Nuclear reactor thermal hydraulic acceleration calculation method based on modular parallel idea

Abstract

The invention discloses a nuclear reactor thermal hydraulic acceleration calculation method based on a modular parallel idea. The method comprises the following specific steps: 1, modeling each subsystem of a nuclear reactor system based on a sorted nuclear reactor subsystem list; 2, establishing a coupling boundary on the basis of modeling the subsystems respectively; 3, carrying out initial state parallel calculation according to a set initial boundary condition; 4, establishing a thermal hydraulic boundary information transmission strategy for the subsystem model; 5, advancing the time step, and using a calculation result in the step 4 as an initial thermal hydraulic parameter for calculation of the next time step; and 6, repeating the steps 4 and 5 until all-time parallel computing is completed. According to the method disclosed by the invention, aiming at the thermal hydraulic calculation process of the nuclear reactor, the thermal hydraulic calculation speed of the nuclear reactor system is improved while the thermal hydraulic parameters are accurately calculated.

Description

Technical Field

[0001] The invention relates to the technical field of thermal hydraulic calculation of nuclear reactor system, and in particular to a thermal hydraulic acceleration calculation method of a nuclear reactor based on modular parallel idea. Background Art

[0002] In the design of nuclear power systems, thermal-hydraulic analysis programs for nuclear reactor systems play an important role. Thermal-hydraulic analysis programs can realize rapid iterative analysis and optimization and upgrading of the debugging process plan and test process plan of the test bench through simulation, reduce the construction cost and maintenance cost of physical tests, shorten the design cycle of nuclear power systems, and improve the construction efficiency and quality of physical tests. In view of the development direction of "clean" energy in the world, nuclear energy has become increasingly important, especially in terms of energy security and environmental protection. Therefore, the current demand for thermal-hydraulic analysis of nuclear power systems is also growing. At present, due to the high degree of integration of actual nuclear power systems and the complex actual working environment of system equipment, when using thermal-hydraulic analysis programs to simulate and calculate large nuclear reactor systems, the huge and complex calculation model will significantly reduce the speed of thermal-hydraulic calculations. When calculating transient conditions, the convergence of the model is very poor, which makes it easy to fall into the situation of "dead calculation" and waste computing resources in the thermal-hydraulic calculation process of large nuclear reactors. In summary, when performing thermal-hydraulic calculations for nuclear reactor systems, it is necessary to conduct research on accelerated calculation methods for thermal-hydraulics of nuclear reactor systems. It is expected that this method will be able to provide effective technical support for thermal-hydraulic calculations of large nuclear reactor systems, save computing resource costs, and reduce thermal-hydraulic calculation time. Summary of the invention

[0003] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a nuclear reactor thermal-hydraulic accelerated calculation method based on the modular parallel idea, which can perform thermal-hydraulic calculations based on the modular parallel idea, thereby obtaining accurate thermal-hydraulic parameters in the nuclear reactor system and improving the speed of thermal-hydraulic calculations of the nuclear reactor system.

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

[0005] The thermal hydraulic acceleration calculation method of a nuclear reactor based on modular parallel thinking includes the following steps:

[0006] Step 1: Establish a calculation model for the nuclear reactor subsystem; sort out the list of nuclear reactor subsystems, and model the nuclear reactor subsystems that need to be thermal-hydraulic calculated separately;

[0007] For nuclear reactors and nuclear power plants, the list of nuclear reactor subsystems includes the primary circuit system, the secondary circuit system, the passive injection system and the automatic pressure reduction system.

