Method and system for calculating helium temperature of primary loop of pebble-bed high-temperature gas cooled reactor

Abstract

The invention discloses a method and a system for calculating helium temperature of a primary loop of a pebble-bed high-temperature gas cooled reactor, and relates to the field of nuclear reactor thermal calculation, and the method comprises the following steps: establishing a pebble-bed high-temperature gas cooled reactor grid control body, and further refining to obtain a fine grid required for calculating the helium temperature of the pebble-bed high-temperature gas cooled reactor; establishing a three-dimensional steady-state energy conservation equation of helium flow on the fine grid, and solving helium temperatures in three directions of the cylinder geometry according to the equation; simultaneously establishing energy conservation equations in three directions to obtain node helium temperatures, calculating the helium temperatures of all grid points point by point, and updating the helium temperatures point by point based on an over-relaxation method; the method for calculating the helium temperature of the primary loop of the pebble-bed high-temperature gas cooled reactor is provided by introducing the hypothesis of temperature linear distribution between the nodes, and the helium temperature of the internal flow channel of the reactor core and the helium temperature of the inner pore channel of the reflecting layer can be quickly and correctly calculated, so that an important reference is provided for determining the running state of the reactor core.

Description

Technical Field

[0001] The invention relates to the field of thermal engineering calculation of nuclear reactors, and in particular to a method and system for calculating the temperature of helium in a primary loop of a pebble bed type high temperature gas-cooled reactor. Background Art

[0002] When the pebble bed high temperature gas-cooled reactor operates at ultra-high temperatures, the outlet temperature of helium can reach over 1000°C; under ultra-high temperature conditions, the safety of the reactor needs to be guaranteed at all times.

[0003] The distribution of solid phase materials in the pebble bed high temperature gas-cooled reactor is relatively stable, while the distribution and flow of coolant helium are relatively complex; the flow of helium in the first loop of the pebble bed high temperature gas-cooled reactor needs to pass through the coolant flow channel composed of the pores in the graphite block with the reflective layer and the porous medium channel composed of the gaps between the core fuel balls; due to the uncertainty of the core ball flow and the characteristics of the core dispersed structure, the coolant flow path in the reactor has a certain uncertainty. And the temperature rise of helium after flowing through the core can usually reach 500℃, and the temperature of helium changes greatly during the flow process. Therefore, the temperature calculation space of helium involves the reflective layer flow channel area and the core flow channel area, and the temperature field changes dramatically; according to the structural characteristics and flow channel characteristics of the pebble bed high temperature gas-cooled reactor, it is necessary to establish a fast and accurate helium temperature calculation method. Summary of the invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the technical problem solved by the present invention is to solve the accuracy and real-time problem of helium temperature calculation in a pebble bed high temperature gas-cooled reactor under ultra-high temperature conditions.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for calculating the helium temperature of a primary circuit of a pebble bed high temperature gas-cooled reactor, comprising the following steps:

[0007] The grid control body of the pebble bed high temperature gas-cooled reactor is established to calculate the temperature of the solid components and core fuel of the pebble bed high temperature gas-cooled reactor.

[0008] The fine grid required for helium temperature calculation in pebble bed high temperature gas-cooled reactor is obtained by refining the solid temperature calculation grid control volume.

[0009] The solid temperature is assumed to vary linearly within the fine mesh of adjacent nodes.

[0010] The three-dimensional steady-state energy conservation equation of helium flow is established on the fine grid, and the equation is solved in three directions of the cylindrical geometry to obtain the helium temperature in three directions.

[0011] The energy conservation equations in three directions are combined to obtain the temperature of the node helium, and the helium temperature of all grid points is calculated point by point. The helium temperature is updated point by point based on the super relaxation method, and the calculation results are output.

[0012] As a preferred solution of the method for calculating the primary loop helium temperature of a pebble bed type high temperature gas-cooled reactor described in the present invention, wherein: the refinement on the solid temperature calculation grid control body to obtain the fine grid required for the calculation of the helium temperature of the pebble bed type high temperature gas-cooled reactor includes constructing a solid temperature linear equation in the fine grid of adjacent nodes, and the expression is:

[0013]

[0014] Among them, T solid (x) is the solid temperature at a position x away from node A, is the solid temperature at node A, is the solid temperature at node B, ι is the distance between node A and node B, and x is the distance between the node A and node B.

