Water wall heat storage process identification method, device, equipment and medium of direct current furnace thermal power unit with phase change process

Abstract

The application discloses a water-cooled wall heat storage process identification method of a direct current furnace power generating unit containing a phase change process, a device, equipment and a medium, and relates to the field of water-cooled walls. The method comprises the following steps: a segmented heat flow model of a liquid section and a gas section is established; a phase change heat flow model of a two-phase section is established; an overall heat exchange amount model in the water-cooled wall is determined according to the segmented heat flow model and the phase change heat flow model; a fitness function in the form of a root mean square error of a reference value and an actual value is constructed; the optimization value of a heat exchange parameter in the segmented heat flow model is solved by using a particle swarm algorithm based on the fitness function; the length of the liquid section and the length of the gas section are respectively determined by using the segmented heat flow model according to the overall length of the water-cooled wall and the optimization value of the heat exchange parameter; and the phase change height of the two-phase section and the positions of the sections are determined according to the overall length of the water-cooled wall, the length of the liquid section and the length of the gas section. The application can identify the positions of the phase states of the cold fluid in the water-cooled wall, and clearly determine the state conversion process of the working medium in the water-cooled wall.

Description

Technical Field

[0001] The present application relates to the field of water-cooled walls, and in particular to a method, device, equipment and medium for identifying a heat storage process of a water-cooled wall of a DC furnace-fired power unit involving a phase change process. Background Art

[0002] With the large-scale integration of renewable energy sources into the grid, the challenges facing the security and stability of the power grid are becoming increasingly severe. Ultra-supercritical DC furnace-fired power plants play a vital role in ensuring the safety and stability of the power grid. Current research has only modeled and calculated the inlet and outlet energies of the water-cooled walls of DC furnace-fired power plants. Due to the complex heat transfer process during the transition phase, calculations are difficult, and no calculations are currently available for the flow of working fluids within the water-cooled walls. However, with the increasing frequency of DC furnaces operating under low-load and dynamic conditions, their dynamic characteristics are difficult to assess, particularly those within the water-cooled wall components. Therefore, there is an urgent need to refine the modeling of the working fluid flow within the water-cooled wall and clarify the transition phase within the water-cooled wall to address the difficulty in assessing the heat transfer process within the water-cooled wall due to varying operating conditions. Summary of the Invention

[0003] The purpose of this application is to provide a method, device, equipment and medium for identifying the water-cooled wall heat storage process of a DC furnace-fired power unit containing a phase change process, which can identify the position of each phase state of the cooling fluid in the water-cooled wall and clarify the transition process of the working medium in the water-cooled wall.

[0004] To achieve the above objectives, this application provides the following solutions.

[0005] In the first aspect, the present application provides a method for identifying the heat storage process of a water-cooled wall of a DC furnace-fired power unit containing a phase change process, comprising: dividing the water-cooled wall heat exchange process into a liquid section, a two-phase section, and a gas section according to the state change of the fluid in the water-cooled wall; establishing a segmented heat flow model for the liquid section and the gas section; establishing a phase change heat flow model for the two-phase section; determining the overall heat exchange model in the water-cooled wall according to the segmented heat flow model and the phase change heat flow model; constructing a fitness function in the form of a root mean square error between a reference value and an actual value; the reference value is a heat exchange determined according to the enthalpy change at the inlet and outlet of the water-cooled wall. , the actual value is the overall heat exchange rate obtained by solving the overall heat exchange model using a heat flow algorithm; according to the inlet and outlet temperatures of the liquid segment fluid and the inlet and outlet temperatures of the gas segment fluid, based on the fitness function, a particle swarm algorithm is used to solve the optimized values ​​of the heat exchange parameters in the segmented heat flow model; according to the overall length of the water-cooled wall and the optimized values ​​of the heat exchange parameters in the segmented heat flow model, the segmented heat flow model is used to determine the length of the liquid segment and the length of the gas segment respectively; according to the overall length of the water-cooled wall, the length of the liquid segment and the length of the gas segment, the phase change height of the two-phase segment and the position of each segment are determined.

[0006] In the second aspect, the present application provides a water-cooled wall heat storage process identification device for a DC furnace-fired power unit containing a phase change process, including: a segmentation module, a segmented heat flow model establishment module, a phase change heat flow model establishment module, an overall heat exchange model determination module, a fitness function construction module, a solution module, a length determination module and a phase change height determination module.

