Method and device for evaluating rapid load changing capacity of coal-fired unit

Abstract

The invention relates to a method and device for evaluating the rapid load changing capacity of a coal-fired unit, and the method comprises the steps: firstly, building a coal-fired unit dynamic model which comprises a coal pulverizing system, a boiler and a steam turbine through historical operation data, and determining model parameters based on the operation characteristics of an actual unit; secondly, main steam pressure and power instructions of different load sections are set according to the sliding pressure curve, a variable load capacity test is carried out by adopting a method of increasing the load increasing rate, and meanwhile, the coal feeding amount, the boiler water feeding amount and the adjusting range and the changing rate of a main steam valve are restrained; finally, dynamic changes of key parameters such as main steam pressure and steam-water separator outlet temperature in the variable load process are analyzed, and the actual average load rising rate of the unit is evaluated. According to the invention, the variable load capability of the unit in different load intervals can be accurately evaluated. Therefore, the problems that in the prior art, the load changing capacity of a unit in different load intervals is difficult to accurately evaluate, and the stabilization of new energy power generation fluctuation and the stability of power grid frequency are greatly influenced are solved.

Description

Technical Field

[0001] This application relates to the technical field of power engineering, and particularly relates to a method and device for evaluating the rapid load-changing ability of a coal-fired unit. Background Art

[0002] Under the background of the construction of a new power system, coal-fired units usually serve as the ballast of the power grid and perform climbing tasks in different load intervals to cope with the intermittency and strong randomness characteristics of new energy power generation. During the process of load adjustment operation of the unit, the unit is usually adjusted according to the load command, but the maximum load-changing ability that the unit can withstand during actual operation is not clear.

[0003] Therefore, it is difficult for the existing technology to accurately evaluate the load-changing ability of the unit in different load intervals, which greatly affects the suppression of new energy power generation fluctuations and the stability of the power grid frequency, and urgently needs to be solved. Summary of the Invention

[0004] This application provides a method and device for evaluating the rapid load-changing ability of a coal-fired unit to solve problems such as the difficulty of accurately evaluating the load-changing ability of the unit in different load intervals in the existing technology, which greatly affects the suppression of new energy power generation fluctuations and the stability of the power grid frequency.

[0005] The first aspect of the embodiments of this application provides a method for evaluating the rapid load-changing ability of a coal-fired unit, including the following steps: Based on a pre-constructed dynamic model of the coal-fired unit, determine the main steam pressure set value and the unit power set value of the target coal-fired unit system, and perform load-changing ability test operations under different operating conditions according to the dynamic model of the coal-fired unit, the main steam pressure set value, and the unit power set value to obtain the load-changing simulation results corresponding to the target coal-fired unit system; Based on the load-changing simulation results, analyze the dynamic changes of the main steam pressure and the temperature at the outlet of the steam-water separator of the target coal-fired unit system during the load-changing ability test process, and determine the main steam pressure limit relationship and the steam-water separator outlet temperature limit relationship corresponding to the dynamic model of the coal-fired unit, so as to screen the target load-changing simulation results that meet the preset safety requirements through the main steam pressure limit relationship and the steam-water separator outlet temperature limit relationship; Based on the target load-changing simulation results, calculate the load change rate of the target coal-fired unit system, and determine the maximum load-changing ability of the target coal-fired unit system under the target condition according to the load change rate.

[0006] According to the above technical means, the embodiments of this application rationally formulate commands close to its maximum load-changing ability based on the actual operating load state of the unit, which is of great significance for suppressing new energy power generation fluctuations and stabilizing the power grid frequency.

[0007] Optionally, in an embodiment of the present application, before performing the variable load capacity test operation under different operating conditions based on the pre-constructed dynamic model of the coal-fired unit, it further includes: obtaining the coal input amount, fuel quantity command, and pulverizing system delay time of the target coal-fired unit system, and constructing a pulverizing system model based on the coal input amount, the fuel quantity command, and the pulverizing system delay time; obtaining the outlet parameters of the steam-water separator of the target coal-fired unit system, and determining the corresponding lumped parameters according to the outlet parameters of the steam-water separator, so as to construct a boiler system model based on the lumped parameters and a preset lumped parameter strategy; determining the turbine output power of the target coal-fired unit system based on the preset energy conservation principle, and constructing a turbine system model according to the turbine output power; constructing the dynamic model of the coal-fired unit based on the pulverizing system model, the boiler system model, and the turbine system model.

[0008] According to the above technical means, the embodiment of the present application constructs a dynamic model of the coal-fired unit system based on the energy conservation and mass conservation principles, thereby providing reliable data and theoretical support for the precise regulation of the unit operation.

[0009] Optionally, in an embodiment of the present application, the method of determining the main steam pressure set value and the unit power set value of the target coal-fired unit system based on the pre-constructed dynamic model of the coal-fired unit, and performing the variable load capacity test operation under different operating conditions according to the dynamic model of the coal-fired unit, the main steam pressure set value, and the unit power set value to obtain the variable load simulation result corresponding to the target coal-fired unit system includes: obtaining the sliding pressure curve corresponding to the target coal-fired unit system, and determining the main steam pressure set value and the unit power set value corresponding to the dynamic model of the coal-fired unit according to the sliding pressure curve; obtaining the actual operation characteristics corresponding to the target coal-fired unit system, and constructing the fuel quantity constraint condition, the boiler feed water flow constraint condition, and the valve opening constraint condition corresponding to the dynamic model of the coal-fired unit based on the actual operation characteristics; under the different operating conditions, performing an increasing treatment on the unit power set value at an increasing load rate to obtain the unit power increasing rate set value under each operating condition, and determining the main steam pressure increasing rate set value corresponding to the unit power increasing rate set value; based on the unit power increasing rate set value and the main steam pressure increasing rate set value, and simultaneously combining the fuel quantity constraint condition, the boiler feed water flow constraint condition, and the valve opening constraint condition, performing the variable load capacity test operation under the different operating conditions to obtain the variable load simulation result.

[0010] According to the above technical means, in the embodiment of the present application, the set values of the main steam pressure and the unit power are determined according to the sliding pressure curve of the coal-fired unit. At the same time, based on the operating characteristics of the actual unit, the fuel quantity, the boiler feed water flow rate, and the valve opening are restricted, so as to carry out the variable load capacity test for different operating conditions, and effectively simulate the operating characteristics of the unit under the condition of rapid load change.

[0011] Optionally, in an embodiment of the present application, determining the main steam pressure limit relationship and the steam-water separator outlet temperature limit relationship corresponding to the dynamic model of the coal-fired unit, so as to screen the target variable load simulation results that meet the preset safety requirements through the main steam pressure limit relationship and the steam-water separator outlet temperature limit relationship, includes: obtaining the main steam pressure output value of the dynamic model of the coal-fired unit in the variable load simulation result, and determining the main steam pressure limit relationship corresponding to the dynamic model of the coal-fired unit according to the main steam pressure output value, the preset main steam pressure limit value, and the main steam pressure set value under each operating condition; obtaining the steam-water separator outlet temperature output value of the dynamic model of the coal-fired unit in the variable load simulation result, and determining the steam-water separator outlet temperature limit relationship corresponding to the dynamic model of the coal-fired unit based on the steam-water separator outlet temperature output value, the preset steam-water separator outlet point temperature limit value, and the steam-water separator outlet temperature set value under each operating condition; screening the main steam pressure and the steam-water separator outlet temperature based on the main steam pressure limit relationship and the steam-water separator outlet temperature limit relationship to obtain the target variable load simulation result.

