Numerical analysis system of two-phase discharge load in fast transient process

Abstract

The present application belongs to the technical field of two-phase discharge load analysis, and particularly relates to a two-phase discharge load numerical analysis system in a rapid transient process. In the present application, an analysis object recognition module is used to obtain the discharge system design characteristics of different components, and the obtained characteristics are transmitted to a numerical analysis module through a data transmission module for modeling and calculation. The key parameter information obtained by the numerical analysis module is transmitted to a key mathematical analysis module through the data transmission module. The key mathematical analysis module adopts different numerical analysis methods for different pipelines according to the discharge system design characteristics obtained by the analysis object recognition module. The key mathematical analysis module obtains real-time change data information of the load on each pipeline of the discharge system. The present application standardizes, unifies and simplifies the analysis process from obtaining the thermal hydraulic parameter change to finally obtaining the impact load in the complex two-phase discharge problem, and provides corresponding analysis tools for the mechanical analysis and design optimization of the discharge process.

Description

Technical Field

[0001] This invention belongs to the field of two-phase emission load analysis, specifically relating to a numerical analysis system for two-phase emission loads in a rapid transient process. Background Technology

[0002] Two-phase emission load analysis technology during rapid transient processes is a relatively new technology in various industrial sectors in China. In the design of domestically developed third-generation power units, the use of pilot-operated safety valves—a type of valve with a faster opening time and better automatic overpressure protection function compared to second-generation power plants—led to the development and verification of a complex two-phase emission load analysis method. However, to comprehensively promote this interdisciplinary analysis method, involving thermal hydraulics, mechanics, and structural design, across all industrial sectors, and to standardize, unify, and simplify the analysis process for complex two-phase emission problems, a highly efficient numerical analysis system needs to be developed to meet the requirements of load analysis, safety evaluation, and design optimization, thereby improving design efficiency. Summary of the Invention

[0003] The technical problem solved by this invention is to establish a numerical analysis system for two-phase emission loads in rapid transient processes, which standardizes, unifies, and simplifies the analysis process from obtaining changes in thermal and hydraulic parameters to finally obtaining impact loads in complex two-phase emission problems, and provides corresponding analysis tools for mechanical analysis and design optimization of emission processes.

[0004] The technical solution adopted in this invention is as follows:

[0005] A numerical analysis system for two-phase emission loads during rapid transient processes includes a numerical analysis module, an analysis object identification module, a data transmission module, and a key mathematical analysis module. The analysis object identification module comprises several sub-modules for acquiring emission system design features of different components. These emission system design features are transmitted to the numerical analysis module via the data transmission module for modeling and calculation. The segmentation and geometric information obtained by the numerical analysis module during modeling are transmitted to the analysis object identification module. The key parameter information calculated by the numerical analysis module is transmitted to the key mathematical analysis module via the data transmission module. Based on the emission system design characteristics obtained by the analysis object identification module, the key mathematical analysis module employs different numerical analysis methods for different pipelines. The key mathematical analysis module obtains real-time data on the load changes of each pipeline in the emission system.

[0006] The numerical analysis module uses the parent program as its carrier.

[0007] The parent program should meet the following requirements:

[0008] The parent program is a system-level program capable of conducting thermal-hydraulic analysis, and has been thoroughly verified by separation effect experiments and overall effect experiments, proving that it can reasonably simulate overpressure and discharge.

[0009] The parent program has the ability to simulate valves, pipes, tees, and reducers;

[0010] The parent program should have the ability to simulate transient processes of heat transfer in two-phase flow, and possess corresponding fully validated physical models to simulate critical flow phenomena, flow pattern transition processes, and interphase interactions between vapor and liquid phases.

[0011] The parent program should have good conditions for secondary development.

[0012] The plurality of sub-modules include:

[0013] The first submodule identifies basic information about valve components, including full opening time, valve throat diameter, and vapor-liquid phase displacement.

[0014] The second submodule identifies information about ordinary pipes, which include four types: pipes that are in contact with the outside atmosphere at both ends, pipes that are in contact with the outside atmosphere only at the beginning end, pipes that are in contact with the outside atmosphere only at the end end, and pipes that are not in contact with the outside atmosphere at either end. When modeling the pipes, geometric information such as the number of segments, the length of each segment, and the area are generated based on the design characteristics. The second submodule obtains relevant information for all ordinary pipes.