[0007] The segmentation module is used to divide the water-cooled wall heat exchange process into a liquid section, a two-phase section and a gas section according to the state change of the fluid in the water-cooled wall; the segmentation heat flow model establishment module is used to establish the segmentation heat flow model of the liquid section and the gas section; the phase change heat flow model establishment module is used to establish the phase change heat flow model of the two-phase section; the overall heat exchange model determination module is used to determine the overall heat exchange model in the water-cooled wall according to the segmentation heat flow model and the phase change heat flow model; the fitness function construction module is used to construct a fitness function in the form of the root mean square error between the reference value and the actual value; the reference value is the heat exchange determined according to the enthalpy change at the inlet and outlet of the water-cooled wall, and the actual value is the heat exchange determined according to the enthalpy change at the inlet and outlet of the water-cooled wall. The actual value is the overall heat transfer obtained by solving the overall heat transfer model by using a heat flow algorithm; the solving module is used to solve the optimized values ​​of the heat transfer parameters in the segmented heat flow model by using a particle swarm algorithm based on the fitness function according to the inlet and outlet temperatures of the liquid segment fluid and the inlet and outlet temperatures of the gas segment fluid; the length determination module is used to determine the length of the liquid segment and the length of the gas segment respectively according to the overall length of the water-cooled wall and the optimized values ​​of the heat transfer parameters in the segmented heat flow model using the segmented heat flow model; the phase change height determination module is used to determine the phase change height of the two-phase segment and the position of each segment according to the overall length of the water-cooled wall, the length of the liquid segment and the length of the gas segment.

[0008] In a third aspect, the present application provides a computer device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-mentioned method for identifying the water-cooled wall heat storage process of a DC furnace-fired power unit containing a phase change process.

[0009] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned method for identifying the water-cooled wall heat storage process of a DC furnace-fired power unit containing a phase change process.

[0010] According to the specific embodiments provided in this application, this application has the following technical effects.

[0011] The present application provides a method, device, equipment and medium for identifying the heat storage process of the water-cooled wall of a DC furnace-fired power unit containing a phase change process. The method accurately models the heat exchange process of each section in the water-cooled wall, describes the heat exchange and characteristic change process of the liquid, phase change process and steam in the water-cooled wall during the dynamic change process, and uses a particle swarm algorithm to optimize the heat exchange parameters in the segmented heat flow model, thereby using the segmented heat flow model to identify the position of each phase state of the cooling fluid in the water-cooled wall and clarify the transition process of the working medium in the water-cooled wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0013] Figure 1 A flow chart of a method for identifying the water-wall heat storage process of a DC furnace-fired power unit including a phase change process provided in one embodiment of the present application.

[0014] Figure 2 This is a schematic diagram of identifying the positions of various working fluid phases within a water-cooled wall according to another embodiment of the present application.

[0015] Figure 3 This is a functional module diagram of a device for identifying the water-wall heat storage process of a DC furnace-fired power plant with a phase change process provided in one embodiment of the present application.

[0016] Figure 4 A schematic diagram of the structure of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0018] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0019] In order to identify the position of the liquid, two-phase, vapor and other states of the cooling fluid in the water wall, in an exemplary embodiment, as shown in FIG. Figure 1As shown, a method for identifying the water-wall heat storage process of a DC furnace-fired power unit including a phase change process is provided, including the following steps 101 to 108.

[0020] Step 101: According to the state change of the fluid in the water-cooled wall, the water-cooled wall heat exchange process is divided into a liquid section, a two-phase section and a gas section.

[0021] Step 102: Establish a segmented heat flow model for the liquid segment and the gas segment.

[0022] Step 103: Establish a phase change heat flow model for the two-phase segment.

[0023] Step 104: Determine an overall heat exchange model in the water-cooled wall according to the segmented heat flow model and the phase change heat flow model.

[0024] Step 105: Construct a fitness function in the form of a root mean square error between a reference value and an actual value; the reference value is the heat transfer determined according to the enthalpy change at the inlet and outlet of the water-cooled wall, and the actual value is the overall heat transfer obtained by solving the overall heat transfer model using a heat flow algorithm.

