tightness of the model is poor, it is necessary to close the faces of the model. If the water tightness of the model is good, output the Monte Carlo geometry file.

[0016] Furthermore, a preferred method is proposed, wherein the meshing of the watertight CAD model comprises:

[0017] Set the parameters of the mesh of the CAD model for water tightness;

[0018] Draw the tetrahedral mesh. If the mesh does not meet the standard, you need to redraw the mesh. If the mesh meets the standard, output the mesh file.

[0019] The grid file is converted into a Monte Carlo grid file.

[0020] Furthermore, a preferred method is proposed, wherein step three comprises:

[0021] According to the calculation requirements of the Monte Carlo method, the Monte Carlo geometry file is input into the Monte Carlo calculation program, and based on the Monte Carlo geometry, the CSG model construction method is used to obtain the fuel rod geometry solid model constructed by the CSG+CAD method.

[0022] Furthermore, a preferred method is proposed, in which the error of the neutron calculation result is 0 to 5×10 -4 , that is, the accuracy requirement is met.

[0023] Based on the same inventive concept, the present invention also proposes a CAD and CSG coupling modeling system for a petal-shaped spiral fuel rod of a reactor, the system comprising:

[0024] A geometric model building unit, used to build a fuel rod geometric model and output a CAD geometric file;

[0025] A processing unit, used for processing the CAD geometry file and outputting a Monte Carlo geometry file for Monte Carlo method simulation;

[0026] A geometric entity construction unit, used to input the Monte Carlo geometry file into the Monte Carlo neutronics calculation program, and to construct a petal-shaped spiral fuel rod geometric entity based on the CSG and CAD modeling method;

[0027] The post-processing unit is used to repeatedly iterate the Monte Carlo neutronics calculation results until the calculation results meet the accuracy requirements and then post-process the results.

[0028] Based on the same inventive concept, the present invention also proposes a computer device, including a memory and a processor, wherein a computer program is stored in the memory. When the processor runs the computer program stored in the memory, the processor executes a CAD and CSG coupling modeling method for a reactor petal-shaped spiral fuel rod according to any one of the above-mentioned methods.

[0029] Based on the same inventive concept, the present invention also proposes a computer-readable storage medium, on which a computer program is stored. When the computer program is run by a processor, the steps of a CAD and CSG coupling modeling method for a reactor petal-shaped spiral fuel rod as described in any of the above items are executed.

[0030] The present invention is beneficial in that:

[0031] The present invention overcomes the compatibility problem between CAD models and CSG. CAD models are usually used to represent complex geometric shapes, such as surfaces and curves, and are suitable for the design of complex and free-form shapes. However, these models are incompatible with CSG (Constructive Solid Geometry) models due to their geometric complexity during Monte Carlo simulation, which makes it difficult to convert them into simple geometric bodies suitable for the Monte Carlo method, thereby affecting the efficiency and accuracy of the calculation. The CAD and CSG coupling modeling method proposed in the present invention first uses CAD to establish a geometric model, and then couples it with the CSG model through certain processing, thereby solving the compatibility problem between CAD complex geometry and CSG simple geometry.

[0032] Furthermore, the inventors have aimed at the problem that the Monte Carlo method itself has high requirements for computing resources, especially when dealing with large-scale and complex geometric models, which often leads to low computing efficiency and affects the speed of the entire simulation process and the efficiency of resource utilization. By effectively coupling CAD and CSG, the computational geometry can be simplified, thereby reducing the amount of calculation and resource consumption required for simulation. Further, through iterative calculation, the calculation accuracy is gradually optimized, unnecessary calculation redundancy is reduced, and the calculation efficiency is improved.

[0033] The invention is applied to the field of nuclear reactor design. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A flow chart of a CAD and CSG coupling modeling method for a reactor petal-shaped spiral fuel rod according to the first embodiment;

[0035] Figure 2 A specific modeling schematic diagram of a CAD and CSG coupling modeling method for a reactor petal-shaped spiral fuel rod according to the eleventh embodiment;

[0036] Figure 3 This is a schematic diagram of the simulation results of the effective proliferation coefficient of the cylindrical fuel rod constructed by the three methods of CSG, CAD and CAD+CSG as described in the eleventh embodiment. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0038] Implementation method 1, see Figure 1 This embodiment describes a CAD and CSG coupling modeling method for a reactor petal-shaped spiral fuel rod, the method comprising:

[0039] Step 1: Establish the fuel rod geometry model and output the CAD geometry file;

[0040] Step 2: Process the CAD geometry file and output the Monte Carlo geometry file for Monte Carlo method simulation;

[0041] Step 3: Input the Monte Carlo geometry file into the Monte Carlo neutronics calculation program, and construct the petal-shaped spiral fuel rod geometry entity based on the CSG and CAD modeling method;

[0042] Step 4: Repeat the iterative Monte Carlo neutronics calculation results until the calculation results meet the accuracy requirements, and then post-process the results.