[0015] As a preferred solution of the method for calculating the primary loop helium temperature of a pebble bed high temperature gas-cooled reactor described in the present invention, the three-dimensional steady-state energy conservation equation of the helium flow is expressed as follows:

[0016]

[0017] Among them, c p is the heat capacity of helium, is the mass flow rate of helium, T gas is the helium temperature, λ gas is the thermal conductivity of helium, h is the heat transfer coefficient between helium and solid, S is the heat transfer area between helium and solid, T solid is the temperature of the solid;

[0018] The three-dimensional steady-state energy conservation equation for helium flow on a cylindrical geometry is expressed as:

[0019]

[0020] Where r is the radial position of the grid point, is the radial component of the helium mass flow rate, θ is the circumferential position of the grid point, is the circumferential component of the helium mass flow rate, z is the circumferential position of the grid point, is the component of helium mass flow rate in the circumferential direction.

[0021] As a preferred solution of the method for calculating the helium temperature of the first loop of a pebble bed type high temperature gas-cooled reactor described in the present invention, wherein: the equations are solved in three directions of cylindrical geometry respectively. The helium temperatures in the three directions are obtained by discretizing the steady-state energy conservation equation of the helium flow in three directions of cylindrical geometry respectively according to the characteristics of the pebble bed type high temperature gas-cooled reactor core system, and obtaining the radial energy conservation equation, the circumferential energy conservation equation, and the circumferential energy conservation equation;

[0022] The radial energy conservation equation is expressed as:

[0023]

[0024] Among them, h r is the equivalent heat transfer coefficient in the radial direction, S r is the equivalent heat transfer area in radial direction;

[0025] The circumferential energy conservation equation is expressed as:

[0026]

[0027] Among them, h θ is the equivalent heat transfer coefficient in the circumferential direction, S θ is the equivalent heat transfer area in the circumferential direction;

[0028] The axial energy conservation equation is expressed as:

[0029]

[0030] Among them, h z is the equivalent heat transfer coefficient in the axial direction, S z is the equivalent heat transfer area in the axial direction.

[0031] As a preferred solution of the method for calculating the helium temperature of the first loop of a pebble bed high temperature gas-cooled reactor described in the present invention, wherein: the energy conservation equations in three directions are combined to obtain the temperature of the node helium. The actual temperature of the helium at the current node is calculated based on the energy conservation equations combined with the temperatures in three directions. The expression is:

[0032]

[0033]

[0034] in, is the helium gas mass source at the current node, is the helium gas temperature at node B, is the energy transferred by helium through lateral heat conduction, T s is the gas inlet temperature of the helium gas mass source.

[0035] As a preferred solution of the method for calculating the primary loop helium temperature of a pebble bed high temperature gas-cooled reactor described in the present invention, the point-by-point updating of the helium temperature based on the super-relaxation method is to calculate the actual helium temperature of the node by combining energy conservation equations in different directions, and then update the helium temperature of the grid point by the super-relaxation method, and the expression is:

[0036]

[0037] in, is the updated helium temperature at node B, is the helium temperature before update at node B, and sor is the over-relaxation factor.

[0038] As a preferred solution of the method for calculating the primary loop helium temperature of a pebble bed high temperature gas-cooled reactor described in the present invention, wherein: the point-by-point updating of the helium temperature based on the super-relaxation method also includes judging whether the iterative solution of the helium temperature field converges, judging whether the stage error meets the conditions, and proceeding to the next step if converged, and continuing the iterative calculation based on the updated helium temperature field if not converged;

[0039] After updating the helium temperature of the grid points based on the super-relaxation method, the error of the iterative calculation is measured by the interpolation of the ratio of the helium temperature before and after the update and 1, which is expressed as:

[0040]

[0041] Among them, Error is the helium temperature calculation error, max is the maximum value among all grid points,

[0042] T New is the updated grid point helium temperature, T Old is the helium temperature of the grid point before updating;

[0043] Whether the helium temperature calculation has converged is determined by judging whether the helium temperature calculation error is less than the convergence limit set before the calculation. If it converges, the next step is performed. If it does not converge, the iterative calculation is continued based on the updated helium temperature field, which is expressed as:

[0044] Error≤ξ

[0045] Among them, ξ is the convergence limit set before calculation.