[0012] According to the above technical means, the embodiment of the present application utilizes the corresponding limit values of the main steam pressure and the steam-water separator outlet temperature during the unit load change, thereby avoiding the occurrence of situations such as unstable unit operation and reduced energy efficiency, and effectively reducing the probability of occurrence of safety risks.

[0013] Optionally, in an embodiment of the present application, the mathematical expressions of the main steam pressure limit relationship and the steam-water separator outlet temperature limit relationship are:

[0014] |P st -P sts |≤ΔP

[0015] |T m -T ms |≤ΔT

[0016] Wherein, P st represents the main steam pressure output value of the dynamic model of the coal-fired unit; P sts represents the set value of the main steam pressure; ΔP represents the main steam pressure limit value; T m represents the steam-water separator outlet temperature output value of the dynamic model of the coal-fired unit; Tms represents the set value of the outlet temperature of the steam-water separator; ΔT represents the temperature limit value at the outlet point of the steam-water separator.

[0017] According to the above technical means, the embodiments of the present application can analyze the dynamic changes of the main steam pressure and the intermediate point temperature of the unit during the load change process, and thus use this as a limit to the load change ability of the unit.

[0018] The embodiments of the second aspect of the present application provide an evaluation device for the rapid load change ability of a coal-fired unit, including: a load change ability test module, configured to determine the set value of the main steam pressure and the set value of the unit power of the target coal-fired unit system based on a pre-constructed dynamic model of the coal-fired unit, so as to perform load change ability test operations under different operating conditions according to the dynamic model of the coal-fired unit, the set value of the main steam pressure, and the set value of the unit power, and obtain the load change simulation result corresponding to the target coal-fired unit system; an analysis module, configured to analyze the dynamic changes of the main steam pressure and the outlet point temperature of the steam-water separator of the target coal-fired unit system during the load change ability test process based on the load change simulation result, and determine the main steam pressure limit relationship and the outlet temperature limit relationship of the steam-water separator corresponding to the dynamic model of the coal-fired unit, so as to screen the target load change simulation results that meet the preset safety requirements through the main steam pressure limit relationship and the outlet temperature limit relationship of the steam-water separator; a calculation module, configured to calculate the load change rate of the target coal-fired unit system based on the target load change simulation result, so as to determine the maximum load change ability of the target coal-fired unit system under the target operating condition according to the load change rate.

[0019] Optionally, in an embodiment of the present application, it further includes: a pulverizing system model construction module, configured to obtain the coal feed amount, the fuel quantity command, and the pulverizing system delay time of the target coal-fired unit system before performing the load change ability test operation under different operating conditions based on the pre-constructed dynamic model of the coal-fired unit, and construct a pulverizing system model based on the coal feed amount, the fuel quantity command, and the pulverizing system delay time; a boiler system model construction module, configured to obtain the outlet parameters of the steam-water separator of the target coal-fired unit system, and determine the corresponding lumped parameters according to the outlet parameters of the steam-water separator, so as to construct a boiler system model based on the lumped parameters and a preset lumped parameter strategy; a steam turbine system model construction module, configured to determine the output power of the steam turbine of the target coal-fired unit system based on the preset energy conservation principle, and construct a steam turbine system model according to the output power of the steam turbine; a modeling module, configured to construct the dynamic model of the coal-fired unit based on the pulverizing system model, the boiler system model, and the steam turbine system model.

[0020] Optionally, in an embodiment of the present application, the variable load capacity test module includes: a first acquisition unit, configured to acquire the sliding pressure curve corresponding to the target coal-fired unit system, and determine the main steam pressure setting value and the unit power setting value corresponding to the coal-fired unit dynamic model according to the sliding pressure curve; a constraint establishment unit, configured to acquire the actual operating characteristics corresponding to the target coal-fired unit system, and construct fuel quantity constraint conditions, boiler feed water flow constraint conditions, and valve opening constraint conditions corresponding to the coal-fired unit dynamic model based on the actual operating characteristics; a setting unit, configured to perform an increasing process on the unit power setting value at an increasing load rate under different operating conditions to obtain the unit power increasing rate setting value for each operating condition, and determine the main steam pressure increasing rate setting value corresponding to the unit power increasing rate setting value; an execution unit, configured to perform variable load capacity test operations under different operating conditions based on the unit power increasing rate setting value and the main steam pressure increasing rate setting value, and in combination with the fuel quantity constraint conditions, the boiler feed water flow constraint conditions, and the valve opening constraint conditions, to obtain the variable load simulation result.

[0021] Optionally, in an embodiment of the present application, the analysis module includes: a first determination unit, configured to acquire the main steam pressure output value of the coal-fired unit dynamic model in the variable load simulation result, and determine the main steam pressure limit relationship corresponding to the coal-fired unit dynamic model according to the main steam pressure output value, a preset main steam pressure limit value, and the main steam pressure setting value for each operating condition; a second determination unit, configured to acquire the outlet temperature output value of the steam-water separator of the coal-fired unit dynamic model in the variable load simulation result, and determine the outlet temperature limit relationship of the steam-water separator corresponding to the coal-fired unit dynamic model based on the outlet temperature output value of the steam-water separator, a preset outlet temperature limit value of the steam-water separator outlet point, and the outlet temperature setting value of the steam-water separator for each operating condition; a screening unit, configured to screen the main steam pressure and the outlet temperature of the steam-water separator based on the main steam pressure limit relationship and the outlet temperature limit relationship of the steam-water separator to obtain the target variable load simulation result.

[0022] Optionally, in an embodiment of the present application, the mathematical expressions of the main steam pressure limit relationship and the outlet temperature limit relationship of the steam-water separator are:

[0023] |P st -P sts |≤ΔP

[0024] |T m -T ms |≤ΔT

[0025] Wherein, P stRepresents the main steam pressure output value of the dynamic model of the coal-fired unit; P sts Represents the set value of the main steam pressure; ΔP represents the limit value of the main steam pressure; T m Represents the outlet temperature output value of the steam-water separator of the dynamic model of the coal-fired unit; T ms Represents the set value of the outlet temperature of the steam-water separator; ΔT represents the limit value of the temperature at the outlet point of the steam-water separator.

[0026] The third aspect of the present application provides an electronic device, including: a memory, a processor, and a computer program stored on the memory and executable on the processor. The processor executes the program to implement the method for evaluating the rapid load-changing ability of a coal-fired unit as described in the above embodiments.

[0027] The fourth aspect of the present application provides a computer-readable storage medium, and the computer-readable storage medium stores a computer program, which when executed by a processor, implements the method for evaluating the rapid load-changing ability of a coal-fired unit as described above.

