A deaerator simulation method based on pipe network model multi-node combined distribution parameter simulation

Abstract

The application discloses a kind of based on pipe network model multi-node combination distribution parameter simulation deaerator simulation method, comprising: the physical structure of deaerator is analyzed, it is divided into liquid droplet spray zone, steam bubble zone at least two functional sections, multi-node division is carried out for each functional section;At least one of the physical parameters of flow velocity, pressure, temperature, density is defined for each node;Using distribution parameter method, based on the mutual coupling relationship between nodes, fluid flow, heat transfer and material diffusion process are simulated;Combined with mass conservation equation, energy conservation equation and momentum conservation equation, the physical parameter dynamic change of each node is numerically solved using finite difference method, the physical parameter distribution results of all nodes are output, and the deaerator simulation is completed.The present application can solve the problem that the traditional deaerator simulation model in the prior art cannot reflect the multi-node parameter distribution characteristics, and the precision and calculation efficiency are difficult to balance.

Description

Technical Field

[0001] This invention belongs to the field of power plant simulation technology, specifically relating to a deaerator simulation method based on multi-node combined distributed parameter simulation of a pipeline network model. Background Technology

[0002] Deaerators are crucial components in power plants, used to remove dissolved oxygen from water and prevent corrosion of pipelines. Existing deaerator simulation methods often employ single-node models or simplified pipe network models, failing to accurately depict the interactions and parameter spatial distribution characteristics of multiple nodes within a complex system. These methods generally suffer from insufficient simulation accuracy and high computational complexity. Therefore, a new simulation method is urgently needed that considers the distribution characteristics of multiple nodes within the deaerator while offering high simulation accuracy and efficiency. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a deaerator simulation method based on multi-node combined distributed parameter simulation of pipeline network model to address the shortcomings of the prior art. This method can solve the problems in the prior art where traditional deaerator simulation models cannot reflect the multi-node parameter distribution characteristics and the difficulty in balancing accuracy and computational efficiency.

[0004] To achieve the above objectives, this invention provides a deaerator simulation method based on multi-node combined distributed parameter simulation of a pipeline network model, comprising: The physical structure of the deaerator is analyzed and divided into at least two functional sections: a droplet spray zone and a steam bubbling zone. Each functional section is further divided into multiple nodes. Define at least one physical parameter among flow rate, pressure, temperature, and density for each node; The distributed parameter method is used to simulate fluid flow, heat transfer and mass diffusion processes based on the mutual coupling relationship between nodes; By combining the mass conservation equation, energy conservation equation, and momentum conservation equation, the finite difference method is used to numerically solve the dynamic changes of the physical parameters of each node, output the distribution results of the physical parameters of all nodes, and complete the deaerator simulation.

[0005] In the above scheme, the droplet spray area is the main area of ​​gas-liquid interaction. The droplet spray area is divided into two-dimensional nodes in the horizontal and vertical directions, where each node represents a local physical state.

[0006] In the above scheme, the steam bubbling zone is a mixing area of ​​steam and liquid. The node division of the steam bubbling zone is based on the flow characteristics of the fluid and the laws of fluid mechanics, and adopts a two-dimensional node division method with horizontal and vertical directions. Each node represents a local physical state.

[0007] In the above scheme, when the distributed parameter method simulates the fluid flow process, a pipeline-based model is used to calculate the fluid flow between nodes. The pressure difference and flow rate between nodes are modeled through a nonlinear relationship to simulate the flow characteristics inside the deaerator.

[0008] In the above scheme, when the distributed parameter method simulates the heat transfer and mass diffusion process, it is necessary to consider the temperature of the fluid and the mass diffusion phenomenon between nodes.

[0009] In the above scheme, the step of using the finite difference method to numerically solve for the dynamic changes of the physical parameters of each node includes: The time differential terms in the mass conservation equation, energy conservation equation, and momentum conservation equation are transformed into finite difference forms for iterative solution.