[0025] Step 106: According to the inlet and outlet temperatures of the liquid segment fluid and the inlet and outlet temperatures of the gas segment fluid, based on the fitness function, a particle swarm algorithm is used to solve the optimal values ​​of the heat exchange parameters in the segmented heat flow model.

[0026] Step 107: According to the overall length of the water-cooled wall and the optimized values ​​of the heat exchange parameters in the segmented heat flow model, the segmented heat flow model is used to respectively determine the length of the liquid section and the length of the gas section.

[0027] Step 108: Determine the phase change height of the two-phase segment and the position of each segment based on the overall length of the water-cooled wall, the length of the liquid segment, and the length of the gas segment.

[0028] By implementing the above steps 101 to 108 and accurately modeling the heat absorption process of the working medium in the water-cooled wall, the heat exchange and characteristic change process of the liquid, phase change, and steam in the water-cooled wall during the dynamic change process are described.

[0029] In another exemplary embodiment of the present application, the water-cooled wall heat exchange process is divided into three sections: liquid section, two-phase section, and gas section, based on the state of the fluid in the water-cooled wall (liquid, two-phase, steam). The two-phase section refers to a process in which gas-liquid mixing exists. Since the ratio of gas to liquid at different positions in this process is significantly different, the heat exchange process is difficult to accurately quantify.

[0030] In another exemplary embodiment of the present application, it is assumed that the water-cooled wall is equivalent to an overall length of The pipeline is divided into If there are multiple heat exchange units, the above step 102 can be replaced by the following steps 201 to 202.

[0031] Step 201: Establish the first-order differential equation of the fluid applicable to both the liquid section and the gas section:

[0032] ;

[0033] Where, For the The metal heat capacity of the tube wall of each heat exchange unit is obtained from the boiler manual and calculation. For the tube wall The temperature on each heat exchange unit, For the cold fluid The temperature on each heat exchange unit, For the hot fluid The temperatures on each heat exchange unit, the starting point temperature and the end temperature of the tube wall, cold fluid and hot fluid are all known quantities. For the The equivalent thermal resistance of the cold fluid in each heat exchange unit, For the The equivalent thermal resistance of the thermal fluid in each heat exchange unit, , , , , For the The heat capacity flow rate of the cold fluid in each heat exchange unit, For the The heat capacity flow rate of the thermal fluid in each heat exchange unit, , , is the mass flow rate of the cold fluid, is the mass flow rate of the thermal fluid, and Obtained through thermal power unit measurement points, 、 is the specific heat of the hot and cold fluids, which is the quantity to be identified. is the first intermediate quantity, is the second intermediate quantity, For the The thermal conductivity of the inner wall of each heat exchange unit, For the The thermal conductivity of the outer wall of each heat exchange unit. .

[0034] Step 202: Solve the first-order differential equation to obtain a segmented heat flow model applicable to both the liquid segment and the gas segment:

[0035] ;

[0036] ;

[0037] Where, for At the moment the cold fluid The temperature of each heat exchange unit, The unit length of fluid flowing through The time delay of each heat exchange unit, For the cold fluid The temperature of each heat exchange unit, for At the moment the tube wall The temperature on each heat exchange unit, for At the moment the cold fluid The temperature of each heat exchange unit, for At the moment the thermal fluid The temperature on each heat exchange unit, For the initial moment The wall temperature of each heat exchange unit. In the heat exchange process The time constant of each heat exchange unit, .

[0038] In another exemplary embodiment of the present application, according to the first-order differential equation of the fluid, the same differential equation is solved for the heat transfer process of the two-phase phase change process, because the phase change process approaches infinity, so , and the heat flow model of the two-phase segment is obtained by limiting it:

[0039] ;

[0040] ;

[0041] Where, for The wall temperature of the two-phase section at time t, for The temperature of the cold fluid in the two-phase section at time t, for The temperature of the thermal fluid at that moment. is the wall temperature of the two-phase heat exchanger at the initial moment, which is determined by the position of the previous liquid cold fluid. , It is a function of the pressure inside the water-cooled wall, and its value is determined based on the two-phase area table of water vapor. is the equivalent thermal resistance of the thermal fluid, is the heat transfer resistance of the two-phase fluid, is the time constant of the two-phase segment; is the heat capacity flow of the cold fluid in the two-phase section, is the thermal conductance of the two-phase heat exchanger. 、 、 Respectively 、 、 The calculation method is consistent.