[0028] The fifth aspect of the present application provides a computer program product, including a computer program, and the computer program is executed to implement the method for evaluating the rapid load-changing ability of a coal-fired unit as described above.

[0029] Therefore, the embodiments of the present application have the following beneficial effects:

[0030] The embodiments of the present application can obtain the historical operation data of the target coal-fired unit system, and construct a dynamic model of the coal-fired unit corresponding to the target coal-fired unit system according to the historical operation data; based on the dynamic model of the coal-fired unit, perform load-changing ability test operations under different operating conditions to obtain the load-changing simulation results corresponding to the target coal-fired unit system, and analyze the dynamic changes of the main steam pressure and the outlet temperature of the steam-water separator of the target coal-fired unit system during the load-changing ability test according to the load-changing simulation results to screen the target load-changing simulation results that meet the preset safety requirements; based on the target load-changing simulation results, calculate the load change rate of the target coal-fired unit system to determine the maximum load-changing ability of the target coal-fired unit system under specific conditions according to the load change rate. The present application reasonably formulates an instruction close to its maximum load-changing ability based on the actual operating load state of the unit, which is of great significance for suppressing the fluctuations of new energy power generation and stabilizing the grid frequency. Thus, the problems that it is difficult to accurately evaluate the load-changing ability of the unit in different load intervals in the prior art, which greatly affects the suppression of new energy power generation fluctuations and the stability of the grid frequency, are solved.

[0031] The additional aspects and advantages of the present application will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present application. Description of the Drawings

[0032] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description of embodiments in conjunction with the accompanying drawings, where:

[0033] Figure 1 It is a flowchart of a method for evaluating the rapid load-changing ability of a coal-fired unit according to an embodiment of the present application;

[0034] Figure 2 It is a schematic diagram of the control structure of a supercritical coal-fired unit provided by an embodiment of the present application;

[0035] Figure 3 It is a schematic diagram of the sliding pressure curve of a 350MW supercritical coal-fired unit provided by an embodiment of the present application;

[0036] Figure 4 It is a schematic diagram of the power change process during the load increase stage of a 350MW supercritical coal-fired unit provided by an embodiment of the present application;

[0037] Figure 5 It is a schematic diagram of the main steam pressure change process during the load increase stage of a 350MW supercritical coal-fired unit provided by an embodiment of the present application;

[0038] Figure 6 It is a schematic diagram of the intermediate point temperature change process during the load increase stage of a 350MW supercritical coal-fired unit provided by an embodiment of the present application;

[0039] Figure 7 It is a schematic diagram of the valve opening control process during the load increase stage of a 350MW supercritical coal-fired unit provided by an embodiment of the present application;

[0040] Figure 8 It is a schematic diagram of the coal feeding amount control process during the load increase stage of a 350MW supercritical coal-fired unit provided by an embodiment of the present application;

[0041] Figure 9 It is a schematic diagram of the boiler feed water control process during the load increase stage of a 350MW supercritical coal-fired unit provided by an embodiment of the present application;

[0042] Figure 10 It is an example diagram of an apparatus for evaluating the rapid load-changing ability of a coal-fired unit according to an embodiment of the present application;

[0043] Figure 11 It is a schematic diagram of the structure of an electronic device provided by an embodiment of the present application.

[0044] Among them, 10 - an evaluation device for the rapid load-changing ability of a coal-fired unit; 100 - a load-changing ability test module, 200 - an analysis module, 300 - a calculation module; 1101 - a memory, 1102 - a processor, 1103 - a communication interface. Specific embodiments

[0045] Embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application and should not be construed as a limitation of the present application.

[0046] An evaluation method and device for the rapid load-changing ability of a coal-fired unit according to an embodiment of the present application will be described below with reference to the accompanying drawings. In response to the problems mentioned in the above background art, the present application provides an evaluation method for the rapid load-changing ability of a coal-fired unit. In this method, historical operation data of a target coal-fired unit system is obtained, and a coal-fired unit dynamic model corresponding to the target coal-fired unit system is constructed based on the historical operation data; based on the coal-fired unit dynamic model, a load-changing ability test operation is performed under different operating conditions to obtain a load-changing simulation result corresponding to the target coal-fired unit system, and the dynamic changes of the main steam pressure and the temperature at the outlet point of the steam-water separator of the target coal-fired unit system during the load-changing ability test process are analyzed according to the load-changing simulation result to screen out a target load-changing simulation result that meets the preset safety requirements; based on the target load-changing simulation result, the load change rate of the target coal-fired unit system is calculated to determine the maximum load-changing ability of the target coal-fired unit system under specific operating conditions according to the load change rate. The present application rationally formulates an instruction close to its maximum load-changing ability based on the actual operating load state of the unit, which is of great significance for suppressing the fluctuation of new energy power generation and stabilizing the grid frequency. Thereby, the problems in the prior art that it is difficult to accurately evaluate the load-changing ability of the unit in different load intervals, which greatly affects the suppression of the fluctuation of new energy power generation and the stability of the grid frequency, are solved.

[0047] Specifically, Figure 1 is a flowchart of an evaluation method for the rapid load-changing ability of a coal-fired unit provided by an embodiment of the present application.

[0048] As Figure 1 shown, the evaluation method for the rapid load-changing ability of the coal-fired unit includes the following steps:

[0049] In step S101, based on a pre-constructed coal-fired unit dynamic model, the main steam pressure set value and the unit power set value of the target coal-fired unit system are determined, and a load-changing ability test operation is performed under different operating conditions according to the coal-fired unit dynamic model, the main steam pressure set value, and the unit power set value to obtain a load-changing simulation result corresponding to the target coal-fired unit system.

[0050] In the embodiments of the present application, first, the historical operation data of the coal-fired unit system can be used, and combined with the principles of energy conservation and mass conservation, a dynamic model of the coal-fired unit including the coal pulverizing system, boiler, and steam turbine can be established. The corresponding model parameters can be determined according to the actual operation characteristics of the unit, and the unit power and main steam pressure of the dynamic model of the coal-fired unit can be controlled by the proportional-integral-derivative (PID) plus feedforward method, thereby providing a technical basis and support for subsequent variable load capacity tests.

[0051] Optionally, in an embodiment of the present application, before performing the variable load capacity test operation under different operating conditions based on the pre-constructed dynamic model of the coal-fired unit, it further includes: obtaining the coal input amount, fuel quantity command, and coal pulverizing system delay time of the target coal-fired unit system, and constructing a coal pulverizing system model based on the coal input amount, fuel quantity command, and coal pulverizing system delay time; obtaining the outlet parameters of the steam-water separator of the target coal-fired unit system, and determining the corresponding lumped parameters according to the outlet parameters of the steam-water separator, so as to construct a boiler system model based on the lumped parameters and the preset lumped parameter strategy; determining the steam turbine output power of the target coal-fired unit system based on the preset energy conservation principle, and constructing a steam turbine system model according to the steam turbine output power; constructing a dynamic model of the coal-fired unit based on the coal pulverizing system model, boiler system model, and steam turbine system model.

