A method, apparatus and storage medium for simulating and solving a boiler dynamic model

Abstract

This invention provides a method, apparatus, and storage medium for simulating and solving a dynamic boiler model. Based on mass and energy conservation, the combustion process equations are obtained. A segmented counter-current heat exchanger model of the steam-water working fluid heat exchange process is established using the dynamic energy flow method. Based on mass and momentum conservation, the flow process equations of the steam-water working fluid are obtained. Given various thermodynamic coefficients and the initial thermodynamic state of the boiler, and based on the input timing commands such as coal feed rate and air supply, the dynamic results of the main steam pressure, main steam flow rate, and main steam temperature within that time period are obtained. This invention solves the problems of poor compatibility and high complexity in existing power system frequency regulation simulations, providing an easily solvable dynamic model for supercritical DC boilers. It can be used as a boiler model in power simulations, more accurately describing the boiler dynamic response during secondary frequency regulation.

Description

Technical Field

[0001] This invention relates to the field of thermal system analysis technology, and in particular to a method, apparatus and storage medium for simulating and solving dynamic models of boilers. Background Technology

[0002] Currently, research on thermal power unit models mainly focuses on model building and parameter identification. Based on the varying degrees of research into the thermodynamic system mechanism, modeling methods for thermal power units can be categorized into three types: white-box models, black-box models, and gray-box models. White-box models are models of thermal power units built based on fundamental physical laws. Generally, white-box models often divide the thermal power plant's thermodynamic system into multiple components, such as boilers and economizers, and perform mathematical modeling on each component separately, often equating them to heat exchanger models. The modeling process generally involves writing equations for thermodynamic parameters such as temperature and pressure within the thermal components based on certain assumptions and fundamental laws such as energy conservation and mass conservation. However, for components in thermal power plants, such as boilers, even if they are equating to counter-current heat exchangers, it is difficult to solve them due to the spatiotemporal coupling and nonlinearity of thermodynamic partial differential equations. In existing research, the dynamic energy flow method, through spatial discretization of a one-dimensional heat exchanger, has achieved the solution of the heat transfer equations. Combining the boiler's combustion and flow equations, a dynamic model of the boiler can be obtained. Based on this model, the simulation of a one-dimensional countercurrent heat exchanger model of a boiler can be achieved by using the general differential equation solving method.

[0003] In terms of application, the frequency problem of the power grid is becoming increasingly prominent due to the large-scale integration of high-proportion renewable energy sources into the power system. Previous boiler models used in power system simulations were simplified lumped-parameter models with few input parameters and could not accurately reflect the various thermodynamic processes within the boiler. To more accurately obtain the dynamic response of thermal power units during frequency regulation, a more refined model is needed to describe the energy conversion processes within the thermal power unit. However, traditional multidimensional thermal models have poor compatibility with power system frequency regulation simulations, necessitating simplification of complex thermodynamic models and solution methods. Summary of the Invention

[0004] This invention provides a method, apparatus, and storage medium for solving dynamic model simulations of boilers, in order to address the problems of poor compatibility and high complexity in existing power system frequency regulation simulations.

[0005] This invention provides a method for simulating and solving a dynamic model of a boiler, comprising:

[0006] Input the model parameters and initial values ​​of the state variables, determine whether the next moment to be simulated has reached the maximum simulation time, and generate the judgment result;

[0007] If the maximum simulation time has not been reached based on the judgment result, the thermodynamic state of the boiler model at the next moment is calculated.

[0008] Read the input command at the current moment and the thermodynamic state of the boiler model at the previous moment, and calculate the flue gas flow rate, initial flue gas temperature, steam-water working medium temperature and flue gas temperature of the boiler model at the current moment.

[0009] Set the initial value of the steam-water working fluid flow rate for each segment at the current time, and calculate the steam-water working fluid density, qualitative temperature, and qualitative density for each segment of the boiler model at the current time.

[0010] Based on the qualitative temperature and qualitative density of the steam and water working fluid in each section of the boiler model at the current moment, the specific heat capacity and pressure of the steam and water working fluid in this section of the boiler model are calculated through the physical property equation, and the flow rate of the steam and water working fluid in each section of the boiler model at the current moment is calculated.

[0011] Compare the initial value of the steam and water working fluid flow rate of each boiler model segment at the current moment with the calculated value of the steam and water working fluid flow rate of each boiler model segment at the current moment, generate calculation results, and calculate the metal wall temperature of each boiler model segment at the current moment using the calculation formula based on the calculation results.

[0012] Update the boiler model's thermal state at the current moment. Based on multiple input data, and according to the given model parameters and the thermal state at time zero, complete the simulation of the boiler's one-dimensional segmented countercurrent heat exchanger model for a set time period, and obtain the dynamic results of the main steam pressure, main steam flow rate, and main steam temperature during this time period under the initial and input conditions.

[0013] According to the boiler dynamic model simulation solution method provided by the present invention, the input model parameters, determining whether the next moment to be simulated has reached the maximum simulation time, and generating a determination result include:

[0014] The input model parameters include the heat released per unit of coal combustion, the specific heat capacity of flue gas, the heat transfer coefficient between flue gas and metal wall, the heat transfer coefficient between steam-water working fluid and metal wall, the resistance coefficient of steam-water working fluid, and the valve flow coefficient.

[0015] The initial values ​​of the state variables include the flue gas temperature, steam-water working fluid temperature, metal wall temperature, steam-water working fluid density, steam-water working fluid flow rate, and steam-water working fluid pressure for each segment of the segmented heat exchanger model.