[0042] In another exemplary embodiment of the present application, according to the mechanism models of the liquid segment, gas segment, and two-phase segment (segmented heat flow model and phase change heat flow model) obtained above, especially the inlet and outlet temperatures of the liquid segment and gas segment (the inlet temperature of the liquid segment is , the outlet temperature of the liquid section is ; The inlet temperature of the gas section is The outlet temperature of the gas section is ), the above step 104 can be replaced by the following steps 301~302.

[0043] Step 301: Based on the segmented heat flow model and the phase change heat flow model, the heat exchange model of each segment is determined as follows:

[0044] ;

[0045] ;

[0046] ;

[0047] Where, is the heat transfer of the liquid section, is the number of segments of the liquid segment, For the tube wall The temperature change on each heat exchange unit, is the heat exchange of the gas section, is the number of segments of the gas segment; is the heat transfer of the two-phase section, is the metal heat capacity of the two-phase segment, is the temperature change of the fluid in the two-phase section.

[0048] Step 302: Add the heat transfer models of each section to obtain the overall heat transfer model in the water-cooled wall: Where, For overall heat exchange.

[0049] In another exemplary embodiment of the present application, the fitness function is:

[0050] ;

[0051] Where, is the fitness function; is a known quantity, , For the initial moment The wall temperature of each heat exchange unit, is the inlet temperature of the cooling fluid in the water wall, is the outlet temperature of the cooling fluid in the water wall, is the temperature of the hot fluid at the water wall inlet, is the temperature of the hot fluid outlet of the water-cooled wall, is the pressure inside the water-cooled wall, is the mass flow rate of the cold fluid, is the mass flow rate of the thermal fluid. is the heat transfer parameter, , For the The thermal conductivity of the inner wall of each heat exchange unit, For the The thermal conductivity of the outer wall of each heat exchange unit, For the The heat capacity flow rate of the cold fluid working medium of each heat exchange unit, For the The heat capacity flow rate of the hot fluid working medium in each heat exchange unit, is the time constant of the two-phase segment, In the heat exchange process The time constant of each heat exchange unit; is the initial population size, For the The baseline value of a population, , is the enthalpy as a function of temperature and pressure; For the The actual value of a population.

[0052] In another exemplary embodiment of the present application, the heat transfer parameters in the overall heat transfer model are identified based on the relevant data of different load sections, and the optimized heat transfer parameters are obtained by particle swarm optimization. , heat transfer parameters , output Assume that the initial population is , through the particle swarm initialization Value, according to the fitness function to solve the appropriate parameter value after convergence .

[0053] The general process of the particle swarm algorithm is as follows S1-S4.

[0054] S1. Initialize the particle population. Initialize, Obtained from the actual operating data of thermal power units.

[0055] S2. Replace the and Substitute it into the fitness function to get the root mean square error.

[0056] S3. Update particle value , iterate the particle state.

[0057] S4. Setting the error criterion If it is greater than this value, it will continue to return to S2, otherwise, it will jump out of the loop and get the final optimized value.

[0058] The heat transfer parameters are identified and processed by the particle swarm algorithm, and finally the heat transfer parameters between different phase segments in the water-cooled wall can be obtained, including the optimized values ​​of the heat transfer parameters in the segmented heat flow model of the liquid segment and the gas segment, and the optimized values ​​of the heat transfer parameters in the phase change heat flow model of the two-phase segment.

[0059] In another exemplary embodiment of the present application, both the gas segment and the liquid segment are The calculation ends at the moment, It is about the temperature inside the water wall and pressure The function of is determined according to the two-phase region table of water vapor. Compared with the above formula, when The calculation ends when , When is the corresponding segment number of liquid segment and gas segment. and Therefore, the above step 107 can be replaced by the following steps 401 to 404.

[0060] Step 401: Based on the optimized values ​​of the heat exchange parameters in the segmented heat flow model, the segmented heat flow model is used to successively calculate the temperature of the cold fluid in each heat exchange unit starting from the first heat exchange unit until the temperature of the cold fluid in the heat exchange unit is equal to the preset fluid temperature. The calculation is stopped, and the number of calculations is determined as the number of segments of the liquid segment.