[0043] The complex geometry of the CAD model and the simplified form of the CSG geometry are well compatible. After simplifying the model using the CSG method, the Monte Carlo method can be effectively simulated. Through the coupled modeling of CAD and CSG, the processing method of complex geometry is simplified, the complexity of the calculation process is reduced, and the efficiency of the simulation calculation is improved. The iterative calculation method can gradually improve the accuracy of the results during the calculation process, while avoiding the waste of resources with a one-time high amount of calculation. Through the Monte Carlo neutronics calculation results of the iterative CSG+CAD model, the error of the neutronics calculation results is 0~5×10 -4 That is, the accuracy requirements are met.

[0044] CAD models are generally represented by precise geometric bodies and can contain complex surfaces, curves, etc.; while CSG models are composed of simple geometric bodies (such as spheres, cubes, cylinders, etc.) combined through Boolean operations. Due to the complexity of CAD models, directly using these models for Monte Carlo simulations often leads to inefficiencies. By combining CAD models with CSG models, the calculation process can be simplified and the computational complexity can be reduced. Monte Carlo methods are often used in random sampling simulations to solve complex neutron physics problems. In addition, the Boolean operation characteristics of CSG (such as intersection, difference, union, etc.) also make it more efficient to handle various boundaries and conditions in complex geometric models.

[0045] Embodiment 2. This embodiment further limits the CAD and CSG coupling modeling method of a reactor petal-shaped spiral fuel rod described in embodiment 1. The fuel rod geometric model in step 1 includes: a cylindrical fuel rod and a petal-shaped spiral fuel rod, and the petal-shaped spiral fuel rod includes a petal fuel rod with 2 to 8 petals; the geometric characteristic parameters of the petal-shaped spiral fuel rod include: an outer convex arc radius r, an inner concave arc radius R, a connection length l between the outer convex arc and the inner concave arc, a height H of the fuel rod, and a pitch P of the fuel rod.

[0046] The geometric structure of the petal-shaped spiral fuel rod is relatively complex, and its geometric features (such as the number of petals, outer convex arc radius, inner concave arc radius, connection length, pitch, etc.) require high-precision geometric modeling. The use of CAD for preliminary modeling can ensure the accurate representation of the fuel rod geometry and avoid the geometric distortion or simplification problems that may occur in traditional modeling methods. Especially in the representation of spiral shapes, CAD can directly describe spiral curves, surfaces and other complex geometric features, making subsequent CSG modeling more accurate. The high flexibility of the CAD model can accurately model all key geometric parameters of the petal-shaped spiral fuel rod, including but not limited to the outer convex arc radius r, the inner concave arc radius R, the pitch P and other parameters. This allows the model to not only accurately describe the complex shape of the fuel rod, but also accurately reflect the impact of its geometric characteristics on reactor performance.

[0047] In this embodiment, the geometric model of the fuel rod is modeled by CAD, which avoids the problem of high computational complexity that may be encountered when directly using complex surfaces for Monte Carlo simulation. Through the coupling of CAD and CSG, efficient calculation of complex geometric bodies can be achieved, the resources and time required for calculation can be reduced, and the simulation process can be optimized.

[0048] Furthermore, when CAD is combined with CSG for modeling, boundary conditions can be effectively handled to ensure that the boundaries in the simulation process are accurate and correct, and to avoid affecting the reliability of the calculation results due to geometric representation errors. For example, in the simulation process, the accuracy of key areas such as the geometric boundaries and contact surfaces of the petal-shaped spiral fuel rods is crucial. Through CAD modeling, these boundary conditions can be highly accurate, and when Monte Carlo calculations are performed using CSG simplified geometry, there will be no deviation in the simulation results due to geometric inaccuracies.

