A method and system for cross-scale coupling of a reactor thermal-hydraulic system

Abstract

The embodiment of the present application provides a kind of reactor thermal fluid system cross-scale coupling method and system, comprising: the commercial CFD program is divided into multiple flow sub-modules with the thermal hydraulic program different from the scale of the commercial CFD program;According to the cross-scale coupling requirement, the mutual call and data transmission logic of each flow sub-module are determined;The input and output data of each flow sub-module are converted by corresponding data format conversion processing, and the third-party library required by each flow sub-module is compiled to realize cross-scale thermal hydraulic coupling;Wherein, the data format conversion processing includes: the mutual conversion of the data format of the input and output data and the general mass data format based on mass non-uniform data format library is realized.The embodiment of the present application solves the technical problem that the commercial CFD program and other professional programs are coupled in the prior art, which has limitations, so that the data support for complex large-scale non-uniform discrete structure is not enough, which affects the later development of fine simulation.

Description

Technical Field

[0001] This invention relates to a cross-scale coupling method and system for reactor thermal fluid systems. Background Technology

[0002] In the field of reactor thermal-hydraulic engineering, previous numerical simulations used for reactor design analysis were based on programs with high levels of model simplification, including reactor system thermal-hydraulic programs and core subchannel thermal-hydraulic programs. Due to the simplification assumptions they employ, these programs cannot accurately capture the significant effects of 3D flow heat transfer.

[0003] Computational fluid dynamics (CFD) programs do not rely on empirical relationships for flow and heat transfer, but instead calculate thermal-hydraulic properties by directly solving (simplified) Navier-Stokes equations and energy equations. Based on the turbulence model used, CFD programs can be categorized by their level of detail: Direct Numerical Simulation (DNS), Large Eddy Simulation (LES), and Reynolds-Averaged Turbulence Simulation (RANS). In general, reactor thermal-hydraulic programs can be divided into four different scale levels: the finest local scale (DNSCFD programs), a finer local scale (LES and RANS CFD programs), component scale (subchannel programs and low-precision CFD programs), and system scale (system programs). It is worth noting that although there is a trend for CFD programs to replace other thermal-hydraulic programs, due to the extremely large mesh size required for complex geometries (even for engineered RANS turbulence models), the strong reliance of CFD calculation settings on user experience, and the significant investment required for CFD calculation verification and uncertainty analysis, CFD programs are currently mostly used only to simulate reactor chamber phenomena where 3D flow and heat transfer effects are significant. Of course, there are exceptions. The U.S. National Laboratory plans to use an exascale supercomputer to couple the open-source spectral method CFD program Nek5000 with the open-source neutron physics Monte Carlo program OpenMC (ExaSMR project) and use it for the analysis of small modular reactors (SMRs), providing a benchmark example for SMRs.

[0004] Currently, to combine the advantages of different scale thermal-hydraulic programs, it is necessary to carry out multi-scale thermal-hydraulic program coupling. A typical coupling scheme is: subchannel programs calculate core thermal-hydraulic characteristics; CFD programs calculate chamber flow and heat transfer; and system programs calculate other parts of the reactor system.

[0005] Meanwhile, within the reactor, especially in the core region, there are close coupling effects between thermal hydraulics and physical processes such as neutron physics, fuel rod behavior, structural mechanics, and chemistry. These different fields have previously developed their own specialized procedures according to their respective disciplines. When determining the coupling method for the reactor's thermal-fluid systems, it is also necessary to ensure that the coupling method is applicable to other specialized procedures.