[0052] It should be noted that the embodiments of the present application can establish a coal pulverizing system model, boiler, and steam turbine model according to the historical operation data of the coal-fired unit system, and determine the corresponding model parameters according to the actual operation characteristics of the unit. Taking a 350MW supercritical unit as an example, its main design parameters are shown in the following table:

[0053] Table 1

[0054]

[0055] Specifically, the dynamic characteristics of the coal pulverizing system model in the above dynamic model of the coal-fired unit describe the relationship between the coal input amount and the fuel quantity command, and can be expressed by the following mathematical model:

[0056]

[0057] Among them, r B represents the actual amount of pulverized coal entering the boiler, with the unit of t / h; u B represents the fuel quantity command, with the unit of t / h; τ represents the delay time in the coal pulverizing system, with the unit of s.

[0058] Secondly, in the embodiments of the present application, the boiler system model in the dynamic model of the coal-fired unit can be established by the lumped parameter method. That is to say, in the embodiments of the present application, the parameters at the outlet of the steam-water separator are used as the lumped parameters to construct the dynamic model of the boiler heating surface.

[0059] During the actual implementation process, the mass conservation relationship of the boiler system is:

[0060]

[0061] Among them, V t represents the boiler volume, with the unit of m 3 ; ρ m represents the density of the steam at the outlet of the steam-water separator, with the unit of kg / m 3 ; D fw represents the boiler feed water flow rate, with the unit of t / h; D s represents the flow rate at the outlet of the superheater, with the unit of t / h.

[0062] The energy conservation relationship of the boiler system is:

[0063]

[0064] Among them, h m represents the specific enthalpy of the steam at the outlet of the steam-water separator, with the unit of kJ / kg; h fw represents the specific enthalpy of the boiler feed water, with the unit of kJ / kg; h s represents the specific enthalpy of the steam at the outlet of the superheater, with the unit of kJ / kg; k0 represents the heat gain of the steam and water.

[0065] In the specific implementation process, the turbine system model in the embodiments of the present application can be established based on the principle of energy conservation; ignoring the losses of mass and energy such as air leakage, the power of the turbine can be calculated by the following formula:

[0066]

[0067] Among them, N e represents the output power of the turbine, with the unit of MW; η represents the turbine efficiency, with the unit of %; h st represents the specific enthalpy of the main steam, with the unit of kJ / kg; h fw represents the specific enthalpy of the boiler feed water, with the unit of kJ / kg; H c represents the heat absorbed by the condenser, with the unit of kJ; D r represents the reheated steam flow rate, with the unit of t / h; h r o represents the specific enthalpy of the hot reheated steam, with the unit of kJ / kg; h r i represents the specific enthalpy of the cold reheated steam, with the unit of kJ / kg.

[0068] In addition, the heat absorption of the reheated steam and the condenser in the embodiments of the present application is proportional to the output power of the unit. Therefore, Equation (4) can be transformed into:

[0069] Ne = ηD st (h st -h fw ) + βNe(5)

[0070] Further simplifying Equation (5), we can obtain:

[0071] Ne = k1D st (h fw -h e )(6)

[0072] where u t represents the main steam valve opening; the unit is the k1 coefficient.

[0073] It should be noted that, as Figure 2 shown, the PID control loop in the embodiments of the present application mainly adjusts key parameters such as the unit power and the main steam pressure through feedback and feedforward control strategies; the main steam valve is used to adjust the output power of the unit, the fuel quantity is used to control the main steam pressure, and the temperature at the outlet of the steam separator is adjusted by the boiler feed water; at the same time, the power command can be superimposed with the PID control outputs of the fuel quantity and the boiler feed water through the feedforward channel to achieve precise control of the unit operation.

[0074] Therefore, the embodiments of the present application construct a dynamic model of the coal-fired unit system based on the principles of energy conservation and mass conservation, thereby providing reliable data and theoretical support for the precise control of the unit operation.

[0075] Furthermore, the embodiments of the present application also need to set the main steam pressure and power commands for different load segments according to the sliding pressure curve for different operating conditions, and use the method of increasing the load rate to conduct the variable load capacity test. At the same time, the adjustment ranges and change rates of the coal feeding quantity, the boiler feed water quantity, and the main steam valve are restricted to simulate the operating characteristics of the unit under rapid load change conditions, and the corresponding variable load simulation results are obtained.

[0076] Optionally, in an embodiment of the present application, based on a pre-constructed dynamic model of a coal-fired unit, the main steam pressure set value and the unit power set value of the target coal-fired unit system are determined, and a variable load capacity test operation is performed under different operating conditions according to the dynamic model of the coal-fired unit, the main steam pressure set value, and the unit power set value, so as to obtain a variable load simulation result corresponding to the target coal-fired unit system, including: obtaining the sliding pressure curve corresponding to the target coal-fired unit system, and determining the main steam pressure set value and the unit power set value corresponding to the dynamic model of the coal-fired unit according to the sliding pressure curve; obtaining the actual operating characteristics corresponding to the target coal-fired unit system, and constructing the fuel quantity constraint condition, the boiler feed water flow constraint condition, and the valve opening constraint condition corresponding to the dynamic model of the coal-fired unit based on the actual operating characteristics; under different operating conditions, performing an increasing process on the unit power set value at an increasing load rate to obtain the unit power increasing rate set value under each operating condition, and determining the main steam pressure increasing rate set value corresponding to the unit power increasing rate set value; based on the unit power increasing rate set value and the main steam pressure increasing rate set value, and simultaneously combining the fuel quantity constraint condition, the boiler feed water flow constraint condition, and the valve opening constraint condition, performing a variable load capacity test operation under different operating conditions to obtain a variable load simulation result.

[0077] As a feasible implementation manner, in the embodiment of the present application, the variable load capacity assessment is performed by taking the coal-fired unit increasing the load from 180 MW to 220 MW as an example. According to the Figure 3 sliding pressure curve shown as follows, the main steam pressure setting rule is as follows:

[0078] When the output power command is lower than 100 MW, the main steam pressure is maintained at 8.68 MPa; when the output power command is between 100 MW and 310 MW, the main steam pressure linearly increases to 24.2 MPa; when the output power command exceeds 310 MW, the main steam pressure is maintained at 24.2 MPa.

[0079] In the embodiment of the present application, the unit power set value increases from 180 MW to 220 MW, and the rising rate of the power set value starts from 0.5% Pe / min. In each simulation experiment, the rising rate is increased successively, and each increase is 0.01% Pe / min; the main steam pressure set value of the corresponding unit linearly changes from 14.52 MPa to 17.51 MPa.

[0080] Meanwhile, corresponding constraint conditions are set for the control quantity according to the operating characteristics of the actual unit, including the fuel quantity constraint condition, the boiler feed water flow constraint condition, and the valve opening constraint condition. During the actual execution process, the specific constraint conditions can be set as follows: the speed limit of the coal feeding quantity is 1.4 t / h, the maximum value is 250 t / h, and the minimum value is 45 t / h; the speed limit of the boiler feed water is 15 t / h, the maximum value is 1500 t / h, and the minimum value is 190 t / h; the speed limit of the main steam valve is 3%, the maximum value is 100%, and the minimum value is 45%.

