Method and apparatus for determining temperature of nuclear reactor fuel rods

Abstract

This application relates to a method and apparatus for determining the temperature of nuclear reactor fuel rods. The method includes: spatially dividing a target fuel rod to obtain multiple control volumes corresponding to the target fuel rod; inputting relevant data from the multiple control volumes into preset thermal conductivity models corresponding to each control volume; and jointly solving the multiple preset thermal conductivity models to obtain multiple current temperature data corresponding to each control volume. The preset thermal conductivity models include a heat energy change function, a heat conduction function, and an internal heat source function. The multiple current temperature data are temperature data under the condition that the heat energy change data, heat energy exchange data, and internal heat release data satisfy a preset energy balance relationship. This method can accurately calculate the temperature data of each control volume under the condition of satisfying the energy balance relationship, thereby significantly improving the accuracy and reliability of calculating the internal temperature distribution of nuclear fuel rods.

Description

Technical Field

[0001] This application relates to the field of nuclear reactor technology, and in particular to a method and apparatus for determining the temperature of nuclear reactor fuel rods. Background Technology

[0002] Nuclear reactor fuel rods are the core components for power generation in a nuclear energy system. They are typically composed of stacked fuel pellets, which are tightly encapsulated within a metal cladding with excellent corrosion resistance and neutronic properties. The fuel rods are arranged in an array within the reactor core. When a fission reaction occurs within the fuel pellets, it releases enormous amounts of energy, most of which is converted into heat.

[0003] Nuclear reactor fuel assemblies have high power density, which can easily lead to high fuel and cladding surface temperatures. High fuel temperatures can cause fuel pellets to melt, expand, or even break down the cladding, resulting in radioactive material leaks and serious accidents. Simultaneously, the cladding temperature must be strictly controlled to prevent corrosion or strength degradation under high temperature and intense radiation environments. Therefore, accurate temperature distribution calculations for fuel rods are crucial for the safe operation and performance optimization of nuclear reactors.

[0004] Therefore, there is an urgent need for a method that can accurately and reliably determine the internal temperature distribution of nuclear reactor fuel rods. Summary of the Invention

[0005] Therefore, it is necessary to provide a method and apparatus for determining the temperature of nuclear reactor fuel rods that can accurately and reliably calculate the temperature distribution of fuel rods, addressing the aforementioned technical problems.

[0006] In a first aspect, this application provides a method for determining the temperature of nuclear reactor fuel rods, including:

[0007] The target fuel rod is spatially divided to obtain multiple control bodies corresponding to the target fuel rod;

[0008] The relevant data of the multiple control bodies are input into the multiple preset heat conduction models corresponding to the multiple control bodies respectively, and the multiple preset heat conduction models are solved jointly to obtain multiple current temperature data corresponding to the multiple control bodies respectively.

[0009] The preset heat conduction model includes a heat energy change function, a heat conduction function, and an internal heat source function. The heat energy change function is used to determine the heat energy change data of the control body; the heat conduction function is used to determine the heat energy exchange data of the control body; the internal heat source function is used to determine the internal heat release data of the control body; and the multiple current temperature data are temperature data under the condition that the heat energy change data, the heat energy exchange data, and the internal heat release data satisfy a preset energy balance relationship.

[0010] In one embodiment, the spatial division of the target fuel rod to obtain multiple control bodies corresponding to the target fuel rod includes:

[0011] Obtain multiple material regions of the target fuel rod; the multiple material regions include at least a gas core region, a fuel pellet region, and a cladding region arranged from the inside out;

[0012] The gas core region, the fuel pellet region, and the cladding region are divided to obtain at least one gas core control body, at least one fuel pellet control body, and at least one cladding control body distributed radially along the target fuel rod.

[0013] In one embodiment, the heat exchange data includes the heat exchange data between the control body and its adjacent adjacent medium; the adjacent medium corresponding to the intermediate gas core control body in the gas core region includes the central axis boundary; the intermediate gas core control body is a gas core control body passing through the central axis of the target fuel rod;

[0014] The preset thermal conductivity model corresponding to the intermediate gas core control body also includes an adiabatic boundary condition; the adiabatic boundary condition is used to indicate that the heat exchange data of the intermediate gas core control body relative to the central axis boundary is zero in the heat conduction function.

[0015] In one embodiment, the heat exchange data includes the heat exchange data between the control body and its adjacent adjacent medium; the adjacent medium corresponding to the outer cladding control body of the cladding region includes an external cooling medium; the outer cladding control body is the outermost cladding control body of the target fuel rod;

[0016] The preset thermal conductivity model corresponding to the outer shell control body also includes convection boundary conditions; the convection boundary conditions are used to indicate that, in the heat conduction function, the heat energy exchange data of the outer shell control body relative to the external cooling medium is determined according to the convection heat exchange mode.

[0017] In one embodiment, the step of inputting relevant data of the plurality of control bodies into the plurality of preset heat conduction models corresponding to the plurality of control bodies, and jointly solving the plurality of preset heat conduction models to obtain the plurality of current temperature data corresponding to the plurality of control bodies includes:

[0018] Acquire relevant data for multiple control bodies; the relevant data includes geometric data, material property data, heat release rate data, historical temperature data at the previous time step, and the time step length corresponding to the previous time step for each control body; the time step length is the time interval between the previous time step and the current time step;

[0019] The relevant data of the multiple control bodies are input into the multiple preset thermal conductivity models, and the multiple preset thermal conductivity models are solved jointly to obtain the multiple current temperature data of the multiple control bodies at the current time step.

[0020] In one embodiment, the step of inputting the relevant data of the multiple control bodies into multiple preset thermal conductivity models, and jointly solving the multiple preset thermal conductivity models to obtain multiple current temperature data of the multiple control bodies at the current time step includes:

[0021] For each control body, based on the thermal energy change function corresponding to the control body, a first mapping relationship is obtained between the historical temperature data, the current temperature data to be solved, the geometric data, the material property data, the time step, and the thermal energy change data of the control body;

[0022] Based on the heat conduction function corresponding to the control body, a second mapping relationship is obtained between the geometric data, material property data, and current temperature data to be solved of the control body, the geometric data, material property data, and current temperature data to be solved of the adjacent control bodies, and the heat energy exchange data of the control body.