[0006] In the realm of CFD programs, compared to open-source CFD programs (such as OpenFOAM, TrioCFD, and Code_Saturne), commercial CFD programs (such as FLUENT, CFX, STAR-CCM+, and TransAT) are widely used internationally due to their comprehensive functionality, superior user experience, abundant learning resources, high code maintainability, and stable, fixed versions (without publicly available source code). Furthermore, program verification and validation are relatively convenient and easy. In the nuclear industry, these commercial CFD programs have also received considerable attention, usage, and secondary development. A typical secondary development scenario involves coupling these programs with other specialized programs (such as system programs and sub-channel programs in reactor thermal engineering) through interfaces provided by commercial CFD programs. However, current coupling methods have certain limitations, the most significant being the artificially constructed temporary data mapping between programs. This artificially constructed temporary data mapping method often only supports relatively simple correspondences and lacks sufficient support for complex, large-scale, non-uniform discrete structures. This limitation is an obstacle that needs to be overcome for later refined simulations (such as core pin-by-pin or even sub-pin simulations, or coupling with other physics programs). Summary of the Invention

[0007] To address the technical problem that the coupling of commercial CFD programs with other professional programs in existing technologies has limitations, resulting in insufficient data support for complex, large-scale, non-uniform discrete structures and affecting subsequent refined simulations, this invention provides a cross-scale coupling method and system for reactor thermal fluid systems.

[0008] The embodiments of the present invention are achieved through the following technical solutions:

[0009] In a first aspect, embodiments of the present invention provide a cross-scale coupling method for a reactor thermal-fluid system, comprising:

[0010] The commercial CFD program and the thermal hydraulic program of a different scale are divided into multiple process sub-modules for cross-scale coupling and mutual calling.

[0011] The mutual calling and data transfer logic of each process sub-module is determined based on the cross-scale coupling requirements;

[0012] The input and output data of each process sub-module are processed by corresponding data format conversion and compiled with the third-party libraries required by each process sub-module to achieve cross-scale thermal-hydraulic coupling.

[0013] The data format conversion process includes: converting the data format of the input / output data to and from a general large-capacity data format based on a large-capacity non-uniform data format library.

[0014] Furthermore, the large-capacity non-uniform data format library includes a general-purpose large-capacity data processing and data mapping library.

[0015] Furthermore, the general-purpose large-capacity data processing and data mapping library includes a general-purpose grid / field database; the general-purpose large-capacity data processing and data mapping library includes: MED, an open-source grid / field data processing, storage and mapping library developed by CEA in France; DataTransferKit, an open-source data processing and mapping library developed by the CASL project in the United States; and MOAB&MBCoupler, an open-source grid / field data processing and mapping library developed by the NEAMS project in the United States.

[0016] Furthermore, the cross-scale coupling requirements include explicit coupling iteration, fixed-point semi-implicit coupling iteration, JFNK coupling iteration, and / or Anderson accelerated coupling iteration.

[0017] Furthermore, the third-party libraries required by each process sub-module include the data mapping library and / or parallel computing library required by each process sub-module.

[0018] Furthermore, the data format conversion process also includes: enabling mutual conversion between general data file formats and typical commonly used data file formats.

[0019] Secondly, embodiments of the present invention provide a cross-scale coupling method for a reactor thermal fluid system, comprising:

[0020] Based on the callback function of the secondary development interface or Adapter interface of the commercial CFD program, the commercial CFD program and the thermal hydraulic program of a different scale are divided into multiple process sub-modules for cross-scale coupling and mutual calling, and the mutual calling and data transmission logic of each process sub-module is determined according to the cross-scale coupling requirements.

[0021] Based on a general-purpose large-capacity data processing and data mapping library, the conversion between the input and output data of each process sub-module and the general-purpose large-capacity data format is realized through the coupling interface of each process sub-module.

[0022] The input and output data of each process submodule through the corresponding coupling interface are compiled with the third-party libraries required by each process submodule to achieve cross-scale thermal-hydraulic coupling.

[0023] Furthermore, the secondary development interfaces for commercial CFD programs include UDFs for ANSYS FLUENT and / or User Fortran for ANSYS CFX; the adapter interfaces for commercial CFD programs include adapter interfaces for the coupling tool MPCCI and / or adapter interfaces based on PreCICE.