[0010] In the above scheme, the physical parameter results output by the deaerator simulation method include the temperature distribution, pressure distribution, and flow distribution of each node, which are used for the design optimization and performance evaluation of the deaerator.

[0011] Furthermore, to achieve the above objectives, this invention also proposes a deaerator simulation device based on multi-node combined distributed parameter simulation of a pipeline network model, comprising: The partitioning module is used to analyze the physical structure of the deaerator, dividing it into at least two functional sections: a droplet spray zone and a steam bubbling zone. For each functional section, multiple nodes are partitioned. The parameter definition module is used to define at least one physical parameter among flow rate, pressure, temperature, and density for each node; The simulation module is used to simulate fluid flow, heat transfer, and mass diffusion processes using the distributed parameter method based on the mutual coupling relationship between nodes; The calculation and result output module is used to combine the mass conservation equation, energy conservation equation and momentum conservation equation, and use the finite difference method to numerically solve the dynamic changes of the physical parameters of each node, output the distribution results of the physical parameters of all nodes, and complete the deaerator simulation.

[0012] Furthermore, to achieve the above objectives, the present invention also proposes a deaerator simulation device based on the simulation of multi-node combined distributed parameters of a pipeline network model. The deaerator simulation device based on the simulation of multi-node combined distributed parameters of a pipeline network model includes: a memory, a processor, and a deaerator simulation program based on the simulation of multi-node combined distributed parameters of a pipeline network model stored in the memory and executable on the processor. The deaerator simulation program based on the simulation of multi-node combined distributed parameters of a pipeline network model is configured to implement the above-mentioned deaerator simulation method based on the simulation of multi-node combined distributed parameters of a pipeline network model.

[0013] Furthermore, to achieve the above objectives, the present invention also proposes a storage medium storing a deaerator simulation program based on the multi-node combined distributed parameter simulation of a pipeline network model. When the deaerator simulation program based on the multi-node combined distributed parameter simulation of a pipeline network model is executed by a processor, the above-mentioned deaerator simulation method based on the multi-node combined distributed parameter simulation of a pipeline network model is implemented.

[0014] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: This invention provides a deaerator simulation method based on multi-node combined distributed parameter simulation of a pipe network model. This method solves the problems of traditional deaerator simulation models in the prior art failing to reflect the multi-node parameter distribution characteristics and the difficulty in balancing accuracy and computational efficiency. The method of this invention, through multi-node combination partitioning, can accurately describe the spatial distribution of thermodynamic parameters in different regions inside the deaerator, overcoming the deficiency of single-node models in reflecting internal gradients. By using the distributed parameter method to couple the flow, heat transfer, and mass transfer processes of each node, it fully considers the mutual influence between multiple nodes, resulting in simulation accuracy significantly higher than traditional simplified pipe network models. Compared to three-dimensional CFD methods, this invention uses a two-dimensional pipe network model combined with the finite difference method, significantly reducing the computational load and making it suitable for engineering design and online simulation applications. Through modeling the nonlinear pressure difference-flow relationship between nodes, it can accurately simulate the complex flow characteristics inside the deaerator, and is particularly suitable for performance prediction under varying operating conditions. Attached Figure Description

[0015] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a flowchart illustrating a deaerator simulation method based on multi-node combined distributed parameters of a pipeline network model, as described in Embodiment 1 of the present invention.

[0016] Figure 2 This is an architecture diagram of a deaerator simulation method based on multi-node combined distributed parameter simulation of a pipeline network model, as described in Embodiment 1 of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0018] It should be understood that the sequence number of each step in the embodiment does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0019] Example 1 This application provides a deaerator simulation method based on multi-node combined distributed parameter simulation of a pipeline network model. Please refer to [link to relevant documentation]. Figure 1-2 ,include: S1. Analyze the physical structure of the deaerator and divide it into at least two functional sections: a droplet spray zone and a steam bubbling zone. For each functional section, perform multi-node division.

