High-parameter porous steam jet condensing pressure oscillation coupling simulation method and system

Abstract

The invention provides a high-parameter porous steam jet condensation pressure oscillation coupling simulation method and system. The method comprises the following steps: S1, establishing geometric models of a single hole and a cooling water pool; s2, determining and calculating a fluid domain, grid division, a numerical solver and a physical model; s3, determining the outlet saturated steam pressure, the mass flow rate and the water temperature of a cooling water tank of the single hole, generating a numerical model, and generating and outputting a calculation result; s4, a calculation result output through CFD analysis in the step S3 is compared with a known test result; s5, determining changes of the cooling water flow rate and the steam plume pressure at the single-hole steam-liquid interface along with time; s6, single-phase water jet CFD analysis is carried out, and finally the overall pressure oscillation characteristic in the cooling water pool under the high-parameter steam jet condensation working condition is obtained. The method greatly reduces the number of grids, saves the calculation cost and human resources, and is suitable for rapid analysis evaluation and design verification of the pressure oscillation characteristics of the pressure relief device of the nuclear power plant.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power plant dedicated safety system design, and in particular to a high-parameter porous steam jet condensation pressure oscillation coupling simulation method and system. Background Art

[0002] In the prior art, the phenomenon of steam jets being sprayed into supercooled water and undergoing direct contact condensation (DCC) with the supercooled water is common in many industrial settings. The condensation of the steam jet in the supercooled water forms a limited plume-shaped vapor-containing area, also known as a steam plume. What occurs in and near the steam plume is a complex two-phase flow process accompanied by the exchange of mass, momentum, and energy. This process is accompanied by a variety of physical phenomena such as liquid film acceleration, condensation of steam on the liquid film, droplet entrainment, droplet deposition, and liquid film rupture, making the steam jet impact and pressure oscillation characteristics very complex.

[0003] The vapor-liquid interface of a steam jet condensation exhibits periodic variations, primarily consisting of three stages: bubble growth, propagation, and detachment. These periodic variations in the vapor-liquid interface can cause pressure oscillations in the steam jet. The steam mass flow rate and subcooled water temperature have a particularly significant influence on these pressure oscillations.

[0004] Steam jet condensation is currently widely used in the nuclear industry as an emergency cooling method, for example in the pressure relief systems of pressurized water reactor (PWR) nuclear power plants. Nuclear power plants utilize the principles and advantages of steam jet condensation to discharge high-temperature, high-pressure steam generated in the reactor's primary circuit after an accident into the cooling water pool through a special pressure relief device (equipment) immersed in the cooling water pool. This passively depressurizes the system and protects the plant's operational safety. The pressure relief device features a porous structure to increase the contact surface between the steam and the cooling water, further enhancing the condensation effect.

[0005] When the pressure relief device is in operation, the pressure oscillations caused by the condensation of the steam jet can cause potential damage to the pressure relief device itself, the cooling water pool structure, and other equipment arranged in the pool, including:

[0006] 1. Apply alternating impact dynamic loads to nearby equipment or structures.

[0007] 2. The back-impact force caused by the high-speed steam jet has the potential to damage the pressure relief device itself.

[0008] Therefore, the industry is particularly concerned about the pressure oscillation problem caused by high-parameter (high temperature, high pressure) steam jet condensation, especially the harm of pressure oscillation to equipment and structures, and how to formulate corresponding preventive and mitigation measures.

[0009] To address the above issues, current work is mainly based on technical solutions such as experimental research and simulation analysis. However, the current solutions have significant limitations, mainly reflected in the following aspects:

[0010] First, due to experimental limitations, most experimental studies on the oscillation characteristics of steam jet condensation pressure have been conducted on small scales and at low parameters (low steam flow, pressure, and temperature). While experimental results and data can be obtained, and some semi-empirical formulas can be derived through fitting, the limitations of theoretical research prevent these results from being directly extrapolated to the high-parameter operating conditions (higher steam flow, pressure, and temperature) of engineering prototypes, limiting their application in engineering.

[0011] Second, in terms of the applicability of simulation analysis, the simulation analysis method based on Computational Fluid Dynamics (CFD) can simulate some typical steam jet pressure oscillation characteristics (such as intermittent oscillation). However, due to the need to simultaneously simulate non-steady-state physical processes such as high-speed jets, high-speed condensation phase changes, and multiphase flows, extremely high requirements are placed on the accuracy, efficiency, and stability of the solver. For some high-parameter porous steam jet working conditions, the simulation analysis results are still sensitive to the physical model and mesh. Overall, there is currently a lack of a universal simulation analysis method for dealing with problems related to steam jet condensation pressure oscillation.

[0012] 3. In terms of simulation analysis engineering applications, the pressure relief device is usually a porous structure, and the cooling water pool is also large in volume. The geometric structures of the two are complex and the number of grids is huge. In areas where the pressure and gas volume fraction change dramatically, in order to capture the dynamic characteristics of the vapor-liquid interface, the grid must be encrypted, resulting in an astronomical increase in the number of grids. In addition, in order to ensure numerical stability, an extremely small time step needs to be set, resulting in extremely long simulation calculations, which is unacceptable in engineering. The high difficulty of coupling physical models makes it even more difficult to ensure numerical stability during the calculation process, resulting in low accuracy.

[0013] For pressure relief devices protecting nuclear power plants, the oscillating pressure amplitude caused by steam jets during operation is a crucial input for the design of related equipment and structures, requiring detailed analysis through testing combined with CFD technology. Therefore, high-reliability numerical simulation of steam jet condensation pressure oscillations remains a crucial tool in engineering design.

[0014] In view of this, the inventors of the present application have designed a high-parameter porous steam jet condensation pressure oscillation coupled simulation method and system in order to overcome the above technical problems. Summary of the Invention

[0015] The technical problem to be solved by the present invention is to overcome the defects of low calculation efficiency and low accuracy of calculation results in the prior art, and to provide a high-parameter porous steam jet condensation pressure oscillation coupling simulation method and system.

[0016] The present invention solves the above technical problems through the following technical solutions:

[0017] A high-parameter porous steam jet condensation pressure oscillation coupling simulation method is characterized in that the simulation method includes the following steps:

[0018] S1. Establish the geometric model of the single hole and cooling water pool according to the structure and hole size of the pressure relief device;

[0019] S2. Determine the computational fluid domain, meshing, numerical solver, and physical model based on the geometric model established in step S1;

[0020] S3. Determine the outlet saturated steam pressure, mass flow rate, and cooling water pool temperature of the single hole according to the high-parameter steam jet condensation operating conditions, generate a numerical model using the parameter settings of step S2, conduct a multiphase flow CFD analysis of the high-parameter single-hole steam jet condensation pressure oscillation, and generate and output the calculation results;

[0021] S4, comparing the calculation results output by the CFD analysis in step S3 with the known test results; if the relative error is less than a preset limit, the calculation is terminated and all CFD analysis results are output; otherwise, the iterative correction process from step S3 to step S4 is repeated;

[0022] S5. Establishing a simplified pressure oscillation model based on the steam jet condensation process, and using the calculation results output in step S4 to determine the changes in the cooling water flow rate and the steam plume pressure at the single-hole steam-liquid interface over time;

[0023] S6. Using the calculation results of the simplified pressure oscillation model in step S5 as the porous outlet boundary conditions, a numerical model of the porous pressure relief device and the cooling water pool based on the engineering prototype is established, and a single-phase water jet CFD analysis is carried out. Finally, the overall pressure oscillation characteristics in the cooling water pool under high-parameter steam jet condensation conditions are obtained.