[0008] Step 2: Establish coupling boundaries: Based on the nuclear reactor subsystem model established in step 1, establish coupling boundaries at the connection points corresponding to the subsystems connected in the overall system;

[0009] For the primary loop system, the secondary side steam drum of the steam generator of the secondary loop system exchanges heat with the inverted U-shaped tube of the steam generator of the primary loop system. The steam drum area of ​​the secondary loop system is added and modeled as a coupling boundary on the primary loop system model, and a thermal-hydraulic information transmission interface for the fluid in the connection part between the primary loop system model and the secondary loop system model is established; the DVI injection pipeline installation inlet of the passive injection system is connected to the core descending section of the pressure vessel of the primary loop system, and the pressure balance pipeline inlet on the passive injection system is connected to the cold section of the main pipeline of the primary loop system. The DVI injection pipeline installation inlet area and the pressure balance pipeline inlet area on the system are added and modeled as coupling boundaries on the primary system model, and the thermal hydraulic information transmission interface of the fluid in the connection part with the passive injection system model in the primary system model is established; the top outlet pipeline of the pressurizer of the automatic pressure reduction system is connected to the top of the pressurizer of the primary system, and the top outlet pipeline area of ​​the pressurizer on the automatic pressure reduction system is added and modeled as a coupling boundary on the primary system model, and the thermal hydraulic information transmission interface of the fluid in the connection part with the automatic pressure reduction system model in the primary system model is established;

[0010] For the secondary loop system, the inverted U-shaped tube of the steam generator of the primary loop system exchanges heat with the steam drum on the secondary side of the steam generator of the secondary loop system. The inverted U-shaped tube area of ​​the steam generator of the primary loop system is added and modeled as a coupling boundary on the secondary loop system model, and a thermal hydraulic information transmission interface for the fluid in the connection part between the secondary loop system model and the primary loop system model is established.

[0011] For the passive safety injection system, the core descending section of the pressure vessel of the primary loop system is connected to the DVI safety injection pipeline safety inlet of the passive safety injection system, and the main pipeline cold section of the primary loop system is connected to the pressure balance pipeline inlet on the passive safety injection system. The core descending section area of ​​the pressure vessel and the main pipeline cold section area on the primary loop system are added and modeled as coupling boundaries on the passive safety injection system model, and a thermal hydraulic information transmission interface for the fluid in the connection part between the passive safety injection system model and the primary loop system model is established;

[0012] For the automatic pressure reduction system, the top of the regulator of the primary circuit system is connected to the outlet pipeline of the top of the regulator of the automatic pressure reduction system. The top area of ​​the regulator of the primary circuit system is added and modeled as a coupling boundary on the automatic pressure reduction system model, and a thermal hydraulic information transmission interface of the fluid in the connection part between the automatic pressure reduction system model and the primary circuit system model is established;

[0013] Step 3: Parallel calculation of initial state; setting initial boundary conditions for each nuclear reactor subsystem model according to the operating conditions to be carried out, including steady-state operating conditions and accident transient conditions; then parallel calculation is carried out for each separated nuclear reactor subsystem model to obtain the initial thermal-hydraulic parameters of each nuclear reactor subsystem model at the start time T0 of the operating condition calculated according to the initial boundary conditions;

[0014] Step 4: Thermal-hydraulic boundary information transmission of nuclear reactor subsystem model: Establish an information transmission strategy between systems for thermal-hydraulic calculation of nuclear reactor subsystem, the specific contents are as follows:

[0015] The thermal-hydraulic calculation results of the subsystem model are used as the coupling boundary conditions corresponding to the subsystem model connected to it for simulation calculation; the thermal-hydraulic parallel calculation is performed on each subsystem model, and the working condition is advanced to the nth time step Tn. The fluid physical property parameters adjacent to the coupling boundary in the subsystem model obtained by the thermal-hydraulic calculation are used as the coupling boundary conditions corresponding to the subsystem model connected to the subsystem model, where n = 0, 1, 2, 3, ..., N, and the physical property parameters include: pressure, temperature, cavitation fraction, density, and flow rate;

[0016] Step 5: Time step advancement; use the calculation results in step 4 as the initial thermal-hydraulic parameters for the next time step; use the thermal-hydraulic parameter results of each subsystem model calculated at time Tn as the thermal-hydraulic initial conditions at time Tn+1;

[0017] Step 6: Repeat steps 4 and 5 until the full-time parallel calculation is completed to realize the full-time nuclear reactor thermal hydraulic calculation process.