[0049] Embodiment 3: This embodiment further defines the CAD and CSG coupling modeling method for a reactor petal-shaped spiral fuel rod described in Embodiment 2. Step 2 includes:

[0050] Perform watertightness treatment on the petal-shaped spiral fuel rod to obtain a watertight CAD model;

[0051] Partition and mesh the watertight CAD model to obtain Monte Carlo geometry files and mesh files for simulation and post-processing.

[0052] In the process of modeling reactor fuel rods, it is very important to ensure that the model is watertight. In this embodiment, by performing watertight treatment on the petal-shaped spiral fuel rods, potential gaps or water leakage problems in the model can be eliminated, and the physical accuracy of each part in the reactor simulation process can be ensured, especially in the simulation of related physical processes such as nuclear reactions and heat conduction, which can avoid errors or instability caused by incomplete models.

[0053] By partitioning the CAD model, that is, naming different areas according to actual conditions for Monte Carlo calculations, the material type, temperature, etc. are set according to the partitions. The Monte Carlo method is often used in the simulation of nuclear reactors, especially when dealing with complex problems such as particle transport and reaction rate. In this embodiment, the method combined with the geometry file and the mesh file can effectively use random sampling to obtain a more accurate numerical solution. By generating special geometry files and mesh files for the fuel rod morphology, the efficiency and accuracy of the simulation can be improved, especially when dealing with the dynamic behavior of multi-nuclear reactor systems, local details can be better captured.

[0054] The petal-shaped spiral fuel rod has a relatively complex geometry. The coupled modeling method combining CAD and CSG can better handle this complex shape and adapt to the changes in different design requirements. The CSG method makes the operation of complex geometries more flexible and can be easily adjusted and modified to meet the needs of different designs.

[0055] The coupled CAD and CSG modeling methods can simulate nuclear reactor fuel rods more accurately, especially when considering multi-physics coupling problems such as nuclear reaction, heat conduction, fluid flow, etc., which can provide designers with more detailed and accurate simulation data. When using the Monte Carlo method for particle tracking and radiation transfer simulation, combined with detailed grid and geometric information, it can conduct a more in-depth analysis of various physical processes in the reactor.

[0056] Embodiment 4: This embodiment further defines the CAD and CSG coupling modeling method of a reactor petal-shaped spiral fuel rod described in Embodiment 3. The partitioning process of the watertight CAD model includes:

[0057] Group and name the watertightness CAD models;

[0058] Check the water tightness of the model. If the water tightness of the model is poor, it is necessary to close each surface of the model. If the water tightness of the model is good, output the Monte Carlo geometry file. -7 , then the model has good water tightness, otherwise its water tightness is worse.

[0059] By grouping and naming the watertightness CAD model and partitioning it, the entire reactor model can be made more structured and modular. This processing method helps to analyze different areas separately in the subsequent simulation process, thereby improving calculation efficiency and accuracy. By setting appropriate boundary conditions for each partition, the physical environment of different areas can be simulated. For example, some areas may involve problems such as heat conduction and fluid flow, while other areas may only involve the stability of the geometric structure. By setting boundary conditions reasonably, it can be ensured that the simulation results of each area are consistent with the actual situation.

[0060] By outputting high-quality geometry files, CAD modeling results can be directly used in Monte Carlo simulation, thus reducing the error and workload of data conversion. This coupling method makes the simulation process more efficient while ensuring a high degree of consistency between the geometric model and the physical simulation.

[0061] Embodiment 5: This embodiment further defines the CAD and CSG coupling modeling method of a reactor petal-shaped spiral fuel rod described in Embodiment 3. The meshing of the watertight CAD model includes:

[0062] Set the parameters of the mesh of the CAD model for water tightness;

[0063] Draw the tetrahedral mesh. If the mesh does not meet the standard, you need to redraw the mesh. If the mesh meets the standard, output the mesh file. If the mesh quality is close to 1, the mesh is more standard, otherwise it means the mesh is less standard.

[0064] The grid file is converted into a Monte Carlo grid file.

[0065] By setting the parameters of the mesh and drawing the tetrahedral mesh, it is possible to ensure that the geometric accuracy of the model can be effectively converted into a numerical model. Whether the mesh meets the standard is an important factor in ensuring the simulation accuracy. If the mesh quality meets the standard, it means that the mesh structure is suitable for high-precision calculations. If it does not meet the standard, it can be improved by redrawing the mesh, which ensures the quality of the mesh and effectively avoids calculation errors caused by poor mesh.

