Calculation Method and Device for Boiler Heat Storage Coefficient for Primary Frequency Regulation Analysis

Abstract

An embodiment of the present invention provides a method and device for calculating the boiler heat storage coefficient for primary frequency modulation analysis. The method includes: inputting the collected boiler operation data into a boiler steady-state model to calculate the initial values of the model parameters and the thermodynamic state quantities of each heat exchange unit segment; reading the valve opening step signal at the current simulation time step; when the cumulative simulation time is less than the primary frequency modulation time, iteratively calculate the thermodynamic state quantities of the heat exchange unit segments one by one, and gradually update the initial values of the thermodynamic state quantities of the heat exchange unit segments according to the thermodynamic state quantities obtained from the iterative calculation and the set simulation time step; when the cumulative simulation time is greater than or equal to the primary frequency modulation time, output the thermodynamic state quantities of the heat exchange unit segments, and calculate the heat storage coefficients of each heat exchange unit segment and the boiler heat storage coefficient. The embodiment of the present invention can determine the heat storage coefficient under the current working condition according to real-time monitoring data, providing an effective means for accurately grasping the primary frequency modulation capabilities of thermal power units and systems during operation.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of power system and thermal system analysis, and particularly to a method and device for calculating the boiler heat storage coefficient for primary frequency regulation analysis. Background Art

[0002] With the continuous increase in the proportion of renewable energy, the frequency stability of the power system is under great pressure and challenges. As the main power generation body in China for a long time in the future, thermal power units will undertake the main frequency regulation tasks in the new power system.

[0003] The commonly used primary frequency regulation model of thermal power units in the power grid currently includes the governor and the steam turbine part. During primary frequency regulation, when the speed deviation exceeds the dead zone, the Digital Electro-Hydraulic (DEH) control system of the steam turbine adjusts the valve opening, and the main steam flow will change, and the boiler heat storage is released or stored. The thermal parameters in the boiler (such as steam pressure and temperature) will change accordingly. In the current primary frequency regulation simulation analysis, the dynamic change of the boiler main steam pressure is not considered, but it is assumed that the main steam pressure is constant at 1. The standard boiler model recommended by IEEE provided in power grid transient simulation software such as BPA was proposed by F.P. De Mello in 1991. In the past frequency simulation analysis, this boiler model was rarely used, mainly for two reasons: one is that less attention has been paid to the primary frequency regulation ability of the unit in the past, and it is generally considered that the main steam pressure can be maintained stable during primary frequency regulation. The other is the lack of calculation methods for corresponding model parameters (such as the heat storage coefficient), resulting in the inability to be used for the dynamic analysis of the frequency response of actual units.

[0004] During the heat exchange process of the boiler, heat is stored in the tube wall metal and the steam-water working medium. The boiler heat storage reflects the ability to maintain the required output power of the unit during primary frequency regulation. The boiler heat storage coefficient is the main parameter to measure the heat storage ability and primary frequency regulation ability of the unit. However, the boiler heat storage coefficient is not a constant, but changes with the unit operating conditions, and fixed parameters cannot truly reflect the frequency regulation ability of the unit. Therefore, it needs to be determined online. In order to accurately grasp the true primary frequency regulation ability of the unit and the system, it is necessary to determine the boiler heat storage coefficient online. Summary of the Invention

[0005] In view of the defects existing in the prior art, the embodiments of the present invention provide a method and device for calculating the boiler heat storage coefficient for primary frequency regulation analysis.

[0006] An embodiment of the present invention provides a method for calculating the boiler heat storage coefficient for primary frequency regulation analysis, including: inputting the collected boiler operation data into the boiler steady-state model to calculate the initial values of the model parameters and the thermodynamic state quantities of each heat exchange unit segment; wherein, the boiler is modeled as a plurality of sequentially connected heat exchange unit segments by means of spatial segmentation; inputting the model parameters and the initial values of the thermodynamic state quantities of the heat exchange unit segments into the boiler dynamic model; reading the valve opening step signal at the current simulation time step; in response to the cumulative simulation time being less than the primary frequency regulation time, iteratively calculating the thermodynamic state quantities of the heat exchange unit segments segment by segment, and gradually updating the initial values of the thermodynamic state quantities of the heat exchange unit segments according to the thermodynamic state quantities obtained from the iterative calculation and the set simulation time step; in response to the cumulative simulation time being greater than or equal to the primary frequency regulation time, obtaining the output results of the thermodynamic state quantities of the heat exchange unit segments; calculating the heat storage coefficients of each heat exchange unit segment according to the output results of the thermodynamic state quantities, and obtaining the boiler heat storage coefficient according to the heat storage coefficients of each heat exchange unit segment.

[0007] An embodiment of the present invention further provides a device for calculating the boiler heat storage coefficient for primary frequency regulation analysis, including: a boiler steady-state model solving module, configured to: input the collected boiler operation data into the boiler steady-state model to calculate the initial values of the model parameters and the thermodynamic state quantities of each heat exchange unit segment; wherein, the boiler is modeled as a plurality of sequentially connected heat exchange unit segments by means of spatial segmentation; a boiler dynamic model solving module, configured to: input the model parameters and the initial values of the thermodynamic state quantities of the heat exchange unit segments into the boiler dynamic model; read the valve opening step signal at the current simulation time step; in response to the cumulative simulation time being less than the primary frequency regulation time, iteratively calculate the thermodynamic state quantities of the heat exchange unit segments segment by segment, and gradually update the initial values of the thermodynamic state quantities of the heat exchange unit segments according to the thermodynamic state quantities obtained from the iterative calculation and the set simulation time step; in response to the cumulative simulation time being greater than or equal to the primary frequency regulation time, obtain the output results of the thermodynamic state quantities of the heat exchange unit segments; a boiler heat storage coefficient calculation module, configured to: calculate the heat storage coefficients of each heat exchange unit segment according to the output results of the thermodynamic state quantities, and obtain the boiler heat storage coefficient according to the heat storage coefficients of each heat exchange unit segment.

[0008] An embodiment of the present invention further provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein when the processor executes the program, the steps of the method for calculating the boiler heat storage coefficient for primary frequency regulation analysis as described in any one of the above are implemented.

[0009] An embodiment of the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for calculating the boiler heat storage coefficient for primary frequency modulation analysis as described in any one of the above are implemented.

[0010] An embodiment of the present invention also provides a computer program product, including a computer program. When the computer program is executed by a processor, the steps of the method for calculating the boiler heat storage coefficient for primary frequency modulation analysis as described in any one of the above are implemented.

[0011] The method and device for calculating the boiler heat storage coefficient for primary frequency modulation analysis provided by the embodiments of the present invention input the collected boiler operation data into the boiler steady-state model, calculate the initial values of the model parameters and the thermodynamic state quantities of each heat exchange unit segment, input the initial values of the model parameters and the thermodynamic state quantities of the heat exchange unit into the boiler dynamic model, read the valve opening step signal at the current simulation time step, in response to the cumulative simulation time being less than the primary frequency modulation time, iteratively calculate the thermodynamic state quantities of the heat exchange unit segment by segment, and gradually update the initial values of the thermodynamic state quantities of the heat exchange unit according to the thermodynamic state quantities obtained by the iterative calculation and the set simulation time step. In response to the cumulative simulation time being greater than or equal to the primary frequency modulation time, obtain the output result of the thermodynamic state quantities of the heat exchange unit, calculate the heat storage coefficient of each heat exchange unit segment according to the output result of the thermodynamic state quantities, and obtain the boiler heat storage coefficient according to the heat storage coefficients of each heat exchange unit segment. It can determine the heat storage coefficient under the current working condition based on real-time monitoring data, providing an effective means for accurately grasping the primary frequency modulation ability of thermal power units and systems during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0013] Figure 1 is one of the schematic flowcharts of the method for calculating the boiler heat storage coefficient for primary frequency modulation analysis provided by the embodiments of the present invention;