[0016] The next moment to be simulated is compared with the maximum simulation time to generate a judgment result.

[0017] According to the boiler dynamic model simulation solution method provided by the present invention, the step of reading the input command at the current moment and the thermodynamic state of the boiler model at the previous moment, and calculating the flue gas flow rate, initial flue gas temperature, steam-water working fluid temperature and flue gas temperature of the boiler model at the current moment, includes:

[0018] Read the input commands at the current moment, including coal feed rate, air supply rate, steam-water working medium temperature at the steam-water separator outlet, steam-water working medium flow rate at the steam-water separator outlet, and valve opening; and read the boiler model thermodynamic state at the previous moment.

[0019] Calculate the flue gas flow rate, initial flue gas temperature, steam-water working fluid temperature, and flue gas temperature of the boiler model at the current moment according to the set formula.

[0020] According to the boiler dynamic model simulation solution method provided by the present invention, the step of setting the initial value of the steam-water working fluid flow rate for each segment at the current time, and calculating the steam-water working fluid density, steam-water working fluid qualitative temperature, and qualitative density for each segment of the boiler model at the current time includes:

[0021] The initial value of the flow rate of each segment of the working medium at the current moment can be set or the flow rate of the working medium at the previous moment can be taken as the initial value.

[0022] The formula is used to calculate the density of the steam-water working medium, the qualitative temperature of the steam-water working medium, and the qualitative density of the working medium for each segment of the boiler model at the current moment.

[0023] According to the boiler dynamic model simulation solution method provided by the present invention, the step of comparing the initial value of the steam and water working fluid flow rate of each segment of the boiler model at the current moment with the calculated value of the steam and water working fluid flow rate of each segment of the boiler model at the current moment to generate calculation results, and calculating the metal wall temperature of each segment of the boiler model at the current moment according to the calculation results and the calculation formula, includes:

[0024] The initial value of the steam and water working fluid flow rate of each boiler model at the current moment is compared with the calculated steam and water working fluid flow rate of each boiler model at the current moment to generate a comparison result.

[0025] If the deviation of the comparison result is greater than the set threshold, then the convergence has not occurred, and the average value of the two results is repeatedly set as the initial value of the flow rate of the soda working fluid.

[0026] If the comparison result is less than or equal to the set threshold, then the process has not converged. The metal wall temperature of each segment of the boiler model at the time of the retaining ring is then calculated.

[0027] According to the boiler dynamic model simulation solution method provided by the present invention, updating the current thermodynamic state of the boiler model includes:

[0028] The model of the segmented heat exchanger includes the flue gas temperature, steam-water working fluid temperature, metal wall temperature, steam-water working fluid density, steam-water working fluid flow rate, and steam-water working fluid pressure for each segment.

[0029] The present invention also provides a boiler dynamic model simulation and solution device, comprising:

[0030] The data acquisition module is used to input model parameters and initial values ​​of state variables, determine whether the next moment to be simulated has reached the maximum simulation time, and generate the judgment result.

[0031] The thermodynamic state calculation module is used to calculate the thermodynamic state of the boiler model at the next moment if the maximum simulation time has not been reached, based on the judgment result.

[0032] The first parameter calculation module is used to read the input command at the current moment and the thermodynamic state of the boiler model at the previous moment, and calculate the flue gas flow rate, initial flue gas temperature, steam-water working medium temperature and flue gas temperature of the boiler model at the current moment.

[0033] The second parameter calculation module is used to set the initial value of the steam-water working fluid flow rate for each segment at the current time, and to calculate the steam-water working fluid density, steam-water working fluid qualitative temperature, and qualitative density for each segment of the boiler model at the current time.

[0034] The third parameter calculation module is used to calculate the specific heat capacity and pressure of the steam and water working medium of each boiler model segment based on the qualitative temperature and qualitative density of the steam and water working medium at the current moment, and to calculate the steam and water working medium flow rate of each boiler model segment at the current moment through the physical property equation.

[0035] The fourth parameter calculation module compares the initial value of the steam and water working fluid flow rate of each boiler model at the current moment with the calculated value of the steam and water working fluid flow rate of each boiler model at the current moment, generates calculation results, and calculates the metal wall temperature of each boiler model at the current moment using the calculation formula based on the calculation results.

[0036] The boiler model simulation solution module is used to update the current thermal state of the boiler model. Based on multiple input data, according to the given model parameters and the thermal state at time zero, it completes the simulation of the boiler one-dimensional segmented countercurrent heat exchanger model for a set period, and obtains the dynamic results of main steam pressure, main steam flow rate and main steam temperature during this period under the initial and input conditions.

[0037] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the boiler dynamic model simulation solution method as described above.

[0038] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the boiler dynamic model simulation solution method as described above.

[0039] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the boiler dynamic model simulation solution method as described above.