[0046] Another object of the present invention is to provide a primary loop helium temperature calculation system for a pebble bed high temperature gas-cooled reactor, which can solve the problems of calculation delay and insufficient accuracy of existing methods in dealing with complex flow channels and high temperature conditions through data addition and temperature prediction calculation. Real-time monitoring and prediction of the temperature change of helium in a nuclear reactor improves the operating safety and efficiency of the reactor.

[0047] To solve the above technical problems, the present invention provides the following technical solutions: a primary loop helium temperature calculation system for a pebble bed high temperature gas-cooled reactor, comprising: a grid generation module, a temperature calculation module, an energy conservation equation solving module, an iterative solution and super-relaxation update module, and an output and data processing module.

[0048] The grid generation module is used to create a three-dimensional grid control body of a pebble bed high temperature gas-cooled reactor and refine the solid temperature calculation grid.

[0049] The temperature calculation module calculates the temperature of the solid component.

[0050] The energy conservation equation solving module is based on the existing solid temperature distribution and utilizes the physical properties of helium to establish and solve the three-dimensional steady-state energy conservation equation of helium, and solves the radial, circumferential and axial directions respectively in a cylindrical coordinate system.

[0051] The iterative solution and super-relaxation update module introduces a relaxation factor, optimizes the iterative process, reduces the calculation time, and updates the helium temperature point by point.

[0052] The output and data processing module processes and outputs the calculation results.

[0053] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the method for calculating the primary loop helium temperature of a pebble bed high temperature gas-cooled reactor as described above are implemented.

[0054] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a method for calculating the primary-loop helium temperature of a pebble-bed high-temperature gas-cooled reactor as described above.

[0055] Beneficial effects of the invention: By introducing the assumption of linear temperature distribution between nodes, the invention derives a method for calculating the helium temperature of the first circuit of a pebble bed high temperature gas-cooled reactor, which can quickly and correctly calculate the helium temperature of the flow channel inside the core and the pores in the reflective layer, thereby providing an important reference for determining the operating status of the core. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0057] Figure 1An overall flow chart of a method for calculating the primary loop helium temperature of a pebble bed type high temperature gas-cooled reactor provided in the first embodiment of the present invention;

[0058] Figure 2 A schematic diagram of the assumption of linear distribution of adjacent node temperatures in a method for calculating the primary loop helium temperature of a pebble bed high temperature gas-cooled reactor provided in the first embodiment of the present invention;

[0059] Figure 3 A structural diagram of a primary loop helium temperature calculation system for a pebble bed type high temperature gas-cooled reactor provided in a second embodiment of the present invention;

[0060] Figure 4 A schematic diagram of the flow channel distribution of a primary circuit of a pebble bed type high temperature gas-cooled reactor in a method for calculating the helium temperature of a primary circuit of a pebble bed type high temperature gas-cooled reactor provided in a third embodiment of the present invention;

[0061] Figure 5 This is a diagram showing the distribution results of the primary loop helium temperature of a pebble bed type high temperature gas-cooled reactor at different core radial directions calculated in a method for calculating the primary loop helium temperature of a pebble bed type high temperature gas-cooled reactor provided in the third embodiment of the present invention. DETAILED DESCRIPTION

[0062] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0063] Example 1

[0064] Reference Figure 1-2 , which is an embodiment of the present invention, provides a method for calculating the helium temperature of a primary circuit of a pebble bed high temperature gas-cooled reactor, characterized in that:

[0065] The present invention first uses a solid temperature calculation program to calculate the temperature of solid components and core fuel of a pebble bed high temperature gas-cooled reactor; then, according to the model grid division situation, it is assumed that the solid temperatures of adjacent nodes change linearly, and the helium temperature in the direction of the node is calculated using a one-dimensional energy conservation equation; then, the energy conservation equations in different directions are combined for the node to obtain the helium temperature of the node; finally, the helium temperature of the node is updated based on the super relaxation method, and the solution is iteratively solved until the entire helium temperature field converges.