[0024] Furthermore, the coupling interface is also used to enable the conversion between general data file formats and typical commonly used data file formats.

[0025] Thirdly, embodiments of the present invention provide a cross-scale coupling system for a reactor thermal fluid system, comprising:

[0026] The partitioning unit is used to divide a commercial CFD program and a thermal hydraulic program of a different scale into multiple process sub-modules for cross-scale coupling and mutual invocation.

[0027] The unit is used to determine the mutual calling and data transfer logic of each process sub-module based on the cross-scale coupling requirements;

[0028] The compilation unit is used to compile the input and output data of each process submodule, processed by the corresponding data format conversion unit, with the third-party libraries required by each process submodule to achieve cross-scale thermo-hydraulic coupling; and

[0029] The data format conversion processing unit is used to convert the data format of the input / output data to and from the general large-capacity data format based on the general large-capacity data processing and data mapping library.

[0030] Compared with the prior art, the embodiments of the present invention have the following advantages and beneficial effects:

[0031] This invention discloses a cross-scale coupling method and system for a reactor thermal-hydraulic system. It divides a commercial CFD program and a thermal-hydraulic program of a different scale into multiple inter-process sub-modules for cross-scale coupling. The inter-process sub-modules' inter-process calling and data transfer logic is determined based on cross-scale coupling requirements. The input and output data of each sub-module, processed through corresponding data format conversion, are compiled with the required third-party libraries to achieve cross-scale thermal-hydraulic coupling. This solves the technical problem in the prior art where the coupling of commercial CFD programs with other professional programs is limited, resulting in insufficient data support for complex, large-scale, non-uniform discrete structures, thus affecting subsequent refined simulations. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of a cross-scale coupling method for a reactor thermal fluid system.

[0034] Figure 2 This is a schematic diagram of another cross-scale coupling method for reactor thermal fluid systems.

[0035] Figure 3 This is a schematic diagram of the reactor's thermal fluid system.

[0036] Figure 4 This is a schematic diagram of the coupled architecture of the first mode.

[0037] Figure 5 This is a schematic diagram of the coupled architecture of the second mode.

[0038] Figure 6 This is a schematic diagram of the coupled architecture of the third mode. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0040] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other embodiments, well-known structures, circuits, materials, or methods have not been specifically described in order to avoid obscuring the invention.

[0041] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "an embodiment," "an example," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. Moreover, those skilled in the art will understand that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0042] In the description of this invention, the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0043] Example

[0044] To address the limitations of existing commercial CFD programs coupled with other specialized programs, resulting in insufficient data support for complex, large-scale, non-uniform discrete structures and hindering subsequent refined simulations, this invention provides, in a first aspect, a cross-scale coupling method for reactor thermal-fluid systems. (Refer to...) Figure 1 As shown, it includes:

[0045] S1. Divide the commercial CFD program and the thermal hydraulic program of a different scale into multiple process sub-modules for cross-scale coupling and mutual calling.

[0046] S2. Determine the mutual calling and data transfer logic of each process sub-module based on the cross-scale coupling requirements;

[0047] S3. Compile the input and output data of each process sub-module, which have been converted and processed according to the corresponding data format, with the third-party libraries required by each process sub-module to achieve cross-scale thermal-hydraulic coupling.

[0048] The data format conversion process includes: converting the data format of the input / output data to and from a general large-capacity data format based on a large-capacity non-uniform data format library.

[0049] Optionally, data format conversion can be implemented through a coupling interface. A commercial CFD program can be divided into multiple first-process sub-modules, and at least one thermal hydraulic program to be coupled with the commercial CFD program can be divided into multiple second-process sub-modules. The first-process sub-modules of the commercial CFD program can be uniformly converted through a single coupling interface, or each first-process sub-module can be converted through its own coupling interface. Similarly, the multiple second-process sub-modules of each of the at least one thermal hydraulic program to be coupled with the commercial CFD program can be converted through a single interface, or each second-process sub-module can be converted through its own coupling interface.