[0023] Based on the internal heat source function corresponding to the control body, a third mapping relationship is obtained between the geometric data, the heat release rate data, and the internal heat release data of the control body;

[0024] Based on the first mapping relationship, the second mapping relationship, the third mapping relationship, and the input related data, the temperature data of multiple control bodies under the condition that the thermal energy change data, the thermal energy exchange data, and the internal heat release data satisfy a preset energy balance relationship are obtained, so as to obtain multiple current temperature data.

[0025] Secondly, this application also provides a device for determining the temperature of nuclear reactor fuel rods, comprising:

[0026] The partitioning module is used to spatially partition the target fuel rod to obtain multiple control bodies corresponding to the target fuel rod;

[0027] The determination module is used to input the relevant data of the multiple control bodies into multiple preset heat conduction models corresponding to the multiple control bodies, and jointly solve the multiple preset heat conduction models to obtain multiple current temperature data corresponding to the multiple control bodies.

[0028] The preset heat conduction model includes a heat energy change function, a heat conduction function, and an internal heat source function. The heat energy change function is used to determine the heat energy change data of the control body; the heat conduction function is used to determine the heat energy exchange data of the control body; the internal heat source function is used to determine the internal heat release data of the control body; and the multiple current temperature data are temperature data under the condition that the heat energy change data, the heat energy exchange data, and the internal heat release data satisfy a preset energy balance relationship.

[0029] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the method for determining the temperature of nuclear reactor fuel rods provided in the first aspect of this application.

[0030] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for determining the temperature of nuclear reactor fuel rods provided in the first aspect of this application.

[0031] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the method for determining the temperature of nuclear reactor fuel rods provided in the first aspect of this application.

[0032] The aforementioned method and apparatus for determining the temperature of nuclear reactor fuel rods involves spatially dividing the target fuel rod to obtain multiple control bodies corresponding to the target fuel rod. Relevant data from these multiple control bodies are input into preset thermal conductivity models corresponding to each control body. The multiple preset thermal conductivity models are then jointly solved to obtain multiple current temperature data corresponding to each control body. The preset thermal conductivity models include a thermal energy change function, a heat conduction function, and an internal heat source function. The thermal energy change function is used to determine the thermal energy change data of the control body, the heat conduction function is used to determine the heat exchange data of the control body, and the internal heat source function is used to determine the internal heat release data of the control body. The multiple current temperature data are temperature data where the thermal energy change data, heat exchange data, and internal heat release data satisfy a preset energy balance relationship. This application embodiment decomposes the fuel rod into multiple computable discrete control volumes, enabling the model to more accurately capture the temperature gradient and heat transfer path inside and on the surface of the fuel rod. By inputting the relevant data of each control volume into a preset heat conduction model and performing joint solution, the temperature data of each control volume under the condition of satisfying the energy balance relationship can be accurately calculated, avoiding the simplification error that may exist in the macroscopic model, thereby significantly improving the accuracy and reliability of the calculation of the internal temperature distribution of nuclear fuel rods. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a diagram illustrating the application environment of a method for determining the temperature of nuclear reactor fuel rods in one embodiment.

[0035] Figure 2 This is a flowchart illustrating a method for determining the temperature of nuclear reactor fuel rods in one embodiment;

[0036] Figure 3 This is a schematic diagram of the process of spatially dividing the target fuel rod in one embodiment;

[0037] Figure 4 This is a schematic diagram of the control volume mesh division for an annular fuel rod in one embodiment;

[0038] Figure 5 This is a schematic diagram of the process for obtaining multiple current temperature data in one embodiment;

[0039] Figure 6 This is a flowchart illustrating the process of obtaining multiple current temperature data in another embodiment;

[0040] Figure 7 This is a flowchart illustrating a method for determining the temperature of nuclear reactor fuel rods in another embodiment;

[0041] Figure 8 A structural block diagram of a nuclear reactor fuel rod temperature determination device in one embodiment;

[0042] Figure 9 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0044] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0045] The method for determining the temperature of nuclear reactor fuel rods provided in this application can be applied to, for example... Figure 1 In the application environment shown, terminal 102 communicates with server 104 via a network. A data storage system can store the data that server 104 needs to process. The data storage system can be integrated onto server 104 or placed in the cloud or on another network server. Terminal 102 or server 104 can spatially divide the target fuel rod for temperature determination to obtain multiple control bodies corresponding to the target fuel rod. Then, the relevant data of the multiple control bodies are input into the preset thermal conductivity models corresponding to the multiple control bodies, and the multiple preset thermal conductivity models are jointly solved to obtain multiple current temperature data corresponding to each control body.

[0046] Terminal 102 can be, but is not limited to, various personal computers, laptops, smartphones, tablets, drones, low-altitude aircraft, IoT devices, and portable wearable devices. IoT devices can include smart speakers, smart TVs, smart air conditioners, smart in-vehicle devices, and projection equipment. Portable wearable devices can include smartwatches, smart bracelets, and head-mounted displays. Head-mounted displays can be virtual reality (VR) devices, augmented reality (AR) devices, and smart glasses. Server 104 can be a standalone physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing cloud computing services.

[0047] In one exemplary embodiment, such as Figure 2 As shown, a method for determining the temperature of nuclear reactor fuel rods is provided, which can be applied to... Figure 1 Taking terminal 102 as an example, the explanation includes the following steps 202 to 204. Wherein:

[0048] Step 202: Spatial division of the target fuel rod to obtain multiple control volumes corresponding to the target fuel rod.

[0049] Spatial partitioning refers to dividing the continuous geometric region of the target fuel rod into a series of discretized segments, which are called control volumes. Multiple control volumes are spatially non-overlapping and interconnected, and the boundary surface of one control volume can usually be the boundary surface of its adjacent control volumes.

[0050] Step 204: Input the relevant data of multiple control bodies into the preset heat conduction models corresponding to the multiple control bodies respectively, and solve the multiple preset heat conduction models together to obtain multiple current temperature data corresponding to the multiple control bodies respectively.

[0051] The preset thermal conductivity model includes a thermal energy change function, a heat conduction function, and an internal heat source function. The thermal energy change function is used to determine the thermal energy change data of the control body, the heat conduction function is used to determine the heat exchange data of the control body, and the internal heat source function is used to determine the internal heat release data of the control body. Multiple current temperature data points are temperature data where the thermal energy change data, heat exchange data, and internal heat release data satisfy a preset energy balance relationship. Relevant data for the control body may include geometric property data and material property data used to establish the preset thermal conductivity model and solve for the control body temperature, and may also include data from adjacent media adjacent to the control body.