[0014] Figure 2 is the schematic diagram of the solution process of the boiler steady-state model in the method for calculating the boiler heat storage coefficient for primary frequency modulation analysis provided by the embodiments of the present invention;

[0015] Figure 3 is the schematic diagram of the solution process of the boiler dynamic model in the method for calculating the boiler heat storage coefficient for primary frequency modulation analysis provided by the embodiments of the present invention;

[0016] Figure 4It is the second schematic flow chart of the boiler heat storage coefficient calculation method for primary frequency modulation analysis provided by an embodiment of the present invention;

[0017] Figure 5 It is the schematic structural diagram of the boiler heat storage coefficient calculation device for primary frequency modulation analysis provided by an embodiment of the present invention;

[0018] Figure 6 It is the schematic structural diagram of the electronic device provided by an embodiment of the present invention. Detailed implementation manners

[0019] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0020] Figure 1 It is the first schematic flow chart of the boiler heat storage coefficient calculation method for primary frequency modulation analysis provided by an embodiment of the present invention. As Figure 1 shown, the method includes:

[0021] Step 101: Input the collected boiler operation data into the boiler steady-state model, and calculate the initial values of the model parameters and the thermodynamic state quantities of each heat exchange unit segment; wherein, the boiler is modeled by a spatial segmentation method as a plurality of heat exchange units connected front and back.

[0022] Establish a boiler model that describes the heat transfer and flow of the boiler. Characterize the distributed parameter characteristics of the working medium by a spatial segmentation method, model the boiler model as n heat exchange units connected front and back, and connect each heat exchange unit segment based on the delay effect caused by the fluid heat capacity. For ease of analysis, the lengths of the heat exchange units can be the same.

[0023] Input the collected boiler operation data into the boiler steady-state model, and calculate the initial values of the model parameters and the thermodynamic state quantities of each heat exchange unit segment. Among them, the boiler operation data includes the inlet working medium temperature, outlet working medium temperature, inlet working medium pressure, outlet working medium pressure and the working medium flow rate of the boiler. When the thermal power unit reaches a steady state, the working medium flow rates at each place are the same, and the metal wall temperatures and working medium temperatures at each place do not change with time.

[0024] The thermodynamic state quantities under steady state can be input into the boiler dynamic model as the initial values when solving the boiler dynamic model. The thermodynamic state quantities at the inlet and outlet of the boiler have been acquired by DCS. The thermodynamic state quantities of the intermediate heat exchange unit segments can be calculated based on the DCS-acquired data and the steady-state boiler model, and the unknown model parameters in the model can be determined during the calculation process.

[0025] Step 102: Input the model parameters and the initial values of the thermodynamic state variables of the heat exchange unit into the boiler dynamic model; read the valve opening step signal at the current simulation time step; in response to the cumulative simulation time being less than the primary frequency regulation time, iteratively calculate the thermodynamic state variables of the heat exchange unit segment by segment, and gradually update the initial values of the thermodynamic state variables of the heat exchange unit according to the thermodynamic state variables obtained from the iterative calculation and the set simulation time step; in response to the cumulative simulation time being greater than or equal to the primary frequency regulation time, obtain the output result of the thermodynamic state variables of the heat exchange unit.

[0026] Input the model parameters and the initial values of the thermodynamic state variables of the heat exchange unit into the boiler dynamic model to solve the boiler dynamic model. In the solution of the boiler dynamic model, simulate and solve step by step according to the simulation time step, and accumulate the simulation time. A cumulative simulation time t m can be set, and the initial value of t m is set to Δt. Where Δt is the simulation time step, and it can take the value of the time delay for the working medium to flow through the heat exchange unit. It can be considered that the time delays for the working medium to flow through each heat exchange unit are equal. In response to the cumulative simulation time being less than the primary frequency regulation time, iteratively calculate the thermodynamic state variables of the heat exchange unit segment by segment, and gradually update the initial values of the thermodynamic state variables of the heat exchange unit according to the thermodynamic state variables obtained from the iterative calculation and the set simulation time step; in response to the cumulative simulation time being greater than or equal to the primary frequency regulation time, obtain the output result of the thermodynamic state variables of the heat exchange unit.

[0027] Step 103: Calculate the heat storage coefficients of each segment of the heat exchange unit according to the output result of the thermodynamic state variables, and obtain the boiler heat storage coefficient based on the heat storage coefficients of each segment of the heat exchange unit.

[0028] After obtaining the output results of the thermodynamic state variables of each heat exchange unit, the heat storage coefficients of each segment of the heat exchange unit can be calculated according to the output results of the thermodynamic state variables of each heat exchange unit, and the boiler heat storage coefficient can be obtained based on the heat storage coefficients of each segment of the heat exchange unit.

[0029] The boiler heat storage coefficient calculation method for primary frequency modulation analysis provided by the embodiment of the present invention inputs the collected boiler operation data into the boiler steady-state model, calculates the initial values of the model parameters and the thermodynamic state quantities of each heat exchange unit segment, inputs the initial values of the model parameters and the thermodynamic state quantities of the heat exchange unit segment into the boiler dynamic model, reads the valve opening step signal at the current simulation time step, in response to the cumulative simulation time being less than the primary frequency modulation time, iteratively calculates the thermodynamic state quantities of the heat exchange unit segment by segment, and gradually updates the initial values of the thermodynamic state quantities of the heat exchange unit segment according to the thermodynamic state quantities obtained by the iterative calculation and the set simulation time step. In response to the cumulative simulation time being greater than or equal to the primary frequency modulation time, the output result of the thermodynamic state quantities of the heat exchange unit segment is obtained, the heat storage coefficient of each heat exchange unit segment is calculated according to the output result of the thermodynamic state quantities, and the boiler heat storage coefficient is obtained according to the heat storage coefficients of each heat exchange unit segment, which can determine the heat storage coefficient under the current working condition according to the real-time monitoring data and provides an effective means for accurately grasping the primary frequency modulation ability of thermal power units and systems during operation.

[0030] According to a boiler heat storage coefficient calculation method for primary frequency modulation analysis provided by the embodiment of the present invention, the model parameters include heat transfer rate and resistance coefficient; the process of inputting the collected boiler operation data into the boiler steady-state model and calculating the initial values of the model parameters and the thermodynamic state quantities of each heat exchange unit segment includes: inputting the collected boiler operation data into the boiler steady-state model; setting the initial values of the heat transfer rate and the resistance coefficient; setting the initial value of the heat exchange unit serial number to 1; judging whether the heat exchange unit serial number is less than the total number of heat exchange units; in response to the heat exchange unit serial number being less than the total number of heat exchange units, for the heat exchange unit corresponding to the heat exchange unit serial number, iteratively calculate the thermodynamic state quantity according to whether the preset convergence condition is satisfied or transfer to the next heat exchange unit for processing; in response to the heat exchange unit serial number being greater than or equal to the total number of heat exchange units, update the heat transfer rate and the resistance coefficient according to the comparison result between the preset thermodynamic state parameters of the last heat exchange unit and the corresponding boiler operation data at the boiler model outlet, and then perform cyclic processing, or output the initial values of the model parameters and the thermodynamic state quantities of each heat exchange unit segment.