[0024] According to one embodiment of the present invention, step S2 includes the following steps:

[0025] Step S 21 , start the meshing software and import the geometric model created in step S1;

[0026] Step S 22 , establish computational fluid domain;

[0027] Step S 23, set the surface mesh, volume mesh and boundary layer mesh parameters;

[0028] Step S 24 , generate structured or unstructured grids;

[0029] Step S 25 , Check whether the mesh quality meets the requirements; if not, return to step S 23 Re-adjust the surface mesh, volume mesh, and boundary layer mesh parameters; if satisfied, save the simulation file and record the computational fluid domain and meshing parameters;

[0030] Step S 26 , select the physical model and numerical solver;

[0031] Step S 27 , set the numerical solver parameters and physical model parameters;

[0032] Step S 28 , save the simulation file, and record the numerical solver parameters and physical model parameters.

[0033] According to one embodiment of the present invention, step S3 includes the following steps:

[0034] S 31 , import the step S 24 The mesh generated in ;

[0035] S 32 , enter the step S 27 Generate a numerical model using the numerical solver parameters and physical model parameters recorded in ;

[0036] S 33 2. Determine the single-hole outlet saturated steam pressure, mass flow rate and cooling water pool temperature based on the high-parameter steam jet condensation working conditions, and complete the boundary condition setting;

[0037] S 34 2. Start CFD numerical solution, carry out multiphase flow CFD analysis of high-parameter single-hole steam jet condensation pressure oscillation, and generate calculation results;

[0038] S 35 , determine whether the CFD calculation results converge; if not, go to step S 32 , readjust the numerical solver and physical model parameters, and save the CFD calculation results if converged.

[0039] According to one embodiment of the present invention, step S4 includes the following steps:

[0040] S 41 , for the step S 35Based on the CFD calculation results, the equilibrium steam plume length, the oscillation pressure amplitude at the single hole outlet, and the oscillation pressure main frequency are extracted;

[0041] S 42 , confirm whether there is a known test result; if so, go to step S 43 Verify the CFD calculation results; if they do not exist, save the CFD calculation results and proceed to step S 44 ;

[0042] S 43 , the step S 41 Compare the CFD calculation results with the known test results, calculate the relative error between the two, and determine whether it is less than the preset error limit; if not, enter step S 32 Reset the numerical solver parameters and physical model parameters; if satisfied, stop the calculation and save the CFD calculation results;

[0043] S 44 , confirm whether all multiphase flow CFD analysis of high-parameter single-hole steam jet condensation pressure oscillation is completed; if not, proceed to step S 32 Start the analysis of the next working condition; if it is completed, save the CFD calculation results of all working conditions and record the equilibrium steam plume length, oscillation pressure amplitude at the single hole outlet, and oscillation pressure main frequency.

[0044] According to one embodiment of the present invention, the step S 41 The equilibrium plume length includes the length of the periodically changing plume from the beginning of growth to the time when the plume reaches equilibrium with the surrounding cooling water after the steam jet condenses into the cooling water.

[0045] According to one embodiment of the present invention, the step S 41 The oscillating pressure amplitude at the single hole outlet includes: the oscillating pressure formed by condensation after the steam jet enters the cooling water through the single hole and propagates downstream along the jet direction, and the oscillating pressure amplitude at each downstream point is expressed as the difference between the maximum and minimum pressure changes within one oscillation cycle.

[0046] According to one embodiment of the present invention, the step S 41 The main frequency of the oscillating pressure includes: the frequency component with the most concentrated energy in the periodically changing oscillating pressure signal when the steam jet condenses after entering the cooling water.

[0047] According to one embodiment of the present invention, step S5 includes the following steps:

[0048] S 51Based on the periodic expansion and contraction characteristics of the steam plume after a single-hole steam jet enters the cooling water, a simplified oscillation dynamic equation is established with the cooling water mass element near the vapor-liquid interface between the steam plume and the surrounding cooling water as the research object;

[0049] S 52 2. Based on the gas adiabatic expansion model, the correlation between plume pressure and plume length is established;

[0050] S 53 , the step S 52 Substitute the correlation equation into the step S 51 The ordinary differential equation related to the plume length is obtained from the oscillatory dynamics equation, and the relationship between the plume length and time is obtained;

[0051] S 54 According to step S 53 , the step S 44 The calculation results are used to find the relationship between the cooling water flow rate at the vapor-liquid interface and time; according to the step S 53 , the step S 44 The calculation results and the step S 52 The relationship between the steam plume pressure and time is obtained by the correlation formula.

[0052] S 55 , record the relationship between the cooling water flow rate at the vapor-liquid interface and the time, and the relationship between the vapor plume pressure and the time, which are used to set the boundary conditions for the porous jet CFD analysis of the engineering prototype pressure relief device.

[0053] According to one embodiment of the present invention, step S6 includes the following steps:

[0054] S 61 , establish numerical models of porous pressure relief devices and cooling water pools based on nuclear power plant engineering prototypes;

[0055] S 62 According to step S 61 The established geometric model determines the computational fluid domain, meshing, numerical solver and physical model;

[0056] S 63 According to step S 55 Based on the results recorded in , set the porous outlet as a pressure outlet boundary condition or a velocity outlet boundary condition;

[0057] S 64 , adopt the step S 62 and the step S 63 The numerical model was generated by setting the parameters, and a single-phase water jet CFD analysis of the porous pressure relief device based on the nuclear power plant engineering prototype was carried out, and the calculation results were generated;

[0058] S 65 , confirm whether the CFD analysis of the single-phase water jet working conditions of all porous pressure relief devices is completed; if not, go to step S 64 Start CFD analysis of the next working condition; if completed, save the CFD calculation results of all working conditions, and record the oscillation pressure amplitude and oscillation pressure main frequency near the porous pressure relief device and various locations in the cooling water pool.