[0015] The third submodule is used to obtain information about some special types of connectors, including reducers and tees. This information includes: the cross-sectional area of ​​both sides of the reducer, the height of the reducer, the inner diameter and length of the tee in the main flow direction, and the inner diameter and length of the tee in the branch flow direction.

[0016] The fourth submodule identifies the connection relationships of all structural components in the system, numbers all elbows connecting upstream and downstream pipes, identifies the bending radius and bending angle of the elbows, and stores the relevant information.

[0017] The data transmission module transmits the emission system design features obtained by the analysis object identification module to the numerical analysis module, and transmits the liquid phase velocity, vapor phase velocity, liquid phase density, vapor phase density, pressure, and cavitation fraction information obtained by the numerical analysis module directly or indirectly to the key mathematical analysis module.

[0018] The analysis object identification module transmits relevant information to the data transmission module at transient time 0, but the key parameter information calculated by the data transmission module at each transient calculation time should be transmitted to the key mathematical analysis module.

[0019] After reading and obtaining the design characteristics of the emission system, the data transmission module will combine the analyzed transient initial state with its two-phase numerical solution module and call critical flow model, interphase heat and mass transfer model, flow pattern conversion model, interface tracking model, etc. to carry out transient calculations of complex two-phase emission processes.

[0020] The key mathematical analysis module calculates the load time history curve of each discharge pipeline in real time according to the pipeline type.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] (1) The present invention provides a two-phase emission load numerical analysis system for a fast transient process, which can not only perform thermal-hydraulic analysis of the reactor system, but also has a real-time load calculation function.

[0023] (2) The present invention provides a numerical analysis system for two-phase emission load in a rapid transient process, which can be applied to the analysis of emission load of pilot-operated safety valves and provides technical support for safety evaluation and design optimization;

[0024] (3) The present invention provides a two-phase emission load numerical analysis system for a rapid transient process, which provides design improvement suggestions for pipeline material optimization through simulation analysis; and provides design improvement suggestions for the setting value design of the pneumatic pressure relief valve of the pressure regulator in the design demonstration of the unit emission system.

[0025] (4) The present invention provides a numerical analysis system for two-phase emission load in a fast transient process. This numerical analysis system can be applied to emission load analysis of autonomous small reactor automatic depressurization system, design of domestic pilot-operated safety valve, analysis of two-phase emission problems, and other analyses involving two-phase emission processes in the industry can also use this numerical analysis system to complete design optimization and design evaluation. Therefore, it has a very broad application prospect.

[0026] (5) The present invention provides a numerical analysis system for two-phase emission load in a fast transient process, which provides a necessary analysis tool for complex two-phase emission problems in industry and fills the technical gap in the lack of a standardized numerical analysis system for complex two-phase emission load in China. Attached Figure Description

[0027] Figure 1 This invention provides a schematic diagram of a two-phase emission load numerical analysis system for a rapid transient process. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] like Figure 1 As shown, the present invention provides a numerical analysis system for two-phase emission loads in a fast transient process, including a numerical analysis module. The numerical analysis module uses a parent program as a carrier, and the parent program should meet the following requirements:

[0032] (a) The parent program is a system-level program that can be used to carry out thermal-hydraulic analysis, and has been fully verified by separation effect experiments and overall effect experiments, proving that it can reasonably simulate physical processes such as overpressure and discharge.

[0033] (b) The parent program has the ability to simulate structural components such as valves, pipes, tees, reducers, etc.

[0034] (c) The parent program should have the ability to simulate transient processes of heat transfer in two-phase flow and have corresponding fully validated physical models to simulate critical flow phenomena, flow pattern transition processes, and interphase interactions between vapor and liquid phases.

[0035] (d) The parent program should have good secondary development capabilities;

[0036] The object identification module is designed for complex two-phase emission processes, which typically involve structures such as valves, pipes, tees, and pressure relief boxes. This module is further divided into several sub-modules to acquire the emission system design characteristics of different components.

[0037] The first submodule identifies basic information about valve components, including full opening time, valve throat diameter, and vapor-liquid phase displacement.