[0031] The unknown model parameters in the boiler model (including the boiler steady-state model and the boiler dynamic model) include heat transfer rate and resistance coefficient. When inputting the collected boiler operation data into the boiler steady-state model and calculating the initial values of the model parameters and the thermodynamic state quantities of each heat exchange unit segment, the following process is executed:

[0032] Input the collected boiler operation data into the boiler steady-state model; set the initial values of the heat transfer rate and the resistance coefficient; set the initial value of the heat exchange unit serial number to 1; determine whether the heat exchange unit serial number is less than the total number n of heat exchange units; in response to the heat exchange unit serial number being less than the total number n of heat exchange units, for the heat exchange unit corresponding to the heat exchange unit serial number, iteratively calculate the thermodynamic state quantity according to whether the preset convergence condition is satisfied or transfer to the next heat exchange unit for processing; wherein, if the convergence condition is satisfied, transfer to the next heat exchange unit for processing; if the convergence condition is not satisfied, iteratively calculate the thermodynamic state quantity; in response to the heat exchange unit serial number being greater than or equal to the total number of heat exchange units, update the heat transfer rate and the resistance coefficient and then perform cyclic processing according to the comparison result between the preset thermodynamic state parameters of the last heat exchange unit of the boiler model and the corresponding boiler operation data at the outlet of the boiler model, or output the initial values of the model parameters and the thermodynamic state quantities of each section of the heat exchange unit.

[0033] According to the comparison result between the preset thermodynamic state parameters of the last heat exchange unit of the boiler model and the corresponding boiler operation data at the outlet of the boiler model, if the result converges, output the initial values of the model parameters and the thermodynamic state quantities of each section of the heat exchange unit according to the current calculation result; if the result does not converge, update the heat transfer rate and the resistance coefficient and then perform cyclic processing. Among them, updating the heat transfer rate and the resistance coefficient and then performing cyclic processing means repeating the above steps from setting the initial value of the heat exchange unit serial number to 1 after updating the heat transfer rate and the resistance coefficient.

[0034] The boiler heat storage coefficient calculation method for primary frequency modulation analysis provided by the embodiments of the present invention realizes the accurate determination of the initial values of the model parameters and the thermodynamic state quantities of each section of the heat exchange unit.

[0035] According to a boiler heat storage coefficient calculation method for primary frequency modulation analysis provided by the embodiments of the present invention, the iterative calculation of the thermodynamic state quantity or the transfer to the next heat exchange unit for processing includes: setting the qualitative temperature of the working medium, calculating the physical properties of the working medium according to the qualitative temperature of the working medium, calculating the thermodynamic state quantity of the next section of the heat exchange unit according to the physical properties of the working medium and the boiler steady-state model, and calculating the average working medium temperature in the heat exchange unit according to the thermodynamic state quantity; wherein, the physical properties of the working medium include the specific heat capacity at constant pressure, and the thermodynamic state quantity includes the inlet working medium temperature, the working medium pressure, the working medium density, and the metal wall temperature; in response to the difference between the average working medium temperature and the qualitative temperature of the working medium being less than or equal to the allowable error, increment the heat exchange unit serial number by 1 and transfer to the processing step of determining whether the heat exchange unit serial number is less than the total number of heat exchange units; in response to the difference between the average working medium temperature and the qualitative temperature of the working medium being greater than the allowable error, update the qualitative temperature of the working medium and then transfer to the processing step of calculating the physical properties of the working medium according to the qualitative temperature of the working medium.

[0036] In the solution of the boiler steady-state model, the thermodynamic state quantity of the iterative calculation is determined through the following process or transferred to the next heat exchange unit for processing:

[0037] Set the qualitative temperature of the working medium as the inlet working medium temperature of each heat exchange unit, calculate the physical properties of the working medium according to the qualitative temperature of the working medium, calculate the thermodynamic state quantity of the next heat exchange unit according to the physical properties of the working medium and the boiler steady-state model, and calculate the average working medium temperature in the currently processed heat exchange unit according to the thermodynamic state quantity of the currently processed heat exchange unit and the thermodynamic state quantity of the next heat exchange unit; the average working medium temperature can be taken as the average of the inlet working medium temperature and the outlet working medium temperature of the heat exchange unit. The outlet working medium temperature of the heat exchange unit is the inlet working medium temperature of the next heat exchange unit. Among them, the physical properties of the working medium include the specific heat capacity at constant pressure, and the thermodynamic state quantity includes the inlet working medium temperature, the working medium pressure, the working medium density and the metal wall temperature.

[0038] In response to the difference between the average working medium temperature and the qualitative temperature of the working medium being less than or equal to the set allowable error, increment the heat exchange unit number by 1 and transfer to the processing step of determining whether the heat exchange unit number is less than the total number of heat exchange units, that is, start to process the next heat exchange unit, and the thermodynamic state quantity of the next-next heat exchange unit can be obtained according to the thermodynamic state quantity of the next heat exchange unit.

[0039] In response to the difference between the average working medium temperature and the qualitative temperature of the working medium being greater than the set allowable error, after updating the qualitative temperature of the working medium, transfer to the processing step of calculating the physical properties of the working medium according to the qualitative temperature of the working medium, that is, continue to process the current heat exchange unit according to the updated qualitative temperature of the working medium until the difference between the average working medium temperature and the qualitative temperature of the currently processed heat exchange unit is less than or equal to the set allowable error, and then transfer to the next heat exchange unit for processing. Among them, when updating the qualitative temperature of the working medium, the average of the average working medium temperature and the qualitative temperature of the working medium can be used as the updated qualitative temperature of the working medium.

[0040] The boiler heat storage coefficient calculation method for primary frequency modulation analysis provided by the embodiments of the present invention further improves the accuracy of determining the initial values of the model parameters and the thermodynamic state quantities of each section of the heat exchange unit.

[0041] A method for calculating the boiler heat storage coefficient for primary frequency modulation analysis according to an embodiment of the present invention. After comparing the preset thermodynamic state parameters of the last heat exchange unit with the corresponding boiler operation data at the outlet of the boiler model, update the heat transfer rate and the resistance coefficient and then perform cyclic processing, or output the initial values of the model parameters and the thermodynamic state quantities of each section of the heat exchange unit, including: in response to the difference between the preset thermodynamic state parameters of the last heat exchange unit and the corresponding boiler operation data at the outlet of the boiler model being greater than the allowable error, update the heat transfer rate and the resistance coefficient, and go to the processing step of setting the initial value of the heat exchange unit serial number to 1; in response to the difference between the preset thermodynamic state parameters of the last heat exchange unit and the corresponding boiler operation data at the outlet of the boiler model being less than or equal to the allowable error, obtain the initial values of the model parameters and the thermodynamic state quantities of each section of the heat exchange unit according to the current values of the heat transfer rate and the resistance coefficient and the calculation results of the thermodynamic state quantities of each section of the heat exchange unit.

[0042] According to the comparison result of the preset thermodynamic state parameters of the last heat exchange unit of the boiler model and the corresponding boiler operation data at the outlet of the boiler model, update the heat transfer rate and the resistance coefficient and then perform cyclic processing, or output the initial values of the model parameters and the thermodynamic state quantities of each section of the heat exchange unit.

[0043] Among them, in response to the difference between the preset thermodynamic state parameters of the last heat exchange unit of the boiler model and the corresponding boiler operation data at the outlet of the boiler model being greater than the set allowable error, update the heat transfer rate and the resistance coefficient, and go to the processing step of setting the initial value of the heat exchange unit serial number to 1, that is, according to the updated heat transfer rate and resistance coefficient, repeat the processing process starting from setting the initial value of the heat exchange unit serial number to 1.

[0044] In response to the difference between the preset thermodynamic state parameters of the last heat exchange unit of the boiler model and the corresponding boiler operation data at the outlet of the boiler model being less than or equal to the allowable error, obtain the initial values of the model parameters and the thermodynamic state quantities of each section of the heat exchange unit according to the current values of the heat transfer rate and the resistance coefficient and the calculation results of the thermodynamic state quantities of each section of the heat exchange unit, and complete the solution of the boiler steady-state model.