[0050] Therefore, this invention, by introducing a large-capacity non-uniform data format library into the traditional coupling method system, achieves high-precision data transfer between various thermal hydraulic programs through the mutual conversion between the data format of the input and output data and the general large-capacity data format based on the large-capacity non-uniform data format library. At the same time, it ensures the parallel scalability of the coupling method and the compatibility with various program data formats. This solves the technical problem in the prior art where the coupling of commercial CFD programs with other professional programs is limited, resulting in insufficient data support for complex large-scale non-uniform discrete structures, which affects the subsequent fine simulation.

[0051] Furthermore, the large-capacity non-uniform data format library includes a general-purpose large-capacity data processing and data mapping library.

[0052] Furthermore, the general-purpose large-capacity data processing and data mapping library includes a general-purpose grid / field database; the general-purpose large-capacity data processing and data mapping library includes: MED, an open-source grid / field data processing, storage and mapping library developed by CEA in France; DataTransferKit, an open-source data processing and mapping library developed by the CASL project in the United States; and MOAB&MBCoupler, an open-source grid / field data processing and mapping library developed by the NEAMS project in the United States.

[0053] Furthermore, the cross-scale coupling requirements include explicit coupling iteration, fixed-point semi-implicit coupling iteration, JFNK coupling iteration, and / or Anderson accelerated coupling iteration.

[0054] Traditional coupling methods are based on the interfaces of the coupled programs (such as secondary development interfaces or adapter interfaces provided by commercial CFD programs, or other pre-developed functional and data interfaces from source code programs). The program interface should be able to support one or more typical coupling iteration schemes in the coupled computation process, including explicit, fixed-point semi-implicit iteration, JFNK iteration, and Anderson acceleration, etc.

[0055] Furthermore, the third-party libraries required by each process sub-module include the data mapping library and / or parallel computing library required by each process sub-module.

[0056] Furthermore, the data format conversion process also includes: enabling mutual conversion between general data file formats and typical commonly used data file formats.

[0057] After selecting a suitable high-capacity data processing and mapping library (either an internationally available open-source library or a domestically developed one) to provide a universal high-capacity data format, the program coupling interface should handle the conversion between the input / output data format and the universal high-capacity data format. Considering that some commercial programs may only be able to transfer data via files, in addition to implementing data format conversion in memory, it is also necessary to implement the conversion between universal data file formats and typical commonly used data file formats. For the selected high-capacity data processing and mapping library, it is necessary to ensure that it supports common spatial discretization forms such as structured and unstructured meshes and different types of field data (considering different spatial support methods such as scalar fields, vector fields, and node / cell centers).

[0058] Secondly, embodiments of the present invention provide a cross-scale coupling method for a reactor thermal-fluid system, referring to... Figure 2 As shown, it includes:

[0059] S1. Based on the callback function of the secondary development interface or Adapter interface of the commercial CFD program, the commercial CFD program and the thermal hydraulic program of a different scale are divided into multiple process sub-modules for cross-scale coupling and mutual calling, and the mutual calling and data transmission logic of each process sub-module is determined according to the cross-scale coupling requirements.

[0060] S2. Based on a general-purpose large-capacity data processing and data mapping library, the conversion between the input and output data of each process sub-module and the general-purpose large-capacity data format is realized through the coupling interface of each process sub-module;

[0061] S3. Compile the input and output data of each process submodule through the corresponding coupling interface with the third-party libraries required by each process submodule to achieve cross-scale thermal-hydraulic coupling.

[0062] Furthermore, the coupling interface is also used to enable the conversion between general data file formats and typical commonly used data file formats.