[0061] Step 402: Based on the optimized values ​​of the heat exchange parameters in the segmented heat flow model, the segmented heat flow model is used to calculate the temperature of the cold fluid in each heat exchange unit in reverse order starting from the last heat exchange unit until the temperature of the cold fluid in the heat exchange unit is equal to the preset fluid temperature. The calculation stops and the number of calculations is determined as the number of segments of the gas segment.

[0062] From the above steps 401 to 402, it can be seen that the calculation starts from the first heat exchange unit in the liquid section and starts from the last heat exchange unit in the gas section, and the liquid section and gas section and The values ​​are different.

[0063] Step 403: Based on the overall length of the water-cooled wall and the number of liquid segments, use the formula , obtain the length of the liquid segment; where, is the length of the liquid segment, is the number of segments of the liquid segment, is the overall length of the water-cooled wall, is the total number of heat exchange units.

[0064] Step 404: Based on the overall length of the water wall and the number of gas segments, use the formula , get the length of the gas segment; where, is the length of the gas segment, is the number of segments of the gas segment.

[0065] In another exemplary embodiment of the present application, after identifying the above content, the overall heat transfer capacity of the liquid and gaseous fluids is obtained, and the temperature at the water wall outlet and the phase transition point of the cold fluid working medium can be accurately determined. Therefore, the phase transition height in the middle of the entire heat exchange process can be determined. The calculation formula for the phase transition height of the two-phase section is:

[0066] ;

[0067] Where, is the phase transition height of the two-phase segment.

[0068] From this, we can get the position and height of the gas, liquid and two-phase regions in the entire water-cooled wall, such as Figure 2 shown. Figure 2 The liquid working medium section is the liquid section, the steam section is the gas section, and the phase change process corresponds to the two-phase section. Ultimately, this application achieves the precise characterization of the phase change process in the water-cooled wall of a thermal power unit, especially the position and height of each phase zone.

[0069] This application is based on the heat flow algorithm to realize the identification of the phase change process in the water-cooled wall, so as to accurately quantify the working fluid in the water-cooled wall, evaluate the heat transfer characteristics of the working fluid in the water-cooled wall, and provide guarantee for subsequent water supply control.

[0070] Based on the same inventive concept, embodiments of the present application also provide a device for identifying the water-wall thermal storage process of a DC furnace-fired power unit with a phase change process, which is used to implement the aforementioned method for identifying the water-wall thermal storage process of a DC furnace-fired power unit with a phase change process. The solution provided by this device is similar to the solution described in the aforementioned method. Therefore, the specific limitations of one or more embodiments of the device for identifying the water-wall thermal storage process of a DC furnace-fired power unit with a phase change process provided below can be found in the aforementioned limitations of the method for identifying the water-wall thermal storage process of a DC furnace-fired power unit with a phase change process, and will not be further elaborated here.

[0071] In an exemplary embodiment, Figure 3 As shown, a water-cooled wall heat storage process identification device for a DC furnace-fired power unit with a phase change process is provided, which includes: a segmentation module, a segmented heat flow model establishment module, a phase change heat flow model establishment module, an overall heat exchange model determination module, a fitness function construction module, a solution module, a length determination module and a phase change height determination module.

[0072] The segmentation module is used to divide the water-cooled wall heat exchange process into a liquid section, a two-phase section and a gas section according to the state change of the fluid in the water-cooled wall; the segmentation heat flow model establishment module is used to establish the segmentation heat flow model of the liquid section and the gas section; the phase change heat flow model establishment module is used to establish the phase change heat flow model of the two-phase section; the overall heat exchange model determination module is used to determine the overall heat exchange model in the water-cooled wall according to the segmentation heat flow model and the phase change heat flow model; the fitness function construction module is used to construct a fitness function in the form of the root mean square error between the reference value and the actual value; the reference value is the heat exchange determined according to the enthalpy change at the inlet and outlet of the water-cooled wall, and the actual value is the heat exchange determined according to the enthalpy change at the inlet and outlet of the water-cooled wall. The actual value is the overall heat transfer obtained by solving the overall heat transfer model by using a heat flow algorithm; the solving module is used to solve the optimized values ​​of the heat transfer parameters in the segmented heat flow model by using a particle swarm algorithm based on the fitness function according to the inlet and outlet temperatures of the liquid segment fluid and the inlet and outlet temperatures of the gas segment fluid; the length determination module is used to determine the length of the liquid segment and the length of the gas segment respectively according to the overall length of the water-cooled wall and the optimized values ​​of the heat transfer parameters in the segmented heat flow model using the segmented heat flow model; the phase change height determination module is used to determine the phase change height of the two-phase segment and the position of each segment according to the overall length of the water-cooled wall, the length of the liquid segment and the length of the gas segment.