[0059] According to one embodiment of the present invention, the step S 62 The following steps are included:

[0060] S 621 , start the grid division software, import the step S 61 The geometric model established in

[0061] S 622 , establish computational fluid domain;

[0062] S 623 , set the surface mesh, volume mesh and boundary layer mesh parameters;

[0063] S 624 , generate structured or unstructured grids;

[0064] S 625 , check whether the grid quality meets the requirements; if not, return to step S 623 Re-adjust the surface mesh, volume mesh, and boundary layer mesh parameters; if satisfied, save the simulation file and record the computational fluid domain and meshing parameters;

[0065] S 626 , select the physical model and numerical solver;

[0066] S 627 , set the numerical solver parameters and physical model parameters;

[0067] S 628 , save the simulation file, and record the numerical solver parameters and physical model parameters.

[0068] According to one embodiment of the present invention, the step S 64 The following steps are included:

[0069] S 641 , import the step S 625 The mesh generated in ;

[0070] S 642 , enter the step S 628 Generate a numerical model using the numerical solver parameters and physical model parameters recorded in ;

[0071] S 643 According to step S 63 Complete the boundary condition setting by recording the porous outlet boundary condition parameters in ;

[0072] S 644 2. Start CFD numerical solution, carry out CFD analysis of porous jet, and generate calculation results;

[0073] S 645 , determine whether the CFD calculation results converge; if not, go to step S 642 , readjust the numerical solver and physical model parameters; if converged, save the CFD calculation results.

[0074] The present invention also provides a high-parameter porous steam jet condensation pressure oscillation coupled simulation system, which is characterized in that the simulation system adopts the high-parameter porous steam jet condensation pressure oscillation coupled simulation method described above, and the simulation system includes:

[0075] The geometric modeling module establishes the geometric model of single-hole jet or multi-hole jet based on the actual geometric dimensions of the multi-hole pressure relief device and the cooling water pool;

[0076] A calculation setting module, which determines the computational fluid domain, mesh division, numerical solver and physical model based on the geometric model;

[0077] The boundary condition module determines the single-hole outlet saturated steam pressure, mass flow rate, and cooling water pool temperature according to the high-parameter steam jet condensation working conditions, and sets the single-hole steam jet boundary conditions;

[0078] Single-hole jet module, used to conduct CFD analysis of high-parameter single-hole steam jet condensation pressure oscillations and generate calculation results, outputting the equilibrium steam plume length, oscillation pressure amplitude at the single-hole outlet, and oscillation pressure main frequency;

[0079] The iterative correction module compares the calculation results output by CFD analysis with known test results and iteratively corrects the calculation results whose errors are greater than the preset limit;

[0080] Pressure Oscillation Module: Uses a simplified pressure oscillation model to determine and record the time-varying changes in cooling water velocity and plume pressure at the vapor-liquid interface of a single hole, which is used to set the outlet boundary conditions in the calculation of multi-hole jets.

[0081] The porous jet module establishes numerical models of a porous pressure relief device and a cooling water pool based on an engineering prototype, and conducts single-phase water jet CFD analysis to obtain the overall pressure oscillation characteristics in the cooling water pool under high-parameter steam jet condensation conditions.

[0082] The present invention also provides an electronic device, which is characterized in that the electronic device includes: a processor and a memory, the memory stores programs or instructions that can be run on the processor, and the programs or instructions are executed by the processor to implement the high-parameter porous steam jet condensation pressure oscillation coupling simulation method as described above.

[0083] The present invention also provides a readable storage medium, which is characterized in that the readable storage medium stores a program or instruction, and when the program or instruction is executed by a processor, the high-parameter porous steam jet condensation pressure oscillation flow coupling simulation method as described above is implemented.

[0084] The positive progress effect of the present invention is:

[0085] The high-parameter porous steam jet condensation pressure oscillation coupled simulation method and system of the present invention imports the numerical model of the nuclear power plant pressure relief device and cooling water pool through CFD simulation software, generates a grid and performs CFD solution calculations. The simulation method replaces the CFD simulation of the porous steam jet with a simplified pressure oscillation model, which not only avoids the generation of fine grids, but also cleverly solves the difficulties of CFD solving complex multiphase flow (including rapid phase change) problems, and can maximize the use of known experimental data to simplify the numerical model. At the same time, the simulation method also significantly reduces the number of grids, saves computing costs and human resources, and is suitable for rapid analysis and evaluation of the pressure oscillation characteristics of the nuclear power plant pressure relief device and design verification. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which like reference numerals represent like features throughout, wherein:

[0087] Figure 1 It is a schematic flow chart of the high-parameter porous steam jet condensation pressure oscillation coupled simulation method of the present invention.

[0088] Figure 2 This is a flow chart of the method for setting the high-parameter single-hole steam jet geometric model, computational fluid domain, grid division and model parameters in the high-parameter multi-hole steam jet condensation pressure oscillation coupled simulation method of the present invention.

[0089] Figure 3 This is a flow chart of the single-hole jet CFD calculation method in the high-parameter multi-hole steam jet condensation pressure oscillation coupled simulation method of the present invention.

[0090] Figure 4 This is a flow chart of the iterative correction calculation method for high-parameter single-hole steam jet in the high-parameter multi-hole steam jet condensation pressure oscillation coupled simulation method of the present invention.

[0091] Figure 5 This is a flow chart of a simplified method for establishing a pressure oscillation model in the high-parameter porous steam jet condensation pressure oscillation coupled simulation method of the present invention.

[0092] Figure 6 This is a flow chart of the porous jet CFD calculation method in the high-parameter porous steam jet condensation pressure oscillation coupled simulation method of the present invention.

[0093] Figure 7 Schematic diagram of the structure of the electronic device of the present invention. DETAILED DESCRIPTION

[0094] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0095] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Reference will now be made in detail to preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to represent the same or similar parts.

[0096] Furthermore, although the terms used in the present invention are selected from well-known and commonly used terms, some terms mentioned in the present specification may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description herein.

[0097] Furthermore, it is required that the present invention be understood not only by the actual terms used but also by the meanings connoted by each term.

[0098] like Figure 1 As shown, the present invention discloses a high-parameter porous steam jet condensation pressure oscillation coupled simulation method, which includes the following steps:

[0099] Step S1: Establish a geometric model of a single hole (eg, including a single hole upstream connecting pipe) and a cooling water pool according to the structure and hole size (eg, hole diameter) of the pressure relief device.

[0100] In this example, to simplify the geometric modeling of the actual pressure relief device and reduce the amount of subsequent CFD calculations, only a single-hole steam jet was simulated, with the same hole diameter as the actual pressure relief device. The length of the upstream connecting pipe of the single hole should be greater than 10 times the nominal pipe diameter to ensure sufficient development of turbulent flow.

[0101] Step S2: determining the computational fluid domain, meshing, numerical solver and physical model according to the geometric model established in step S1.

[0102] like Figure 2 As shown, Figure 2A flow chart of the high-parameter single-hole steam jet geometric model, computational fluid domain, grid division, and model parameter setting method is shown.

[0103] Preferably, step S2 includes the following steps:

[0104] Step S 21 , start the meshing software and import the geometric model created in step S1.

[0105] Step S 22 , establish the computational fluid domain.