[0081] Thus, the embodiment of the present application determines the set values of the main steam pressure and the unit power according to the sliding pressure curve of the coal-fired unit. Meanwhile, based on the operating characteristics of the actual unit, the fuel quantity, the boiler feed water flow, and the valve opening are constrained, mainly including the limitation of the upper and lower limit ranges and the change rate, so as to carry out the variable load capacity test for different operating conditions to simulate the operating characteristics of the unit under the condition of rapid load change.

[0082] In step S102, based on the variable load simulation results, analyze the dynamic changes of the main steam pressure and the temperature at the outlet point of the steam-water separator in the target coal-fired unit system during the variable load capacity test, and determine the main steam pressure limit relationship and the steam-water separator outlet temperature limit relationship corresponding to the coal-fired unit dynamic model, so as to screen the target variable load simulation results that meet the preset safety requirements through the main steam pressure limit relationship and the steam-water separator outlet temperature limit relationship.

[0083] Furthermore, the embodiment of the present application also needs to analyze the dynamic changes of the main steam pressure and the intermediate point temperature (i.e., the temperature at the outlet point of the steam-water separator) during the variable load test, so as to screen out the simulation results that meet the safety requirements (i.e., the target variable load simulation results).

[0084] Optionally, in an embodiment of the present application, determining the main steam pressure limit relationship and the steam-water separator outlet temperature limit relationship corresponding to the coal-fired unit dynamic model to screen the target variable load simulation results that meet the preset safety requirements through the main steam pressure limit relationship and the steam-water separator outlet temperature limit relationship includes: obtaining the main steam pressure output value of the coal-fired unit dynamic model in the variable load simulation results, and determining the main steam pressure limit relationship corresponding to the coal-fired unit dynamic model according to the main steam pressure output value, the preset main steam pressure limit value, and the main steam pressure set value under each operating condition; obtaining the steam-water separator outlet temperature output value of the coal-fired unit dynamic model in the variable load simulation results, and determining the steam-water separator outlet temperature limit relationship corresponding to the coal-fired unit dynamic model based on the steam-water separator outlet temperature output value, the preset steam-water separator outlet point temperature limit value, and the steam-water separator outlet temperature set value under each operating condition; screening the main steam pressure and the steam-water separator outlet temperature based on the main steam pressure limit relationship and the steam-water separator outlet temperature limit relationship to obtain the target variable load simulation results.

[0085] After that, the embodiments of the present application can analyze the dynamic changes of the main steam pressure and the intermediate point temperature during the variable load test to screen out the simulation results that meet the safety requirements.

[0086] Thus, the embodiments of the present application utilize the corresponding limit values of the main steam pressure and the outlet temperature of the steam-water separator during the unit load change process, thereby avoiding situations such as unstable unit operation and reduced energy efficiency, and effectively reducing the probability of occurrence of safety risks.

[0087] Optionally, in an embodiment of the present application, the mathematical expressions of the main steam pressure limit relationship and the outlet temperature limit relationship of the steam-water separator are:

[0088] |P st -P sts |≤ΔP

[0089] |T m -T ms |≤ΔT

[0090] Wherein, P st represents the main steam pressure output value of the dynamic model of the coal-fired unit; P sts represents the set value of the main steam pressure; ΔP represents the main steam pressure limit value; T m represents the outlet temperature output value of the steam-water separator of the dynamic model of the coal-fired unit; T ms represents the set value of the outlet temperature of the steam-water separator; ΔT represents the limit value of the outlet point temperature of the steam-water separator.

[0091] Specifically, during the unit load change process, the limit relationship of the main steam pressure is as follows:

[0092] |P st -P sts |≤ΔP (7)

[0093] Wherein, P st represents the main steam pressure output value of the unit model, with the unit of MPa; P sts represents the set value of the main steam pressure during the unit load change process, with the unit of MPa; ΔP represents the main steam pressure limit value, with the unit of MPa. In the embodiments of the present application, this value can be taken as 0.5 MPa.

[0094] In addition, during the unit load change process, the limit relationship of the outlet temperature of the steam-water separator is as follows:

[0095] |T m -T ms |≤ΔT (8)

[0096] Wherein, T mRepresents the output value of the temperature at the outlet of the moisture separator of the unit model, with the unit of °C; T ms Represents the set value of the temperature at the outlet of the moisture separator of the unit model, with the unit of °C; ΔT represents the limit value of the temperature at the outlet point of the moisture separator, with the unit of °C. In the embodiments of the present application, this value can be taken as 10 °C.

[0097] Thus, the embodiments of the present application can analyze the dynamic changes of the main steam pressure and the intermediate point temperature of the unit during the load change process, and thereby use this as a basis to limit the load change capacity of the unit.

[0098] In step S103, based on the target load change simulation result, calculate the load change rate of the target coal-fired unit system, so as to determine the maximum load change capacity of the target coal-fired unit system under specific working conditions according to the load change rate.

[0099] Furthermore, the embodiments of the present application can also calculate the load change rate of the unit based on the filtered simulation results (i.e., the target load change simulation results), and finally determine the maximum load change capacity of the unit under specific working conditions.

[0100] Among them, in the output of the coal-fired unit dynamic model, the actual load increase rate of the coal-fired unit can be calculated by the following formula:

[0101]

[0102] Among them, v represents the unit regulation rate, with the unit of MW / min; N1 represents the target load command, with the unit of MW; N0 represents the initial steady-state load of the unit, with the unit of MW; t1 represents the time when the unit load first reaches within the load regulation dead zone, with the unit of min, where the load regulation dead zone is taken as 90% of the target load.

[0103] Thus, the embodiments of the present application can evaluate the actual average load increase rate of the unit by analyzing the dynamic changes of key parameters such as the main steam pressure and the temperature at the outlet of the moisture separator during the load change process, so as to accurately evaluate the load change capacity of the unit in different load intervals such as the low load interval.

[0104] The following illustrates the execution effect of the method for evaluating the rapid load change capacity of the coal-fired unit of the present application by combining with the drawings.

[0105] Figure 4 It is a schematic diagram of the power change process during the load increase stage of a 350MW supercritical coal-fired unit. As Figure 4 shown, the selected simulation process with the maximum load change rate of the unit shows that the response ability of the coal-fired unit under rapid load change conditions is significant, among which, Figure 4The red line represents the power set value, and the blue line represents the actual power value simulated by the model. When the power set value of the unit starts to change at 500s, the coal-fired unit can accurately track the load command and exhibits good dynamic response characteristics. Actual tests show that the load increase rate achieved by the coal-fired unit during this process is 1.69% Pe / min, which is close to the variable load capacity limit of the coal-fired unit.