[0073] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Figure 4As shown. The computer device includes a processor, memory, an input / output (I / O) interface, and a communication interface. The processor, memory, and I / O interface are connected via a system bus, and the communication interface is connected to the system bus via the I / O interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The database of the computer device is used to store the length and position of each segment. The I / O interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals via a network connection. When executed by the processor, the computer program implements a method for identifying the water-cooled wall heat storage process of a DC furnace-fired power unit containing a phase change process.

[0074] Those skilled in the art will understand that Figure 4 The structure shown in the figure is merely a block diagram of a portion of the structure related to the solution of the present application and does not constitute a limitation on the computer device to which the solution of the present application is applied. A specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement. In an exemplary embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor implements the steps of the above-mentioned method embodiments when executing the computer program.

[0075] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0076] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0077] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. In particular, any reference to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0078] The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processors involved in the various embodiments provided herein may include, but are not limited to, general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic units, data processing logic units based on quantum computing, and the like.

[0079] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0080] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core concept of this application. At the same time, for those skilled in the art, based on the concept of this application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for identifying the water-wall heat storage process of a DC furnace-fired power unit with a phase change process, characterized in that: include: According to the state change of the fluid in the water wall, the water wall heat transfer process is divided into liquid section, two-phase section and gas section; Establish segmented heat flow models for liquid and gas segments; Establish a phase change heat flow model for the two-phase segment; Determining an overall heat exchange model within the water-cooled wall according to the segmented heat flow model and the phase change heat flow model; Constructing a fitness function in the form of a root mean square error between a reference value and an actual value; the reference value is a heat transfer value determined based on the enthalpy change at the inlet and outlet of the water wall, and the actual value is an overall heat transfer value obtained by solving the overall heat transfer model using a heat flow algorithm; According to the inlet and outlet temperatures of the liquid segment fluid and the inlet and outlet temperatures of the gas segment fluid, based on the fitness function, a particle swarm algorithm is used to solve the optimal values ​​of the heat exchange parameters in the segmented heat flow model; According to the overall length of the water-cooled wall and the optimized values ​​of the heat exchange parameters in the segmented heat flow model, the length of the liquid section and the length of the gas section are determined respectively using the segmented heat flow model; Determine the phase change height of the two-phase section and the position of each section based on the overall length of the water-cooled wall, the length of the liquid section, and the length of the gas section; Establish a segmented heat flow model for the liquid and gas segments, including: The first-order differential equation for the fluid applicable to both the liquid and gas sections is: Where, For the The heat capacity of the tube wall metal of each heat exchange unit, For the tube wall The temperature on each heat exchange unit, For the cold fluid The temperature on each heat exchange unit, For the hot fluid The temperature on each heat exchange unit, For the The equivalent thermal resistance of the cold fluid in each heat exchange unit, For the The equivalent thermal resistance of the thermal fluid in each heat exchange unit, , , , , For the The heat capacity flow rate of the cold fluid in each heat exchange unit, For the The heat capacity flow rate of the thermal fluid in each heat exchange unit, is the first intermediate quantity, is the second intermediate quantity, For the The thermal conductivity of the inner wall of each heat exchange unit, For the Thermal conductivity of the outer wall of each heat exchange unit; Solving the first-order differential equation, the segmented heat flow model applicable to both the liquid and gas segments is obtained: ； ； Where, for At the moment the cold fluid The temperature of each heat exchange unit, The unit length of fluid flowing through The time delay of each heat exchange unit, For the cold fluid The temperature of each heat exchange unit, for At the moment the tube wall The temperature on each heat exchange unit, for At the moment the cold fluid The temperature of each heat exchange unit, for At the moment the thermal fluid The temperature on each heat exchange unit, In the heat exchange process The time constant of each heat exchange unit, For the initial moment The wall temperature of each heat exchange unit; The phase change heat flow model is: ； ； Where, for The wall temperature of the two-phase section at time t, for The temperature of the cold fluid in the two-phase section at time t, for The temperature of the thermal fluid at that moment, is the wall temperature of the two-phase heat exchanger at the initial moment, is the equivalent thermal resistance of the thermal fluid, is the heat transfer resistance of the two-phase fluid, is the time constant of the two-phase segment; is the heat capacity flow of the cold fluid in the two-phase section, is the thermal conductance of the two-phase heat exchanger.