[0018] Preferably, the primary loop system model includes a pressure vessel, a hot section of the main pipeline, a cold section of the main pipeline, a transition section of the main pipeline, a main pump, a pressurizer, an inverted U-shaped tube of the steam generator, a cold tube end of the lower water chamber of the steam generator and a hot tube end of the lower water chamber of the steam generator, wherein the pressure vessel model in the primary loop system model includes a core descending section, a lower chamber, a lower head, a core flow area, an upper chamber and an upper head; the secondary loop system model includes a steam drum on the secondary side of the steam generator, a steam-water separator, a feed water descending ring pipe, a feed water pipe and a feed water boundary, a steam chamber, a steam outlet and a steam discharge boundary; the passive injection system model includes a pressure balance pipeline, a full-pressure make-up water tank, an ACC injection tank, an outer shell pressure water tank, a DVI injection pipeline, a full-pressure injection pipeline, an ACC injection pipeline, a low-pressure injection pipeline and a valve; the automatic pressure reduction system model includes a pressurizer top outlet pipeline, a pressure reduction valve and its corresponding pressure reduction pipeline, and a pressure reduction discharge outlet boundary.

[0019] Preferably, in step 4, for the primary system model, the calculated results of the physical property parameters of the fluid in the inverted U-tube area of ​​the steam generator in the primary system model will be used as the inverted U-tube coupling boundary condition in the secondary system model, the calculated results of the physical property parameters of the fluid in the core descending section area of ​​the pressure vessel in the primary system model will be used as the core descending section coupling boundary condition in the passive injection system model, the calculated results of the physical property parameters of the fluid in the main pipeline cold section area in the primary system model will be used as the main pipeline cold section coupling boundary condition in the passive injection system model, and the calculated results of the physical property parameters of the fluid in the top area of ​​the pressurizer in the primary system model will be used as the pressurizer top area coupling boundary condition in the automatic depressurization system model; the thermal-hydraulic parameters calculated by the primary system model are accurately transferred to the secondary system model, the passive injection system model, and the automatic depressurization system model to achieve cross-model coupling.

[0020] For the secondary system model, the calculation results of the physical parameters of the fluid in the steam drum area in the secondary system model will be used as the steam drum coupling boundary conditions in the primary system model; the thermal-hydraulic parameters calculated by the secondary system model will be accurately transferred to the primary system model to achieve cross-model coupling.

[0021] For the passive safety injection system model, the calculation results of the physical parameters of the fluid in the DVI safety injection pipeline installation inlet area in the passive safety injection system model will be used as the DVI safety injection pipeline installation inlet coupling boundary conditions in the primary system model, and the calculation results of the physical parameters of the fluid in the pressure balance pipeline inlet area in the passive safety injection system model will be used as the pressure balance pipeline inlet coupling boundary conditions in the primary system model; the thermal-hydraulic parameters calculated by the passive safety injection system model will be accurately transferred to the primary system model to realize cross-model coupling.

[0022] For the automatic pressure reduction system model, the calculation results of the physical parameters of the fluid in the top outlet pipeline area of ​​the regulator in the automatic pressure reduction system model will be used as the coupling boundary conditions of the top outlet pipeline area of ​​the regulator in the primary system model; the thermal-hydraulic parameters calculated by the automatic pressure reduction system model will be accurately transferred to the primary system model to realize cross-model coupling.

[0023] Through steps 1 to 6, the thermal-hydraulic calculation process of the nuclear reactor system based on the modular parallel idea is completed. Based on the modular parallel idea, a large nuclear reactor system model is split into multiple subsystem models for parallel calculation, which simplifies the calculation model. The accurate calculation of the thermal-hydraulic parameters of the nuclear reactor system is completed by establishing coupling boundaries between the subsystem models. The thermal-hydraulic calculation process of the nuclear reactor is optimized through the above method, and the speed of the thermal-hydraulic calculation of the nuclear reactor is improved.