[0106] Step S 23 , set the surface mesh, volume mesh and boundary layer mesh parameters.

[0107] Step S 24 , generate structured or unstructured grids.

[0108] Step S 25 , Check whether the mesh quality meets the requirements; if not, return to step S 23 Re-adjust the surface mesh, volume mesh, and boundary layer mesh parameters; if satisfied, save the simulation file and record the computational fluid domain and meshing parameters.

[0109] Step S 26 , select the physical model (such as turbulence model, multiphase flow model, phase change model, etc.) and numerical solver.

[0110] Step S 27 , set the numerical solver parameters (such as time step, number of iterations, relaxation factor, etc.) and physical model parameters.

[0111] Step S 28 , save the simulation file, and record the numerical solver parameters and physical model parameters.

[0112] Step S3: Determine the outlet saturated steam pressure, mass flow rate, and cooling water pool temperature of the single hole according to the high-parameter steam jet condensation operating conditions, and use the parameter settings of step S2 to generate a numerical model, carry out multiphase flow (including rapid phase change) CFD analysis of high-parameter single-hole steam jet condensation pressure oscillation, and generate and output the calculation results.

[0113] like Figure 3 As shown, Figure 3 A flow chart of a single-hole jet CFD calculation method in one embodiment is shown.

[0114] Preferably, step S3 includes the following steps:

[0115] Step S 31 , import the step S 24The mesh generated in .

[0116] Step S 32 , enter the step S 27 Generate a numerical model using the numerical solver parameters and physical model parameters recorded in .

[0117] Step S 33 , determine the single-hole outlet saturated steam pressure, mass flow rate and cooling water pool water temperature according to the high-parameter steam jet condensation working conditions, and complete the boundary condition setting.

[0118] Step S 34 , start CFD numerical solution, carry out multiphase flow (including rapid phase change) CFD analysis of high-parameter single-hole steam jet condensation pressure oscillation, and generate calculation results.

[0119] Step S 35 , determine whether the CFD calculation results converge; if not, go to step S 32 , readjust the numerical solver and physical model parameters, and save the CFD calculation results if converged.

[0120] Wherein, judging whether the CFD calculation result is converged may further preferably include: if the CFD calculation result at least meets the following convergence evaluation criteria, then the CFD calculation result is considered to be converged.

[0121] The convergence evaluation criteria include: the root mean square residual is less than or equal to 10 -3 ; The change of steam plume pressure at the single hole outlet remains basically constant within each oscillation cycle.

[0122] Step S4: Compare the calculation results output by the CFD analysis in step S3 with the known test results; if the relative error is less than the preset limit, the calculation ends and all CFD analysis results are output; otherwise, the iterative correction process from step S3 to step S4 is repeated.

[0123] like Figure 4 As shown, Figure 4 A flow chart of an iterative correction calculation method for high-parameter single-hole steam jet in one embodiment is shown.

[0124] Preferably, the step S4 includes the following steps:

[0125] Step S 41 , for the step S 35 Based on the CFD calculation results, the equilibrium steam plume length, the oscillation pressure amplitude at the single hole outlet, and the main frequency of the oscillation pressure are extracted.

[0126] Among them, the expression corresponding to the oscillation pressure amplitude at the single hole outlet is:

[0127] p a =p max -p min

[0128] Among them, p a is the oscillation pressure amplitude at the single hole outlet, p max is the maximum value of the oscillation pressure within one oscillation period, p min It is the minimum value of the oscillation pressure within one oscillation period.

[0129] Preferably, the step S 41 The equilibrium plume length includes the length of the periodically changing plume from the beginning of growth to the time when the plume reaches equilibrium with the surrounding cooling water after the steam jet condenses into the cooling water.

[0130] The oscillating pressure amplitude at the single hole outlet includes: the oscillating pressure formed by condensation after the steam jet enters the cooling water through the single hole and propagates downstream along the jet direction, and the oscillating pressure amplitude at each downstream location is expressed as the difference between the maximum and minimum pressure changes within one oscillation cycle.

[0131] The main frequency of the oscillating pressure includes: the frequency component with the most concentrated energy in the periodically changing oscillating pressure signal after the steam jet condenses after entering the cooling water.

[0132] Step S 42 , confirm whether there is a known test result; if so, go to step S 43 Verify the CFD calculation results; if they do not exist, save the CFD calculation results and proceed to step S 44 .

[0133] Step S 43 , the step S 41 Compare the CFD calculation results with the known test results, calculate the relative error between the two, and determine whether it is less than the preset error limit; if not, enter step S 32 Reset the numerical solver parameters and physical model parameters; if satisfied, stop the calculation and save the CFD calculation results.

[0134] The expression for judging whether the relative error is less than the preset error limit is:

[0135]

[0136] Among them, (p a ) CFD is the oscillation pressure amplitude at the outlet of a single hole within one oscillation cycle calculated using CFD software, (p a ) expis the oscillation pressure amplitude at the single hole outlet within one oscillation period determined based on the test data, and ε is the preset error limit.

[0137] The preset error limits include: a relative error of the oscillation pressure amplitude at a single hole outlet within one oscillation cycle is 10%.

[0138] Step S 44 , confirm whether all high-parameter single-hole steam jet condensation pressure oscillation multiphase flow (including rapid phase change) CFD analysis is completed; if not, go to step S 32 Start the analysis of the next working condition; if it is completed, save the CFD calculation results of all working conditions and record the equilibrium steam plume length, oscillation pressure amplitude at the single hole outlet, and oscillation pressure main frequency.

[0139] Step S5: establishing a simplified pressure oscillation model based on the steam jet condensation process, and using the calculation results output in step S4 to determine the changes in the cooling water flow rate and steam plume pressure at the single-hole steam-liquid interface over time.

[0140] like Figure 5 As shown, Figure 5 A flow chart showing a method for establishing a simplified pressure oscillation model according to an embodiment is shown.

[0141] Preferably, step S5 includes the following steps:

[0142] Step S 51 According to the periodic expansion and contraction characteristics of the steam plume after a single-hole steam jet enters the cooling water, a simplified oscillation dynamic equation is established with the cooling water mass element near the vapor-liquid interface between the steam plume and the surrounding cooling water as the research object.

[0143] Here, the simplified oscillatory dynamics equation is established based on the periodic variation characteristics of the vapor plume, and its basic assumptions include:

[0144] Ignore the heat and mass transfer between steam and cooling water, and only consider the changes in macroscopic pressure and volume.

[0145] When the steam jet enters the cooling water, the plume expands. When the steam jet condenses, the plume contracts. The volume change of the plume is completely cyclical.

[0146] All energy losses (viscous losses, etc.) are neglected.