2. The method for identifying the water-wall heat storage process of a DC furnace-fired power plant with a phase change process according to claim 1, characterized in that: Determining an overall heat exchange model within the water wall based on the segmented heat flow model and the phase change heat flow model specifically includes: According to the segmented heat flow model and the phase change heat flow model, the heat exchange model of each segment is determined as follows: ； ； ； Where, is the heat transfer of the liquid section, is the number of segments of the liquid segment, For the The heat capacity of the tube wall metal of each heat exchange unit, For the tube wall The temperature change on each heat exchange unit, The unit length of fluid flowing through The time delay of each heat exchange unit, for At the moment the tube wall The temperature on each heat exchange unit, for At the moment the cold fluid The temperature of each heat exchange unit, For the working fluid The equivalent thermal resistance of the cold fluid in each heat exchange unit; is the heat exchange of the gas section, is the number of segments of the gas segment; is the heat transfer of the two-phase section, is the metal heat capacity of the two-phase segment, is the temperature change of the fluid in the two-phase section, is the wall temperature of the two-phase heat exchanger at the initial moment, for The temperature of the cold fluid in the two-phase section at time t, is the heat transfer resistance of the two-phase fluid; Adding the heat transfer models of each section, the overall heat transfer model in the water-cooled wall is obtained as follows: Where, For overall heat exchange.

3. The method for identifying the water-wall heat storage process of a DC furnace-fired power plant with a phase change process according to claim 1, characterized in that: The fitness function is: ； Where, is the fitness function; is a known quantity, , For the initial moment The wall temperature of each heat exchange unit, is the inlet temperature of the cooling fluid in the water wall, is the outlet temperature of the cooling fluid of the water wall, is the temperature of the hot fluid at the water wall inlet, is the temperature of the hot fluid outlet of the water-cooled wall, is the pressure inside the water-cooled wall, is the mass flow rate of the cold fluid, is the mass flow rate of the thermal fluid; is the heat transfer parameter, , For the The thermal conductivity of the inner wall of each heat exchange unit, For the The thermal conductivity of the outer wall of each heat exchange unit, For the The heat capacity flow rate of the cold fluid working medium of each heat exchange unit, For the The heat capacity flow rate of the hot fluid working medium in each heat exchange unit, is the time constant of the two-phase segment, In the heat exchange process The time constant of each heat exchange unit; is the initial population size, For the The baseline value of a population, , is the enthalpy as a function of temperature and pressure; For the The actual value of a population.

4. The method for identifying the water-wall heat storage process of a DC furnace-fired power plant with a phase change process according to claim 1, characterized in that: According to the overall length of the water-cooled wall and the optimized values ​​of the heat exchange parameters in the segmented heat flow model, the segmented heat flow model is used to determine the length of the liquid section and the length of the gas section, respectively, specifically including: According to the optimized values ​​of the heat exchange parameters in the segmented heat flow model, the segmented heat flow model is used to successively calculate the temperature of the cold fluid in each heat exchange unit starting from the first heat exchange unit until the temperature of the cold fluid in the heat exchange unit equals the preset fluid temperature, and the calculation is stopped, and the number of calculations is determined as the number of segments of the liquid segment; According to the optimized values ​​of the heat exchange parameters in the segmented heat flow model, the segmented heat flow model is used to calculate the temperature of the cold fluid in each heat exchange unit in reverse order starting from the last heat exchange unit until the temperature of the cold fluid in the heat exchange unit equals the preset fluid temperature. The calculation is stopped, and the number of calculations is determined as the number of segments of the gas segment; According to the overall length of the water-cooled wall and the number of liquid segments, the formula , obtain the length of the liquid segment; where, is the length of the liquid segment, is the number of segments of the liquid segment, is the overall length of the water-cooled wall, is the total number of heat exchange units; According to the overall length of the water-cooled wall and the number of gas segments, the formula , get the length of the gas segment; where, is the length of the gas segment, is the number of segments of the gas segment.