[0106] Figures 5 to 9 It shows the process of the unit model rising from 180MW to 220MW at a load increase rate of 1.69% Pe / min. Specifically, Figure 5 It is a schematic diagram of the main steam pressure change process during the load increase stage of a 350MW supercritical coal-fired unit;

[0107] Figure 6 It is a schematic diagram of the intermediate point temperature change process during the load increase stage of a 350MW supercritical coal-fired unit. As Figure 5 and Figure 6 shown, during the load increase process, due to the insufficient speed of steam generation by the boiler, the main steam pressure fails to fully follow the command, and the deviation gradually expands, approaching 0.5MPa. With the replenishment of the coal feeding amount, the steam generation capacity of the boiler gradually increases, and the main steam pressure finally tends to the set value. The intermediate point temperature is also affected by the insufficient fuel supply and deviates from the set value. However, with the adjustment of the boiler feed water and fuel amount, the intermediate point temperature gradually returns to the target value, indicating that the dynamic response of the boiler gradually matches the load command.

[0108] Figure 7 It is a schematic diagram of the valve opening control process during the load increase stage of a 350MW supercritical coal-fired unit; Figure 8 It is a schematic diagram of the coal feeding amount control process during the load increase stage of a 350MW supercritical coal-fired unit; Figure 9 It is a schematic diagram of the boiler feed water control process during the load increase stage of a 350MW supercritical coal-fired unit. Figure 7 、 Figure 8 and Figure 9 show the action process of the unit control quantity during this period. The main steam valve opening, coal feeding amount, and boiler feed water increase rapidly in the initial stage of regulation to meet the change requirements of the power command. However, in the later stage of regulation, as the coal feeding amount gradually meets the load demand, the valve opening slowly decreases and finally stabilizes at a certain value. After the regulation ends, they respectively stabilize at the new steady-state values to ensure continuous support for the unit load change. Among them, the coal feeding amount experiences a short-term downward adjustment during the regulation process and then tends to be stable.

[0109] The following evaluation method for the rapid variable load capacity of the coal-fired unit based on this application evaluates the load increase capacity of the unit in the remaining load segments.

[0110] Table 2 shows the maximum load increase capacity assessment of the unit and the corresponding main steam pressure and intermediate point temperature deviation in different load intervals.

[0111] Table 2

[0112]

[0113] Generally speaking, as shown in Table 2, with the increase of the initial load, the actual average load increase speed shows an increasing trend, reaching a maximum of 2.97% Pe / min and a minimum of 1.36% Pe / min; compared with the load increase process of 90MW - 130MW, the actual average load increase speed of the unit in the load increase process of 310MW - 345MW has increased by 2.18 times; the limitations of the main steam pressure and the intermediate point temperature are more obvious in the medium and low load intervals, approaching 0.5MPa and 10°C respectively. In the high load interval, the deviations of both are less than the limit values, and the actual average load increase rate of the unit is mainly restricted by the speed limit of the control quantity.

[0114] According to the assessment method for the rapid load change capacity of a coal-fired unit proposed in the embodiment of the present application, by obtaining the historical operation data of the target coal-fired unit system and constructing a coal-fired unit dynamic model corresponding to the target coal-fired unit system based on the historical operation data; based on the coal-fired unit dynamic model, performing load change capacity test operations under different operating conditions to obtain the load change simulation results corresponding to the target coal-fired unit system, and analyzing the dynamic changes of the main steam pressure and the temperature at the outlet of the steam-water separator of the target coal-fired unit system during the load change capacity test process according to the load change simulation results to screen the target load change simulation results that meet the preset safety requirements; based on the target load change simulation results, calculating the load change rate of the target coal-fired unit system to determine the maximum load change capacity of the target coal-fired unit system under specific conditions according to the load change rate. The present application rationally formulates an instruction close to its maximum load change capacity based on the actual operating load state of the unit, which is of great significance for suppressing the fluctuation of new energy power generation and stabilizing the grid frequency.

[0115] Secondly, an assessment device for the rapid load change capacity of a coal-fired unit proposed in the embodiment of the present application is described with reference to the accompanying drawings.

[0116] Figure 10 It is a block diagram of the assessment device for the rapid load change capacity of a coal-fired unit in the embodiment of the present application.

[0117] As Figure 10 shown, the assessment device 10 for the rapid load change capacity of the coal-fired unit includes: a load change capacity test module 100, an analysis module 200, and a calculation module 300.

[0118] Among them, the variable load capacity test module 100 is used to determine the main steam pressure setting value and the unit power setting value of the target coal-fired unit system based on a pre-constructed dynamic model of the coal-fired unit, so as to perform variable load capacity test operations under different operating conditions according to the dynamic model of the coal-fired unit, the main steam pressure setting value and the unit power setting value, and obtain the variable load simulation result corresponding to the target coal-fired unit system.

[0119] The analysis module 200 is used to analyze the dynamic changes of the main steam pressure and the temperature at the outlet of the steam-water separator of the target coal-fired unit system during the variable load capacity test process based on the variable load simulation result, and determine the main steam pressure limit relationship and the steam-water separator outlet temperature limit relationship corresponding to the dynamic model of the coal-fired unit, so as to screen the target variable load simulation results that meet the preset safety requirements through the main steam pressure limit relationship and the steam-water separator outlet temperature limit relationship.

[0120] The calculation module 300 is used to calculate the load change rate of the target coal-fired unit system based on the target variable load simulation result, so as to determine the maximum variable load capacity of the target coal-fired unit system under the target condition according to the load change rate.

[0121] Optionally, in an embodiment of the present application, the evaluation device 10 for the rapid variable load capacity of the coal-fired unit in the embodiment of the present application further includes: a pulverizing system model construction module, a boiler system model construction module, a steam turbine system model construction module, and a modeling module.

[0122] Among them, the first construction unit is used to obtain the coal input amount, the fuel quantity command and the pulverizing system delay time of the target coal-fired unit system before performing the variable load capacity test operation under different operating conditions based on the pre-constructed dynamic model of the coal-fired unit, and construct a pulverizing system model based on the coal input amount, the fuel quantity command and the pulverizing system delay time.

[0123] The first acquisition unit is used to acquire the outlet parameters of the steam-water separator of the target coal-fired unit system, and determine the corresponding lumped parameters according to the outlet parameters of the steam-water separator, so as to construct a boiler system model based on the lumped parameters and a preset lumped parameter strategy.

[0124] The first determination unit is used to determine the output power of the steam turbine of the target coal-fired unit system based on the preset principle of energy conservation, and construct a steam turbine system model according to the output power of the steam turbine.

[0125] The second construction unit is used to construct a dynamic model of the coal-fired unit based on the pulverizing system model, the boiler system model and the steam turbine system model.

[0126] Optionally, in an embodiment of the present application, the variable load capacity test module 100 includes: a first acquisition unit, a constraint establishment unit, a setting unit, and an execution unit.

[0127] Among them, the first acquisition unit is used to acquire the sliding pressure curve corresponding to the target coal-fired unit system, and determine the main steam pressure setting value and the unit power setting value corresponding to the dynamic model of the coal-fired unit according to the sliding pressure curve.

[0128] The constraint establishment unit is used to acquire the actual operation characteristics corresponding to the target coal-fired unit system, and based on the actual operation characteristics, construct the fuel quantity constraint condition, the boiler feed water flow constraint condition and the valve opening constraint condition corresponding to the dynamic model of the coal-fired unit.