[0052] In this embodiment, for each control body, the preset thermal conductivity model of the control body includes a thermal energy change function, a heat conduction function, and an internal heat source function. The thermal energy change function can be used to calculate the rate of change of the stored heat inside the control body based on the relevant data of the control body and the current temperature data of the control body; the heat conduction function can be used to calculate the heat exchange power of the control body based on the relevant data of the control body, the current temperature data of the control body, the relevant data of the adjacent control bodies, and the current temperature data of the adjacent control bodies; the internal heat source function can be used to calculate the internal heat release power generated by the control body itself based on the relevant data of the control body.

[0053] For example, for each control body, the terminal inputs the relevant data of the control body into the preset heat conduction model corresponding to the control body, determines the temperature data under the condition that the heat energy change data, heat energy exchange data and internal heat release data in each preset heat conduction model all satisfy the preset energy balance relationship, and obtains multiple current temperature data corresponding to multiple control bodies respectively. That is, the current temperature data of multiple control bodies obtained can make the heat energy change data, heat energy exchange data and internal heat release data in each preset heat conduction model all satisfy the preset energy balance relationship.

[0054] In the above-mentioned method for determining the temperature of nuclear reactor fuel rods, the target fuel rod is spatially divided to obtain multiple control bodies corresponding to the target fuel rod. The relevant data of the multiple control bodies are input into the preset thermal conductivity models corresponding to the multiple control bodies respectively. The multiple preset thermal conductivity models are jointly solved to obtain multiple current temperature data corresponding to the multiple control bodies. The preset thermal conductivity models include a thermal energy change function, a heat conduction function, and an internal heat source function. The thermal energy change function is used to determine the thermal energy change data of the control body, the heat conduction function is used to determine the heat exchange data of the control body, and the internal heat source function is used to determine the internal heat release data of the control body. The multiple current temperature data are temperature data under the condition that the thermal energy change data, heat exchange data, and internal heat release data satisfy a preset energy balance relationship. This application embodiment decomposes the fuel rod into multiple computable discrete control volumes, enabling the model to more accurately capture the temperature gradient and heat transfer path inside and on the surface of the fuel rod. By inputting the relevant data of each control volume into a preset heat conduction model and performing joint solution, the temperature data of each control volume under the condition of satisfying the energy balance relationship can be accurately calculated, avoiding the simplification error that may exist in the macroscopic model, thereby significantly improving the accuracy and reliability of the calculation of the internal temperature distribution of nuclear fuel rods.

[0055] In practical applications, fuel rods in the reactor core mainly bear the heat transfer in the radial direction. In some embodiments, a radial partitioning method can be used to discretize the target fuel rod along its radial direction into a series of concentric ring-shaped control volumes. Each control volume can represent the physical characteristics of the fuel rod within a certain radial range. By calculating the heat exchange between these ring-shaped units, the radial temperature distribution of the fuel rod can be determined.

[0056] The following description uses a fuel rod including a central hole as an example to further illustrate this application.

[0057] In order to reduce the peak temperature of the fuel pellets at the center of the fuel rod, prevent the pellets from melting due to excessive temperature, and alleviate the swelling and deformation of the pellets caused by fission gas, the target fuel rod in this application embodiment may include a central hole, that is, a central channel is reserved in the center of the fuel pellet and filled with gas to form a gas core region.

[0058] In one embodiment, such as Figure 3 As shown, step 202 includes steps 302 to 304. Wherein:

[0059] Step 302: Obtain multiple material regions of the target fuel rod, including at least a gas core region, a fuel pellet region, and a cladding region arranged from the inside out.

[0060] For example, please refer to Figure 4The target fuel rod may include a core region, a fuel pellet region, and a cladding region. Optionally, the target fuel rod may also include an air gap region. The core region, fuel pellet region, air gap region, and cladding region are distributed sequentially from the inside to the outside along the radial direction within the fuel rod. The terminal can identify and acquire multiple material regions of the target fuel rod.

[0061] Step 304: Divide the gas core region, fuel pellet region and cladding region to obtain at least one gas core control body, at least one fuel pellet control body and at least one cladding control body distributed radially along the target fuel rod.

[0062] The terminal in this application embodiment can use a division rule of equal radial thickness for each material region to obtain multiple control bodies.

[0063] For example, the terminal acquires the dimensional information of each material region, including the radial thickness of each material region. The terminal can determine the radial thickness of the control body in each material region based on the radial thickness of each material region and the preset number of control bodies corresponding to each material region. For example, dividing the radial thickness of a material region (i.e., outer diameter minus inner diameter) by the preset number of control bodies in the material region yields the equal radial thickness of each control body in that material region.

[0064] In this embodiment, by spatially radially dividing the target fuel rod including the central hole, thermal modeling and joint solution can be performed by combining the geometric and material properties of each control body, thereby reliably determining the temperature distribution inside the fuel rod with the central hole.

[0065] In some embodiments, the heat transfer function of the preset heat conduction model used to calculate the heat exchange data in step 204 includes the heat exchange data between the control body and its adjacent adjacent media.

[0066] The adjacent medium can refer to any entity or condition that is in direct contact with a face or boundary surface of the control body and is capable of exchanging heat with it. Depending on the location of the control body within the fuel rod, the adjacent medium can take different forms.

[0067] For example, the adjacent media of a fuel pellet control body within a fuel pellet region can be another fuel pellet control body radially inward and another fuel pellet control body radially outward. When a control body is located at the interface of two different materials, such as a fuel pellet control body at the interface of a fuel pellet region and an air gap region, its adjacent media can include another fuel pellet control body radially inward and an air gap control body radially outward.

[0068] For example, for the outermost cladding control body of the fuel rod, its adjacent medium may include another cladding control body radially inward and adjacent to it, and the cooling medium outside the fuel rod. For the innermost core control body of the fuel rod, its adjacent medium may include another core control body radially outward and adjacent to it, and a central axis boundary radially inward, which is used to indicate the boundary conditions that may exchange heat with the control body.

[0069] In one embodiment, the adjacent medium corresponding to the intermediate gas core control body in the gas core region includes the central axis boundary, and the intermediate gas core control body is a gas core control body that passes through the central axis of the target fuel rod.