[0040] This invention provides a method, system, and storage medium for simulating and solving a boiler dynamic model. It derives the combustion process equations based on mass and energy conservation, establishes a segmented counter-current heat exchanger model for the steam-water working fluid heat exchange process using the dynamic energy flow method, and obtains the steam-water working fluid flow process equations based on mass and momentum conservation. Given various thermodynamic coefficients and the initial thermodynamic state of the boiler, and based on input timing commands such as coal feed rate and air supply, it obtains the dynamic results of main steam pressure, main steam flow rate, and main steam temperature within that time period. This invention can provide an easily solvable dynamic model for once-through boilers in supercritical units, and can be used as a boiler model in power simulations, more accurately describing the boiler dynamic response during secondary frequency regulation. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0042] Figure 1 This is one of the flowcharts illustrating a boiler dynamic model simulation solution method provided by the present invention;

[0043] Figure 2 This is the second flowchart of a boiler dynamic model simulation solution method provided by the present invention;

[0044] Figure 3 This is the third flowchart of a boiler dynamic model simulation solution method provided by the present invention;

[0045] Figure 4 This is the fourth flowchart of a boiler dynamic model simulation solution method provided by the present invention;

[0046] Figure 5 This is the fifth flowchart of a boiler dynamic model simulation solution method provided by the present invention;

[0047] Figure 6 This is a schematic diagram of the module connection of a boiler dynamic model simulation and solving device provided by the present invention;

[0048] Figure 7 This is a flowchart of the overall architecture of a boiler dynamic model simulation and solving device provided by the present invention;

[0049] Figure 8 This is a schematic diagram of the structure of the electronic device provided by the present invention.

[0050] Figure label:

[0051] 110: Data acquisition module; 120: Thermodynamic state calculation module; 130: First parameter calculation module; 140: Second parameter calculation module; 150: Third parameter calculation module; 160: Fourth parameter calculation module; 170: Boiler model simulation solution module;

[0052] 810: Processor; 820: Communication interface; 830: Memory; 840: Communication bus. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0054] The following is combined Figures 1-5 This invention describes a method for simulating and solving a boiler dynamic model, comprising:

[0055] S100: Input model parameters and initial values ​​of state variables, determine whether the next moment to be simulated has reached the maximum simulation time, and generate the judgment result;

[0056] S200. If the maximum simulation time has not been reached based on the judgment result, calculate the thermodynamic state of the boiler model at the next moment.

[0057] S300: Read the input command at the current moment and the thermodynamic state of the boiler model at the previous moment, and calculate the flue gas flow rate, initial flue gas temperature, steam-water working medium temperature and flue gas temperature of the boiler model at the current moment.

[0058] S400: Set the initial value of the steam-water working fluid flow rate for each segment at the current time, and calculate the steam-water working fluid density, steam-water working fluid qualitative temperature, and qualitative density for each segment of the boiler model at the current time.

[0059] S500. Based on the qualitative temperature and qualitative density of the steam and water working fluid in each section of the boiler model at the current moment, calculate the specific heat capacity and pressure of the steam and water working fluid in this section of the boiler model through the physical property equation, and calculate the steam and water working fluid flow rate of each section of the boiler model at the current moment.

[0060] S600. Compare the initial value of the steam and water working fluid flow rate of each boiler model segment at the current moment with the calculated value of the steam and water working fluid flow rate of each boiler model segment at the current moment, generate calculation results, and calculate the metal wall temperature of each boiler model segment at the current moment using the calculation formula based on the calculation results.

[0061] S700: Update the current boiler model thermal state. Based on the input data and the given model parameters and the thermal state at time zero, complete the simulation of the boiler one-dimensional segmented countercurrent heat exchanger model for the set time period, and obtain the dynamic results of the main steam pressure, main steam flow rate and main steam temperature during this time period under the initial and input conditions.

[0062] In this invention, the modeling object is a once-through boiler of a supercritical unit, and the main components modeled are the furnace and the superheater. The furnace primarily considers the combustion process, while the superheater primarily considers the heat exchange and flow processes of the steam-water working fluid.

[0063] In the combustion process, based on mass conservation, the flue gas flow rate is obtained from the coal feed rate and air supply rate; based on energy conservation, the flue gas temperature is obtained from the heat released during coal combustion. In the steam-water working fluid heat exchange process, a dynamic energy flow method is used to establish a segmented counter-current heat exchanger model, calculating the steam-water working fluid, metal wall, and flue gas temperatures for each heat exchanger segment. In the steam-water working fluid flow process, based on mass conservation, the equations for steam-water working fluid flow rate and density are obtained; based on momentum conservation, the pressure loss caused by the steam-water working fluid flow is obtained.

[0064] For the boiler dynamic model proposed in this invention, the time-series simulation is given as follows: Basic settings include given thermodynamic coefficients and initial model state; inputs include time-series commands for coal feed rate, air supply rate, steam-water separator outlet working fluid temperature, steam-water separator outlet working fluid flow rate, and valve opening; outputs include time-series results for main steam pressure, main steam flow rate, and main steam temperature. The time-series simulation method used is the implicit Euler method. One-dimensional piecewise segmentation is used to discretize the space, avoiding the solution difficulties caused by spatiotemporal coupling.

[0065] Determine whether the next time step to be simulated has reached the maximum simulation time, and generate a determination result, including:

[0066] S101, The input model parameters include the heat released per unit of coal combustion, the specific heat capacity of flue gas, the heat transfer coefficient between flue gas and metal wall, the heat transfer coefficient between steam-water working fluid and metal wall, the resistance coefficient of steam-water working fluid, and the valve flow coefficient.

[0067] S102, The initial values ​​of the state variables include the flue gas temperature, steam-water working fluid temperature, metal wall temperature, steam-water working fluid density, steam-water working fluid flow rate, and steam-water working fluid pressure of each segment of the segmented heat exchanger model.

[0068] S103. Compare and judge the next moment to be simulated with the maximum simulation time, and generate a judgment result.