[0129] The setting unit is used to perform an increasing load rate process on the unit power setting value under different operating conditions to obtain the unit power increasing rate setting value under each operating condition, and determine the main steam pressure increasing rate setting value corresponding to the unit power increasing rate setting value.

[0130] The execution unit is used to perform the variable load capacity test operation under different operating conditions based on the unit power increasing rate setting value and the main steam pressure increasing rate setting value, and combine the fuel quantity constraint condition, the boiler feed water flow constraint condition and the valve opening constraint condition to obtain the variable load simulation result.

[0131] Optionally, in an embodiment of the present application, the analysis module 200 includes: a first determination unit, a second determination unit and a screening unit.

[0132] Among them, the second determination unit is used to acquire the main steam pressure output value of the dynamic model of the coal-fired unit in the variable load simulation result, and determine the main steam pressure limit relationship corresponding to the dynamic model of the coal-fired unit according to the main steam pressure output value, the preset main steam pressure limit value and the main steam pressure setting value under each operating condition.

[0133] The third determination unit is used to acquire the outlet temperature output value of the steam-water separator of the dynamic model of the coal-fired unit in the variable load simulation result, and based on the outlet temperature output value of the steam-water separator, the preset outlet temperature limit value of the steam-water separator point and the outlet temperature setting value of the steam-water separator under each operating condition, determine the outlet temperature limit relationship of the steam-water separator corresponding to the dynamic model of the coal-fired unit.

[0134] The screening unit is used to screen the main steam pressure and the outlet temperature of the steam-water separator based on the main steam pressure limit relationship and the outlet temperature limit relationship of the steam-water separator to obtain the target variable load simulation result.

[0135] Optionally, in an embodiment of the present application, the mathematical expressions of the main steam pressure limit relationship and the outlet temperature limit relationship of the steam-water separator are:

[0136] |P st -P sts |≤ΔP

[0137] |T m -T ms |≤ΔT

[0138] Wherein, P st represents the main steam pressure output value of the dynamic model of the coal-fired unit; P sts represents the set value of the main steam pressure; ΔP represents the limit value of the main steam pressure; T m represents the outlet temperature output value of the steam-water separator of the dynamic model of the coal-fired unit; T ms represents the set value of the outlet temperature of the steam-water separator; ΔT represents the limit value of the outlet temperature at the steam-water separator outlet point.

[0139] It should be noted that the foregoing explanation of the embodiments of the evaluation method for the rapid load change ability of coal-fired units is also applicable to the evaluation device for the rapid load change ability of the coal-fired units in this embodiment, and will not be elaborated here.

[0140] An evaluation device for the rapid load change ability of a coal-fired unit according to an embodiment of the present application includes a load change ability test module 100, configured to obtain historical operation data of a target coal-fired unit system, and construct a coal-fired unit dynamic model corresponding to the target coal-fired unit system according to the historical operation data; an analysis module 200, configured to perform a load change ability test operation under different operating conditions based on the coal-fired unit dynamic model, so as to obtain a load change simulation result corresponding to the target coal-fired unit system, and analyze the dynamic changes of the main steam pressure and the outlet temperature at the steam-water separator outlet point of the target coal-fired unit system during the load change ability test process according to the load change simulation result, so as to screen out a target load change simulation result that meets the preset safety requirements; a calculation module 300, configured to calculate the load change rate of the target coal-fired unit system based on the target load change simulation result, so as to determine the maximum load change ability of the target coal-fired unit system under specific operating conditions according to the load change rate. The present application rationally formulates an instruction close to its maximum load change ability based on the actual operating load state of the unit, which is of great significance for suppressing the fluctuation of new energy power generation and stabilizing the power grid frequency.

[0141] Figure 11 It is a schematic structural diagram of an electronic device provided by an embodiment of the present application. The electronic device may include:

[0142] A memory 1101, a processor 1102, and a computer program stored on the memory 1101 and executable on the processor 1102.

[0143] When the processor 1102 executes the program, it implements the evaluation method for the rapid load change ability of the coal-fired unit provided in the above embodiment.

[0144] Further, the electronic device further includes:

[0145] A communication interface 1103 for communication between the memory 1101 and the processor 1102.

[0146] A memory 1101 for storing a computer program that can run on the processor 1102.

[0147] The memory 1101 may include a high-speed RAM memory and may also include non-volatile memory, such as at least one disk memory.

[0148] If the memory 1101, the processor 1102, and the communication interface 1103 are implemented independently, the communication interface 1103, the memory 1101, and the processor 1102 can be interconnected via a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 11 only a thick line is used to represent it in the figure, but it does not mean that there is only one bus or one type of bus.

[0149] Optionally, in a specific implementation, if the memory 1101, the processor 1102, and the communication interface 1103 are integrated on a single chip, the memory 1101, the processor 1102, and the communication interface 1103 can communicate with each other through an internal interface.

[0150] The processor 1102 may be a Central Processing Unit (CPU), or an Application Specific Integrated Circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0151] The embodiments of the present application also provide a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the evaluation method for the rapid load-changing ability of a coal-fired unit as described above is implemented.

[0152] The embodiments of the present application also provide a computer program product, including a computer program, and when the computer program is executed, it is used to implement the evaluation method for the rapid load-changing ability of a coal-fired unit as described above.

[0153] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc., mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0154] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of this application, the meaning of "N" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0155] Any process or method description shown in the flowchart or described in other ways herein can be understood as representing a module, segment, or part of code including one or N executable instructions for implementing a customized logic function or process, and the scope of the preferred embodiments of this application includes additional implementations, where the functions can be executed in a substantially simultaneous manner or in the reverse order according to the involved functions, rather than in the order shown or discussed, which should be understood by those skilled in the art to which the embodiments of this application pertain.

[0156] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a definite sequence list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or in conjunction with these instruction execution systems, apparatuses, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection part (electronic device) having one or N wirings, a portable computer disk cartridge (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically by optically scanning the paper or other media, followed by editing, interpretation, or otherwise processing as appropriate, and then storing it in a computer memory.

[0157] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. If implemented using hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application-specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0158] Those of ordinary skill in the art of this technology can understand that all or part of the steps carried by the methods of the above embodiments can be completed by instructing relevant hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiments.

[0159] In addition, each functional unit in various embodiments of the present application may be integrated into one processing module, may exist separately as individual physical units, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. When the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0160] The above-mentioned storage medium may be a read-only memory, a magnetic disk, an optical disc, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. An evaluation method for the rapid load-changing ability of a coal-fired unit, characterized in that, Including the following steps: Based on a pre - constructed dynamic model of a coal - fired unit, determine the main steam pressure set value and the unit power set value of the target coal - fired unit system, and perform variable load capacity test operations under different operating conditions according to the coal - fired unit dynamic model, the main steam pressure set value, and the unit power set value to obtain the variable load simulation results corresponding to the target coal - fired unit system; Based on the variable load simulation results, analyze the dynamic changes of the main steam pressure and the temperature at the outlet of the steam - water separator of the target coal - fired unit system during the variable load capacity test process, and determine the main steam pressure limit relationship and the steam - water separator outlet temperature limit relationship corresponding to the coal - fired unit dynamic model, so as to screen the target variable load simulation results that meet the preset safety requirements through the main steam pressure limit relationship and the steam - water separator outlet temperature limit relationship; Based on the target variable load simulation results, calculate the load change rate of the target coal - fired unit system, and determine the maximum variable load capacity of the target coal - fired unit system under the target operating conditions according to the load change rate.