[0066] Step 1: Establish the pebble bed high temperature gas-cooled reactor grid control body according to the pebble bed high temperature gas-cooled reactor solid temperature calculation program, and obtain the temperature of the pebble bed high temperature gas-cooled reactor solid components and core fuel by calculation.

[0067] The fine grid required for the helium temperature calculation of the pebble bed high temperature gas-cooled reactor is obtained by refining the solid temperature calculation grid control volume. It is assumed that the solid temperature changes linearly in the fine grid of adjacent nodes:

[0068]

[0069] Among them, T solid (x) is the solid temperature at a position x away from node A, is the solid temperature at node A, is the solid temperature at node B, ι is the distance between node A and node B, and x is the distance between the node A and node B.

[0070] Step 2: According to the three-dimensional steady-state energy conservation equation of helium flow, the expression is:

[0071]

[0072] Among them, c p is the heat capacity of helium, is the mass flow rate of helium, T gas is the helium temperature, λ gas is the thermal conductivity of helium, h is the heat transfer coefficient between helium and solid, S is the heat transfer area between helium and solid, T solid is the temperature of the solid.

[0073] The three-dimensional steady-state energy conservation equation for helium flow based on cylindrical geometry is expressed as:

[0074]

[0075] Where r is the radial position of the grid point, is the radial component of the helium mass flow rate, θ is the circumferential position of the grid point, is the circumferential component of the helium mass flow rate, z is the circumferential position of the grid point, is the component of helium mass flow rate in the circumferential direction.

[0076] Discretizing the steady-state energy conservation equation of helium flow in three directions of cylindrical geometry, we can obtain:

[0077] The radial energy conservation equation is expressed as:

[0078]

[0079] Among them, h r is the equivalent heat transfer coefficient in the radial direction, S r is the equivalent heat transfer area in the radial direction.

[0080] The circumferential energy conservation equation is expressed as

[0081]

[0082] Among them, h θ is the equivalent heat transfer coefficient in the circumferential direction, S θ is the equivalent heat transfer area in the circumferential direction.

[0083] The axial energy conservation equation is expressed as

[0084]

[0085] Among them, h z is the equivalent heat transfer coefficient in the circumferential direction, S z is the equivalent heat transfer area in the circumferential direction.

[0086] Step 3: Reference Figure 2 , under the assumption that the solid temperature of adjacent nodes changes linearly, ignoring the heat conduction of helium and only considering the heat transfer of helium and convection, the theoretical calculation formula of helium temperature in different directions is expressed as:

[0087] Ignoring the heat conduction of helium and only considering the radial one-dimensional energy conservation equation for the heat transfer between helium and convection, it can be expressed as:

[0088]

[0089] in, is the radial helium mass flow rate, T gas,r (r) is the helium temperature at the position r from the A node, h r is the radial equivalent heat transfer coefficient between helium and solid components or core fuel, S r is the radial equivalent heat exchange area between helium and solid components or core fuel, ΔR is the radial distance between node A and node B, T soild,r (r) is the solid temperature at the position r from the A node where the helium is located.

[0090] Applying the assumption that the solid temperature between adjacent nodes changes linearly, the theoretical calculation formula for the radial helium temperature can be obtained by ignoring the heat conduction of helium and only considering the heat transfer between helium and convection:

[0091]

[0092] Among them, T u,r (r) is the difference between the helium temperature and the solid temperature at a position r away from node A.

[0093] Ignoring the heat conduction of helium and only considering the circumferential one-dimensional energy conservation equation for the heat transfer between helium and convection, it can be expressed as:

[0094]

[0095] in, is the mass flow rate of helium in the circumferential direction, T gas,θ (θ) is the helium temperature at the distance θ from the A node, h θ is the circumferential equivalent heat transfer coefficient between helium and solid components or core fuel, S θ is the circumferential equivalent heat exchange area between helium and solid components or core fuel, R is the radial position coordinate of helium, Δθ is the circumferential distance between node A and node B, T soild,θ (θ) is the solid temperature at the position θ where the helium is located away from node A.