[0069] The judgment result is divided into two cases: determining the next moment to be simulated. If the maximum simulation time has been reached, the result is output directly; if the maximum simulation time has not been reached, the calculation of the thermodynamic state of the boiler model at the next moment is performed.

[0070] Read the input command at the current moment and the thermodynamic state of the boiler model at the previous moment, and calculate the flue gas flow rate, initial flue gas temperature, steam-water working fluid temperature and flue gas temperature of the boiler model at the current moment, including:

[0071] S201. Read the input commands at the current moment, including coal feed rate, air supply rate, steam-water working medium temperature at the steam-water separator outlet, steam-water working medium flow rate at the steam-water separator outlet, valve opening, and read the boiler model thermodynamic state at the previous moment.

[0072] S202. Calculate the flue gas flow rate, initial flue gas temperature, steam-water working fluid temperature, and flue gas temperature of the boiler model at the current moment according to the set formula.

[0073] In this invention, the flue gas flow rate D of the boiler model at the current moment is calculated according to the following equation. h and the initial flue gas temperature T h(1) ;

[0074]

[0075] Where B is the coal feed rate; D k D is the air supply volume. h c is the flue gas flow rate; k T is the specific heat capacity of air. k c represents air temperature, which can be taken as ambient temperature; h T is the specific heat capacity of the flue gas. h(1) This represents the initial flue gas temperature of the boiler model.

[0076] The current temperature T of the steam-water working fluid in each segment of the boiler model is calculated using the following equation. c(j) | τ+Δτ and flue gas temperature;

[0077]

[0078] Among them, T c(j) | τ+Δτ T represents the initial steam-water working fluid temperature of the boiler model at the current moment j; w(j) | τ T represents the metal wall temperature of the boiler model at the previous time step j; c(j+1) | τ k represents the final steam-water working fluid temperature of the boiler model at the previous moment j; c A c G is the heat transfer coefficient between the steam-water working fluid and the metal wall; c(j) | τ The steam-water working fluid flow rate, heat capacity, and flow rate for the boiler model at the previous time step j are represented by the product of the steam-water working fluid flow rate and specific heat capacity; T h(j+1) |τ+Δτ The current temperature of the flue gas at the end of segment j of the boiler model; T h(j) | τ k represents the initial flue gas temperature of the boiler model at the previous moment j; h A h G is the heat transfer coefficient between flue gas and metal wall; h | τ The flue gas flow rate and heat capacity of the boiler model at the previous moment are numerically taken as the product of the steam and water working fluid flow rate and specific heat capacity.

[0079] The process of setting initial values ​​for the flow rates of the steam-water working fluid at each current moment, and calculating the density, qualitative temperature, and qualitative density of the steam-water working fluid for each segment of the boiler model at the current moment, includes:

[0080] S301. The initial value of the flow rate of each segment of the working medium at the current moment can be set or the flow rate of the working medium at the previous moment can be taken as the initial value.

[0081] S302. Calculate the density of the steam-water working medium, the qualitative temperature of the steam-water working medium, and the qualitative density of the working medium for each segment of the boiler model at the current moment using the set formula.

[0082] In this invention, the flow rate D of the working fluid for each segment at the current moment is set. c(j) The initial value can be taken as the flow rate of the working fluid in the previous moment.

[0083] The steam-water working fluid density ρ of each segment of the boiler model at the current moment is calculated using the following equation. c(j) | τ+Δτ

[0084]

[0085] Where, ρ c(j) | τ+Δτ ρ is the working fluid density of the boiler model at the current time segment j; c(j) | τ D represents the density of the steam-water working fluid in the boiler model at the previous time step j; c(j+1) D represents the steam-water working fluid flow rate at the end of the boiler model at the current moment j; c(j) Δt represents the steam-water working fluid flow rate at the beginning of the j-th segment of the boiler model at the current time; Fl represents the internal volume of each segment of the boiler model; Δτ represents the time interval between the previous time and the current time.

[0086] The qualitative temperature of the steam-water working fluid in each segment of the boiler model at the current moment is calculated using the following equation. Qualitative density

[0087]

[0088] in, T represents the qualitative temperature of the boiler model at the current moment j; c(j) T represents the temperature of the steam-water working fluid at the beginning of segment j of the boiler model at the current moment; c(j+1) The temperature of the steam-water working fluid at the end of the boiler model segment j at the current moment; ρ is the qualitative density of the steam-water working fluid in the boiler model at the current time segment j; c(j) Let be the density of the steam-water working fluid at the end of the boiler model segment j at the current moment.

[0089] The initial values ​​of the steam and water working fluid flow rates for each boiler segment at the current moment are compared with the calculated values ​​of the steam and water working fluid flow rates for each boiler segment at the current moment to generate calculation results. Based on the calculation results, the metal wall temperature of each boiler segment at the current moment is calculated using a calculation formula, including:

[0090] S401. Compare the initial value of the steam and water working fluid flow rate of each boiler model at the current moment with the calculated steam and water working fluid flow rate of each boiler model at the current moment, and generate the comparison result.

[0091] S402. If the deviation of the comparison result is greater than the set threshold, then the convergence has not occurred. The average value of the two is repeatedly set as the initial value of the flow rate of the soda working fluid.

[0092] S403. If the comparison result is that the deviation is less than or equal to the set threshold, then the convergence has not occurred. Calculate the metal wall temperature of each segment of the boiler model at the time of the retaining ring.