[0147] When the steam jet enters the cooling water, the net force acting on the cooling water mass element near the vapor-liquid interface is equal to the product of the difference between the steam plume pressure and the average pressure of the cooling water surrounding the steam plume and the surface area of ​​the vapor-liquid interface. The simplified oscillation dynamics equation is as follows:

[0148]

[0149] Where m is the mass of the cooling water element near the vapor-liquid interface at the single hole outlet, x is the distance from the single hole outlet cross section, t is the time, p is the vapor plume pressure, p0 is the average pressure of the cooling water around the vapor plume, and S is the surface area of ​​the vapor-liquid interface.

[0150] Assuming that the shape of the vapor plume is spherical, the expression for the vapor-liquid interface surface area is:

[0151] S=4πx 2

[0152] Substituting the vapor-liquid interface surface area expression into the simplified oscillation dynamics equation, we further obtain:

[0153]

[0154] Step S 52 , Based on the gas adiabatic expansion model, the correlation between plume pressure and plume length is established.

[0155] The gas adiabatic expansion model is established based on the assumption that heat and mass transfer between steam and cooling water is neglected. The corresponding expression is:

[0156]

[0157] Where V0 is the equilibrium plume volume, V is the plume volume, and κ is the steam adiabatic index.

[0158] Assuming that the shape of the plume is spherical, the expression for the plume volume is:

[0159] V=4πx 3 / 3

[0160] Where x0 is the equilibrium plume length.

[0161] Substituting the plume volume expression into the gas adiabatic expansion model, the relationship between plume pressure and plume length is obtained as follows:

[0162]

[0163] Step S 53 , the step S 52 Substitute the correlation equation into the step S 51 The ordinary differential equation related to the vapor plume length is obtained from the oscillatory dynamics equation, and the relationship between the vapor plume length and time is calculated.

[0164] The ordinary differential equation related to the plume length is the step S 52 The expression corresponding to the gas adiabatic expansion model is substituted into the simplified oscillation dynamics equation of step S51, and the corresponding equation is as follows:

[0165]

[0166] Perform a first-order Taylor expansion on the right side of the above equation at x=x0, and further organize it to obtain:

[0167]

[0168] Let x′=x-x0, The above equation can be simplified into the following form:

[0169]

[0170] Where x′ is the difference between the instantaneous plume length and the equilibrium plume length, and ω is the oscillation angular frequency.

[0171] The relationship between the oscillation angular frequency and the oscillation pressure main frequency is as follows:

[0172] ω=2πf

[0173] Where f is the main frequency of oscillation pressure.

[0174] Solving the above ordinary differential equation, we can further obtain the relationship between the length of the vapor plume and time as follows:

[0175]

[0176] Where A is the length amplitude of the steam plume at the single hole outlet, is the initial phase.

[0177] The initial phase represents the state of the plume at the initial moment. It is generally assumed that the plume is in equilibrium at the initial moment, and the corresponding initial phase is as follows:

[0178]

[0179] Step S 54 According to step S 53 , the step S 44 The calculation results are used to find the relationship between the cooling water flow rate at the vapor-liquid interface and time; according to the step S 53 , the step S 44 The calculation results and the step S 52 The relationship between the steam plume pressure and time is obtained by the correlation formula.

[0180] The relationship between the cooling water flow rate at the vapor-liquid interface and time can be obtained by 53 The relationship between the length of the vapor plume and time obtained in the above equation is obtained by taking the first-order derivative of time, and the corresponding expression is as follows:

[0181]

[0182] Where u is the cooling water velocity at the vapor-liquid interface.

[0183] The main frequency f of the oscillation pressure and the length amplitude A of the steam plume at the single hole outlet are unknown coefficients, which can be obtained by the step S 44 The calculation results are determined and then inserted into the above expression to obtain the complete relationship between the cooling water flow rate at the vapor-liquid interface and time.

[0184] The relationship between the steam plume pressure and time can be obtained by step S 53 The relationship between the length of the vapor plume and time obtained in step S 52 The correlation between the plume pressure and plume length obtained in the previous section is solved together, and the corresponding expression is as follows:

[0185]

[0186] Perform a first-order Taylor expansion on the right side of the above expression at t=0 and further organize it to obtain:

[0187]

[0188] The maximum and minimum values ​​of the plume pressure within one oscillation period are:

[0189]

[0190] The expression corresponding to the oscillation pressure amplitude is:

[0191]

[0192] Substituting the oscillation pressure amplitude expression into the relationship between the cooling water velocity at the vapor-liquid interface and the vapor plume pressure and time, we can further sort out the following:

[0193]

[0194]

[0195] Among them, the oscillation pressure main frequency f, the oscillation pressure amplitude p a and the equilibrium plume length x0 are unknown coefficients, which can be obtained by 44 The calculation results or known test data are used to determine the

[0196] Step S 55 , record the relationship between the cooling water flow rate at the vapor-liquid interface and the time, and the relationship between the vapor plume pressure and the time, which are used to set the boundary conditions for the porous jet CFD analysis of the engineering prototype pressure relief device.

[0197] Step S6: Use the calculation results of the simplified pressure oscillation model in step S5 as the porous outlet boundary conditions, establish a numerical model of the porous pressure relief device and the cooling water pool based on the engineering prototype, and carry out single-phase water jet CFD analysis. Finally, obtain the overall pressure oscillation characteristics in the cooling water pool under high-parameter steam jet condensation conditions.

[0198] like Figure 6 As shown, Figure 6 A flow chart showing a CFD calculation method for porous jet flow according to an embodiment of the present invention is shown.

[0199] Preferably, step S6 includes the following steps:

[0200] Step S 61 , establish a numerical model of the porous pressure relief device and cooling water pool based on the nuclear power plant engineering prototype.

[0201] Step S 62 According to step S 61 The established geometric model determines the computational fluid domain, meshing, numerical solver and physical model.

[0202] Preferably, the step S 62 The following steps are included:

[0203] Step S 621 , start the grid division software, import the step S 61 The geometric model established in .

[0204] Step S 622 , establish the computational fluid domain.

[0205] Step S 623 , set the surface mesh, volume mesh and boundary layer mesh parameters.

[0206] Step S 624 , generate structured or unstructured grids.

[0207] Step S 625 , check whether the grid quality meets the requirements; if not, return to step S 623 Re-adjust the surface mesh, volume mesh, and boundary layer mesh parameters; if satisfied, save the simulation file and record the computational fluid domain and meshing parameters.

[0208] Step S 626 , select the physical model (such as turbulence model, etc.) and the numerical solver.

[0209] Step S 627, set the numerical solver parameters (such as time step, number of iterations, relaxation factor, etc.) and physical model parameters.

[0210] Step S 628 , save the simulation file, and record the numerical solver parameters and physical model parameters.

[0211] Step S 63 According to step S 55 , set the porous outlet as a pressure outlet boundary condition or a velocity outlet boundary condition.

[0212] Step S 64 , adopt the step S 62 and the step S 63 The numerical model was generated based on the parameter settings, and a single-phase water jet CFD analysis of the porous pressure relief device based on the nuclear power plant engineering prototype was carried out, and the calculation results were generated.