[0020] Specifically, in this embodiment, a detailed analysis of the physical structure of the power unit deaerator is first required to determine the main functional sections within the deaerator and to perform multi-node meshing. Based on structural parameters, multi-node meshing of each functional section is completed, and simulation input conditions are determined based on boundary parameters, providing a foundation for subsequent numerical simulations of fluid flow, heat transfer, and mass exchange. In this embodiment, the main functional sections of the deaerator include a droplet spray zone and a steam bubbling zone: The droplet spray region is the main area of ​​gas-liquid interaction, involving droplet formation and vapor bubble transport. This region needs to be divided into two dimensions using multiple nodes, namely horizontal and vertical nodes, each node representing a local physical state.

[0021] Steam bubbling zone: This is the mixing region of steam and liquid, where liquid flows and bubbles rise. The division of this zone should consider the fluid flow characteristics, such as steam velocity and bubble rise velocity. Within this zone, node division also needs to be based on fluid mechanics principles. For example, the node division of the steam bubbling zone needs to match the flow characteristics of steam velocity and bubble rise velocity, with denser node arrangement in areas of rapid velocity changes and sparser node arrangement in areas of gentle velocity changes. The steam bubbling zone also employs a two-dimensional node division method, both horizontally and vertically, where each node represents a local physical state.

[0022] In this embodiment, the multi-node division of each functional section should be based on the structural characteristics of the deaerator and the characteristics of fluid flow to determine the number and location of nodes, so as to achieve the purpose of accurately simulating fluid flow, heat transfer and mass exchange.

[0023] S2 defines at least one physical parameter among flow rate, pressure, temperature, and density for each node, and establishes the material and energy exchange relationship between nodes.

[0024] Specifically, in this embodiment, each node dividing a functional segment needs to define corresponding physical parameters, including flow rate, pressure, temperature, density, and other physical parameters. Furthermore, it establishes material and energy exchange relationships between nodes, namely, the mass flow rate and heat exchange between nodes.

[0025] S3 uses the distributed parameter method to simulate fluid flow, heat transfer, and mass diffusion processes based on the mutual coupling relationship between nodes.

[0026] In this embodiment, the distributed parameter method is used to simulate the dynamic behavior of the fluid during processes such as fluid flow, heat transfer, and mass diffusion. It can be understood that the distributed parameter method simulates fluid motion, temperature changes, and mass diffusion based on the coupling between nodes. Flow process simulation: A pipe network-based model is used to calculate the fluid flow between nodes, considering the mutual influence between nodes. The pressure difference and flow rate between nodes are modeled using a nonlinear relationship to simulate the flow characteristics inside the deaerator.

[0027] Heat transfer and mass diffusion: Consider the temperature and mass diffusion phenomena of fluids between nodes. For example, fluids connected by pipes may experience temperature changes due to heat exchange, accompanied by mass diffusion.

[0028] Subsequent steps involve numerically solving for the thermodynamic changes within each node, such as temperature gradients and flow rate changes, to achieve an accurate simulation of the entire deaerator's internal state.

[0029] S4 combines the mass conservation equation, energy conservation equation, and momentum conservation equation, and uses the finite difference method to numerically solve the dynamic changes of the physical parameters of each node, outputting the distribution results of the physical parameters of all nodes, and completing the deaerator simulation.

[0030] Specifically, this embodiment combines the mass conservation equation, energy conservation equation, and momentum conservation equation, and uses the finite difference method for numerical solution. These equations describe the dynamic changes of the fluid within the deaerator, particularly the changes in flow velocity, pressure, and temperature. The final output shows the distribution of physical parameters such as temperature, pressure, and flow rate at each node, providing data support for the design optimization and performance evaluation of the deaerator. The method provided in this embodiment can accurately simulate the flow characteristics of the fluid within the deaerator.