[0093] In this invention, based on the qualitative temperature and qualitative density of the steam-water working medium in each section of the boiler model at the current moment, the specific heat capacity and pressure of the steam-water working medium in this section of the boiler model are calculated by the physical property equation, wherein the calculated pressure is the steam-water working medium pressure at the end of each section of the boiler model.

[0094] The steam-water working fluid flow rate D of each segment of the boiler model at the current moment is calculated using the following equation. c(j)

[0095]

[0096] Among them, P c(j) P represents the initial steam-water working fluid pressure of the boiler model at the current moment j; c(j+1) ζ represents the final steam-water working fluid pressure of the boiler model at the current moment j; cσ D is the drag coefficient of the steam-water working fluid. c(j) ρ represents the steam-water working fluid flow rate at the beginning of segment j of the boiler model at the current time. c(j) D represents the density of the steam-water working fluid in the boiler model at the current moment j; c(1) The initial steam-water working fluid flow rate of the boiler model at the current moment; kv is the valve flow coefficient; cv is the main steam valve opening of the boiler model at the current moment; P (1)This represents the initial steam-water working fluid pressure of the boiler model at the current moment.

[0097] The metal wall temperature T of each segment of the boiler model at the current moment is calculated using the following equation. w(j) ;

[0098]

[0099] Among them, R c(j) Let k be the thermal resistance between the steam-water working fluid and the metal wall of the boiler model at the current moment j; c A c G is the heat transfer coefficient between the steam / water working fluid and the metal wall; c(j) R represents the heat capacity flow rate of the steam-water working fluid in the boiler model at the current time j, numerically expressed as the product of the steam-water working fluid flow rate and its specific heat capacity; h k represents the thermal resistance between the flue gas and the metal wall of the boiler model at the current moment. h A h G is the heat transfer coefficient between the flue gas and the metal wall. h T represents the heat capacity flow rate of the flue gas in the boiler model at the current moment, numerically expressed as the product of the flue gas flow rate and the specific heat capacity; w(j) T represents the metal wall temperature of the boiler model at the current moment (j segment); w0(j) T represents the metal wall temperature of the boiler model at the previous time step j; h(j) T represents the initial flue gas temperature of the boiler model at the current moment j; c(j+1) T represents the final steam-water working fluid temperature of the boiler model at the current moment j; c(j) T represents the initial steam-water working fluid temperature of the boiler model at the current moment j; h(j+1) M represents the final flue gas temperature of the boiler model at the current moment j; w c is the mass of each metal wall segment; w Δτ is the specific heat capacity of the metal wall; Δτ is the time interval between the previous moment and the current moment.

[0100] Update the current thermal state of the boiler model, including the flue gas temperature, steam-water working fluid temperature, metal wall temperature, steam-water working fluid density, steam-water working fluid flow rate, and steam-water working fluid pressure for each segment of the segmented heat exchanger model.

[0101] Based on the input commands for coal feeding, air supply, water flow rate, water temperature, and valve opening, and according to the given model parameters and the thermal state at time zero, the above steps are used to simulate a certain period of time for the boiler's one-dimensional segmented countercurrent heat exchanger model, and obtain the dynamic results of main steam pressure, main steam flow rate, and main steam temperature during this period under the initial and input conditions.

[0102] The boiler dynamic model proposed in this invention has higher accuracy and more parameters with practical physical significance compared to power simulation boiler models. Compared to thermodynamic three-dimensional boiler models, it trades model accuracy for simpler simulation and faster solution. For the needs of power system frequency regulation simulation, the boiler dynamic model and simulation method proposed in this invention can reflect the secondary frequency regulation process of thermal power units more accurately, enabling the power grid to more accurately grasp the secondary frequency regulation capability of the units.

[0103] This invention discloses a boiler dynamic model simulation solution method. Based on mass and energy conservation, the combustion process equations are obtained. A segmented counter-current heat exchanger model of the steam-water working fluid heat exchange process is established using the dynamic energy flow method. Based on mass and momentum conservation, the flow process equations of the steam-water working fluid are obtained. Given various thermodynamic coefficients and the initial thermodynamic state of the boiler, and based on the input timing commands such as coal feed rate and air supply, the dynamic results of the main steam pressure, main steam flow rate, and main steam temperature within that time period are obtained. This invention can provide an easily solvable dynamic model for once-through boilers in supercritical units, and can be used as a boiler model in power simulations, more accurately describing the boiler dynamic response during secondary frequency regulation.

[0104] refer to Figure 6 and Figure 7 The present invention also discloses a boiler dynamic model simulation and solution device, comprising:

[0105] The data acquisition module 110 is used to input model parameters and initial values ​​of state variables, determine whether the next moment to be simulated has reached the maximum simulation time, and generate a judgment result.

[0106] Thermodynamic state calculation module 120 is used to calculate the thermodynamic state of the boiler model at the next moment if the maximum simulation time has not been reached based on the judgment result.

[0107] The first parameter calculation module 130 is used to read the input command at the current moment and the thermodynamic state of the boiler model at the previous moment, and calculate the flue gas flow rate, the initial flue gas temperature, the steam-water working medium temperature and the flue gas temperature of each section of the boiler model at the current moment.

[0108] The second parameter calculation module 140 is used to set the initial value of the flow rate of the steam-water working medium for each segment at the current time, and to calculate the density of the steam-water working medium, the qualitative temperature of the steam-water working medium, and the qualitative density of the boiler model for each segment at the current time.