[0066] By converting the grid file into a Monte Carlo grid file, it can be directly applied to the particle transport simulation of the Monte Carlo method. The Monte Carlo method is widely used in the simulation of particle transport in nuclear reactors. This file conversion allows the modeling work to be seamlessly connected with the subsequent numerical simulation, improving work efficiency. The coupling method of CAD and CSG provides high flexibility, which can not only accurately describe complex geometric shapes, but also make appropriate adjustments according to actual needs during the modeling process, and is suitable for different types of engineering and physical problems.

[0067] Embodiment 6: This embodiment further defines the CAD and CSG coupling modeling method of a reactor petal-shaped spiral fuel rod described in Embodiment 1, and the step 3 includes:

[0068] According to the calculation requirements of the Monte Carlo method, the Monte Carlo geometry file is input into the Monte Carlo calculation program, and based on the Monte Carlo geometry, the CSG model construction method is used to obtain the fuel rod geometry solid model constructed by the CSG+CAD method.

[0069] Specific modeling process: First, use the CSG model construction method to build a closed space for accommodating the Monte Carlo geometry model, place the Monte Carlo geometry file in the closed space, and then select different faces of the closed space respectively, and use the programming language to set different boundary conditions for each face according to actual needs. The boundary condition types include: total reflection boundary condition, vacuum boundary condition, transmission boundary condition, periodic boundary condition, and white boundary condition.

[0070] CAD can provide highly accurate and detailed geometric descriptions, which is suitable for the design of complex geometric structures, and is particularly suitable for accurately modeling the complex shapes of reactor fuel rods, such as petal-shaped spiral structures. CAD models can capture complex surfaces, shapes and details, which is conducive to simulating and analyzing the physical and mechanical properties of fuel rods. The CSG method can construct geometric models through Boolean operations (union, intersection, difference) of basic geometric bodies (such as cubes, spheres, cylinders, etc.). This makes the construction process simpler and more efficient, especially when dealing with more regular geometric bodies, it can reduce the complexity and amount of calculation of the model. By combining the modeling methods of CAD and CSG, the calculation process can be simplified while maintaining design accuracy, thereby improving modeling efficiency.

[0071] Embodiment 7: This embodiment further defines the CAD and CSG coupling modeling method for a reactor petal-shaped spiral fuel rod described in Embodiment 1, when the error of the neutron calculation result is 0 to 5×10 -4 , that is, the accuracy requirement is met.

[0072] Embodiment 8: A CAD and CSG coupling modeling system for a reactor petal-shaped spiral fuel rod according to this embodiment, the system comprises:

[0073] A geometric model building unit, used to build a fuel rod geometric model and output a CAD geometric file;

[0074] A processing unit, used for processing the CAD geometry file and outputting a Monte Carlo geometry file for Monte Carlo method simulation;

[0075] The geometric entity construction unit is used to input the Monte Carlo file into the Monte Carlo neutronics calculation program, and construct the petal-shaped spiral fuel rod geometric entity based on the CSG and CAD modeling method; specifically: the CAD model of the petal-shaped spiral fuel rod is placed in the closed interval constructed by the CSG model, so as to obtain the CAD+CSG model of the petal-shaped spiral fuel rod.

[0076] The post-processing unit is used to repeat iterative calculations until the accuracy of the neutronics calculation results meets the requirements, and then post-process the results.

[0077] Embodiment 9. A computer device described in this embodiment includes a memory and a processor, wherein a computer program is stored in the memory. When the processor runs the computer program stored in the memory, the processor executes a CAD and CSG coupling modeling method for a reactor petal-shaped spiral fuel rod according to any one of embodiments 1 to 7.

[0078] Embodiment 10. A computer-readable storage medium described in this embodiment has a computer program stored thereon, and when the computer program is executed by a processor, the steps of a CAD and CSG coupling modeling method for a reactor petal-shaped spiral fuel rod as described in any one of embodiments 1 to 7 are executed.