[0031] Specifically, this embodiment focuses on the droplet spray region and details the implementation process of the method in this embodiment: The droplet flow in the droplet spray region is considered as the mainstream fluid. For each node in the droplet spray region, a general expression for parameter calculation can be derived from the following mathematical derivation.

[0032] First, the basic mass conservation equation for the droplet flow within the droplet spray region is constructed, as shown in equation (1). Flow exists in multiple directions at different nodes, and also includes the condensation flow generated during the droplet flow and surrounding vapor heat exchange and condensation: (1) In the formula, The density of spray droplets within a node of the deaerator's droplet spray zone, in kg / m³. 3 ; The total heat transfer area of ​​the spray droplet flow within the node of the deaerator droplet spray zone, in m². 2 ; The flow rate of spray droplets within a node of the deaerator droplet spray zone is expressed in kg / s. The condensation flow rate within a node of the deaerator droplet spray zone is expressed in kg / s. t The simulation calculation time for the simulation model is expressed in seconds. x The horizontal movement direction (lateral) within the deaerator; y The vertical direction of movement (longitudinal) within the deaerator.

[0033] Within a node, by simultaneously integrating the spatial location both horizontally and vertically, the expression is made free of partial derivatives with respect to spatial location, thus unifying all flows as the total flow into and out of the node: (2) In the formula, The volume of spray droplets within a node of the deaerator droplet spray zone, in meters. 3 .

[0034] In equation (2), the differential derivative terms with respect to time are transformed into a difference expression, as shown in the following equation: (3) In the formula, Δ t The simulation time step is in seconds.

[0035] In the droplet spray region, the mainstream fluid, the spray droplets, remain in a supercooled state. Other parameters cannot be calculated using only density as a single parameter; therefore, a mathematical derivation based on the energy conservation equation was performed. The basic energy conservation equation for the spray droplets is shown below. The spray droplets absorb heat from the surrounding steam. Q sp ), and the energy flow and heat exchange processes in multiple directions are also represented in different nodes.

[0036] (4) In the formula, The value of spray droplets within a node of the deaerator droplet spray zone is expressed in kJ / kg. Q sp The heat exchange within a node of the deaerator droplet spray zone is expressed in kW.

[0037] After integrating the spatial location, we obtain a transformed energy conservation expression that does not involve spatial location. The total energy flow through a node is represented by the inlet and outlet flow enthalpy values ​​and the heat transfer at the node. (5) In equation (5), the corresponding differential terms are transformed into difference terms for processing, as shown in the following equation: (6) In the droplet spray region, assuming the spray droplet flow is in a supercooled state, pressure can be calculated using two parameters: density and enthalpy. Other parameters, such as water, require calculations based on the fundamental physical properties of water. (7) In the formula, The pressure of the spray droplets within the node of the deaerator droplet spray zone, in MPa; f These are the basic calculation relationships for water properties.

[0038] Pressure difference between nodes within the droplet spray zone ( ) and flow ( The relationship between them can be represented in the following form: (8) In the formula, The pressure difference between adjacent nodes in the deaerator droplet spray zone, in MPa; This is the flow resistance coefficient. k This is a correction factor.

[0039] Within the droplet spray region, vapor condenses around the droplets. The outflow rate from a node needs to be added to the vapor condensation rate within the node. This allows us to determine the outflow from a node to each of its adjacent nodes in each direction. )as follows: ou = (9) In the formula, ou This represents the outflow from a node to each adjacent node in each direction. The pressure difference between adjacent nodes in different directions; This refers to the traffic flowing into the node.

[0040] The calculation of the steam bubbling zone can be referenced from the droplet spray zone, and will not be elaborated here.

[0041] Output the physical parameter distribution results of all nodes to complete the deaerator simulation.