[0024] Compared with the existing technology, the present invention has the following advantages:

[0025] The method of the present invention performs thermal-hydraulic calculations of nuclear reactor systems based on a modular parallel approach, and has significant advantages for the thermal-hydraulic calculation process of large nuclear reactor systems. The method of the present invention adopts a method of separate subsystem modeling, parallel calculation, and mutual coupling, which achieves accurate calculation of thermal-hydraulic parameters of the nuclear reactor system while reducing the cost of computing resources and improving the speed of thermal-hydraulic calculations of the nuclear reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The figure is a flow chart of the method of the present invention.

[0027] Figure 2 Schematic diagram of establishing the coupling boundary between the primary and secondary systems.

[0028] Figure 3 Schematic diagram of establishing coupling boundaries for the primary system, passive injection system, and automatic pressure reduction system DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings in the examples of the present invention.

[0030] The technical solution flow chart of the present invention is as follows Figure 1 As shown in the figure, the thermal hydraulic acceleration calculation method of nuclear reactor based on modular parallel thinking has the following steps:

[0031] Step 1: Establish a calculation model for the nuclear reactor subsystem; sort out the list of nuclear reactor subsystems, and model the nuclear reactor subsystems that need to be thermal-hydraulic calculated separately;

[0032] For nuclear reactor nuclear power plants, the list of nuclear reactor subsystems sorted out includes the primary loop system, the secondary loop system, the passive injection system, and the automatic pressure reduction system. The primary loop system model includes the pressure vessel, the hot section of the main pipeline, the cold section of the main pipeline, the transition section of the main pipeline, the main pump, the stabilizer, the steam generator inverted U-shaped tube, the cold pipe end of the lower water chamber of the steam generator, and the hot pipe end of the lower water chamber of the steam generator. The pressure vessel model in the primary loop system model includes the core descending section, the lower chamber, the lower head, the core flow area, the upper chamber, and the upper head. ; The secondary loop system model includes the steam drum on the secondary side of the steam generator, the steam-water separator, the feedwater downpipe, the feedwater pipe and the feedwater boundary, the steam chamber, the steam outlet and the steam discharge boundary; the passive injection system model includes the pressure balance pipeline, the full-pressure make-up water tank, the ACC injection tank, the outer shell pressure water tank, the DVI injection pipeline, the full-pressure injection pipeline, the ACC injection pipeline, the low-pressure injection pipeline, and the valve; the automatic pressure reduction system model includes the top outlet pipeline of the regulator, the pressure reduction valve and its corresponding pressure reduction pipeline, and the pressure reduction discharge outlet boundary;

[0033] Step 2: Establish coupling boundaries; Based on the nuclear reactor subsystem model established in step 1, establish coupling boundaries at the connection points corresponding to the subsystems connected in the overall system; The overall system is split into subsystems for modeling coupling boundaries. Figure 2 and Figure 3 As shown, Figure 2 A schematic diagram showing the establishment of the coupling boundary between the primary and secondary loop systems is shown. Figure 3 The schematic diagram of establishing coupling boundary between primary loop system, passive injection system and automatic pressure reduction system is shown;

[0034] like Figure 2 As shown in , for the primary loop system, the secondary side steam drum of the steam generator of the secondary loop system exchanges heat with the inverted U-shaped tube of the steam generator of the primary loop system, and the steam drum area of ​​the secondary loop system is added and modeled as a coupling boundary on the primary loop system model; Figure 3 As shown, the DVI injection pipeline installation inlet of the passive injection system is connected to the pressure vessel core descending section of the primary system, the pressure balance pipeline inlet on the passive injection system is connected to the cold section of the primary system main pipeline, and the DVI injection pipeline installation inlet area and the pressure balance pipeline inlet area on the passive injection system are added and modeled as coupling boundaries on the primary system model; the pressurizer top outlet pipeline of the automatic depressurization system is connected to the pressurizer top of the primary system, and the pressurizer top outlet pipeline area on the automatic depressurization system is added and modeled as a coupling boundary on the primary system model;

[0035] For the secondary circuit system, the inverted U-shaped tube of the steam generator of the primary circuit system exchanges heat with the secondary side steam drum of the steam generator of the secondary circuit system. The inverted U-shaped tube area of ​​the steam generator of the primary circuit system is added and modeled as a coupling boundary on the secondary circuit system model.