[0070] The preset thermal conductivity model corresponding to the intermediate air core control body also includes adiabatic boundary conditions. The adiabatic boundary conditions are used to indicate that the heat exchange data of the intermediate air core control body relative to the central axis boundary is zero in the heat conduction function.

[0071] For example, for the intermediate core control body, in addition to the adjacent control bodies on the radially outer side, the adjacent medium on its radially inner side is defined as the central axis boundary, which represents the geometric boundary condition. When determining its heat exchange data, such as heat exchange power, the terminal uses an adiabatic boundary condition at the center of the target fuel rod. The heat exchange power of the intermediate core control body is zero compared to the central axis boundary; that is, the heat exchange data of the intermediate core control body mainly considers the heat input from its radially outer adjacent control bodies. It is understood that, in calculating the energy balance of the intermediate core control body, the embodiments of this application do not consider heat flowing in or out through the central axis.

[0072] In this embodiment, by applying an adiabatic boundary condition to the central axis boundary of the innermost gas core control body in the precisely radially divided control body, the heat transfer in the central region of the fuel rod can be accurately and physically processed, ensuring the reliability of the calculation results.

[0073] In one embodiment, the adjacent medium corresponding to the outer cladding control body of the cladding region includes an external cooling medium, and the outer cladding control body is the outermost cladding control body of the target fuel rod.

[0074] The preset heat conduction model corresponding to the outer shell control body also includes convection boundary conditions. The convection boundary conditions are used to indicate the heat exchange power of the outer shell control body relative to the external cooling medium in the heat conduction function. The heat exchange data is determined according to the heat exchange mode of convection.

[0075] For example, the outermost cladding control body of the target fuel rod can be in direct contact with the reactor's cooling system. Besides the adjacent control bodies on its radially inner side, the adjacent medium on its radially outer side is defined as the external cooling medium. A convection boundary condition is introduced into the preset thermal conductivity model corresponding to the outer cladding control body. This convection boundary condition indicates how the heat transfer function quantifies the heat exchange between the surface of the outer cladding control body and the external cooling medium. The heat exchange data can be determined based on the convection heat transfer mechanism, thereby accurately reflecting the process of heat removal from the fuel rod to the coolant.

[0076] In this embodiment, by applying convection boundary conditions to the outer surface boundary of the outermost shell control body in the precisely radially divided control body, the heat transfer at the shell surface in contact with the cooling medium can be accurately and physically handled, ensuring the reliability of the calculation results.

[0077] In one exemplary embodiment, such as Figure 5 As shown, step 204 includes steps 502 to 504. Wherein:

[0078] Step 502: Obtain relevant data for multiple control bodies, including geometric data, material property data, heat release rate data, historical temperature data at the previous time step, and the time step length corresponding to the previous time step.

[0079] The time step is the time interval between the previous time step and the current time step.

[0080] In this embodiment of the application, for each control body, the relevant data of the control body may include the control body's own data and the data of the adjacent medium of the control body. For example, the relevant data of the control body may include the control body's geometric data, the control body's material property data, the control body's heat release rate data, the control body's historical temperature data in the previous time step, and the time step length. The relevant data of the control body may also include the geometric data and material property data of the adjacent control bodies.

[0081] Please continue to refer to this. Figure 4 For the outermost cladding control body, the relevant data also includes data on the external cooling medium. For the gas core control body in the gas core region, the air gap control body in the air gap region, and the cladding control body in the cladding region, there are also internal heat sources after irradiation, but they are smaller than the heat released by the fission of the fuel pellet control body. In actual calculations, the internal heat release data calculated by the internal heat source function corresponding to the gas core control body, air gap control body, and cladding control body can be regarded as 0.

[0082] Step 504: Input the relevant data of multiple control bodies into multiple preset heat conduction models, and solve the multiple preset heat conduction models together to obtain multiple current temperature data of multiple control bodies at the current time step.

[0083] For example, for each control body, the relevant data of the control body is input into the preset heat conduction model of the control body, and the temperature data is determined under the condition that the heat energy change data, heat energy exchange data and internal heat release data of each control body satisfy the preset energy balance relationship. Multiple current temperature data corresponding to multiple control bodies are obtained. That is, the current temperature data of multiple control bodies obtained can make the heat energy change data, heat energy exchange data and internal heat release data in each preset heat conduction model satisfy the preset energy balance relationship.

[0084] In this embodiment, by acquiring relevant data such as geometry, physical properties, heat release rate, historical temperature and time step of each control body, and using these data to jointly solve the preset thermal conductivity model covering different material regions, the temperature distribution inside the nuclear fuel rod at the current time step can be accurately and in real time determined.

[0085] In one exemplary embodiment, such as Figure 6 As shown, step 504 includes steps 602 to 608. Wherein:

[0086] Step 602: For each control volume, based on the corresponding thermal energy change function of the control volume, obtain the first mapping relationship between the historical temperature data, the current temperature data to be solved, the geometric data, the material property data, the time step, and the thermal energy change data of the control volume.

[0087] The thermal energy change function can be used to characterize the first mapping relationship between the historical temperature data of the control volume, the current temperature data to be solved, geometric data, material property data, time step, and thermal energy change data.

[0088] Among them, geometric data may include mass, material property data may include specific heat capacity, and thermal energy change data may include thermal energy change rate.

[0089] For example, the thermal energy change function can be expressed as:

[0090] ;

[0091] Wherein, the function value represents the rate of change of thermal energy of control volume i, M i To control the mass of body i, C pi To control the specific heat capacity of volume i, For time step, Here is the current temperature data of the control volume i to be solved. The historical temperature data for control body i.

[0092] Step 604: Based on the heat conduction function corresponding to the control volume, obtain the geometric data, material property data, current temperature data to be solved, geometric data, material property data, current temperature data to be solved of adjacent control volumes, and the second mapping relationship between the heat energy exchange data of the control volume.

[0093] The heat conduction function can be used to characterize the second mapping relationship between the geometric data, material property data, current temperature data to be solved, geometric data, material property data, current temperature data to be solved, and heat exchange data of the control body.

[0094] Among them, the heat exchange data may include heat exchange power, and the material property data may include the corresponding relationship data between the temperature and thermal conductivity of the control body material, that is, the material property data includes the thermal conductivity of the control body at different temperatures.