[0038] The second submodule identifies information about ordinary pipes, which include four types: pipes that are in contact with the outside atmosphere at both ends (type 1 pipes), pipes that are in contact with the outside atmosphere only at the beginning end (type 2 pipes), pipes that are in contact with the outside atmosphere only at the end end (type 3 pipes), and pipes that are not in contact with the outside atmosphere at either end (type 4 pipes). When modeling the pipes, geometric information such as the number of segments, the length of each segment, and the area are generated based on the design characteristics. The second submodule obtains relevant information for all ordinary pipes.

[0039] The third submodule is used to obtain information about some special types of connectors, mainly including reducers, tees, etc. This information includes: the cross-sectional area of ​​both sides of the reducer, the height of the reducer, the inner diameter and length of the tee in the main flow direction, and the inner diameter and length of the tee in the branch flow direction.

[0040] The fourth submodule identifies the connection relationships of all structural components in the system, numbers all elbows connecting upstream and downstream pipes, identifies the bending radius and bending angle of the elbows, and stores the relevant information.

[0041] The data transmission module transmits the emission system design features obtained by the analysis object identification module to the numerical analysis module, and transmits the liquid phase velocity, vapor phase velocity, liquid phase density, vapor phase density, pressure, and cavitation fraction information obtained by the numerical analysis module directly or indirectly to the key mathematical analysis module.

[0042] The six parameters—liquid phase velocity, vapor phase velocity, liquid phase density, vapor phase density, pressure, and cavitation fraction—are parameters that can be directly obtained by solving the basic equations of the numerical analysis module. If some of these parameters cannot be directly obtained through the basic equations, they need to be converted into the above six parameters through certain means. For example, if the numerical analysis module can obtain the internal energy calculation results, the density value can be indirectly obtained through the pressure and internal energy values.

[0043] The analysis object identification module only needs to pass relevant information to the data transfer module at transient time 0, but it should also pass the key parameter information calculated by the data transfer module at each transient calculation time to the key mathematical analysis module. After reading and obtaining the design characteristics of the emission system, the data transfer module will combine the analyzed transient initial state with its two-phase numerical solution module, and call critical flow model, interphase heat and mass transfer model, flow pattern transformation model, interface tracking model, etc. to carry out transient calculations of complex two-phase emission processes.

[0044] It is recommended that the data transmission module transmit the key parameter results to the key mathematical analysis module every 0.0001 seconds;

[0045] The key mathematical analysis module is the core module of this system (referred to as module 3). Its function is to calculate and obtain the load time history curve of each discharge pipeline in real time according to the pipeline type.

[0046] (a) For Type 1 pipelines, the two-phase discharge load should consider the inlet pressure term, inlet kinetic energy term, outlet pressure term, outlet kinetic energy term, and acceleration term for each segment. The load on the pipeline caused by the fluid is the result of the combined effect of the above five terms. The kinetic energy term and acceleration term should be considered separately for the liquid phase and the vapor phase, and the acceleration term should be applied to each segment of the pipeline before integration.

[0047] (b) For Type 2 pipelines, the two-phase discharge load should consider the inlet pressure term, the inlet kinetic energy term, and the acceleration term of each segment. The load on the pipeline caused by the fluid is the result of the combined effect of the above three terms. The kinetic energy term and the acceleration term should be considered separately for the liquid phase and the vapor phase, and the acceleration term should be carried out separately for each segment of the pipeline before integration.

[0048] (c) For Type 3 pipelines, the two-phase discharge load should consider the outlet pressure term, outlet kinetic energy term, and acceleration term of each segment. The load on the pipeline caused by the fluid is the result of the combined effect of the above three terms. The kinetic energy term and acceleration term should be considered separately for the liquid phase and the vapor phase, and the acceleration term should be carried out separately for each segment of the pipeline before integration.

[0049] (d) For type 4 pipelines, the two-phase discharge loads are considered only for the acceleration terms of each segment. The acceleration terms should be considered separately for the liquid and vapor phases, and then integrated after the acceleration terms are applied to each segment of the pipeline.

[0050] (e) For reducers, they are first treated as pipes with different cross-sections and classified as type 4 pipes. For tees, they are generally connected to other pipes in the system, so they are considered together with the pipes connected to them in load calculations.