[0109] The third parameter calculation module 150 is used to calculate the specific heat capacity and pressure of the steam and water working medium of each boiler model segment based on the qualitative temperature and qualitative density of the steam and water working medium at the current moment, and to calculate the steam and water working medium flow rate of each boiler model segment at the current moment through the physical property equation.

[0110] The fourth parameter calculation module 160 is used to compare the initial value of the steam and water working fluid flow rate of each boiler model at the current moment with the calculated value of the steam and water working fluid flow rate of each boiler model at the current moment, generate calculation results, and calculate the metal wall temperature of each boiler model at the current moment according to the calculation results and the calculation formula.

[0111] The boiler model simulation solution module 170 is used to update the current thermal state of the boiler model. Based on multiple input data, according to the given model parameters and the thermal state at time zero, it completes the simulation of the boiler one-dimensional segmented countercurrent heat exchanger model for a set period, and obtains the dynamic results of main steam pressure, main steam flow rate and main steam temperature during this period under the initial and input conditions.

[0112] The data acquisition module includes input model parameters such as the heat released per unit of coal combustion, the specific heat capacity of flue gas, the heat transfer coefficient between flue gas and metal wall, the heat transfer coefficient between steam-water working fluid and metal wall, the resistance coefficient of steam-water working fluid, and the valve flow coefficient.

[0113] The initial values ​​of the state variables include the flue gas temperature, steam-water working fluid temperature, metal wall temperature, steam-water working fluid density, steam-water working fluid flow rate, and steam-water working fluid pressure for each segment of the segmented heat exchanger model.

[0114] The first parameter calculation module reads the input commands at the current moment, including coal feed rate, air supply rate, steam-water working medium temperature at the steam-water separator outlet, steam-water working medium flow rate at the steam-water separator outlet, and valve opening, and reads the thermodynamic state of the boiler model at the previous moment.

[0115] Calculate the flue gas flow rate, initial flue gas temperature, steam-water working fluid temperature, and flue gas temperature of the boiler model at the current moment according to the set formula.

[0116] The second parameter calculation module allows for setting the initial value of the flow rate of each segment of the working fluid at the current moment, or taking the flow rate of the working fluid from the previous moment as the initial value.

[0117] The formula is used to calculate the density of the steam-water working medium, the qualitative temperature of the steam-water working medium, and the qualitative density of the working medium for each segment of the boiler model at the current moment.

[0118] The fourth parameter calculation module compares the initial value of the steam and water working fluid flow rate of each boiler model at the current moment with the calculated steam and water working fluid flow rate of each boiler model at the current moment, and generates a comparison result.

[0119] If the deviation of the comparison result is greater than the set threshold, then the convergence has not occurred, and the average value of the two results is repeatedly set as the initial value of the flow rate of the soda working fluid.

[0120] If the comparison result is less than or equal to the set threshold, then the process has not converged. The metal wall temperature of each segment of the boiler model at the time of the retaining ring is then calculated.

[0121] The boiler dynamic model simulation and solving device disclosed in this invention obtains the combustion process equations based on mass and energy conservation, establishes a segmented counter-current heat exchanger model of the steam-water working fluid heat exchange process using the dynamic energy flow method, and obtains the steam-water working fluid flow process equations based on mass and momentum conservation. Given various thermodynamic coefficients and the initial thermodynamic state of the boiler, and based on the input timing commands such as coal feed rate and air supply, the dynamic results of main steam pressure, main steam flow rate, and main steam temperature within that time period are obtained. This invention can provide an easily solvable dynamic model for once-through boilers in supercritical units, and can be used as a boiler model in power simulation, more accurately describing the boiler dynamic response of the secondary frequency regulation process.

[0122] Figure 8 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 8 As shown, the electronic device may include a processor 810, a communication interface 820, a memory 830, and a communication bus 840. The processor 810, communication interface 820, and memory 830 communicate with each other via the communication bus 840. The processor 810 can call logical instructions in the memory 830 to execute a boiler dynamic model simulation solution method. This method includes: inputting model parameters and initial values ​​of state variables, determining whether the next moment to be simulated has reached the maximum simulation time, and generating a determination result.

[0123] If the maximum simulation time has not been reached based on the judgment result, the thermodynamic state of the boiler model at the next moment is calculated.

[0124] Read the input command at the current moment and the thermodynamic state of the boiler model at the previous moment, and calculate the flue gas flow rate, initial flue gas temperature, steam-water working medium temperature and flue gas temperature of the boiler model at the current moment.

[0125] Set the initial value of the steam-water working fluid flow rate for each segment at the current time, and calculate the steam-water working fluid density, qualitative temperature, and qualitative density for each segment of the boiler model at the current time.

[0126] Based on the qualitative temperature and qualitative density of the steam and water working fluid in each section of the boiler model at the current moment, the specific heat capacity and pressure of the steam and water working fluid in this section of the boiler model are calculated through the physical property equation, and the flow rate of the steam and water working fluid in each section of the boiler model at the current moment is calculated.

[0127] Compare the initial value of the steam and water working fluid flow rate of each boiler model segment at the current moment with the calculated value of the steam and water working fluid flow rate of each boiler model segment at the current moment, generate calculation results, and calculate the metal wall temperature of each boiler model segment at the current moment using the calculation formula based on the calculation results.