[0042] Example 2 This application provides a deaerator simulation device based on multi-node combined distributed parameter simulation of a pipeline network model, including: The partitioning module is used to analyze the physical structure of the deaerator, dividing it into at least two functional sections: a droplet spray zone and a steam bubbling zone. For each functional section, multiple nodes are partitioned. The parameter definition module is used to define at least one physical parameter among flow rate, pressure, temperature, and density for each node; The simulation module is used to simulate fluid flow, heat transfer, and mass diffusion processes using the distributed parameter method based on the mutual coupling relationship between nodes; The calculation and result output module is used to combine the mass conservation equation, energy conservation equation and momentum conservation equation, and use the finite difference method to numerically solve the dynamic changes of the physical parameters of each node, output the distribution results of the physical parameters of all nodes, and complete the deaerator simulation.

[0043] Example 3 This application also provides a deaerator simulation device based on the multi-node combination distributed parameter simulation of a pipeline network model, such as a smartphone, tablet, laptop, desktop computer, rack server, blade server, tower server, or cabinet server (including independent servers or server clusters composed of multiple servers) that can execute programs.

[0044] The deaerator simulation equipment based on the multi-node combined distributed parameter simulation of the pipeline network model includes, but is not limited to: a memory, a processor, and a deaerator simulation program based on the multi-node combined distributed parameter simulation of the pipeline network model stored on the memory and capable of running on the processor. The deaerator simulation program based on the multi-node combined distributed parameter simulation of the pipeline network model is configured to implement a deaerator simulation method based on the multi-node combined distributed parameter simulation of the pipeline network model.

[0045] In this embodiment, the memory (i.e., the readable storage medium) includes flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), and programmable read-only memory (PROM). The memory can also be an external storage device for a deaerator simulation device based on the multi-node combined distributed parameter simulation of a pipeline network model, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the real-time simulation device. Of course, the memory can also include both internal storage units and external storage devices of the deaerator simulation device based on the multi-node combined distributed parameter simulation of a pipeline network model. In this embodiment, the memory is typically used to store the operating system and various application software installed on the deaerator simulation device based on the multi-node combined distributed parameter simulation of a pipeline network model, such as the program code of the deaerator simulation device based on the multi-node combined distributed parameter simulation of a pipeline network model in Embodiment 2. Furthermore, the memory can also be used to temporarily store various types of data that have been output or will be output.

[0046] In some embodiments, the processor may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chip. This processor is typically used to control the overall operation of a deaerator simulation device based on the distributed parameter simulation of a multi-node combination from a pipe network model. In this embodiment, the processor is used to run program code stored in memory or process data, for example, to run a deaerator simulation device based on the distributed parameter simulation of a multi-node combination from a pipe network model, to implement the deaerator simulation method based on the distributed parameter simulation of a multi-node combination from a pipe network model in Embodiment 1.

[0047] Example 4 This application also provides a storage medium, such as flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, disk, optical disk, server, App store, etc. This storage medium stores a deaerator simulation program based on the distributed parameters of a multi-node combination of a pipeline network model. When this deaerator simulation program is executed by a processor, it implements the corresponding functions. The storage medium in this embodiment is used for a deaerator simulation device based on the distributed parameters of a multi-node combination of a pipeline network model, and when executed by a processor, it implements a deaerator simulation method based on the distributed parameters of a multi-node combination of a pipeline network model.

[0048] It should be noted that, depending on the implementation needs, the various steps described in this application can be broken down into more steps, or two or more steps or parts of the steps can be combined into new steps to achieve the purpose of this invention.

[0049] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A deaerator simulation method based on multi-node combined distributed parameter simulation of a pipeline network model, characterized in that, include: The physical structure of the deaerator is analyzed and divided into at least two functional sections: a droplet spray zone and a steam bubbling zone. Each functional section is further divided into multiple nodes. Define at least one physical parameter among flow rate, pressure, temperature, and density for each node; The distributed parameter method is used to simulate fluid flow, heat transfer and mass diffusion processes based on the mutual coupling relationship between nodes; By combining the mass conservation equation, energy conservation equation, and momentum conservation equation, the finite difference method is used to numerically solve the dynamic changes of the physical parameters of each node, output the distribution results of the physical parameters of all nodes, and complete the deaerator simulation.