[0095] For example, the heat conduction function can be expressed as:

[0096] ;

[0097] The function value represents the heat exchange power of control volume i. The thermal conductivity between control body i and its adjacent control body i-1, Let i be the thermal conductivity between control body i+1 and its adjacent control body i. Here is the current temperature data of the control volume i to be solved. The current temperature data of the control volume i-1 to be solved. The current temperature data of the control volume i+1 to be solved.

[0098] The thermal conductivity between control body i and its adjacent control body i-1 is determined by the area (contact area) at the interface between them based on the geometric data of control body i and control body i-1, the heat transfer distance based on the geometric data of control body i and control body i-1, the thermal conductivity of control body i based on the current temperature data of control body i, the thermal conductivity of control body i-1 based on the current temperature data of control body i-1, and the thermal conductivity of control body i-1 based on the current temperature data of control body i-1. This is combined with the contact area, the heat transfer distance, and the thermal conductivity of control body i and control body i-1.

[0099] It should be noted that adiabatic boundary conditions can be applied to the intermediate gas core control volume, and the heat transfer function of the intermediate gas core control volume can be expressed as:

[0100] ;

[0101] The function value represents the heat exchange power of the intermediate gas core control body. The thermal conductivity between the intermediate air core control body and its adjacent control body on its radially outer side. The current temperature data of the intermediate gas core control body to be solved. The current temperature data of the adjacent control volume on its radial outer side is to be solved.

[0102] It should be noted that convective boundary conditions can be applied to the outermost shell control volume, and the heat transfer function of the outer shell control volume can be expressed as:

[0103] ;

[0104] The function value represents the heat exchange power of the outer casing control body. The thermal conductivity between the outer casing control body and its adjacent radially inner control body is [not specified]. The current temperature data of the outer casing control body to be solved. The current temperature data of the adjacent control volume on its radially inner side is to be solved, where H is the convective heat transfer coefficient, and T is the temperature of the adjacent control volume on its radially inner side. b This refers to the mainstream temperature of the external medium.

[0105] Step 606: Based on the internal heat source function corresponding to the control body, obtain the third mapping relationship between the geometric data, heat release rate data and internal heat release data of the control body.

[0106] The internal heat source function can be used to characterize the third mapping relationship between the geometric data, heat release rate data, and internal heat release data of the control volume.

[0107] The internal heat release data may include the internal heat release power, the geometric data may include the volume of the control body, and the heat release rate data may include the volumetric heat release rate of the control body.

[0108] For example, the internal heat source function can be expressed as:

[0109] ;

[0110] The function value represents the internal heat release power of control volume i. This represents the volumetric heat release rate of control volume i. This represents the volume of control volume i.

[0111] It should be noted that for the gas core control body in the gas core region, the air gap control body in the air gap region, and the shell control body in the shell region, the volumetric heat release rate of the control body can be 0, that is, its corresponding internal heat release power is 0.

[0112] Step 608: Based on the first mapping relationship, the second mapping relationship, the third mapping relationship, and the input related data, obtain the temperature data of multiple control bodies under the preset energy balance relationship, including thermal energy change data, thermal energy exchange data, and internal heat release data, so as to obtain multiple current temperature data.

[0113] The preset energy balance relationship can be defined as the sum of thermal energy change data and internal heat release data.

[0114] For example, the heat conduction equation that satisfies the preset energy balance relationship in the preset heat conduction model can be expressed as:

[0115] .

[0116] For example, relevant data is input into a preset heat conduction model. Based on the first mapping relationship, the second mapping relationship, the third mapping relationship in the preset heat conduction model, and the preset energy balance relationship, the heat conduction equation of each control body is constructed. The heat conduction equations of each control body are solved jointly to obtain the current temperature data of each control body.

[0117] For example, for each control body, the historical temperature data, geometric data, material property data, and time step of the control body are input into the corresponding thermal energy change function to obtain the first correspondence between the thermal energy change data of the control body and the current temperature data to be solved. The geometric data and material property data of the control body, as well as the geometric data and material property data of adjacent control bodies, are input into the corresponding thermal energy change function to obtain the second correspondence between the heat exchange data of the control body, the current temperature data to be solved for the control body, and the current temperature data to be solved for adjacent control bodies. The geometric data and heat release rate data of the control body are input into the corresponding internal heat source function to obtain the internal heat release data of the control body. Based on the first and second correspondences, the temperature data of multiple control bodies under the condition that the thermal energy change data, heat exchange data, and internal heat release data satisfy a preset energy balance relationship are obtained to obtain multiple current temperature data.

[0118] In one possible implementation, the terminal can use a catch-up method to jointly solve multiple preset thermal conductivity models to obtain multiple current temperature data corresponding to multiple control bodies.

[0119] For example, the terminal can acquire the current temperature first data of each control body, and for each control body, update the second correspondence relationship corresponding to the control body based on the current temperature first data of the control body and the current temperature first data of the adjacent control bodies. That is, by combining the current temperature first data, geometric data, and material property data of the control body, as well as the current temperature first data, geometric data, and material property data of the adjacent control bodies, the thermal conductivity data between the control body and the adjacent control bodies is determined, and the second correspondence relationship corresponding to the control body is updated based on the thermal conductivity data.

[0120] The terminal can obtain thermal energy change data, thermal energy exchange data, and internal heat release data based on the first correspondence and the updated second correspondence, and obtain the current temperature iteration data of each control body under the preset energy balance relationship. If the difference between the current temperature first data and the current temperature iteration data of each control body does not meet the difference threshold condition, the current temperature iteration data of each control body is used as the updated current temperature first data, and the process of updating the second correspondence and obtaining the current temperature iteration data of each control body is iteratively executed until the difference between the current temperature first data and the current temperature iteration data of each control body meets the difference threshold condition.

[0121] The current temperature data refers to the initial temperature data or the temperature data obtained in the previous iteration step.

[0122] For example, the terminal can acquire the initial current temperature data of each control body, determine the thermal conductivity of each control body based on the initial current temperature data, and determine the thermal conductivity between each control body and its adjacent control bodies by combining the geometric data of the control bodies and the thermal conductivity. Based on the determined thermal conductivity, the second correspondence is updated, and multiple preset thermal conductivity models are jointly solved to obtain the iterative current temperature data of each control body. If the difference between the iterative current temperature data and the initial current temperature data is less than a preset threshold, the iterative current temperature data is determined to be the current temperature data of multiple control bodies. If the difference between the iterative current temperature data and the initial current temperature data is greater than or equal to the preset threshold, the iterative current temperature data replaces the initial current temperature data, and the process of determining the thermal conductivity between each control body and its adjacent control bodies, updating the second correspondence, and jointly solving multiple preset thermal conductivity models is repeated until the difference between the iterative current temperature data and the initial current temperature data of each control body is less than the preset threshold.