[0045] Figure 2 It is a schematic diagram of the solution process of the boiler steady-state model in the method for calculating the boiler heat storage coefficient for primary frequency modulation analysis provided by the embodiment of the present invention. As Figure 2 shown, the inner layer iteratively calculates the thermodynamic state parameters, and the outer layer iteratively calculates the two model parameters of the resistance coefficient f and the heat transfer rate q between the flue gas and the boiler tube wall. h The main steps include:

[0046] ① Input the operating conditions (the working medium temperature, pressure, and flow rate at the inlet and outlet of the boiler, where the working medium flow rate is the same at each position under steady state) according to the boiler structure parameters and the measured DCS data, and set the number of segments of the heat exchange unit to n.

[0047] ② Set the initial values of the heat transfer rate q h and the working medium flow resistance coefficient f.

[0048] ③ Starting from the i = 1st segment, set the initial value of the working medium qualitative temperature as the working medium temperature at the inlet of the i-th segment according to the measured DCS data (for i = 1, it is the working medium temperature at the outlet of the economizer).

[0049] ④ Use coolprop (the working medium thermophysical property calculation library) to calculate the density and specific heat capacity of the working medium, and calculate the inlet working medium temperature, working medium pressure, and metal wall temperature of the (i + 1)-th segment of the working medium according to the steady-state equation (the equation of the boiler steady-state model) (the mass flow rate can be calculated from the working medium pressure).

[0050] ⑤ Calculate the average temperature of the working medium in the i-th segment and compare it with the qualitative temperature. When it is greater than the allowable error, update the qualitative temperature (it can be updated according to the average value of the qualitative temperature and the average temperature, and when the qualitative temperature changes, the density and specific heat capacity at constant pressure change), and repeat step ④; when it is less than the allowable error, i = i + 1.

[0051] ⑥ When i ≥ n, compare the difference between the temperature (it can be the working medium temperature at the outlet of the n-th segment) and working medium pressure of the n-th segment of the working medium and the main steam temperature and working medium pressure measured by DCS (referring to the working medium temperature and pressure at the outlet of the boiler). When the difference is greater than the allowable error, update the heat transfer rate and resistance coefficient, and repeat steps ③, ④, and ⑤; when the difference is less than the allowable error, stop the iteration, output the heat transfer rate and resistance coefficient, as well as the temperature, pressure, density, and metal wall temperature of the working medium in each segment, and obtain the initial values of the model parameters and the thermodynamic state quantities of each heat exchange unit. When comparing the difference between the temperature and pressure of the n-th segment of the working medium and the main steam temperature and pressure measured by DCS, if either the temperature or pressure of the working medium is greater than the allowable error, it is considered that the difference is greater than the allowable error. The allowable errors corresponding to the temperature and pressure can be set separately.

[0052] The method for calculating the boiler heat storage coefficient for primary frequency modulation analysis provided by the embodiment of the present invention further improves the accuracy of determining the initial values of the model parameters and the thermodynamic state quantities of each heat exchange unit segment.

[0053] According to a method for calculating the boiler heat storage coefficient for primary frequency modulation analysis provided by the embodiment of the present invention, the boiler steady-state model is expressed as:

[0054]

[0055] Where, T c,i+1Represents the inlet working medium temperature of the (i + 1)-th heat exchange unit, T w,i Represents the metal wall temperature of the i-th heat exchange unit, kA e Represents the heat transfer coefficient between the steam-water working medium and the pipe wall, G c,i Represents the heat capacity flow rate of the steam-water working medium in the i-th heat exchange unit, T c,i Represents the inlet working medium temperature of the i-th heat exchange unit, q h Represents the heat transfer rate between the flue gas and the boiler pipe wall, L i Represents the length of the i-th heat exchange unit, p c,i+1 Represents the working medium pressure of the (i + 1)-th heat exchange unit, p c,i Represents the working medium pressure of the i-th heat exchange unit, f represents the resistance coefficient Represents the working medium flow rate of the i-th heat exchange unit; A c Represents the cross-sectional area of the working medium flow, ρ c,i Represents the working medium density of the i-th heat exchange unit Represents the working medium flow rate of the (i + 1)-th heat exchange unit

[0056] Among them, G c,i Represents the heat capacity flow rate of the steam-water working medium in the i-th heat exchange unit, equal to the mass flow rate and the specific heat capacity at constant pressure c c,p,i The product of. f represents the resistance coefficient, which is related to the wall friction coefficient and the pipe cross-sectional area

[0057] The boiler heat storage coefficient calculation method for primary frequency modulation analysis provided by the embodiments of the present invention realizes reasonable modeling of the boiler steady-state model

[0058] A method for calculating the boiler heat storage coefficient for primary frequency modulation analysis according to an embodiment of the present invention iteratively calculates the thermodynamic state quantities of the heat exchange unit segment by segment, and gradually updates the initial values of the thermodynamic state quantities of the heat exchange unit according to the thermodynamic state quantities obtained by the iterative calculation and the set simulation time step, including: processing the heat exchange unit segment by segment; wherein, when processing the current processing unit, setting the qualitative temperature of the working medium, calculating the physical properties parameters of the working medium according to the qualitative temperature of the working medium, calculating the thermodynamic state quantity of the next heat exchange unit according to the physical properties parameters of the working medium and the boiler dynamic model, and calculating the average working medium temperature in the current processed heat exchange unit according to the initial value of the thermodynamic state quantity of the current processed heat exchange unit and the thermodynamic state quantity of the next heat exchange unit; wherein, the physical properties parameters of the working medium include the specific heat capacity at constant pressure, and the thermodynamic state quantities include the inlet working medium temperature, the working medium pressure, the working medium density and the metal wall temperature; in response to the difference between the average working medium temperature and the qualitative temperature of the working medium being less than or equal to the allowable error, the current heat exchange unit is processed, and the processing of the next heat exchange unit is started; in response to the difference between the average working medium temperature and the qualitative temperature of the working medium being greater than the allowable error, updating the qualitative temperature and repeating the processing of the current heat exchange unit; until all the heat exchange units are processed, increasing the cumulative simulation time by one simulation time step, updating the initial values of the thermodynamic state quantities according to the calculation results of the thermodynamic state quantities of each heat exchange unit, and turning to the processing step of reading the valve opening step signal at the current simulation time step.

[0059] During the iterative processing of the heat exchange unit according to the simulation time step, after the current heat exchange unit meets the convergence condition (the difference between the average working medium temperature and the qualitative temperature of the working medium is less than or equal to the allowable error), the processing of the next heat exchange unit is carried out. After all the heat exchange units are processed, the processing of the next simulation time step is started until the cumulative simulation time is greater than or equal to the primary frequency modulation time, and the output results of the thermodynamic state quantities of each heat exchange unit are obtained.

[0060] Figure 3 It is a schematic diagram of the solution process of the boiler dynamic model in the method for calculating the boiler heat storage coefficient for primary frequency modulation analysis provided by the embodiment of the present invention. The solution process of the boiler dynamic model can be understood as the process of obtaining the thermodynamic state quantities and related parameters during the primary frequency modulation time. As Figure 3 shown, the method includes:

[0061] ① Input the initial values of the state quantities such as the model parameters, the temperature, pressure, density and metal wall temperature of the working medium in each section.

[0062] ② Read the valve opening at the current moment.

[0063] ③ Judge whether the cumulative simulation time t is less than the primary frequency modulation time tm If the cumulative simulation time t is greater than or equal to the primary frequency regulation time t m , output the state variables such as the temperature, pressure, density of the working fluid in each section, and the metal wall temperature.

[0064] ④ If the cumulative simulation time t is less than the primary frequency regulation time t m , calculate the working fluid density of each section of the working fluid in the next time step according to the mass conservation.

[0065] ⑤ Set the initial value of the qualitative temperature of the working fluid in each section to the temperature of the inlet working fluid, and use coolprop to calculate the working fluid pressure and the specific heat capacity at constant pressure.