2. The method according to claim 1, wherein Before performing the variable load capacity test operations under different operating conditions based on the pre - constructed dynamic model of the coal - fired unit, it further includes: Obtain the coal input amount, fuel quantity command, and pulverizing system delay time of the target coal - fired unit system, and construct a pulverizing system model based on the coal input amount, the fuel quantity command, and the pulverizing system delay time; Obtain the outlet parameters of the steam - water separator of the target coal - fired unit system, and determine the corresponding lumped parameters according to the outlet parameters of the steam - water separator, so as to construct a boiler system model based on the lumped parameters and a preset lumped parameter strategy; Based on the preset principle of energy conservation, determine the output power of the steam turbine of the target coal - fired unit system, and construct a steam turbine system model according to the output power of the steam turbine; Construct the dynamic model of the coal - fired unit based on the pulverizing system model, the boiler system model, and the steam turbine system model.

3. The method according to claim 1, characterized in that, The step of determining the main steam pressure set value and the unit power set value of the target coal - fired unit system based on the pre - constructed dynamic model of the coal - fired unit, and performing variable load capacity test operations under different operating conditions according to the coal - fired unit dynamic model, the main steam pressure set value, and the unit power set value to obtain the variable load simulation results corresponding to the target coal - fired unit system includes: Obtain the sliding pressure curve corresponding to the target coal - fired unit system, and determine the main steam pressure set value and the unit power set value corresponding to the coal - fired unit dynamic model according to the sliding pressure curve; Obtain the actual operating characteristics corresponding to the target coal - fired unit system, and construct the fuel quantity constraint condition, the boiler feed water flow constraint condition, and the valve opening constraint condition corresponding to the coal - fired unit dynamic model based on the actual operating characteristics; Under the different operating conditions, perform an increasing treatment on the unit power set value at an increasing load rate to obtain the unit power increasing rate set value for each operating condition, and determine the main steam pressure increasing rate set value corresponding to the unit power increasing rate set value. Based on the set value of the unit power increase rate and the set value of the main steam pressure increase rate, and in combination with the fuel quantity constraint condition, the boiler feed water flow constraint condition, and the valve opening constraint condition, perform the variable load capacity test operation under different operating conditions to obtain the variable load simulation result.

4. The method according to claim 3, wherein The determining the main steam pressure limit relationship and the separator outlet temperature limit relationship corresponding to the dynamic model of the coal-fired unit, so as to screen the target variable load simulation results that meet the preset safety requirements through the main steam pressure limit relationship and the separator outlet temperature limit relationship, includes: Obtain the main steam pressure output value of the dynamic model of the coal-fired unit in the variable load simulation result, and determine the main steam pressure limit relationship corresponding to the dynamic model of the coal-fired unit according to the main steam pressure output value, the preset main steam pressure limit value, and the main steam pressure set value under each operating condition; Obtain the separator outlet temperature output value of the dynamic model of the coal-fired unit in the variable load simulation result, and determine the separator outlet temperature limit relationship corresponding to the dynamic model of the coal-fired unit based on the separator outlet temperature output value, the preset separator outlet point temperature limit value, and the separator outlet temperature set value under each operating condition; Based on the main steam pressure limit relationship and the separator outlet temperature limit relationship, screen the main steam pressure and the separator outlet temperature to obtain the target variable load simulation result.

5. The method according to claim 4, wherein The mathematical expressions of the main steam pressure limit relationship and the separator outlet temperature limit relationship are: |P st -P sts | ≤ ΔP |T m -T ms |≤ΔT Among them, P st represents the main steam pressure output value of the dynamic model of the coal-fired unit; P sts represents the set value of the main steam pressure; ΔP represents the main steam pressure limit value; T m represents the outlet temperature output value of the steam-water separator of the dynamic model of the coal-fired unit; T ms represents the set value of the outlet temperature of the steam-water separator; ΔT represents the temperature limit value at the outlet point of the steam-water separator.

6. An evaluation device for the rapid load-changing ability of a coal-fired unit, characterized in that Including: A variable load capacity test module, configured to determine the main steam pressure set value and the unit power set value of the target coal-fired unit system based on a pre-constructed dynamic model of the coal-fired unit, and perform a variable load capacity test operation under different operating conditions according to the dynamic model of the coal-fired unit, the main steam pressure set value, and the unit power set value, so as to obtain a variable load simulation result corresponding to the target coal-fired unit system; An analysis module, configured to analyze the dynamic changes of the main steam pressure and the separator outlet point temperature of the target coal-fired unit system during the variable load capacity test process based on the variable load simulation result, and determine the main steam pressure limit relationship and the separator outlet temperature limit relationship corresponding to the dynamic model of the coal-fired unit, so as to screen the target variable load simulation results that meet the preset safety requirements through the main steam pressure limit relationship and the separator outlet temperature limit relationship; A calculation module, configured to calculate the load change rate of the target coal-fired unit system based on the target variable load simulation result, and determine the maximum variable load capacity of the target coal-fired unit system under the target condition according to the load change rate.

7. The device according to claim 6, characterized in that, It further includes: A pulverizing system model construction module, which is used to obtain the coal feed quantity, fuel quantity command, and pulverizing system delay time of the target coal-fired unit system before performing the variable load capacity test operation under different operating conditions based on the pre-constructed dynamic model of the coal-fired unit, and construct a pulverizing system model based on the coal feed quantity, the fuel quantity command, and the pulverizing system delay time; A boiler system model construction module, which is used to obtain the outlet parameters of the steam-water separator of the target coal-fired unit system, determine the corresponding lumped parameters according to the outlet parameters of the steam-water separator, and construct a boiler system model based on the lumped parameters and a preset lumped parameter strategy; A steam turbine system model construction module, which is used to determine the steam turbine output power of the target coal-fired unit system based on the preset principle of energy conservation, and construct a steam turbine system model according to the steam turbine output power; A modeling module, which is used to construct the dynamic model of the coal-fired unit based on the pulverizing system model, the boiler system model, and the steam turbine system model.

8. An electronic device, characterized in that, Comprising: A memory, a processor, and a computer program stored on the memory and executable on the processor, where the processor executes the program to implement the evaluation method for the rapid variable load capacity of the coal-fired unit according to any one of claims 1-5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to be used to implement the evaluation method for the rapid variable load capacity of the coal-fired unit according to any one of claims 1-5.

10. A computer program product, comprising a computer program, characterized in that, The computer program is executed to be used to implement the evaluation method for the rapid variable load capacity of the coal-fired unit according to any one of claims 1-5.

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