[0128] Update the boiler model's thermal state at the current moment. Based on multiple input data, and according to the given model parameters and the thermal state at time zero, complete the simulation of the boiler's one-dimensional segmented countercurrent heat exchanger model for a set time period, and obtain the dynamic results of the main steam pressure, main steam flow rate, and main steam temperature during this time period under the initial and input conditions.

[0129] Furthermore, the logical instructions in the aforementioned memory 830 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0130] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute a boiler dynamic model simulation solution method provided by the above methods. The method includes: inputting model parameters and initial values ​​of state variables, determining whether the next moment to be simulated has reached the maximum simulation time, and generating a determination result.

[0131] If the maximum simulation time has not been reached based on the judgment result, the thermodynamic state of the boiler model at the next moment is calculated.

[0132] Read the input command at the current moment and the thermodynamic state of the boiler model at the previous moment, and calculate the flue gas flow rate, initial flue gas temperature, steam-water working medium temperature and flue gas temperature of the boiler model at the current moment.

[0133] Set the initial value of the steam-water working fluid flow rate for each segment at the current time, and calculate the steam-water working fluid density, qualitative temperature, and qualitative density for each segment of the boiler model at the current time.

[0134] Based on the qualitative temperature and qualitative density of the steam and water working fluid in each section of the boiler model at the current moment, the specific heat capacity and pressure of the steam and water working fluid in this section of the boiler model are calculated through the physical property equation, and the flow rate of the steam and water working fluid in each section of the boiler model at the current moment is calculated.

[0135] Compare the initial value of the steam and water working fluid flow rate of each boiler model segment at the current moment with the calculated value of the steam and water working fluid flow rate of each boiler model segment at the current moment, generate calculation results, and calculate the metal wall temperature of each boiler model segment at the current moment using the calculation formula based on the calculation results.

[0136] Update the boiler model's thermal state at the current moment. Based on multiple input data, and according to the given model parameters and the thermal state at time zero, complete the simulation of the boiler's one-dimensional segmented countercurrent heat exchanger model for a set time period, and obtain the dynamic results of the main steam pressure, main steam flow rate, and main steam temperature during this time period under the initial and input conditions.

[0137] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements a boiler dynamic model simulation solution method provided by the above methods, the method comprising: inputting model parameters and initial values ​​of state variables, determining whether the next moment to be simulated has reached the maximum simulation time, and generating a determination result;

[0138] If the maximum simulation time has not been reached based on the judgment result, the thermodynamic state of the boiler model at the next moment is calculated.

[0139] Read the input command at the current moment and the thermodynamic state of the boiler model at the previous moment, and calculate the flue gas flow rate, initial flue gas temperature, steam-water working medium temperature and flue gas temperature of the boiler model at the current moment.

[0140] Set the initial value of the steam-water working fluid flow rate for each segment at the current time, and calculate the steam-water working fluid density, qualitative temperature, and qualitative density for each segment of the boiler model at the current time.

[0141] Based on the qualitative temperature and qualitative density of the steam and water working fluid in each section of the boiler model at the current moment, the specific heat capacity and pressure of the steam and water working fluid in this section of the boiler model are calculated through the physical property equation, and the flow rate of the steam and water working fluid in each section of the boiler model at the current moment is calculated.

[0142] Compare the initial value of the steam and water working fluid flow rate of each boiler model segment at the current moment with the calculated value of the steam and water working fluid flow rate of each boiler model segment at the current moment, generate calculation results, and calculate the metal wall temperature of each boiler model segment at the current moment using the calculation formula based on the calculation results.

[0143] Update the boiler model's thermal state at the current moment. Based on multiple input data, and according to the given model parameters and the thermal state at time zero, complete the simulation of the boiler's one-dimensional segmented countercurrent heat exchanger model for a set time period, and obtain the dynamic results of the main steam pressure, main steam flow rate, and main steam temperature during this time period under the initial and input conditions.

[0144] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0145] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0146] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for simulating and solving a dynamic model of a boiler, characterized in that, include: Input the model parameters and initial values ​​of the state variables, determine whether the next moment to be simulated has reached the maximum simulation time, and generate the judgment result; If the maximum simulation time has not been reached based on the judgment result, the thermodynamic state of the boiler model at the next moment is calculated. Read the input command at the current moment and the thermodynamic state of the boiler model at the previous moment, and calculate the flue gas flow rate, initial flue gas temperature, steam-water working medium temperature and flue gas temperature of the boiler model at the current moment. Set the initial value of the steam-water working fluid flow rate for each segment at the current time, and calculate the steam-water working fluid density, qualitative temperature, and qualitative density for each segment of the boiler model at the current time. Based on the qualitative temperature and qualitative density of the steam and water working fluid in each section of the boiler model at the current moment, the specific heat capacity and pressure of the steam and water working fluid in this section of the boiler model are calculated through the physical property equation, and the flow rate of the steam and water working fluid in each section of the boiler model at the current moment is calculated. Compare the initial value of the steam and water working fluid flow rate of each boiler model segment at the current moment with the calculated value of the steam and water working fluid flow rate of each boiler model segment at the current moment, generate calculation results, and calculate the metal wall temperature of each boiler model segment at the current moment using the calculation formula based on the calculation results. Update the boiler model's thermal state at the current moment. Based on multiple input data, according to the given model parameters and the thermal state at time zero, complete the simulation of the boiler's one-dimensional segmented countercurrent heat exchanger model for a set time period, and obtain the dynamic results of the main steam pressure, main steam flow rate, and main steam temperature during this time period under the initial and input conditions. The input model parameters are used to determine whether the next simulation time has reached the maximum simulation time, and a judgment result is generated, including: The input model parameters include the heat released per unit of coal combustion, the specific heat capacity of flue gas, the heat transfer coefficient between flue gas and metal wall, the heat transfer coefficient between steam-water working fluid and metal wall, the resistance coefficient of steam-water working fluid, and the valve flow coefficient. The initial values ​​of the state variables include the flue gas temperature, steam-water working fluid temperature, metal wall temperature, steam-water working fluid density, steam-water working fluid flow rate, and steam-water working fluid pressure for each segment of the segmented heat exchanger model. The next moment to be simulated is compared with the maximum simulation time to generate a judgment result.