[0036] For the passive injection system, the pressure vessel core descending section of the primary system is connected to the DVI injection pipeline safety inlet of the passive injection system, and the main pipeline cold section of the primary system is connected to the pressure balance pipeline inlet on the passive injection system. The pressure vessel core descending section area and the main pipeline cold section area on the primary system are added and modeled as coupling boundaries on the passive injection system model.

[0037] For the automatic pressure reduction system, the top of the regulator of the primary circuit system is connected to the outlet pipeline of the top of the regulator of the automatic pressure reduction system, and the top area of ​​the regulator of the primary circuit system is added and modeled as a coupling boundary on the automatic pressure reduction system model;

[0038] Step 3: Parallel calculation of initial state; setting initial boundary conditions for each nuclear reactor subsystem model according to the operating conditions to be carried out, including steady-state operating conditions and accident transient conditions; then parallel calculation is carried out for each separated nuclear reactor subsystem model to obtain the initial thermal-hydraulic parameters of each nuclear reactor subsystem model at the start time T0 of the operating condition calculated according to the initial boundary conditions;

[0039] Step 4: Thermal-hydraulic boundary information transmission of nuclear reactor subsystem model: Establish information transmission strategy between subsystems for thermal-hydraulic calculation of nuclear reactor subsystem, the specific contents are as follows:

[0040] The thermal-hydraulic calculation results of the subsystem model are used as the coupling boundary conditions corresponding to the subsystem model connected to it for simulation calculation; the thermal-hydraulic parallel calculation is performed on each subsystem model, and the working condition is advanced to the nth time step Tn. The fluid physical property parameters adjacent to the coupling boundary in the subsystem model obtained by the thermal-hydraulic calculation are used as the coupling boundary conditions corresponding to the subsystem model connected to the subsystem model, where n = 0, 1, 2, 3, ..., N, and the physical property parameters include: pressure, temperature, cavitation fraction, density, and flow rate;

[0041] For the primary loop system model, the calculation results of the physical property parameters of the fluid in the inverted U-tube area of ​​the steam generator in the primary loop system model will be used as the inverted U-tube coupling boundary condition in the secondary loop system model, the calculation results of the physical property parameters of the fluid in the core descending section area of ​​the pressure vessel in the primary loop system model will be used as the core descending section coupling boundary condition in the passive injection system model, the calculation results of the physical property parameters of the fluid in the main pipeline cold section area in the primary loop system model will be used as the main pipeline cold section coupling boundary condition in the passive injection system model, and the calculation results of the physical property parameters of the fluid in the top area of ​​the pressurizer in the primary loop system model will be used as the pressurizer top area coupling boundary condition in the automatic depressurization system model;

[0042] For the secondary loop system model, the calculation results of the physical parameters of the fluid in the steam drum area in the secondary loop system model will be used as the steam drum coupling boundary conditions in the primary loop system model;

[0043] For the passive safety injection system model, the calculation results of the physical parameters of the fluid in the DVI safety injection pipeline installation inlet area in the passive safety injection system model will be used as the DVI safety injection pipeline installation inlet coupling boundary conditions in the primary loop system model, and the calculation results of the physical parameters of the fluid in the pressure balance pipeline inlet area in the passive safety injection system model will be used as the pressure balance pipeline inlet coupling boundary conditions in the primary loop system model;

[0044] For the automatic depressurization system model, the calculation results of the physical parameters of the fluid in the outlet pipeline area at the top of the pressurizer in the automatic depressurization system model will be used as the coupling boundary conditions of the outlet pipeline area at the top of the pressurizer in the primary loop system model;

[0045] Step 5: Time step advancement; use the calculation results in step 4 as the initial thermal-hydraulic parameters for the next time step; use the thermal-hydraulic parameter results of each subsystem model calculated at time Tn as the thermal-hydraulic initial conditions at time Tn+1;

[0046] Step 6: Repeat steps 4 and 5 until the full-time parallel calculation is completed, thus realizing the full-time nuclear reactor thermal hydraulic calculation process;