[0066] ⑥ Calculate the temperature, pressure, and flow rate of the working fluid in each section in the next time step according to the dynamic equation.

[0067] ⑦ Calculate the average value of the inlet and outlet temperatures of the working fluid in the heat exchange unit of each section, and compare it with the qualitative temperature. When it is greater than the allowable error, update the qualitative temperature, and repeat steps ⑤ and ⑥.

[0068] ⑧ Otherwise, let t = t + delta_t (delta_t is the simulation time step), update the initial value of the state variable, and repeat steps ② to ⑦.

[0069] It should be noted that the expression of allowable error is adopted in multiple embodiments. For simplicity, the allowable errors are not distinguished. However, it can be understood that the value of the allowable error can be set according to specific applications.

[0070] The method for calculating the boiler heat storage coefficient for primary frequency regulation analysis provided by the embodiment of the present invention realizes the dynamic solution of the boiler thermal state variables during the primary frequency regulation process.

[0071] According to a method for calculating the boiler heat storage coefficient for primary frequency regulation analysis provided by the embodiment of the present invention, the boiler dynamic model is expressed as:

[0072]

[0073] Where, T c,i+1 (t) represents the inlet working fluid temperature of the (i + 1)-th heat exchange unit at time t, t represents time, and Δt c,i represents the time delay for the working fluid to flow through the i-th heat exchange unit, and T w,i (t - Δt c,i ) represents the metal wall temperature of the i-th heat exchange unit at time t - Δt c,i , kA e represents the heat transfer coefficient between the steam-water working fluid and the pipe wall, G c,i represents the heat capacity flow rate of the steam-water working fluid in the i-th heat exchange unit, and T c,i (t - Δt c,i ) represents t - Δt c,iThe inlet working fluid temperature of the i-th heat exchange unit at a moment, T c,i (t) represents the inlet working fluid temperature of the i-th heat exchange unit at time t, t 0 represents the heat transfer time constant between the metal tube wall and the working fluid, q h represents the heat transfer rate between the flue gas and the boiler tube wall, L i represents the length of the i-th heat exchange unit, T w,i (t - Δt c,i ) represents t - Δt c,i The metal wall temperature of the i-th heat exchange unit at the moment, A c represents the cross-sectional area of the working fluid flow, ρ c,i represents the working fluid density of the i-th heat exchange unit, represents the working fluid flow rate of the i-th heat exchange unit, represents the working fluid flow rate of the (i + 1)-th heat exchange unit, p c,i represents the working fluid pressure of the i-th heat exchange unit, p c,i+1 represents the working fluid pressure of the (i + 1)-th heat exchange unit, and f represents the resistance coefficient.

[0074] The method for calculating the boiler heat storage coefficient for primary frequency modulation analysis provided by the embodiment of the present invention realizes reasonable modeling of the boiler dynamic model.

[0075] According to a method for calculating the boiler heat storage coefficient for primary frequency modulation analysis provided by the embodiment of the present invention, obtaining the boiler heat storage coefficient according to the heat storage coefficients of each section of the heat exchange unit includes: dividing the heat storage coefficients of each section of the heat exchange unit into two heat storage volumes according to the change trend; adding the heat storage coefficients of the heat exchange units in each of the heat storage volumes to obtain the heat storage coefficient of the corresponding heat storage volume.

[0076] For the IEEE standard boiler model, it is divided into two heat storage volumes. When solving the heat storage coefficient of the IEEE standard boiler model, it is divided into two heat storage volumes according to the change trend of the heat storage coefficients of each section of the heat exchange unit, and the heat storage coefficients of the heat exchange units in each heat storage volume are added respectively to obtain the heat storage coefficient of the corresponding heat storage volume, thereby obtaining the heat storage coefficient of the IEEE standard boiler model.

[0077] The method for calculating the boiler heat storage coefficient for primary frequency modulation analysis provided by the embodiment of the present invention realizes the acquisition of the heat storage coefficient of the IEEE standard boiler model.

[0078] According to a method for calculating the boiler heat storage coefficient for primary frequency modulation analysis provided by the embodiment of the present invention, the thermodynamic state quantities include the working fluid pressure and the working fluid flow rate, and calculating the heat storage coefficients of each section of the heat exchange unit according to the output results of the thermodynamic state quantities is expressed as:

[0079]

[0080] Among them, C i represents the heat storage coefficient of the i-th section of the heat exchange unit, and t 1 represents the start time of the simulation solution of the boiler dynamic model, and t e represents the end time of the simulation solution of the boiler dynamic model. represents the working medium flow rate of the i-th section of the heat exchange unit at time t. represents the working medium flow rate of the (i + 1)-th section of the heat exchange unit at time t. represents t 1 the working medium pressure of the i-th section of the heat exchange unit at the moment. represents t e the working medium pressure of the i-th section of the heat exchange unit at the moment, and p N represents the rated pressure of the unit working medium. represents the rated flow rate of the unit working medium.

[0081] The method for calculating the boiler heat storage coefficient for primary frequency modulation analysis provided by the embodiment of the present invention realizes the accurate acquisition of the heat storage coefficient corresponding to the heat exchange unit.

[0082] Figure 4 It is the second schematic flow chart of the method for calculating the boiler heat storage coefficient for primary frequency modulation analysis provided by the embodiment of the present invention. As Figure 4 shown, the method includes:

[0083] S1): Establish a heat transfer and flow model of the boiler. Characterize the distributed parameter characteristics of the working medium by the method of spatial segmentation, and connect each section of the heat exchange unit based on the delay effect caused by the fluid heat capacity.

[0084] S2): The structural parameters in the boiler model are calculated and determined from the boiler structure and thermal instruction manual. Input the operating data such as the temperature, pressure, and flow rate of the working medium collected by the unit DCS into the boiler steady-state model to calculate the initial values of the model parameters and thermal state quantities.

[0085] Calculate the heat exchanger length L i , the cross-sectional area A c for the working medium to flow through, the heat capacity C w of the pipe wall metal, the heat transfer coefficient kA e and other boiler structural parameters according to the boiler design manual and the heat transfer surface specification parameter table of the actual thermal power unit. Take the temperature and pressure of the working medium at the outlet of the economizer in the DCS collected data as the thermal state parameters of the working medium of the first section of the heat exchange unit in the boiler model, take the main steam temperature and main steam pressure as the thermal state parameters of the working medium of the n-th section of the boiler model, and take the main steam flow rate as the flow rate of the working medium in each section.

[0086] In the steady-state form of the boiler model, the state parameters of the working medium in each heat exchange unit can be obtained from the state parameters of the working medium in the previous heat exchange unit. Therefore, when the temperature, pressure, and flow rate of the working medium at the boiler inlet are known and the model parameters are determined, the temperature and pressure of the working medium at the boiler outlet can be obtained by successive recursion. As Figure 2 shown, subtract the calculated values from the measured temperature and pressure of the working medium at the boiler outlet, and solve iteratively to obtain the model parameters q h and f, and obtain the initial values of the thermodynamic state quantities of each heat exchange unit.

[0087] S3): Apply a step signal of the valve opening to the boiler dynamic model, perform iterative calculations on the thermodynamic state quantities of each heat exchange unit segment by segment, and gradually update the initial values of the thermodynamic state quantities of each heat exchange unit according to the set calculation step size.

[0088] Apply a step signal of the valve opening to the boiler model at the steady-state moment t 1 As Figure 3 shown, it is necessary to consider the coupling relationship of the physical properties, temperature, and heat transfer quantity of the working medium during each step of the solution and perform iterative solution. Based on the structural parameters, model parameters, and initial values of the thermodynamic state quantities, perform iterative calculations on the thermodynamic state quantities of each heat exchange unit segment by segment, and gradually update the initial values of the thermodynamic state quantities of each heat exchange unit according to the set calculation step size.