[0096] Applying the assumption that the solid temperature between adjacent nodes changes linearly, the theoretical calculation formula for the radial helium temperature can be obtained by ignoring the heat conduction of helium and only considering the heat transfer between helium and convection:

[0097]

[0098] Among them, T u,θ (θ) is the difference between the helium temperature and the solid temperature at a position θ away from node A;

[0099] Ignoring the heat conduction of helium and only considering the axial one-dimensional energy conservation equation for the heat transfer between helium and convection, it can be expressed as:

[0100]

[0101] in, is the mass flow rate of axial helium, T gas,z (r) is the helium temperature at the position z from the A node, h z is the circumferential equivalent heat transfer coefficient between helium and solid components or core fuel, S z is the circumferential equivalent heat exchange area between helium and solid components or core fuel, ΔZ is the circumferential distance between node A and node B, T soild,z (z) is the solid temperature at the position z from the A node where the helium is located.

[0102] Applying the assumption that the solid temperature between adjacent nodes changes linearly, the theoretical calculation formula for the radial helium temperature can be obtained by ignoring the heat conduction of helium and only considering the heat transfer between helium and convection:

[0103]

[0104]

[0105] Among them, T u,z(z) is the difference between the helium temperature and the solid temperature at a distance z from node A.

[0106] Step 4: After calculating the temperature of the helium in different directions of the node using the theoretical calculation formula of the helium temperature in different directions, the temperature in the three directions is combined according to the law of energy conservation to obtain the calculation formula for calculating the actual temperature of the helium at the node, which is expressed as:

[0107]

[0108]

[0109] in, is the helium gas mass source at this node, is the helium gas temperature at node B, is the energy transferred by helium through lateral heat conduction, T s is the gas inlet temperature of the helium gas mass source.

[0110] After calculating the actual helium temperature of the node by combining the energy conservation equations in different directions, the helium temperature of the grid point is updated by the super relaxation method, which is expressed as:

[0111]

[0112] in, is the updated helium temperature at node B, is the helium temperature before update at node B, and sor is the over-relaxation factor.

[0113] Step 5: After updating the helium temperature of the grid points by the super-relaxation method, the error of the iterative calculation is measured by the interpolation of the ratio of the helium temperature before and after the update with 1, expressed as:

[0114]

[0115] Where Error is the helium temperature calculation error, max is the maximum value among all grid points, T New is the updated grid point helium temperature, T Old is the helium temperature at the grid point before updating.

[0116] Whether the helium temperature calculation has converged is determined by judging whether the helium temperature calculation error is less than the convergence limit set before the calculation. If it converges, the next step is performed. If it does not converge, the iterative calculation is continued based on the updated helium temperature field, which is expressed as:

[0117] Error≤ξ (20)

[0118] Among them, ξ is the convergence limit set before calculation.

[0119] Example 2

[0120] Reference Figure 3 , which is an embodiment of the present invention, provides a system for calculating the primary loop helium temperature of a pebble bed type high temperature gas-cooled reactor, characterized in that it includes a grid generation module, a temperature calculation module, an energy conservation equation solving module, an iterative solution and super relaxation update module, and an output and data processing module.

[0121] The grid generation module is used to create a three-dimensional grid control volume for the pebble bed high temperature gas-cooled reactor and refine the solid temperature calculation grid.

[0122] The temperature calculation module is used to calculate the temperature of solid components.

[0123] The energy conservation equation solving module is based on the existing solid temperature distribution and uses the physical properties of helium to establish and solve the three-dimensional steady-state energy conservation equation of helium, and solves the radial, circumferential and axial directions respectively in the cylindrical coordinate system.

[0124] The iterative solution and super-relaxation update module introduces a relaxation factor, optimizes the iterative process, reduces the calculation time, and updates the helium temperature point by point.

[0125] The output and data processing module processes and outputs the calculation results.

[0126] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program code.

[0127] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0128] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0129] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiment, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0130] Example 3

[0131] Reference Figure 4-5 This is another embodiment of the present invention. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments. This embodiment experiments the existing traditional method and the method of this embodiment respectively.