2. The deaerator simulation method based on multi-node combined distributed parameter simulation of a pipeline network model according to claim 1, characterized in that, The droplet spray region is the main area of ​​gas-liquid interaction. The droplet spray region is divided into two-dimensional nodes in the horizontal and vertical directions, where each node represents a local physical state.

3. The deaerator simulation method based on multi-node combined distributed parameter simulation of a pipeline network model according to claim 1, characterized in that, The steam bubbling zone is a mixing area of ​​steam and liquid. The nodes of the steam bubbling zone are divided according to the flow characteristics of the fluid and the laws of fluid mechanics, using a two-dimensional node division method in both the horizontal and vertical directions. Each node represents a local physical state.

4. The deaerator simulation method based on multi-node combined distributed parameter simulation of a pipeline network model according to claim 1, characterized in that, When simulating fluid flow using the distributed parameter method, a pipeline-based model is used to calculate the fluid flow between nodes. The pressure difference and flow rate between nodes are modeled through a nonlinear relationship to simulate the flow characteristics inside the deaerator.

5. The deaerator simulation method based on multi-node combined distributed parameter simulation of a pipeline network model according to claim 1, characterized in that, When simulating heat transfer and mass diffusion processes using the distributed parameter method, it is necessary to consider the temperature of the fluid and the mass diffusion phenomenon between nodes.

6. The deaerator simulation method based on multi-node combined distributed parameter simulation of a pipeline network model according to claim 1, characterized in that, The numerical solution for the dynamic changes of the physical parameters of each node using the finite difference method includes: The time differential terms in the mass conservation equation, energy conservation equation, and momentum conservation equation are transformed into finite difference forms for iterative solution.

7. The deaerator simulation method based on multi-node combined distributed parameter simulation of a pipeline network model according to claim 1, characterized in that, The physical parameter results output by the deaerator simulation method include the temperature distribution, pressure distribution, and flow distribution of each node, which are used for deaerator design optimization and performance evaluation.

8. A deaerator simulation device based on multi-node combined distributed parameter simulation of a pipeline network model, characterized in that, include: The partitioning module is used to analyze the physical structure of the deaerator, dividing it into at least two functional sections: a droplet spray zone and a steam bubbling zone. For each functional section, multiple nodes are partitioned. The parameter definition module is used to define at least one physical parameter among flow rate, pressure, temperature, and density for each node; The simulation module is used to simulate fluid flow, heat transfer, and mass diffusion processes using the distributed parameter method based on the mutual coupling relationship between nodes; The calculation and result output module is used to combine the mass conservation equation, energy conservation equation and momentum conservation equation, and use the finite difference method to numerically solve the dynamic changes of the physical parameters of each node, output the distribution results of the physical parameters of all nodes, and complete the deaerator simulation.

9. A deaerator simulation device based on multi-node combined distributed parameter simulation of a pipeline network model, characterized in that, The deaerator simulation device based on the multi-node combined distributed parameter simulation of the pipeline network model includes: a memory, a processor, and a deaerator simulation program based on the multi-node combined distributed parameter simulation of the pipeline network model stored on the memory and executable on the processor. The deaerator simulation program based on the multi-node combined distributed parameter simulation of the pipeline network model is configured to implement a deaerator simulation method based on the multi-node combined distributed parameter simulation of the pipeline network model as described in any one of claims 1 to 7.

10. A storage medium, characterized in that, The storage medium stores a deaerator simulation program based on the multi-node combined distributed parameter simulation of the pipeline network model. When the deaerator simulation program based on the multi-node combined distributed parameter simulation of the pipeline network model is executed by the processor, it implements the deaerator simulation method based on the multi-node combined distributed parameter simulation of the pipeline network model as described in any one of claims 1 to 7.

Images