[0047] Through step 1, each subsystem of the nuclear reactor system is modeled separately; through step 2, coupling boundaries between subsystem models are established; through step 3, preliminary thermal-hydraulic parallel calculations of each subsystem model are completed according to initial boundary conditions; through step 4, information transmission of thermal-hydraulic physical property parameters of coupling boundaries is completed, coupling between subsystem models is realized and preparation for the next parallel calculation is carried out; through step 5, time step advancement is performed; through step 6, parallel calculations for the entire period are completed to obtain thermal-hydraulic calculation results of the nuclear reactor system for the entire period; in combination with the above steps, a large nuclear reactor system model is split into multiple subsystem models for parallel calculation based on the idea of ​​modular parallelism, which simplifies the calculation model, and accurate calculations of thermal-hydraulic parameters of the nuclear reactor system are completed by establishing coupling boundaries between subsystem models. The above method optimizes the thermal-hydraulic calculation process of the nuclear reactor and improves the speed of thermal-hydraulic calculation of the nuclear reactor.

Claims

1. A thermal hydraulic acceleration calculation method for a nuclear reactor based on modular parallelism, characterized by: The steps include: Step 1: Establish a calculation model for the nuclear reactor subsystem; sort out the list of nuclear reactor subsystems, and model the nuclear reactor subsystems that need to be thermal-hydraulic calculated separately; For nuclear reactors and nuclear power plants, the list of nuclear reactor subsystems includes the primary circuit system, the secondary circuit system, the passive injection system and the automatic pressure reduction system. Step 2: Establish coupling boundaries: Based on the nuclear reactor subsystem model established in step 1, establish coupling boundaries at the connection points corresponding to the subsystems connected in the overall system; For the primary loop system, the steam drum on the secondary side of the steam generator of the secondary loop system exchanges heat with the inverted U-shaped tube of the steam generator of the primary loop system, and the steam drum area of ​​the secondary loop system is added and modeled as a coupling boundary on the primary loop system model; the DVI injection pipeline installation inlet of the passive injection system is connected to the pressure vessel core descending section of the primary loop system, and the pressure balance pipeline inlet on the passive injection system is connected to the cold section of the main pipeline of the primary loop system, and the DVI injection pipeline installation inlet area and the pressure balance pipeline inlet area on the passive injection system are added and modeled as coupling boundaries on the primary loop system model; the top outlet pipeline of the pressurizer of the automatic depressurization system is connected to the top of the pressurizer of the primary loop system, and the top outlet pipeline area of ​​the pressurizer on the automatic depressurization system is added and modeled as a coupling boundary on the primary loop system model; For the secondary circuit system, the inverted U-shaped tube of the steam generator of the primary circuit system exchanges heat with the secondary side steam drum of the steam generator of the secondary circuit system. The inverted U-shaped tube area of ​​the steam generator of the primary circuit system is added and modeled as a coupling boundary on the secondary circuit system model. For the passive injection system, the pressure vessel core descending section of the primary system is connected to the DVI injection pipeline safety inlet of the passive injection system, and the main pipeline cold section of the primary system is connected to the pressure balance pipeline inlet on the passive injection system. The pressure vessel core descending section area and the main pipeline cold section area on the primary system are added and modeled as coupling boundaries on the passive injection system model. For the automatic pressure reduction system, the top of the regulator of the primary circuit system is connected to the outlet pipeline of the top of the regulator of the automatic pressure reduction system, and the top area of ​​the regulator of the primary circuit system is added and modeled as a coupling boundary on the automatic pressure reduction system model; Step 3: Parallel calculation of initial state; setting initial boundary conditions for each nuclear reactor subsystem model according to the operating conditions to be carried out, including steady-state operating conditions and accident transient conditions; then parallel calculation is carried out for each separated nuclear reactor subsystem model to obtain the initial thermal-hydraulic parameters of each nuclear reactor subsystem model at the start time T0 of the operating condition calculated according to the initial boundary conditions; Step 4: Thermal-hydraulic boundary information transmission of nuclear reactor subsystem model: Establish an information transmission strategy between systems for thermal-hydraulic calculation of nuclear reactor subsystem, the specific contents are as follows: The thermal-hydraulic calculation results of the subsystem model are used as the coupling boundary conditions corresponding to the subsystem model connected to it for simulation calculation; the thermal-hydraulic parallel calculation is performed on each subsystem model, and the working condition is advanced to the nth time step Tn. The fluid physical property parameters adjacent to the coupling boundary in the subsystem model obtained by the thermal-hydraulic calculation are used as the coupling boundary conditions corresponding to the subsystem model connected to the subsystem model, where n = 0, 1, 2, 3, ..., N, and the physical property parameters include: pressure, temperature, cavitation fraction, density, and flow rate; Step 5: Time step advancement; use the calculation results in step 4 as the initial thermal-hydraulic parameters for the next time step; use the thermal-hydraulic parameter results of each subsystem model calculated at time Tn as the thermal-hydraulic initial conditions at time Tn+1; Step 6: Repeat steps 4 and 5 until the full-time parallel calculation is completed to realize the full-time nuclear reactor thermal hydraulic calculation process.