5. The method for identifying the water-wall heat storage process of a DC furnace-fired power plant with a phase change process according to claim 1, characterized in that: The phase change height of the two-phase section is determined based on the overall length of the water-cooled wall, the length of the liquid section, and the length of the gas section. Specifically, the following are included: According to the overall length of the water-cooled wall, the length of the liquid section and the length of the gas section, the formula , to obtain the phase transition height of the two-phase segment; where, is the phase transition height of the two-phase segment, is the overall length of the water-cooled wall, is the length of the liquid segment, is the length of the air segment.

6. A device for identifying the water-wall heat storage process of a DC furnace-fired power unit with a phase change process, characterized in that: include: The segmentation module is used to divide the water-cooled wall heat exchange process into the liquid section, the two-phase section and the gas section according to the state change of the fluid in the water-cooled wall; Segmented heat flow model building module, used to build segmented heat flow models for liquid and gas segments; Phase change heat flow model building module, used to build a phase change heat flow model of the two-phase segment; an overall heat transfer model determination module, configured to determine an overall heat transfer model within the water-cooled wall according to the segmented heat flow model and the phase change heat flow model; A fitness function construction module is used to construct a fitness function in the form of a root mean square error between a reference value and an actual value; the reference value is a heat transfer rate determined based on the enthalpy change at the water wall inlet and outlet, and the actual value is an overall heat transfer rate obtained by solving the overall heat transfer rate model using a heat flow algorithm; A solution module, configured to solve the optimal values ​​of heat exchange parameters in the segmented heat flow model using a particle swarm algorithm based on the fitness function according to the inlet and outlet temperatures of the liquid segment fluid and the inlet and outlet temperatures of the gas segment fluid; a length determination module, configured to determine the length of the liquid section and the length of the gas section respectively according to the overall length of the water-cooled wall and the optimized values ​​of the heat exchange parameters in the segmented heat flow model and using the segmented heat flow model; Phase change height determination module, used to determine the phase change height of the two-phase section and the position of each section according to the overall length of the water-cooled wall, the length of the liquid section and the length of the gas section; Establish a segmented heat flow model for the liquid and gas segments, including: The first-order differential equation for the fluid applicable to both the liquid and gas sections is: Where, For the The heat capacity of the tube wall metal of each heat exchange unit, For the tube wall The temperature on each heat exchange unit, For the cold fluid The temperature on each heat exchange unit, For the hot fluid The temperature on each heat exchange unit, For the The equivalent thermal resistance of the cold fluid in each heat exchange unit, For the The equivalent thermal resistance of the thermal fluid in each heat exchange unit, , , , , For the The heat capacity flow rate of the cold fluid in each heat exchange unit, For the The heat capacity flow rate of the thermal fluid in each heat exchange unit, is the first intermediate quantity, is the second intermediate quantity, For the The thermal conductivity of the inner wall of each heat exchange unit, For the Thermal conductivity of the outer wall of each heat exchange unit; Solving the first-order differential equation, the segmented heat flow model applicable to both the liquid and gas segments is obtained: ； ； Where, for At the moment the cold fluid The temperature of each heat exchange unit, The unit length of fluid flowing through The time delay of each heat exchange unit, For the cold fluid The temperature of each heat exchange unit, for At the moment the tube wall The temperature on each heat exchange unit, for At the moment the cold fluid The temperature of each heat exchange unit, for At the moment the thermal fluid The temperature on each heat exchange unit, In the heat exchange process The time constant of each heat exchange unit, For the initial moment The wall temperature of each heat exchange unit; The phase change heat flow model is: ； ； Where, for The wall temperature of the two-phase section at time t, for The temperature of the cold fluid in the two-phase section at time t, for The temperature of the thermal fluid at that moment, is the wall temperature of the two-phase heat exchanger at the initial moment, is the equivalent thermal resistance of the thermal fluid, is the heat transfer resistance of the two-phase fluid, is the time constant of the two-phase segment; is the heat capacity flow of the cold fluid in the two-phase section, is the thermal conductance of the two-phase heat exchanger.

7. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method for identifying the water-cooled wall heat storage process of a DC furnace-fired power unit containing a phase change process according to any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for identifying the water-cooled wall heat storage process of a DC furnace-fired power plant containing a phase change process according to any one of claims 1 to 5 is implemented.

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