[0123] In this embodiment, a pre-defined thermal conductivity model of the fuel rod based on the control volume method is used to solve the temperature field inside the fuel rod. Combined with the node division of the fuel rod structure with a central hole, a symmetrical adiabatic boundary condition is used to solve the gas in the center of the fuel rod with a central hole, and a convective boundary condition is used on the surface of the fuel rod. The temperature distribution inside the fuel rod with a central hole can be solved relatively reliably.

[0124] In one exemplary embodiment, such as Figure 7 As shown, a method for determining the temperature of fuel rods in a nuclear reactor is provided, the method comprising:

[0125] S1, divide the fuel rod into control volumes to obtain multiple control volumes.

[0126] For example, each material region of the target fuel rod is divided into control volumes along the radial direction, resulting in a total of N control volumes.

[0127] Please continue to refer to this. Figure 4 Based on the analysis requirements, determine the number of control volumes for each material, and divide each material region into control volumes with equal radial thickness, for example... Figure 4 The control body of the annular fuel rod is divided into 3, 5, 2, and 4 control units, respectively, consisting of the gas core, fuel pellets, air gap, and cladding.

[0128] S2, construct the preset heat conduction model for each control body.

[0129] For example, before constructing the preset heat conduction model, the radial heat conduction nodes are positioned at the average radius of the control volume. When one face of the control volume is a boundary surface, the heat conduction nodes are defined on the boundary surface, not at the center of the node. Please refer to [link to relevant documentation]. Figure 4 In the diagram, the dashed line represents the control volume boundary. The interface between the two materials simultaneously defines both the heat conduction node temperature and the control volume boundary. The radial position of the heat conduction node is fixed. For example, Figure 4 The three yellow dots represent the nodes of the three gas core control bodies, the five red dots represent the nodes of the five fuel pellets, the two green dots represent the nodes of the two air gap control bodies, and the four blue dots represent the nodes of the four cladding control bodies. The calculation does not consider the node movement caused by thermal expansion and contraction.

[0130] For example, the thermal conductivity model for a cylindrical structure made of a single material can be expressed as Equation 1:

[0131] ;

[0132] To avoid significant non-conservation of the thermal conductor's mass, the cold density can be used to define (ρV) at the thermally conductive nodes of control volume i. i Item, namely M i Therefore, Formula 1 can be written in the form of Formula 2:

[0133] ;

[0134] In the formula, M represents the mass of coolant in the segment / kg; Q i-1,i Q represents the amount of heat (in W) transferred from the heat-conducting node of control body i-1 to the node of control body i via heat conduction; i+1,i Q represents the amount of heat (in W) transferred from node i+1 to node i via heat conduction; i ’’’ The volumetric heat release rate of control volume i is expressed as W·m. -3 .

[0135] Heat transfer between nodes of the control volume is calculated using the thermal conductivity k of the material itself and the temperature gradient across the nodes, as shown in Formula 3 below:

[0136] ;

[0137] in, This represents the thermal conductivity between the centers of nodes i and j of control volume. This represents the average temperature of control volume j. This represents the average temperature of control volume i.

[0138] The heat transfer between nodes of the control volume is calculated based on the thermal conductivity k of the material itself and the temperature gradient across the nodes, and satisfies Equation 4:

[0139] ;

[0140] Thermal conductivity k is the reciprocal of thermal resistance R, and for any node of the control volume, we have the following formula:

[0141] ;

[0142] in, This is expressed as the thermal resistance from the center node of control volume i to the boundary with control volume i-1. It is represented as the thermal resistance from the center node of control volume i to the boundary of control volume i-1.

[0143] Thermal resistance R is a function of the control volume geometry and thermal conductivity. The average thermal conductivity between control volume nodes in cylindrical coordinates is defined as R. Then we have the following formula six:

[0144] ;

[0145] In the formula, Let be the average thermal conductivity between nodes of control volume i and control volume i+1. The distance in meters between nodes of control body i and nodes of control body i+1; It is the area between interfaces / m 2 .

[0146] in, Satisfying Formula Seven:

[0147] ;

[0148] in, Let be the equivalent radius of the radial control volume i. Let be the axial length of the axial control body j.

[0149] For the finite difference Fourier law approximation at the interface I between control volume i and control volume i+1, we have the following formulas eight and nine:

[0150] ;

[0151] ;

[0152] In the formula, the subscript I represents the physical properties at the interface of the control volume; the superscript "-" represents the average physical quantity corresponding to the location of the node. To control the heat conduction from body i to interface I, Let the radius of the center node (equivalent) of control volume i be . The temperature value of interface I. To control the thermal conductivity of material i, For heat conduction from interface I to control volume i+1, Let the radius of the center node (equivalent) of control volume i+1 be _____. Let i+1 be the thermal conductivity of the material controlling the volume.

[0153] Due to Formula 10:

[0154] ;

[0155] Then we have Formula Eleven:

[0156] ;

[0157] Formula 12 is as follows:

[0158] ;

[0159] Formula thirteen is as follows:

[0160] ;

[0161] Formula fourteen is as follows:

[0162] .

[0163] Once the thermal resistance, geometry, and material physical properties are determined, rearranging and differentiating the time term yields the following heat conduction equation for control volume i, as shown in Formula XV:

[0164] ;

[0165] In the formula, This is the temperature value calculated at the previous time step, in °C.

[0166] For internal boundary conditions and for material surfaces, Formula 15 needs to be modified to introduce either adiabatic or convective boundary conditions. Adiabatic boundary conditions are used at the center of the annular fuel, while convective boundary conditions are used at the cladding surfaces in contact with the fluid.

[0167] Traditional adiabatic boundary conditions are defined as follows (Formula Sixteen):

[0168] ;

[0169] Therefore, for the center point (i=1), i.e. the intermediate air core control volume, the heat conduction equation of Formula XV is transformed into the following Formula XVII:

[0170] ;

[0171] For convective boundary conditions, we have the following formula:

[0172] ;

[0173] In the formula, H is the convective heat transfer coefficient / W·m -2 ·℃ -1 ;T b is the mainstream fluid temperature in °C; j is the node in the subchannel coolant.