[0213] Preferably, the step S 64 The following steps are included:

[0214] Step S 641 , import the step S 625 The mesh generated in .

[0215] Step S 642 , enter the step S 628 Generate a numerical model using the numerical solver parameters and physical model parameters recorded in .

[0216] Step S 643 According to step S 63 Complete the boundary condition settings by recording the porous outlet boundary condition parameters (such as pressure outlet boundary condition or velocity outlet boundary condition) in the .

[0217] Step S 644 , start CFD numerical solution, carry out porous jet CFD analysis, and generate calculation results.

[0218] Step S 645 , determine whether the CFD calculation results converge; if not, go to step S 642 , readjust the numerical solver and physical model parameters; if converged, save the CFD calculation results.

[0219] The step of judging whether the CFD calculation result is converged further includes: if the CFD calculation result at least meets the following convergence evaluation criteria, then the CFD calculation result is considered to be converged.

[0220] The convergence evaluation criteria include: the root mean square residual is less than or equal to 10 -5; The pressure change at the porous outlet remains basically constant within each oscillation cycle.

[0221] Step S 65 , confirm whether the CFD analysis of the single-phase water jet working conditions of all porous pressure relief devices is completed; if not, go to step S 64 Start CFD analysis of the next working condition; if completed, save the CFD calculation results of all working conditions, and record the oscillation pressure amplitude and oscillation pressure main frequency near the porous pressure relief device and various locations in the cooling water pool.

[0222] In particular, it should be noted here that the high-parameter multi-porous steam jet condensation pressure oscillation coupled simulation method of the present invention first takes the high-parameter single-hole steam jet as the calculation object, and obtains the pressure oscillation characteristics (oscillation pressure amplitude, oscillation pressure main frequency) of the single hole through CFD analysis.

[0223] Then, a simplified pressure oscillation model is established to convert the CFD calculation results of the single-hole steam jet into the relationship between the cooling water flow rate and pressure at the steam-liquid interface near the orifice and time.

[0224] Finally, the above relationship is updated to the porous outlet boundary conditions of the CFD analysis of porous single-phase water jets, realizing the equivalent transformation of "single-hole steam jet" to "multi-porous single-phase water jet", making the multi-porous jet pressure oscillation simulation based on the engineering prototype pressure relief device feasible and forming a complete CFD calculation result.

[0225] Specifically, the high-parameter porous steam jet condensation pressure oscillation coupled simulation method of the present invention uses a simplified pressure oscillation model to replace the multiphase flow (including rapid phase change) CFD simulation of the porous steam jet of the pressure relief device. Through the CFD simulation of the high-parameter single-hole steam jet condensation, the simplified pressure oscillation model is used to convert the calculation results into the boundary conditions of the porous single-phase water jet. This not only avoids the generation of fine grids, but also cleverly solves the difficulties of CFD in solving complex multiphase flow problems (such as too small time step and poor numerical stability), successfully converts complex multiphase flow problems into simple single-phase flow problems, and achieves a significant reduction in the number of grids, thereby achieving the purpose of saving calculation costs, which is beneficial for designers to quickly optimize and iterate, and greatly improves the analysis efficiency of the pressure oscillation characteristics of the nuclear power plant pressure relief device.

[0226] The present invention also provides a high-parameter porous steam jet condensation pressure oscillation coupled simulation system, which adopts the high-parameter porous steam jet condensation pressure oscillation coupled simulation method described above. The simulation system includes: a geometric modeling module, a calculation setting module, a boundary condition module, a single-hole jet module, an iterative correction module, a pressure oscillation module and a porous jet module.

[0227] The geometric modeling module establishes a geometric model of a single-hole jet or a multi-hole jet based on the actual geometric dimensions of the multi-hole pressure relief device and the cooling water pool.

[0228] The calculation setting module determines the computational fluid domain, meshing, numerical solver and physical model based on the geometric model.

[0229] The boundary condition module determines the single-hole outlet saturated steam pressure, mass flow rate and cooling water pool water temperature according to the high-parameter steam jet condensation working conditions, and sets the single-hole steam jet boundary conditions.

[0230] The single-hole jet module uses the numerical model generated by the parameter settings of steps S2 and S3 above to carry out high-parameter single-hole steam jet condensation pressure oscillation CFD analysis and generate calculation results, outputting the equilibrium steam plume length, the oscillation pressure amplitude at the single-hole outlet, and the oscillation pressure main frequency.

[0231] The iterative correction module compares the calculation results output by CFD analysis in step S3 with the known test results. If the relative error is less than a preset limit, the calculation ends and all CFD analysis results are output. Otherwise, the iterative correction process from step S3 to step S4 is repeated.

[0232] The pressure oscillation module determines the simplified pressure oscillation model in step S5 based on the calculation results output in step S4, and records the changes in the cooling water flow rate and steam plume pressure at the single-hole vapor-liquid interface over time, which are used to set the outlet boundary conditions in the multi-hole jet calculation.

[0233] The porous jet module uses the calculation results of the simplified pressure oscillation model in step S5 as the porous outlet boundary conditions, establishes a porous pressure relief device and cooling water pool numerical model based on the engineering prototype, and conducts single-phase water jet CFD analysis to ultimately obtain the overall pressure oscillation characteristics in the cooling water pool under high-parameter steam jet condensation conditions.

[0234] like Figure 7 As shown, the present invention further provides an electronic device 100, comprising: a processor 101 and a memory 102, wherein the memory 102 stores programs or instructions that can be executed on the processor 101. The program or instructions are executed by the processor 101 to implement the high-parameter porous steam jet condensation pressure oscillation coupled simulation method described above. In other words, when the program or instructions are executed by the processor 101, each process of the above-mentioned high-parameter porous steam jet condensation pressure oscillation coupled simulation method is implemented, and the same technical effects can be achieved. To avoid repetition, they are not described here.

[0235] The present invention also provides a readable storage medium storing a program or instruction. When executed by a processor, the program or instruction implements the above-described high-parameter porous steam jet condensation pressure oscillation coupled flow simulation method. When executed by a processor, the program or instruction implements each process of the above-described high-parameter porous steam jet condensation pressure oscillation coupled flow simulation method, achieving the same technical effects. To avoid repetition, these steps are not described here.

[0236] In summary, the high-parameter porous steam jet condensation pressure oscillation coupled simulation method and system of the present invention imports the numerical model of the nuclear power plant pressure relief device and cooling water pool through CFD simulation software, generates a grid and performs CFD solution calculations. The simulation method replaces the CFD simulation of porous steam jets with a simplified pressure oscillation model, which not only avoids the generation of fine grids, but also cleverly solves the difficulties of CFD solving complex multiphase flow (including rapid phase change) problems, and can maximize the use of known experimental data to simplify the numerical model. At the same time, the simulation method also greatly reduces the number of grids, saves computing costs and human resources, and is suitable for rapid analysis and evaluation of the pressure oscillation characteristics of nuclear power plant pressure relief devices and design verification.