[0063] An exemplary cross-scale coupling method for reactor thermal fluid systems includes the following steps:

[0064] Step 1: Based on the secondary development interface of commercial CFD programs (such as ANSYS FLUENT's UDF, ANSYS CFX's User Fortran) or Adapter interface (oriented towards the coupling tool MPCCI, or based on PreCICE), and combined with the callback function functionality of the commercial CFD program interface, conduct preparatory work for coupling the commercial CFD program with other scale-specific thermal hydraulic professional programs. This involves dividing the computational flow sub-modules within the program and clarifying the mutual calling logic between the functions of the flow sub-modules. Based on the above division of the flow sub-modules, ensure that the interface can support the required coupling iteration scheme (supporting one or a combination of explicit, fixed-point semi-implicit iteration, JFNK iteration, Anderson acceleration, etc.).

[0065] Step 2: Based on a general-purpose large-capacity data processing and data mapping library, implement the relevant conversions (memory mode & file mode) between input / output data and general-purpose large-capacity data formats in the program interface. It should support common spatial discretization forms such as structured and unstructured grids, and different types of field data (considering scalar fields, vector fields, and different spatial support methods). Currently, internationally renowned general-purpose large-capacity data processing and data mapping libraries include: MED, an open-source grid / field data processing, storage, and mapping library developed by CEA in France; DataTransferKit, an open-source data processing and mapping library developed by the CASL project in the United States (supporting meshless technology); and MOAB & MBCoupler, open-source grid / field data processing and mapping libraries developed by the NEAMS project in the United States.

[0066] Step 3: Based on the software interface developed in the previous steps, define the inter-program interface function call scheme and inter-program data transfer scheme through separate scripts (C++ or Python), third-party software / tools / platforms, or the program's own interface. Compile and run each program together with the required third-party libraries (data mapping libraries, parallel computing libraries) to achieve cross-scale thermo-hydraulic coupling. Reference Figure 4-6 As shown, in the coupled architecture of the three modes, commercial CFD programs run as executable programs, while other programs can run as executable programs or be called as dynamic link libraries (DLL files in Windows systems and shared library files in Linux systems).

[0067] Furthermore, the secondary development interfaces for commercial CFD programs include UDFs for ANSYS FLUENT and / or User Fortran for ANSYS CFX; the adapter interfaces for commercial CFD programs include adapter interfaces for the coupling tool MPCCI and / or adapter interfaces based on PreCICE.

[0068] Thirdly, embodiments of the present invention provide a cross-scale coupling system for a reactor thermal fluid system, referring to... Figure 3 As shown, it includes:

[0069] The partitioning unit is used to divide a commercial CFD program and a thermal hydraulic program of a different scale into multiple process sub-modules for cross-scale coupling and mutual invocation.

[0070] The unit is used to determine the mutual calling and data transfer logic of each process sub-module based on the cross-scale coupling requirements;

[0071] The compilation unit is used to compile the input and output data of each process submodule, processed by the corresponding data format conversion unit, with the third-party libraries required by each process submodule to achieve cross-scale thermo-hydraulic coupling; and

[0072] The data format conversion processing unit is used to convert the data format of the input / output data to and from the general large-capacity data format based on the general large-capacity data processing and data mapping library.

[0073] The principles of the system and method in this embodiment are similar, and will not be repeated here.

[0074] Therefore, the embodiments of the present invention provide a flexible data transfer scheme based on a general data format. The method of the embodiments of the present invention supports multiple coupling iteration schemes, including explicit and semi-implicit coupling methods, which can reasonably meet the coupling requirements of different programs; it can meet the communication requirements of different types of programs for large-capacity non-uniform data; the data transfer scheme in the method of the embodiments of the present invention supports data communication between large-scale parallel computing programs, which can meet the coupling calculation requirements of future numerical reactors; in addition to supporting the efficient coupling of mainstream commercial CFD programs (including ANSYS FLUENT and CFX, etc.) with other thermal programs, it also supports coupling with other physical programs (neutron physics, structural mechanics, etc.).