[0174] Therefore, for the outermost shell control volume (i=N), substituting Equation 18 into Equation 2 yields the following Equation 19:

[0175] .

[0176] S3, input the relevant data of each control body into the preset heat conduction model of each control body.

[0177] By placing all the unknown terms in Formula 15 on the left side of the equation and moving the known terms to the right side, we can reorganize it as Formula 20:

[0178] ;

[0179] That is, there is the following formula in form twenty-one:

[0180] ;

[0181] Similarly, based on formulas 17 and 19, we can obtain formulas 22 and 23 as follows:

[0182] ;

[0183] ;

[0184] In the formula, .

[0185] S4, assuming the temperature of the control volume, calculate the coefficient matrix of the heat conduction equation for each control volume.

[0186] For example, determine the assumed temperature for each control volume. If it is the first iteration, assume an initial value; otherwise, use the result of the previous iteration as the assumed value. Calculate the corresponding material properties at the assumed temperature using the material property table. For the core control volume, the heat source term within the control volume is calculated based on the average volumetric heat flux density of the core and the control volume. Substitute the material properties and heat source term into Formula Thirteen to obtain the coefficient terms of the thermal conductivity equation for each control volume.

[0187] S5 uses the catch-up method to solve for the nodal temperature of the fuel rod control body.

[0188] For example, after determining the coefficients of the heat conduction equation by assuming a temperature, the temperature distribution inside the annular fuel rod at that iteration step can be obtained.

[0189] S6, whether the iteration result satisfies the convergence condition.

[0190] If the difference between the solution results of all nodes in this iteration step and the corresponding control volume temperature in the previous iteration step is less than the convergence criterion, then the calculation is considered to have converged, and S7 is executed to output the fuel rod temperature distribution; otherwise, S4, S5, and S6 are repeated until the calculation convergence condition is met.

[0191] S7 outputs the calculation results.

[0192] In this embodiment, the method for calculating the temperature distribution inside the fuel rod with a central hole uses a heat conduction equation solution method based on the control volume method. The finite difference nodes of the heat conduction equation are used as nodes of the control volume. Symmetric adiabatic boundary conditions are used to solve the central gas of the fuel rod with a central hole. The equations are connected by thermodynamic methods to form a set of linearized equations, which are solved by Gaussian elimination and inverse substitution. The calculation is fast and accurate, and it is suitable for reactor core design iteration and core safety analysis.

[0193] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0194] Based on the same inventive concept, this application also provides a nuclear reactor fuel rod temperature determination device for implementing the above-described method for determining the temperature of nuclear reactor fuel rods. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more embodiments of the nuclear reactor fuel rod temperature determination device provided below can be found in the limitations of the nuclear reactor fuel rod temperature determination method described above, and will not be repeated here.

[0195] In one exemplary embodiment, such as Figure 8 As shown, a device for determining the temperature of nuclear reactor fuel rods is provided, comprising: a dividing module 802 and a determining module 804, wherein:

[0196] The partitioning module 802 is used to spatially partition the target fuel rod to obtain multiple control bodies corresponding to the target fuel rod.

[0197] The determination module 804 is used to input the relevant data of the multiple control bodies into the multiple preset heat conduction models corresponding to the multiple control bodies respectively, and to jointly solve the multiple preset heat conduction models to obtain multiple current temperature data corresponding to the multiple control bodies respectively.

[0198] The preset heat conduction model includes a heat energy change function, a heat conduction function, and an internal heat source function. The heat energy change function is used to determine the heat energy change data of the control body; the heat conduction function is used to determine the heat energy exchange data of the control body; the internal heat source function is used to determine the internal heat release data of the control body; and the multiple current temperature data are temperature data under the condition that the heat energy change data, the heat energy exchange data, and the internal heat release data satisfy a preset energy balance relationship.

[0199] The modules in the aforementioned nuclear reactor fuel rod temperature determination device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the computer device's memory as software, so that the processor can call and execute the corresponding operations of each module.

[0200] In one exemplary embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 9 As shown, this computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and databases. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When executed by the processor, the computer program implements a method for determining the temperature of fuel rods in a nuclear reactor.

[0201] Those skilled in the art will understand that Figure 9 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0202] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method for determining the temperature of nuclear reactor fuel rods provided in the embodiments of this application.

[0203] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps of the above-described method for determining the temperature of nuclear reactor fuel rods provided in the embodiments of this application.

[0204] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0205] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0206] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0207] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for determining the temperature of fuel rods in a nuclear reactor, characterized in that, The method includes: The target fuel rod is spatially divided to obtain multiple control bodies corresponding to the target fuel rod; The relevant data of the multiple control bodies are input into the multiple preset heat conduction models corresponding to the multiple control bodies respectively, and the multiple preset heat conduction models are solved jointly to obtain multiple current temperature data corresponding to the multiple control bodies respectively. The preset heat conduction model includes a heat energy change function, a heat conduction function, and an internal heat source function. The heat energy change function is used to determine the heat energy change data of the control body; the heat conduction function is used to determine the heat energy exchange data of the control body; the internal heat source function is used to determine the internal heat release data of the control body; and the multiple current temperature data are temperature data under the condition that the heat energy change data, the heat energy exchange data, and the internal heat release data satisfy a preset energy balance relationship.

2. The method according to claim 1, characterized in that, The spatial division of the target fuel rod to obtain multiple control bodies corresponding to the target fuel rod includes: Obtain multiple material regions of the target fuel rod; the multiple material regions include at least a gas core region, a fuel pellet region, an air gap region, and a cladding region arranged from the inside out; The gas core region, the fuel pellet region, and the cladding region are divided to obtain at least one gas core control body, at least one fuel pellet control body, at least one air gap control body, and at least one cladding control body distributed radially along the target fuel rod.

3. The method according to claim 2, characterized in that, The heat exchange data includes the heat exchange data between the control body and its adjacent media; the adjacent media corresponding to the intermediate gas core control body in the gas core region includes the central axis boundary; the intermediate gas core control body is a gas core control body that passes through the central axis of the target fuel rod. The preset thermal conductivity model corresponding to the intermediate gas core control body also includes an adiabatic boundary condition; the adiabatic boundary condition is used to indicate that the heat energy exchange data of the intermediate gas core control body relative to the central axis boundary is zero in the heat conduction function.