[0089] S4): Calculate the heat storage coefficient of each heat exchange unit according to the integral value of the net flow rate and the pressure change amount, divide the heat storage volume according to the change trend of the heat storage coefficient, and the sum of the heat storage coefficients of each part is the heat storage coefficient of this heat storage volume, thereby obtaining the heat storage coefficient of the IEEE standard boiler model.

[0090] After solving the dynamic model, the working medium pressure changes from p i,t1 to p i,te . Calculate the heat storage coefficient of each heat exchange unit according to the integral value of the net flow rate and the pressure change amount, and then obtain the boiler heat storage coefficient.

[0091] An embodiment of the present invention provides a method for calculating the boiler heat storage coefficient applicable to primary frequency modulation analysis, including: constructing a mechanism model of the boiler dynamics of a thermal power unit; inputting the operating data such as the temperature, pressure, and flow rate of the working medium collected by the unit DCS into the calculation model under steady state, and iteratively calculating the initial values of the model parameters and thermodynamic state parameters. Next, based on the boiler dynamic model, the boiler heat storage coefficient is calculated through a step simulation of the valve opening. In the step simulation of the valve opening, based on the initial values of the structural parameters, model parameters, and thermodynamic state quantities, the thermodynamic state quantities of each heat exchange unit are iteratively calculated section by section, and the initial values of the thermodynamic state quantities of each heat exchange unit are gradually updated according to the set calculation step. The heat storage coefficient of each heat exchange unit is calculated according to the integral value of the net flow rate and the pressure change amount, and the heat storage volume is divided according to the change trend of the heat storage coefficient to obtain the heat storage coefficient of the IEEE standard boiler model. The embodiment of the present invention can determine the heat storage coefficient under the current working condition according to the DCS real-time monitoring data, providing an effective method for accurately grasping the primary frequency modulation ability of the thermal power unit and the system during operation.

[0092] It should be noted that, for the multiple preferred embodiments given in this embodiment, they can be freely combined on the premise that they do not conflict logically or structurally, and the present invention does not make any limitation in this regard.

[0093] The following describes the device for calculating the boiler heat storage coefficient for primary frequency modulation analysis provided by the embodiment of the present invention. The device for calculating the boiler heat storage coefficient for primary frequency modulation analysis described below can be correspondingly referred to the method for calculating the boiler heat storage coefficient for primary frequency modulation analysis described above.

[0094] Figure 5 It is a schematic structural diagram of the device for calculating the boiler heat storage coefficient for primary frequency modulation analysis provided by the embodiment of the present invention. As Figure 5As shown in the figure, the device includes a boiler steady-state model solving module 10, a boiler dynamic model solving module 20, and a boiler heat storage coefficient calculation module 30, where: The boiler steady-state model solving module 10 is used to: input the collected boiler operation data into the boiler steady-state model, and calculate the initial values of the model parameters and the thermal state quantities of each heat exchange unit; wherein, the boiler is modeled as a plurality of sequentially connected heat exchange units by a spatial segmentation method; The boiler dynamic model solving module 20 is used to: input the model parameters and the initial values of the thermal state quantities of the heat exchange units into the boiler dynamic model; read the valve opening step signal at the current simulation time step; in response to the cumulative simulation time being less than the primary frequency regulation time, iteratively calculate the thermal state quantities of each heat exchange unit segment by segment, and gradually update the initial values of the thermal state quantities of each heat exchange unit according to the thermal state quantities obtained from the iterative calculation and the set simulation time step; in response to the cumulative simulation time being greater than or equal to the primary frequency regulation time, obtain the output results of the thermal state quantities of the heat exchange units; The boiler heat storage coefficient calculation module 30 is used to: calculate the heat storage coefficients of each heat exchange unit segment according to the output results of the thermal state quantities, and obtain the boiler heat storage coefficient according to the heat storage coefficients of each heat exchange unit segment.

[0095] The boiler heat storage coefficient calculation device for primary frequency regulation analysis provided by the embodiment of the present invention inputs the collected boiler operation data into the boiler steady-state model, calculates the initial values of the model parameters and the thermal state quantities of each heat exchange unit segment, inputs the model parameters and the initial values of the thermal state quantities of the heat exchange units into the boiler dynamic model, reads the valve opening step signal at the current simulation time step, in response to the cumulative simulation time being less than the primary frequency regulation time, iteratively calculates the thermal state quantities of each heat exchange unit segment by segment, and gradually updates the initial values of the thermal state quantities of each heat exchange unit according to the thermal state quantities obtained from the iterative calculation and the set simulation time step, in response to the cumulative simulation time being greater than or equal to the primary frequency regulation time, obtains the output results of the thermal state quantities of the heat exchange units, calculates the heat storage coefficients of each heat exchange unit segment according to the output results of the thermal state quantities, and obtains the boiler heat storage coefficient according to the heat storage coefficients of each heat exchange unit segment. It can determine the heat storage coefficient under the current working condition based on real-time monitoring data, providing an effective means for accurately grasping the primary frequency regulation ability of thermal power units and systems during operation.

[0096] Figure 6 is a schematic structural diagram of an electronic device provided by an embodiment of the present invention, as Figure 6As shown in the figure, the electronic device may include: a processor 610, a communications interface 620, a memory 630, and a communication bus 640. Among them, the processor 610, the communications interface 620, and the memory 630 complete communication with each other through the communication bus 640. The processor 610 may call logic instructions in the memory 630 to execute a method for calculating the boiler heat storage coefficient for primary frequency modulation analysis. The method includes: inputting the collected boiler operation data into a boiler steady-state model to calculate the initial values of the model parameters and the thermodynamic state quantities of each heat exchange unit segment; where the boiler is modeled as a plurality of sequentially connected heat exchange units through a spatial segmentation method; inputting the model parameters and the initial values of the thermodynamic state quantities of the heat exchange unit into the boiler dynamic model; reading the valve opening step signal at the current simulation time step; in response to the cumulative simulation time being less than the primary frequency modulation time, iteratively calculating the thermodynamic state quantities of the heat exchange unit segment by segment, and gradually updating the initial values of the thermodynamic state quantities of the heat exchange unit according to the thermodynamic state quantities obtained from the iterative calculation and the set simulation time step; in response to the cumulative simulation time being greater than or equal to the primary frequency modulation time, obtaining the output result of the thermodynamic state quantities of the heat exchange unit; calculating the heat storage coefficient of each heat exchange unit segment according to the output result of the thermodynamic state quantities, and obtaining the boiler heat storage coefficient according to the heat storage coefficients of each heat exchange unit segment.

[0097] In addition, when the logic instructions in the above-mentioned memory 630 are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this 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 for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0098] On the other hand, an embodiment of the present invention further provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the boiler heat storage coefficient calculation method for primary frequency modulation analysis provided by the above-mentioned various methods. The method includes: inputting the collected boiler operation data into the boiler steady-state model to calculate the initial values of the model parameters and the thermodynamic state quantities of each heat exchange unit segment; wherein, the boiler is modeled as a plurality of sequentially connected heat exchange unit segments by means of spatial segmentation; inputting the model parameters and the initial values of the thermodynamic state quantities of the heat exchange unit segments into the boiler dynamic model; reading the valve opening step signal at the current simulation time step; in response to the cumulative simulation time being less than the primary frequency modulation time, iteratively calculating the thermodynamic state quantities of the heat exchange unit segments segment by segment, and gradually updating the initial values of the thermodynamic state quantities of the heat exchange unit segments according to the thermodynamic state quantities obtained from the iterative calculation and the set simulation time step; in response to the cumulative simulation time being greater than or equal to the primary frequency modulation time, obtaining the output results of the thermodynamic state quantities of the heat exchange unit segments; calculating the heat storage coefficients of each heat exchange unit segment according to the output results of the thermodynamic state quantities, and obtaining the boiler heat storage coefficient according to the heat storage coefficients of each heat exchange unit segment.