[0079] Implementation Method 11: See Figure 2 and Figure 3 This embodiment further defines the CAD and CSG coupling modeling method for a reactor petal-shaped spiral fuel rod described in the first embodiment, and is also used to explain the second to seventh embodiments. Specifically:

[0080] Specifically, Figure 2 FIG. 1 is a specific modeling schematic diagram of a CAD and CSG coupling modeling method for a reactor petal-shaped spiral fuel rod according to the present invention. Figure 2 As shown, the geometric model of the fuel rod includes a cylindrical fuel rod (Cylinder Fuel, CF) and a petal-shaped helix fuel rod (Petal-shaped Helix Fuel, PHF), wherein the petal-shaped helix fuel rod includes a petal fuel rod with 2 to 8 petals. In this embodiment, a four-petal-shaped fuel rod (Four Petal-shaped Fuel, FPF) is mainly used as an example for description;

[0081] The model construction includes: determining the geometric characteristic parameters of the petal-shaped spiral fuel rod, including: the outer convex arc radius r, the inner concave arc radius R, the connection length l between the outer convex arc and the inner concave arc, the height H of the fuel rod, and the pitch P of the fuel rod;

[0082] According to the size parameters of the reactor, the values ​​of the outer convex arc r, the inner concave arc R and the connection l of the outer convex arc and the inner concave arc of the petal-shaped fuel rod section are calculated, and the rationality of the values ​​is evaluated, so as to design a petal-shaped fuel rod model with different water-uranium ratios but the same circumscribed circle radius;

[0083] According to the input parameters, the fuel core blocks and cladding of FPF are drawn separately to form the fuel elements.

[0084] After the petal-shaped spiral fuel rod is subjected to watertightness treatment, it is subjected to partitioning treatment and meshing respectively, so as to obtain a Monte Carlo geometry file and a mesh file for simulation and post-processing respectively;

[0085] Specifically, there are two types of processing for the PHF geometry file. One is the Monte Carlo geometry file export process: the models are grouped and named, and then the boundary conditions of the models are set; then the water tightness of the models is checked. If the water tightness of the model is poor, it is necessary to close the faces of the model; if the water tightness of the model is good, the Monte Carlo geometry file is output.

[0086] Another method of exporting a Monte Carlo mesh file is to first set the mesh parameters of the model; then start drawing the tetrahedral mesh, and if the mesh does not meet the standard, redraw the mesh; if the mesh meets the standard, output the mesh file; and finally convert the mesh file into a Monte Carlo mesh file.

[0087] Inputting the Monte Carlo geometry file of the PHF into the Monte Carlo running program, and constructing the CAD+CSG geometry entity of the PHF by using the CSG model construction method;

[0088] Specifically, firstly, based on Monte Carlo geometry and using the CSG model construction method, a fuel rod geometric entity model constructed by CAD+CSG method is obtained; the geometric entities are arrayed to obtain components, and further, the components are arranged in an array to obtain a core; iterative parameters are set, and the neutron transport process of the model is calculated; until the accuracy meets the requirements, the Monte Carlo simulation calculation results are output.

[0089] The geometric entities constructed by the CAD+CSG method are iteratively calculated for multiple times under different conditions until the results meet the accuracy requirements, and the results are post-processed using the Monte Carlo grid file.

[0090] Specifically, the Monte Carlo grid file and the Monte Carlo simulation neutronics calculation results are input into the post-processing software, and a variety of simulation calculation results that conform to physical laws and statistical laws are output.

[0091] Figure 3The simulation results of the effective proliferation coefficient of cylindrical fuel rods constructed by CSG, CAD and CAD+CSG methods are shown in the figure. Figure 3 As shown in the figure, the FPF geometric models constructed by the three model construction methods of CSG, CAD and CAD+CSG have the same k after Monte Carlo simulation. eff The errors are 3.4×10 -4 , 3.6×10 -4 With 3.7×10 -4 , and due to the different ways of model construction, k eff The error is 3.4×10 -4 It can be seen that the FPF model constructed by CAD+CSG model can directly replace the FPF model constructed by CSG and CAD.

[0092] Those skilled in the art will appreciate that the embodiments of the present disclosure may be provided as methods, systems or computer program products. Therefore, the present disclosure may take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, the present disclosure may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0093] The present disclosure is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present disclosure. It should be understood that each process and / or block in the flowchart and / or block diagram and the combination of processes and / or blocks in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing device to work in a specific way, so that the instructions stored in the computer-readable memory produce a product including an instruction device, which implements the functions specified in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0094] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure rather than to limit its protection scope. Although the present disclosure has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that after reading the present disclosure, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the invention, but these changes, modifications or equivalent substitutions are all within the protection scope of the disclosed claims to be approved.