[0237] For those skilled in the art, the above invention disclosure is intended only as an example and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and amendments to this application. Such modifications, improvements, and amendments are suggested in this application and remain within the spirit and scope of the exemplary embodiments of this application.

[0238] At the same time, this application uses specific terms to describe the embodiments of this application. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that "one embodiment," "an embodiment," or "an alternative embodiment" mentioned twice or multiple times in different locations in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application may be appropriately combined.

[0239] Some aspects of the present application can be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software can be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". The processor can be one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors or combinations thereof. In addition, various aspects of the present application may be expressed as computer products located in one or more computer-readable media, which include computer-readable program code. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, tapes...), optical disks (e.g., compact disks CDs, digital versatile disks DVDs...), smart cards, and flash memory devices (e.g., cards, sticks, key drives...).

[0240] A computer-readable medium may include a propagated data signal embodying computer program code, for example, in baseband or as part of a carrier wave. The propagated signal may be in a variety of forms, including electromagnetic, optical, etc., or a suitable combination thereof. A computer-readable medium may be any computer-readable medium other than a computer-readable storage medium that can be connected to an instruction execution system, apparatus, or device to communicate, propagate, or transmit the program for use. The program code on the computer-readable medium may be transmitted via any suitable medium, including radio, cable, fiber optic cable, radio frequency signal, or similar medium, or any combination of the above.

[0241] Similarly, it should be noted that, in order to simplify the presentation of the present disclosure and facilitate understanding of one or more embodiments of the invention, the foregoing description of the embodiments of the present disclosure sometimes combines various features into a single embodiment, figure, or description thereof. However, this disclosure method does not imply that the subject matter of the present disclosure requires more features than those recited in the claims. In fact, embodiments may feature fewer than all the features of a single disclosed embodiment. Some embodiments use numbers to describe the quantity of components or attributes. It should be understood that such numbers used in the embodiment descriptions are, in some instances, modified by the qualifiers "about," "approximately," or "substantially." Unless otherwise indicated, "about," "approximately," or "substantially" indicate that the number can vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate and may vary depending on the desired characteristics of individual embodiments. In some embodiments, numerical parameters should be considered to the specified number of significant digits and adopt the usual method of retaining significant digits. Although the numerical ranges and parameters used to identify the breadth of the ranges in some embodiments of the present disclosure are approximate, in specific embodiments, such numerical values ​​are set as accurately as practicable.

[0242] Although specific embodiments of the present invention have been described above, those skilled in the art will appreciate that these are merely illustrative and that the scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, and such changes and modifications are intended to fall within the scope of the present invention.

Claims

1. A high-parameter porous steam jet condensation pressure oscillation coupled simulation method, characterized in that: The simulation method comprises the following steps: S1. Establish the geometric model of the single hole and cooling water pool according to the structure and hole size of the pressure relief device; S2. Determine the computational fluid domain, meshing, numerical solver, and physical model based on the geometric model established in step S1; S3. Determine the outlet saturated steam pressure, mass flow rate, and cooling water pool temperature of the single hole according to the high-parameter steam jet condensation operating conditions, generate a numerical model using the parameter settings of step S2, conduct a multiphase flow CFD analysis of the high-parameter single-hole steam jet condensation pressure oscillation, and generate and output the calculation results; S4, comparing the calculation results output by the CFD analysis in step S3 with the known test results; if the relative error is less than a preset limit, the calculation is terminated and all CFD analysis results are output; otherwise, the iterative correction process from step S3 to step S4 is repeated; S5. Establishing a simplified pressure oscillation model based on the steam jet condensation process, and using the calculation results output in step S4 to determine the changes in the cooling water flow rate and the steam plume pressure at the single-hole steam-liquid interface over time; S6. Using the calculation results of the simplified pressure oscillation model in step S5 as the porous outlet boundary conditions, a numerical model of the porous pressure relief device and the cooling water pool based on the engineering prototype is established, and a single-phase water jet CFD analysis is carried out. Finally, the overall pressure oscillation characteristics in the cooling water pool under high-parameter steam jet condensation conditions are obtained.

2. The high-parameter porous steam jet condensation pressure oscillation coupled simulation method according to claim 1, characterized in that: The step S2 includes the following steps: Step S 21 , start the meshing software and import the geometric model created in step S1; Step S 22 , establish computational fluid domain; Step S 23 , set the surface mesh, volume mesh and boundary layer mesh parameters; Step S 24 , generate structured or unstructured grids; Step S 25 , Check whether the mesh quality meets the requirements; if not, return to step S 23 Re-adjust the surface mesh, volume mesh, and boundary layer mesh parameters; if satisfied, save the simulation file and record the computational fluid domain and meshing parameters; Step S 26 , select the physical model and numerical solver; Step S 27 , set the numerical solver parameters and physical model parameters; Step S 28 , save the simulation file, and record the numerical solver parameters and physical model parameters.

3. The high-parameter porous steam jet condensation pressure oscillation coupled simulation method according to claim 1, characterized in that: The step S3 includes the following steps: S 31 , import the step S 24 The mesh generated in ; S 32 , enter the step S 27 Generate a numerical model using the numerical solver parameters and physical model parameters recorded in ; S 33 2. Determine the single-hole outlet saturated steam pressure, mass flow rate and cooling water pool temperature based on the high-parameter steam jet condensation working conditions, and complete the boundary condition setting; S 34 2. Start CFD numerical solution, carry out multiphase flow CFD analysis of high-parameter single-hole steam jet condensation pressure oscillation, and generate calculation results; S 35 , determine whether the CFD calculation results converge; if not, go to step S 32 , readjust the numerical solver and physical model parameters, and save the CFD calculation results if converged.

4. The high-parameter porous steam jet condensation pressure oscillation coupled simulation method according to claim 1, characterized in that: The step S4 includes the following steps: S 41 , for the step S 35 Based on the CFD calculation results, the equilibrium steam plume length, the oscillation pressure amplitude at the single hole outlet, and the oscillation pressure main frequency are extracted; S 42 , confirm whether there is a known test result; if so, go to step S 43 Verify the CFD calculation results; if they do not exist, save the CFD calculation results and proceed to step S 44 ; S 43 , the step S 41 Compare the CFD calculation results with the known test results, calculate the relative error between the two, and determine whether it is less than the preset error limit; if not, enter step S 32 Reset the numerical solver parameters and physical model parameters; if satisfied, stop the calculation and save the CFD calculation results; S 44 , confirm whether all multiphase flow CFD analysis of high-parameter single-hole steam jet condensation pressure oscillation is completed; if not, proceed to step S 32 Start the analysis of the next working condition; if it is completed, save the CFD calculation results of all working conditions and record the equilibrium steam plume length, oscillation pressure amplitude at the single hole outlet, and oscillation pressure main frequency.