[0099] On another aspect, an embodiment of the present invention further provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it is implemented to execute the boiler heat storage coefficient calculation method for primary frequency modulation analysis provided by the above-mentioned various methods. The method includes: inputting the collected boiler operation data into the boiler steady-state model to calculate the initial values of the model parameters and the thermodynamic state quantities of each heat exchange unit segment; wherein, the boiler is modeled as a plurality of sequentially connected heat exchange unit segments by means of spatial segmentation; inputting the model parameters and the initial values of the thermodynamic state quantities of the heat exchange unit segments into the boiler dynamic model; reading the valve opening step signal at the current simulation time step; in response to the cumulative simulation time being less than the primary frequency modulation time, iteratively calculating the thermodynamic state quantities of the heat exchange unit segments segment by segment, and gradually updating the initial values of the thermodynamic state quantities of the heat exchange unit segments according to the thermodynamic state quantities obtained from the iterative calculation and the set simulation time step; in response to the cumulative simulation time being greater than or equal to the primary frequency modulation time, obtaining the output results of the thermodynamic state quantities of the heat exchange unit segments; calculating the heat storage coefficients of each heat exchange unit segment according to the output results of the thermodynamic state quantities, and obtaining the boiler heat storage coefficient according to the heat storage coefficients of each heat exchange unit segment.

[0100] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative work.

[0101] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the essence of the above technical solution, 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 enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of each embodiment of the present invention.

Claims

1. A calculation method for the boiler heat storage coefficient used in primary frequency modulation analysis, characterized in that, it includes: Input the collected boiler operation data into the boiler steady-state model to calculate the initial values of the model parameters and the thermodynamic state variables of each heat exchange unit segment; wherein, the boiler is modeled by a spatial segmentation method as multiple heat exchange units connected front and back; Input the model parameters and the initial values of the thermodynamic state variables of the heat exchange unit into the boiler dynamic model; read the valve opening step signal at the current simulation time step; in response to the cumulative simulation time being less than the primary frequency modulation time, iteratively calculate the thermodynamic state variables of the heat exchange unit segment by segment, and gradually update the initial values of the thermodynamic state variables of the heat exchange unit according to the thermodynamic state variables obtained from the iterative calculation and the set simulation time step; in response to the cumulative simulation time being greater than or equal to the primary frequency modulation time, obtain the output result of the thermodynamic state variables of the heat exchange unit; Calculate the heat storage coefficient of each heat exchange unit segment according to the output result of the thermodynamic state variables, and obtain the boiler heat storage coefficient according to the heat storage coefficients of each heat exchange unit segment; The model parameters include the heat transfer rate and the resistance coefficient; the step of inputting the collected boiler operation data into the boiler steady-state model to calculate the initial values of the model parameters and the thermodynamic state variables of each heat exchange unit segment includes: Input the collected boiler operation data into the boiler steady-state model; Set the initial values of the heat transfer rate and the resistance coefficient; Set the initial value of the heat exchange unit serial number to 1; Judge whether the heat exchange unit serial number is less than the total number of heat exchange units; In response to the heat exchange unit serial number being less than the total number of heat exchange units, for the heat exchange unit corresponding to the heat exchange unit serial number, iteratively calculate the thermodynamic state variable according to whether the preset convergence condition is satisfied or transfer to the next heat exchange unit for processing; In response to the heat exchange unit serial number being greater than or equal to the total number of heat exchange units, update the heat transfer rate and the resistance coefficient and then perform cyclic processing according to the comparison result between the preset thermodynamic state parameters of the last heat exchange unit and the corresponding boiler operation data at the outlet of the boiler steady-state model, or output the initial values of the model parameters and the thermodynamic state variables of each heat exchange unit segment; The thermodynamic state variables include the working medium pressure and the working medium flow rate, and the calculation of the heat storage coefficient of each heat exchange unit segment according to the output result of the thermodynamic state variables is expressed as: Among them, C i represents the heat storage coefficient of the i-th heat exchange unit, t 1 represents the start time of the boiler dynamic model simulation solution, t e represents the end time of the boiler dynamic model simulation solution, represents the working medium flow rate of the i-th heat exchange unit at time t, represents the working medium flow rate of the (i + 1)-th heat exchange unit at time t, represents t 1 the working medium pressure of the i-th heat exchange unit at time, represents t e the working medium pressure of the i-th heat exchange unit at time, p N represents the rated pressure of the unit working medium, represents the rated flow rate of the unit working medium.

2. The calculation method for the boiler heat storage coefficient used in primary frequency modulation analysis according to claim 1, characterized in that, The step of iteratively calculating the thermodynamic state variable or transferring to the next heat exchange unit for processing includes: Set the qualitative temperature of the working medium, calculate the physical properties of the working medium according to the qualitative temperature of the working medium, calculate the thermodynamic state variables of the next heat exchange unit segment according to the physical properties of the working medium and the boiler steady-state model, and calculate the average working medium temperature in the heat exchange unit; wherein, the physical properties of the working medium include the specific heat capacity at constant pressure, and the thermodynamic state variables include the inlet working medium temperature, the working medium pressure, the working medium density and the metal wall temperature; In response to the difference between the average working fluid temperature and the qualitative temperature of the working fluid being less than or equal to the allowable error, increment the heat exchange unit serial number by 1 and proceed to the processing step of determining whether the heat exchange unit serial number is less than the total number of heat exchange units; In response to the difference between the average working fluid temperature and the qualitative temperature of the working fluid being greater than the allowable error, after updating the qualitative temperature of the working fluid, proceed to the processing step of calculating the physical properties of the working fluid based on the qualitative temperature of the working fluid.

3. The method for calculating the boiler heat storage coefficient for primary frequency modulation analysis according to claim 2, characterized in that the comparison result between the preset thermodynamic state parameters of the last heat exchange unit and the corresponding boiler operation data at the outlet of the boiler steady-state model is used to update the heat transfer rate and the resistance coefficient and then loop for processing, or output the initial values of the model parameters and the thermodynamic state quantities of each section of the heat exchange unit, including: In response to the difference between the preset thermodynamic state parameters of the last heat exchange unit and the corresponding boiler operation data at the outlet of the boiler steady-state model being greater than the allowable error, update the heat transfer rate and the resistance coefficient and proceed to the processing step of setting the initial value of the heat exchange unit serial number to 1; In response to the difference between the preset thermodynamic state parameters of the last heat exchange unit and the corresponding boiler operation data at the outlet of the boiler steady-state model being less than or equal to the allowable error, obtain the initial values of the model parameters and the thermodynamic state quantities of each section of the heat exchange unit based on the current values of the heat transfer rate and the resistance coefficient and the calculation results of the thermodynamic state quantities of each section of the heat exchange unit.

4. The method for calculating the boiler heat storage coefficient for primary frequency modulation analysis according to claim 3, characterized in that the boiler steady-state model is expressed as: Among them, T c,i+1 represents the inlet working fluid temperature of the (i + 1)-th heat exchange unit, T w,i represents the metal wall temperature of the i-th heat exchange unit, kA e represents the heat transfer coefficient between the steam-water working fluid and the pipe wall, G c,i represents the heat capacity flow rate of the steam-water working fluid in the i-th heat exchange unit, T c,i represents the inlet working fluid temperature of the i-th heat exchange unit, q h represents the heat transfer rate between the flue gas and the boiler pipe wall, L i represents the length of the i-th heat exchange unit, p c,i+1 represents the working fluid pressure of the (i + 1)-th heat exchange unit, p c,i represents the working fluid pressure of the i-th heat exchange unit, f represents the resistance coefficient, represents the working fluid flow rate of the i-th heat exchange unit; A c represents the cross-sectional area of the working fluid flow, ρ c,i represents the working fluid density of the i-th heat exchange unit, represents the working fluid flow rate of the (i + 1)-th heat exchange unit.