[0132] In order to verify the feasibility of the method of the present invention, a modified model of the high temperature gas-cooled reactor nuclear power plant demonstration project HTR-PM was used for calculation verification. Figure 4As shown. Based on the temperature distribution of the core fuel and internal components of the HTR-PM under the full power 250MW operating condition calculated by the solid temperature calculation program, the temperature distribution of the helium in the flow channel with an inlet helium temperature of 250°C and an inlet flow rate of 96kg / s is calculated; Figure 5 The radial temperature distribution of helium at different axial heights of the core is shown. It can be seen that the helium inlet temperature is 250°C. As the helium coolant passes through the core from top to bottom, it is continuously heated. The temperature of the helium coolant gradually increases from top to bottom along the core axis. As the helium goes deeper, the temperature of the helium coolant begins to be unevenly distributed along the radial direction of the core. The temperature in the middle of the core gradually begins to be higher than that outside the core, reaching a maximum of 804°C at the bottom of the core. Table 1 further compares the CFD calculation results and program calculation results under the same calculation conditions. It can be seen that the average cloud of helium outlet calculated by this method is in good agreement with the average helium outlet temperature calculated by CFD software for the core model of pebble bed high temperature gas-cooled reactor. The comparison results show that the helium temperature calculation model of the components of this method can be used for the calculation of helium temperature in the first circuit of pebble bed high temperature gas-cooled reactor.

[0133] Table 1 Comparison of calculation results

[0134] parameter CFD This method Relative error Total reactor power / MW 250 250 / Core power density / (MW / m3) 3.22 3.22 Coolant mass flow rate (kg / s) 96 96 / Average outlet temperature / ℃ 748.3 735.3 1.7％

[0135] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for calculating the primary loop helium temperature of a pebble bed high temperature gas-cooled reactor, characterized in that: include: Establish the pebble bed high temperature gas-cooled reactor grid control body and calculate the temperature of the pebble bed high temperature gas-cooled reactor solid components and core fuel; The fine grid required for helium temperature calculation in pebble bed high temperature gas-cooled reactor is obtained by refining the solid temperature calculation grid control volume; The solid temperature is assumed to vary linearly within the fine mesh of adjacent nodes; The three-dimensional steady-state energy conservation equation of helium flow is established on a fine grid, and the equation is solved in three directions of the cylindrical geometry to obtain the helium temperature in the three directions; The energy conservation equations in three directions are combined to obtain the temperature of the node helium, and the helium temperature of all grid points is calculated point by point. The helium temperature is updated point by point based on the super relaxation method, and the calculation results are output.

2. A method for calculating the primary loop helium temperature of a pebble bed type high temperature gas-cooled reactor according to claim 1, characterized in that: The refinement on the solid temperature calculation grid control body to obtain the fine grid required for the helium temperature calculation of the pebble bed high temperature gas-cooled reactor includes constructing a solid temperature linear equation in the fine grid of adjacent nodes, and the expression is: Among them, T solid (x) is the solid temperature at a position x away from node A, is the solid temperature at node A, is the solid temperature at node B, ι is the distance between node A and node B, and x is the distance between the node A and node B.

3. A method for calculating the primary loop helium temperature of a pebble bed type high temperature gas-cooled reactor as claimed in claim 2, characterized in that: The three-dimensional steady-state energy conservation equation of the helium flow is expressed as: Among them, c p is the heat capacity of helium, is the mass flow rate of helium, T gas is the helium temperature, λ gas is the thermal conductivity of helium, h is the heat transfer coefficient between helium and solid, S is the heat transfer area between helium and solid, T solid is the temperature of the solid; The three-dimensional steady-state energy conservation equation for helium flow on a cylindrical geometry is expressed as: Where r is the radial position of the grid point, is the radial component of the helium mass flow rate, θ is the circumferential position of the grid point, is the circumferential component of the helium mass flow rate, z is the circumferential position of the grid point, is the component of helium mass flow rate in the circumferential direction.