2. The boiler dynamic model simulation solution method according to claim 1, characterized in that, The process of reading the input command at the current moment and the thermodynamic state of the boiler model at the previous moment, and calculating the flue gas flow rate, initial flue gas temperature, steam-water working fluid temperature, and flue gas temperature of the boiler model at the current moment, includes: Read the input commands at the current moment, including coal feed rate, air supply rate, steam-water working medium temperature at the steam-water separator outlet, steam-water working medium flow rate at the steam-water separator outlet, and valve opening; and read the boiler model thermodynamic state at the previous moment. Calculate the flue gas flow rate, initial flue gas temperature, steam-water working fluid temperature, and flue gas temperature of the boiler model at the current moment according to the set formula.

3. The boiler dynamic model simulation solution method according to claim 1, characterized in that, The process of setting initial values ​​for the flow rates of the steam-water working fluid at each current moment, and calculating the density, qualitative temperature, and qualitative density of the steam-water working fluid for each segment of the boiler model at the current moment, includes: The initial value of the flow rate of each segment of the working medium at the current moment is a set value or determined based on the flow rate of the working medium at the previous moment; The formula is used to calculate the density of the steam-water working medium, the qualitative temperature of the steam-water working medium, and the qualitative density of the working medium for each segment of the boiler model at the current moment.

4. The boiler dynamic model simulation solution method according to claim 1, characterized in that, The process of comparing the initial values ​​of the steam and water working fluid flow rates of each boiler model segment at the current moment with the calculated values ​​of the steam and water working fluid flow rates of each boiler model segment at the current moment generates calculation results. Based on the calculation results, the metal wall temperature of each boiler model segment at the current moment is calculated using a calculation formula, including: The initial value of the steam and water working fluid flow rate of each boiler model at the current moment is compared with the calculated steam and water working fluid flow rate of each boiler model at the current moment to generate a comparison result. If the deviation of the comparison result is greater than the set threshold, then the convergence has not occurred, and the average value of the two results is repeatedly set as the initial value of the flow rate of the soda working fluid. If the comparison result shows a deviation less than or equal to a set threshold, then the model has not converged. The metal wall temperature of each segment of the boiler model at the time of the retaining ring is then calculated.

5. The boiler dynamic model simulation solution method according to claim 1, characterized in that, The update of the boiler model's thermal state at the current moment includes: The model of the segmented heat exchanger includes the flue gas temperature, steam-water working fluid temperature, metal wall temperature, steam-water working fluid density, steam-water working fluid flow rate, and steam-water working fluid pressure for each segment.

6. A boiler dynamic model simulation and solution device, using the boiler dynamic model simulation and solution method according to any one of claims 1-5, characterized in that, include: The data acquisition module is used to input model parameters and initial values ​​of state variables, determine whether the next moment to be simulated has reached the maximum simulation time, and generate the judgment result. The thermodynamic state calculation module is used to calculate the thermodynamic state of the boiler model at the next moment if the maximum simulation time has not been reached, based on the judgment result. The first parameter calculation module is used to read the input command at the current moment and the thermodynamic state of the boiler model at the previous moment, and calculate the flue gas flow rate, initial flue gas temperature, steam-water working medium temperature and flue gas temperature of the boiler model at the current moment. The second parameter calculation module is used to set the initial value of the steam-water working fluid flow rate for each segment at the current time, and to calculate the steam-water working fluid density, steam-water working fluid qualitative temperature, and qualitative density for each segment of the boiler model at the current time. The third parameter calculation module is used to calculate the specific heat capacity and pressure of the steam and water working medium of each boiler model segment based on the qualitative temperature and qualitative density of the steam and water working medium at the current moment, and to calculate the steam and water working medium flow rate of each boiler model segment at the current moment through the physical property equation. The fourth parameter calculation module is used to compare the initial value of the steam and water working fluid flow rate of each boiler model at the current moment with the calculated value of the steam and water working fluid flow rate of each boiler model at the current moment, generate calculation results, and calculate the metal wall temperature of each boiler model at the current moment using the calculation formula based on the calculation results. The boiler model simulation solution module is used to update the current thermal state of the boiler model. Based on multiple input data, according to the given model parameters and the thermal state at time zero, it completes the simulation of the boiler one-dimensional segmented countercurrent heat exchanger model for a set period, and obtains the dynamic results of main steam pressure, main steam flow rate and main steam temperature during this period under the initial and input conditions.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the boiler dynamic model simulation solution method as described in any one of claims 1 to 5.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the boiler dynamic model simulation solution method as described in any one of claims 1 to 5.

9. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the boiler dynamic model simulation solution method as described in any one of claims 1 to 5.

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