2. The method for calculating thermal hydraulic acceleration of a nuclear reactor based on modular parallelism according to claim 1, characterized in that: The primary loop system model includes a pressure vessel, a hot section of a main pipeline, a cold section of a main pipeline, a transition section of a main pipeline, a main pump, a pressurizer, an inverted U-shaped tube of a steam generator, a cold tube end of a lower water chamber of a steam generator, and a hot tube end of a lower water chamber of a steam generator, wherein the pressure vessel model in the primary loop system model includes a core descending section, a lower chamber, a lower head, a core flow area, an upper chamber, and an upper head; the secondary loop system model includes a steam drum on the secondary side of a steam generator, a steam-water separator, a feedwater descending ring pipe, a feedwater pipe and a feedwater boundary, a steam chamber, a steam outlet, and a steam discharge boundary; the passive injection system model includes a pressure balance pipeline, a full-pressure make-up water tank, an ACC injection tank, an outer shell pressure water tank, a DVI injection pipeline, a full-pressure injection pipeline, an ACC injection pipeline, a low-pressure injection pipeline, and a valve; the automatic pressure reduction system model includes a pressurizer top outlet pipeline, a pressure reduction valve and its corresponding pressure reduction pipeline, and a pressure reduction discharge outlet boundary.

3. The method for calculating thermal hydraulic acceleration of a nuclear reactor based on modular parallelism according to claim 1, characterized in that: In step 4, for the primary system model, the calculation results of the physical property parameters of the fluid in the inverted U-tube area of ​​the steam generator in the primary system model will be used as the inverted U-tube coupling boundary condition in the secondary system model, the calculation results of the physical property parameters of the fluid in the core descending section area of ​​the pressure vessel in the primary system model will be used as the core descending section coupling boundary condition in the passive injection system model, the calculation results of the physical property parameters of the fluid in the main pipeline cold section area in the primary system model will be used as the main pipeline cold section coupling boundary condition in the passive injection system model, and the calculation results of the physical property parameters of the fluid in the top area of ​​the pressurizer in the primary system model will be used as the pressurizer top area coupling boundary condition in the automatic depressurization system model; For the secondary loop system model, the calculation results of the physical parameters of the fluid in the steam drum area in the secondary loop system model will be used as the steam drum coupling boundary conditions in the primary loop system model; For the passive safety injection system model, the calculation results of the physical parameters of the fluid in the DVI safety injection pipeline installation inlet area in the passive safety injection system model will be used as the DVI safety injection pipeline installation inlet coupling boundary conditions in the primary loop system model, and the calculation results of the physical parameters of the fluid in the pressure balance pipeline inlet area in the passive safety injection system model will be used as the pressure balance pipeline inlet coupling boundary conditions in the primary loop system model; For the automatic depressurization system model, the calculation results of the physical parameters of the fluid in the outlet pipeline area at the top of the regulator in the automatic depressurization system model will be used as the coupling boundary conditions of the outlet pipeline area at the top of the regulator in the primary loop system model.

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