5. The method for calculating the boiler heat storage coefficient for primary frequency modulation analysis according to claim 1, characterized in that iteratively calculate the thermodynamic state quantities of each heat exchange unit section by section, and gradually update the initial values of the thermodynamic state quantities of each heat exchange unit according to the thermodynamic state quantities obtained from the iterative calculation and the set simulation time step, including: Process each heat exchange unit section by section; among them, when processing the current processing unit, set the qualitative temperature of the working fluid, calculate the physical properties of the working fluid based on the qualitative temperature of the working fluid, calculate the thermodynamic state quantity of the next heat exchange unit according to the physical properties of the working fluid and the boiler dynamic model, and calculate the average working fluid temperature in the current processed heat exchange unit according to the initial value of the thermodynamic state quantity of the current processed heat exchange unit and the thermodynamic state quantity of the next heat exchange unit; wherein, the physical properties of the working fluid include the specific heat capacity at constant pressure, and the thermodynamic state quantities include the inlet working fluid temperature, the working fluid pressure, the working fluid density, and the metal wall temperature; In response to the difference between the average working fluid temperature and the qualitative temperature of the working fluid being less than or equal to the allowable error, the current heat exchange unit has been processed, and the processing of the next heat exchange unit is started; in response to the difference between the average working fluid temperature and the qualitative temperature of the working fluid being greater than the allowable error, the qualitative temperature is updated, and the current heat exchange unit is repeatedly processed; until all the heat exchange units are processed, the cumulative simulation time is increased by one simulation time step, the initial value of the thermodynamic state quantity is updated according to the calculation results of the thermodynamic state quantities of each heat exchange unit, and the process proceeds to the step of reading the valve opening step signal at the current simulation time step.

6. The method for calculating the boiler heat storage coefficient for primary frequency modulation analysis according to claim 5, wherein, the boiler dynamic model is expressed as: Among them, T c,i+1 (t) represents the inlet working medium temperature of the (i + 1)-th heat exchange unit at time t, t represents time, and Δt c,i represents the time delay for the working medium to flow through the i-th heat exchange unit, T w,i (t - Δt c,i ) represents the metal wall temperature of the i-th heat exchange unit at time t - Δt c,i , kA e represents the heat transfer coefficient between the steam-water working medium and the pipe wall, G c,i represents the heat capacity flow rate of the steam-water working medium in the i-th heat exchange unit, T c,i (t - Δt c,i ) represents the inlet working medium temperature of the i-th heat exchange unit at time t - Δt c,i , T c,i (t) represents the inlet working medium temperature of the i-th heat exchange unit at time t, t 0 represents the heat exchange time constant between the metal pipe wall and the working medium, q h represents the heat transfer rate between the flue gas and the boiler pipe wall, L i represents the length of the i-th heat exchange unit, T w,i (t - Δt c,i ) represents the metal wall temperature of the i-th heat exchange unit at time t - Δt c,i , A c represents the cross-sectional area of the working medium flow, ρ c,i represents the working medium density of the i-th heat exchange unit, represents the working medium flow rate of the i-th heat exchange unit, represents the working medium flow rate of the (i + 1)-th heat exchange unit, p c,i represents the working medium pressure of the i-th heat exchange unit, p c,i+1 represents the working medium pressure of the (i + 1)-th heat exchange unit, and f represents the resistance coefficient.

7. The method for calculating the boiler heat storage coefficient for primary frequency modulation analysis according to claim 1, wherein, obtaining the boiler heat storage coefficient according to the heat storage coefficients of each heat exchange unit section includes: dividing the heat exchange unit sections into two heat storage volumes according to the change trend of the heat storage coefficients of the heat exchange unit sections; adding the heat storage coefficients of the heat exchange units in each heat storage volume to obtain the heat storage coefficient of the corresponding heat storage volume.

8. A device for calculating the boiler heat storage coefficient for primary frequency modulation analysis, wherein, it includes: A boiler steady-state model solving module, which is used for: inputting the collected boiler operation data into the boiler steady-state model, and calculating the initial values of the model parameters and the thermodynamic state quantities of each heat exchange unit section; wherein, the boiler is modeled by a spatial segmentation method as a plurality of heat exchange units connected in series; the model parameters include the heat transfer rate and the resistance coefficient; the process of inputting the collected boiler operation data into the boiler steady-state model and calculating the initial values of the model parameters and the thermodynamic state quantities of each heat exchange unit section includes: inputting the collected boiler operation data into the boiler steady-state model; setting the initial values of the heat transfer rate and the resistance coefficient; setting the initial value of the heat exchange unit serial number to 1; judging whether the heat exchange unit serial number is less than the total number of heat exchange units; in response to the heat exchange unit serial number being less than the total number of heat exchange units, for the heat exchange unit corresponding to the heat exchange unit serial number, iteratively calculate the thermodynamic state quantity according to whether the preset convergence condition is satisfied or proceed to the next heat exchange unit for processing; in response to the heat exchange unit serial number being greater than or equal to the total number of heat exchange units, update the heat transfer rate and the resistance coefficient according to the comparison result between the preset thermodynamic state parameters of the last heat exchange unit and the corresponding boiler operation data at the outlet of the boiler steady-state model, and then perform cyclic processing, or output the model parameters and the initial values of the thermodynamic state quantities of each heat exchange unit section; The boiler dynamic model solving module is used for: inputting the model parameters and the initial values of the thermal state quantities of the heat exchange units into the boiler dynamic model; reading the valve opening step signal at the current simulation time step; in response to the cumulative simulation time being less than the primary frequency regulation time, iteratively calculating the thermal state quantities of the heat exchange units segment by segment, and gradually updating the initial values of the thermal state quantities of the heat exchange units according to the thermal state quantities obtained from the iterative calculation and the set simulation time step; in response to the cumulative simulation time being greater than or equal to the primary frequency regulation time, obtaining the output results of the thermal state quantities of the heat exchange units; The boiler heat storage coefficient calculation module is used for: calculating the heat storage coefficients of each section of the heat exchange unit according to the output results of the thermal state quantities, and obtaining the boiler heat storage coefficient according to the heat storage coefficients of each section of the heat exchange unit; the thermal state quantities include the working medium pressure and the working medium flow rate, and calculating the heat storage coefficients of each section of the heat exchange unit according to the output results of the thermal state quantities is expressed as: Among them, C i represents the heat storage coefficient of the i-th heat exchange unit, t 1 represents the start time of the simulation solution of the boiler dynamic model, t e represents the end time of the simulation solution of the boiler dynamic model, represents the working medium flow rate of the i-th heat exchange unit at time t, represents the working medium flow rate of the (i + 1)-th heat exchange unit at time t, represents t 1 the working medium pressure of the i-th heat exchange unit at time, represents t e the working medium pressure of the i-th heat exchange unit at time, p N represents the rated pressure of the unit working medium, represents the rated flow rate of the unit working medium.

9. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein, when the processor executes the program, it implements the steps of the boiler heat storage coefficient calculation method for primary frequency regulation analysis according to any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium, on which a computer program is stored, wherein, when the computer program is executed by a processor, it implements the steps of the boiler heat storage coefficient calculation method for primary frequency regulation analysis according to any one of claims 1 to 7.

11. A computer program product, comprising a computer program, wherein, when the computer program is executed by a processor, it implements the steps of the boiler heat storage coefficient calculation method for primary frequency regulation analysis according to any one of claims 1 to 7.

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