[0075] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A cross-scale coupling method for a reactor thermal-fluid system, characterized in that, include: The commercial CFD program and the thermal hydraulic program of a different scale are divided into multiple process sub-modules for cross-scale coupling and mutual calling. The mutual calling and data transfer logic of each process sub-module is determined based on the cross-scale coupling requirements; The input and output data of each process sub-module are processed by corresponding data format conversion and compiled with the third-party libraries required by each process sub-module to achieve cross-scale thermal-hydraulic coupling. The data format conversion process includes: converting the data format of the input / output data to and from a general large-capacity data format based on a large-capacity non-uniform data format library.

2. The cross-scale coupling method for reactor thermal-fluid systems as described in claim 1, characterized in that, The large-capacity non-uniform data format library includes a general-purpose large-capacity data processing and data mapping library.

3. The cross-scale coupling method for reactor thermal-fluid systems as described in claim 2, characterized in that, The general-purpose large-capacity data processing and data mapping library includes a general-purpose grid / field database; the general-purpose large-capacity data processing and data mapping library includes: MED, an open-source grid / field data processing, storage and mapping library developed by CEA in France; DataTransferKit, an open-source data processing and mapping library developed by the CASL project in the United States; and MOAB&MBCoupler, an open-source grid / field data processing and mapping library developed by the NEAMS project in the United States.

4. The cross-scale coupling method for reactor thermal-fluid systems as described in claim 1, characterized in that, The cross-scale coupling requirements include explicit coupling iteration, fixed-point semi-implicit coupling iteration, JFNK coupling iteration, and / or Anderson accelerated coupling iteration.

5. The cross-scale coupling method for reactor thermal-fluid systems as described in claim 1, characterized in that, The third-party libraries required by each process sub-module include the data mapping library and / or parallel computing library required by each process sub-module.

6. The cross-scale coupling method for reactor thermal-fluid systems as described in claim 1, characterized in that, Data format conversion processing also includes: enabling mutual conversion between general data file formats and typical commonly used data file formats.

7. A cross-scale coupling method for a reactor thermal-fluid system, characterized in that, include: Based on the callback function of the secondary development interface or Adapter interface of the commercial CFD program, the commercial CFD program and the thermal hydraulic program of a different scale are divided into multiple process sub-modules for cross-scale coupling and mutual calling, and the mutual calling and data transmission logic of each process sub-module is determined according to the cross-scale coupling requirements. Based on a general-purpose large-capacity data processing and data mapping library, the conversion between the input and output data of each process sub-module and the general-purpose large-capacity data format is realized through the coupling interface of each process sub-module. The input and output data of each process submodule through the corresponding coupling interface are compiled with the third-party libraries required by each process submodule to achieve cross-scale thermal-hydraulic coupling.

8. The cross-scale coupling method for reactor thermal-fluid systems as described in claim 7, characterized in that, The secondary development interfaces for commercial CFD programs include UDFs for ANSYS FLUENT and / or User Fortran for ANSYS CFX; the adapter interfaces for commercial CFD programs include adapter interfaces for the coupling tool MPCCI and / or adapter interfaces based on PreCICE.

9. The cross-scale coupling method for reactor thermal-fluid systems as described in claim 7, characterized in that, The coupling interface is also used to enable the conversion between general data file formats and typical commonly used data file formats.

10. A cross-scale coupling system for a reactor thermal-fluid system, characterized in that, include: The partitioning unit is used to divide a commercial CFD program and a thermal hydraulic program of a different scale into multiple process sub-modules for cross-scale coupling and mutual invocation. The unit is used to determine the mutual calling and data transfer logic of each process sub-module based on the cross-scale coupling requirements; The compilation unit is used to compile the input and output data of each process sub-module through the corresponding data format conversion processing unit and the third-party libraries required by each process sub-module to achieve cross-scale thermal-hydraulic coupling. as well as The data format conversion processing unit is used to convert the data format of the input / output data to and from the general large-capacity data format based on the general large-capacity data processing and data mapping library.

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