Claims

1. A CAD and CSG coupling modeling method for a petal-shaped spiral fuel rod of a reactor, characterized in that: The method comprises: Step 1: Establish the fuel rod geometry model and output the CAD geometry file; Step 2: Process the CAD geometry file and output the Monte Carlo geometry file for Monte Carlo method simulation; Step 3: Input the Monte Carlo file into the Monte Carlo neutronics calculation program, and construct the petal-shaped spiral fuel rod geometric entity based on the CSG and CAD modeling method; Step 4: Repeat the iterative Monte Carlo neutronics calculation results until the calculation results meet the accuracy requirements, and then post-process the results.

2. The CAD and CSG coupling modeling method of a reactor petal-shaped spiral fuel rod according to claim 1 is characterized in that: The fuel rod geometric model in step 1 includes: cylindrical fuel rods and petal-shaped spiral fuel rods, wherein the petal-shaped spiral fuel rods include petal fuel rods with 2 to 8 petals; the geometric characteristic parameters of the petal-shaped spiral fuel rods include: the outer convex arc radius r, the inner concave arc radius R, the connection length l between the outer convex arc and the inner concave arc, the height H of the fuel rod, and the pitch P of the fuel rod.

3. The CAD and CSG coupling modeling method of a reactor petal-shaped spiral fuel rod according to claim 2 is characterized in that: The second step comprises: Perform watertightness treatment on the petal-shaped spiral fuel rod to obtain a watertight CAD model; Partition and mesh the watertight CAD model to obtain Monte Carlo geometry files and mesh files for simulation and post-processing.

4. The CAD and CSG coupling modeling method of a reactor petal-shaped spiral fuel rod according to claim 3 is characterized in that: The partitioning process of the watertight CAD model includes: Group and name the watertightness CAD models; Check the water tightness of the model. If the water tightness of the model is poor, it is necessary to close each surface of the model; if the water tightness of the model is good, output the Monte Carlo geometry file.

5. The CAD and CSG coupling modeling method of a reactor petal-shaped spiral fuel rod according to claim 3 is characterized in that: The meshing of the watertight CAD model comprises: Setting the parameters of the mesh of the CAD model for water tightness; Draw the tetrahedral mesh. If the mesh does not meet the standard, you need to redraw the mesh. If the mesh meets the standard, output the mesh file. The grid file is converted into a Monte Carlo grid file.

6. The CAD and CSG coupling modeling method for a reactor petal-shaped spiral fuel rod according to claim 1 is characterized in that: The step three comprises: According to the calculation requirements of the Monte Carlo method, the Monte Carlo geometry file is input into the Monte Carlo calculation program, and based on the Monte Carlo geometry, the CSG model construction method is used to obtain the fuel rod geometry solid model constructed by the CSG+CAD method.

7. The CAD and CSG coupling modeling method for a reactor petal-shaped spiral fuel rod according to claim 1 is characterized in that: The error of neutron calculation results is 0~5×10 -4 , that is, the accuracy requirement is met.

8. A CAD and CSG coupling modeling system for petal-shaped spiral fuel rods of a reactor, characterized in that: The system comprises: A geometric model building unit, used to build a fuel rod geometric model and output a CAD geometric file; A processing unit, used for processing the CAD geometry file and outputting a Monte Carlo file for Monte Carlo method simulation; A geometric entity construction unit, used to input the Monte Carlo file into the Monte Carlo neutronics calculation program and construct the petal-shaped spiral fuel rod geometric entity using the CSG method; The post-processing unit is used to repeat iterative calculations until the accuracy of the calculation results meets the requirements, and then post-process the results.

9. A computer device, characterized in that: It comprises a memory and a processor, wherein a computer program is stored in the memory, and when the processor runs the computer program stored in the memory, the processor executes a CAD and CSG coupling modeling method for a reactor petal-shaped spiral fuel rod according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, which, when executed by a processor, executes the steps of a CAD and CSG coupling modeling method for a reactor petal-shaped spiral fuel rod as described in any one of claims 1 to 7.

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