4. A method for calculating the primary loop helium temperature of a pebble bed type high temperature gas-cooled reactor as claimed in claim 3, characterized in that: The equations are solved in three directions of cylindrical geometry respectively. The helium temperature in the three directions is based on the characteristics of the core system of the pebble bed high temperature gas-cooled reactor. The steady-state energy conservation equation of the helium flow is discretized in three directions of cylindrical geometry respectively to obtain the radial energy conservation equation, the circumferential energy conservation equation, and the circumferential energy conservation equation; The radial energy conservation equation is expressed as: Among them, h r is the equivalent heat transfer coefficient in the radial direction, S r is the equivalent heat transfer area in radial direction; The circumferential energy conservation equation is expressed as: Among them, h θ is the equivalent heat transfer coefficient in the circumferential direction, S θ is the equivalent heat transfer area in the circumferential direction; The axial energy conservation equation is expressed as: Among them, h z is the equivalent heat transfer coefficient in the axial direction, S z is the equivalent heat transfer area in the axial direction.

5. A method for calculating the primary loop helium temperature of a pebble bed type high temperature gas-cooled reactor according to claim 4, characterized in that: The energy conservation equations in three directions are combined to obtain the temperature of the node helium. The actual temperature of the current node helium is calculated based on the energy conservation equations combining the temperatures in three directions. The expression is: in, is the helium gas mass source at the current node, is the helium gas temperature at node B, is the energy transferred by helium through lateral heat conduction, T s is the gas inlet temperature of the helium gas mass source.

6. A method for calculating the primary loop helium temperature of a pebble bed type high temperature gas-cooled reactor according to claim 5, characterized in that: The point-by-point update of the helium temperature based on the super-relaxation method is to calculate the actual helium temperature of the node by combining the energy conservation equations in different directions, and then update the helium temperature of the grid point by the super-relaxation method. The expression is: in, is the updated helium temperature at node B, is the helium temperature before update at node B, and sor is the over-relaxation factor.

7. A method for calculating the primary loop helium temperature of a pebble bed type high temperature gas-cooled reactor according to claim 6, characterized in that: The updating of the helium temperature point by point based on the super-relaxation method also includes judging whether the iterative solution of the helium temperature field converges, judging whether the stage error meets the conditions, and proceeding to the next step if converged, and continuing the iterative calculation based on the updated helium temperature field if not converged; After updating the helium temperature of the grid points based on the super-relaxation method, the error of the iterative calculation is measured by the interpolation of the ratio of the helium temperature before and after the update and 1, which is expressed as: Among them, Error is the helium temperature calculation error, max is the maximum value among all grid points, T New is the updated grid point helium temperature, T Old is the helium temperature of the grid point before updating; Whether the helium temperature calculation has converged is determined by judging whether the helium temperature calculation error is less than the convergence limit set before the calculation. If it converges, the next step is performed. If it does not converge, the iterative calculation is continued based on the updated helium temperature field, which is expressed as: Error≤ξ Among them, ξ is the convergence limit set before calculation.

8. A system using the method for calculating the primary loop helium temperature of a pebble bed high temperature gas-cooled reactor as claimed in any one of claims 1 to 7, characterized in that: It includes a grid generation module, a temperature calculation module, an energy conservation equation solution module, an iterative solution and super relaxation update module, and an output and data processing module; The grid generation module is used to create a three-dimensional grid control body of the pebble bed high temperature gas-cooled reactor and refine the solid temperature calculation grid; The temperature calculation module is used to calculate the temperature of the solid component; The energy conservation equation solving module is based on the existing solid temperature distribution and uses the physical properties of helium to establish and solve the three-dimensional steady-state energy conservation equation of helium, and solves the radial, circumferential and axial directions respectively in a cylindrical coordinate system; The iterative solution and super-relaxation update module introduces a relaxation factor to optimize the iterative process, reduce the calculation time, and update the helium temperature point by point; The output and data processing module processes and outputs the calculation results.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of a method for calculating the primary loop helium temperature of a pebble bed high temperature gas-cooled reactor according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of a method for calculating the primary-loop helium temperature of a pebble-bed high-temperature gas-cooled reactor as described in any one of claims 1 to 7 are implemented.

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