[0051] The analysis object identification module includes several sub-modules for acquiring emission system design features of different components. These emission system design features are transmitted to the numerical analysis module via a data transmission module for modeling and calculation. The segmentation and geometric information obtained during modeling by the numerical analysis module are transmitted to the analysis object identification module. The key parameter information calculated by the numerical analysis module is transmitted to the key mathematical analysis module via the data transmission module. Based on the emission system design characteristics obtained by the analysis object identification module, the key mathematical analysis module employs different numerical analysis methods for different pipelines. The key mathematical analysis module obtains real-time data on the load changes of each pipeline in the emission system.

[0052] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0053] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A numerical analysis system for two-phase emission loads in a fast transient process, characterized in that, The system includes a numerical analysis module, an analysis object identification module, a data transmission module, and a key mathematical analysis module. The analysis object identification module comprises several sub-modules for acquiring emission system design characteristics of different components. These emission system design characteristics are transmitted to the numerical analysis module via the data transmission module for modeling and calculation. The segmentation and geometric information obtained by the numerical analysis module during modeling are transmitted to the analysis object identification module. The key parameter information calculated by the numerical analysis module is transmitted to the key mathematical analysis module via the data transmission module. Based on the emission system design characteristics obtained by the analysis object identification module, the key mathematical analysis module employs different numerical analysis methods for different pipelines. The key mathematical analysis module obtains real-time data on the load changes of each pipeline in the emission system. The numerical analysis module uses the parent program as its carrier; The parent program should meet the following requirements: The parent program is a system-level program capable of conducting thermal-hydraulic analysis, and has been thoroughly verified by separation effect experiments and overall effect experiments, proving that it can reasonably simulate overpressure and discharge. The parent program has the ability to simulate valves, pipes, tees, and reducers; The parent program should have the ability to simulate transient processes of heat transfer in two-phase flow, and possess corresponding fully validated physical models to simulate critical flow phenomena, flow pattern transition processes, and interphase interactions between vapor and liquid phases. The parent program should have good secondary development capabilities; The plurality of sub-modules include: The first submodule identifies basic information about valve components, including full opening time, valve throat diameter, and vapor-liquid phase displacement. The second submodule identifies information about ordinary pipes, which include four types: pipes that are in contact with the outside atmosphere at both ends, pipes that are in contact with the outside atmosphere only at the beginning end, pipes that are in contact with the outside atmosphere only at the end end, and pipes that are not in contact with the outside atmosphere at either end. When modeling the pipes, the number of segments, the length of each segment, and the area geometry information are generated based on the design characteristics. The second submodule obtains relevant information for all ordinary pipes. The third submodule is used to obtain information about some special types of connectors, including reducers and tees. This information includes: the cross-sectional area of ​​both sides of the reducer, the height of the reducer, the inner diameter and length of the tee in the main flow direction, and the inner diameter and length of the tee in the branch flow direction. The fourth submodule identifies the connection relationships of all structural components in the system, numbers all elbows connecting upstream and downstream pipes, identifies the bending radius and bending angle of the elbows, and stores the relevant information. The key mathematical analysis module calculates the load time history curve of each discharge pipeline in real time according to the pipeline type.

2. The numerical analysis system for two-phase emission loads in a fast transient process according to claim 1, characterized in that, The data transmission module transmits the emission system design features obtained by the analysis object identification module to the numerical analysis module, and transmits the liquid phase velocity, vapor phase velocity, liquid phase density, vapor phase density, pressure, and cavitation fraction information obtained by the numerical analysis module directly or indirectly to the key mathematical analysis module.

3. The numerical analysis system for two-phase emission loads in a fast transient process according to claim 2, characterized in that, The analysis object identification module transmits relevant information to the data transmission module at transient time 0, but the key parameter information calculated by the data transmission module at each transient calculation time should be transmitted to the key mathematical analysis module.

4. The numerical analysis system for two-phase emission loads in a fast transient process according to claim 3, characterized in that, After reading and obtaining the design characteristics of the emission system, the data transmission module will combine the analyzed transient initial state with its two-phase numerical solution module, and call the critical flow model, interphase heat and mass transfer model, flow pattern conversion model, and interface tracking model to carry out transient calculations of complex two-phase emission processes.

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