5. The high-parameter porous steam jet condensation pressure oscillation coupled simulation method according to claim 4, characterized in that: The step S 41 The equilibrium plume length includes the length of the periodically changing plume from the beginning of growth to the time when the plume reaches equilibrium with the surrounding cooling water after the steam jet condenses into the cooling water.

6. The high-parameter porous steam jet condensation pressure oscillation coupled simulation method according to claim 4, characterized in that: The step S 41 The oscillating pressure amplitude at the single hole outlet includes: the oscillating pressure formed by condensation after the steam jet enters the cooling water through the single hole and propagates downstream along the jet direction, and the oscillating pressure amplitude at each downstream point is expressed as the difference between the maximum and minimum pressure changes within one oscillation cycle.

7. The high-parameter porous steam jet condensation pressure oscillation coupled simulation method according to claim 4, characterized in that: The step S 41 The main frequency of the oscillating pressure includes: the frequency component with the most concentrated energy in the periodically changing oscillating pressure signal when the steam jet condenses after entering the cooling water.

8. The high-parameter porous steam jet condensation pressure oscillation coupled simulation method according to claim 1, characterized in that: The step S5 includes the following steps: S 51 Based on the periodic expansion and contraction characteristics of the steam plume after a single-hole steam jet enters the cooling water, a simplified oscillation dynamic equation is established with the cooling water mass element near the vapor-liquid interface between the steam plume and the surrounding cooling water as the research object; S 52 2. Based on the gas adiabatic expansion model, the correlation between plume pressure and plume length is established; S 53 , the step S 52 Substitute the correlation equation into the step S 51 The ordinary differential equation related to the plume length is obtained from the oscillatory dynamics equation, and the relationship between the plume length and time is obtained; S 54 According to step S 53 , the step S 44 The calculation results are used to find the relationship between the cooling water flow rate at the vapor-liquid interface and time; according to the step S 53 , the step S 44 The calculation results and the step S 52 The relationship between the steam plume pressure and time is obtained by the correlation formula; S 55 , record the relationship between the cooling water flow rate at the vapor-liquid interface and the time, and the relationship between the vapor plume pressure and the time, which are used to set the boundary conditions for the porous jet CFD analysis of the engineering prototype pressure relief device.

9. The high-parameter porous steam jet condensation pressure oscillation coupled simulation method according to claim 1, characterized in that: The step S6 includes the following steps: S 61 , establish numerical models of porous pressure relief devices and cooling water pools based on nuclear power plant engineering prototypes; S 62 According to step S 61 The established geometric model determines the computational fluid domain, meshing, numerical solver and physical model; S 63 According to step S 55 Based on the results recorded in , set the porous outlet as a pressure outlet boundary condition or a velocity outlet boundary condition; S 64 , adopt the step S 62 and the step S 63 The numerical model was generated by setting the parameters, and a single-phase water jet CFD analysis of the porous pressure relief device based on the nuclear power plant engineering prototype was carried out, and the calculation results were generated; S 65 , confirm whether the CFD analysis of the single-phase water jet working conditions of all porous pressure relief devices is completed; if not, go to step S 64 Start CFD analysis of the next working condition; if completed, save the CFD calculation results of all working conditions, and record the oscillation pressure amplitude and oscillation pressure main frequency near the porous pressure relief device and various locations in the cooling water pool.

10. The high-parameter porous steam jet condensation pressure oscillation coupled simulation method according to claim 9, characterized in that: The step S 62 The following steps are included: S 621 , start the grid division software, import the step S 61 The geometric model established in S 622 , establish computational fluid domain; S 623 , set the surface mesh, volume mesh and boundary layer mesh parameters; S 624 , generate structured or unstructured grids; S 625 , check whether the grid quality meets the requirements; if not, return to step S 623 Re-adjust the surface mesh, volume mesh, and boundary layer mesh parameters; if satisfied, save the simulation file and record the computational fluid domain and meshing parameters; S 626 , select the physical model and numerical solver; S 627 , set the numerical solver parameters and physical model parameters; S 628 , save the simulation file, and record the numerical solver parameters and physical model parameters.

11. The high-parameter porous steam jet condensation pressure oscillation coupled simulation method according to claim 9, characterized in that: The step S 64 The following steps are included: S 641 , import the step S 625 The mesh generated in ; S 642 , enter the step S 628 Generate a numerical model using the numerical solver parameters and physical model parameters recorded in ; S 643 According to step S 63 Complete the boundary condition setting by recording the porous outlet boundary condition parameters in ; S 644 2. Start CFD numerical solution, carry out CFD analysis of porous jet, and generate calculation results; S 645 , determine whether the CFD calculation results converge; if not, go to step S 642 , readjust the numerical solver and physical model parameters; if converged, save the CFD calculation results.

12. A high-parameter porous steam jet condensation pressure oscillation coupled simulation system, characterized in that: The simulation system adopts the high-parameter porous steam jet condensation pressure oscillation coupled simulation method according to any one of claims 1 to 11, and the simulation system includes: The geometric modeling module establishes the geometric model of single-hole jet or multi-hole jet based on the actual geometric dimensions of the multi-hole pressure relief device and the cooling water pool; A calculation setting module, which determines the computational fluid domain, mesh division, numerical solver and physical model based on the geometric model; The boundary condition module determines the single-hole outlet saturated steam pressure, mass flow rate, and cooling water pool temperature according to the high-parameter steam jet condensation working conditions, and sets the single-hole steam jet boundary conditions; Single-hole jet module, used to conduct CFD analysis of high-parameter single-hole steam jet condensation pressure oscillations and generate calculation results, outputting the equilibrium steam plume length, oscillation pressure amplitude at the single-hole outlet, and oscillation pressure main frequency; The iterative correction module compares the calculation results output by CFD analysis with known test results and iteratively corrects the calculation results whose errors are greater than the preset limit; Pressure Oscillation Module: Uses a simplified pressure oscillation model to determine and record the time-varying changes in cooling water velocity and plume pressure at the vapor-liquid interface of a single hole, which is used to set the outlet boundary conditions in the calculation of multi-hole jets. The porous jet module establishes numerical models of a porous pressure relief device and a cooling water pool based on an engineering prototype, and conducts single-phase water jet CFD analysis to obtain the overall pressure oscillation characteristics in the cooling water pool under high-parameter steam jet condensation conditions.

13. An electronic device, characterized in that: The electronic device includes: a processor and a memory, the memory storing programs or instructions that can be run on the processor, and the programs or instructions are executed by the processor to implement the high-parameter porous steam jet condensation pressure oscillation coupling simulation method as described in any one of claims 1-11.

14. A readable storage medium, characterized in that The readable storage medium stores a program or instruction, and when the program or instruction is executed by the processor, the high-parameter porous steam jet condensation pressure oscillation flow coupling simulation method as described in any one of claims 1-11 is implemented.

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