4. The method according to claim 2, characterized in that, The heat exchange data includes the heat exchange data between the control body and its adjacent media; the adjacent media corresponding to the outer cladding control body of the cladding region includes the external cooling medium; the outer cladding control body is the outermost cladding control body of the target fuel rod; The preset thermal conductivity model corresponding to the outer shell control body also includes convection boundary conditions; the convection boundary conditions are used to indicate that, in the heat conduction function, the heat energy exchange data of the outer shell control body relative to the external cooling medium is determined according to the convection heat exchange mode.

5. The method according to any one of claims 1 to 4, characterized in that, The step of inputting relevant data of multiple control bodies into multiple preset heat conduction models corresponding to each of the multiple control bodies, and jointly solving the multiple preset heat conduction models to obtain multiple current temperature data corresponding to each of the multiple control bodies includes: Acquire relevant data for multiple control bodies; the relevant data includes geometric data, material property data, heat release rate data, historical temperature data at the previous time step, and the time step length corresponding to the previous time step for each control body; the time step length is the time interval between the previous time step and the current time step; The relevant data of the multiple control bodies are input into the multiple preset thermal conductivity models, and the multiple preset thermal conductivity models are solved jointly to obtain the multiple current temperature data of the multiple control bodies at the current time step.

6. The method according to claim 5, characterized in that, The step involves inputting the relevant data of the multiple control entities into multiple preset thermal conductivity models, jointly solving the multiple preset thermal conductivity models, and obtaining multiple current temperature data of the multiple control entities at the current time step, including: For each control body, based on the thermal energy change function corresponding to the control body, a first mapping relationship is obtained between the historical temperature data, the current temperature data to be solved, the geometric data, the material property data, the time step, and the thermal energy change data of the control body. Based on the heat conduction function corresponding to the control body, a second mapping relationship is obtained between the geometric data, material property data, and current temperature data to be solved of the control body, the geometric data, material property data, and current temperature data to be solved of the adjacent control bodies, and the heat energy exchange data of the control body. Based on the internal heat source function corresponding to the control body, a third mapping relationship is obtained between the geometric data of the control body, the heat release rate data, and the internal heat release data; Based on the first mapping relationship, the second mapping relationship, the third mapping relationship, and the input related data, the temperature data of multiple control bodies under the preset energy balance relationship is obtained by acquiring the thermal energy change data, the thermal energy exchange data, and the internal heat release data, so as to obtain multiple current temperature data.

7. The method according to claim 6, characterized in that, Based on the first mapping relationship, the second mapping relationship, the third mapping relationship, and the input related data, the temperature data of multiple control bodies under the preset energy balance relationship is obtained by acquiring the thermal energy change data, the thermal energy exchange data, and the internal heat release data, in order to obtain multiple current temperature data, including: For each control body, the historical temperature data, geometric data, material property data, and time step of the control body are input into the thermal energy change function corresponding to the control body. Based on the first mapping relationship, the first correspondence between the thermal energy change data of the control body and the current temperature data to be solved is obtained. The geometric data and material property data of the control body, as well as the geometric data and material property data of the adjacent control bodies, are input into the thermal energy change function corresponding to the control body. Based on the second mapping relationship, the second correspondence between the thermal energy exchange data of the control body, the current temperature data of the control body to be solved, and the current temperature data of the adjacent control bodies to be solved is obtained. The geometric data and heat release rate data of the control body are input into the internal heat source function corresponding to the control body, and the internal heat release data of the control body is obtained based on the third mapping relationship. Based on the first correspondence and the second correspondence, the temperature data of multiple control bodies under the condition that the thermal energy change data, the thermal energy exchange data, and the internal heat release data satisfy the preset energy balance relationship are obtained, so as to obtain multiple current temperature data.

8. The method according to claim 7, characterized in that, Based on the first and second correspondences, the temperature data of multiple control bodies are obtained under the preset energy balance relationship by acquiring the thermal energy change data, the thermal energy exchange data, and the internal heat release data, in order to obtain multiple current temperature data, including: Obtain the first data of the current temperature of each control unit; For each control body, based on the first data of the current temperature of the control body and the first data of the current temperature of the adjacent control bodies, the second correspondence relationship corresponding to the control body is updated, and based on the first correspondence relationship and the updated second correspondence relationship, the thermal energy change data, the thermal energy exchange data and the internal heat release data are obtained to satisfy the current temperature iteration data of each control body under the preset energy balance relationship. If the difference between the current temperature first data and the current temperature iterative data of each control body does not meet the difference threshold condition, the current temperature iterative data of each control body is used as the updated current temperature first data, and the process of updating the second correspondence and obtaining the current temperature iterative data of each control body is iteratively executed until the difference between the current temperature first data and the current temperature iterative data of each control body meets the difference threshold condition.

9. The method according to claim 8, characterized in that, For each control body, updating the second correspondence relationship corresponding to the control body based on the current temperature first data of the control body and the current temperature first data of the adjacent control bodies includes: For each control body, the thermal conductivity data between the control body and the adjacent control body is determined by combining the current temperature data, geometric data, and material property data of the control body, as well as the current temperature data, geometric data, and material property data of the adjacent control body. The second correspondence between the control bodies is updated based on the thermal conductivity data between the control body and the adjacent control bodies.

10. A device for determining the temperature of fuel rods in a nuclear reactor, characterized in that, The device includes: The partitioning module is used to spatially partition the target fuel rod to obtain multiple control bodies corresponding to the target fuel rod; The determination module is used to input the relevant data of the multiple control bodies into multiple preset heat conduction models corresponding to the multiple control bodies, and jointly solve the multiple preset heat conduction models to obtain multiple current temperature data corresponding to the multiple control bodies. The preset heat conduction model includes a heat energy change function, a heat conduction function, and an internal heat source function. The heat energy change function is used to determine the heat energy change data of the control body; the heat conduction function is used to determine the heat energy exchange data of the control body; the internal heat source function is used to determine the internal heat release data of the control body; and the multiple current temperature data are temperature data under the condition that the heat energy change data, the heat energy exchange data, and the internal heat release data satisfy a preset energy balance relationship.

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