Method for calculating energy storage variation of variable load boiler of coal-fired power generating unit and related equipment

Abstract

The present application relates to coal-fired power generation technology field, disclose a kind of coal-fired generating unit variable load boiler energy storage variation calculation method and related equipment, the method first builds coal-fired generating unit transient model, in combination with unit structure and operating constraint condition, determine maximum variable load rate, variable load rate interval and actual operating load interval;Select a plurality of variable load rate and load interval to carry out variable condition test, calculate the steam heat absorption of each condition, while fitting the steady-state working medium heat absorption function of each load point;Based on the function and variable condition steam heat absorption, the boiler energy storage variation under the specified load interval, corresponding variable load rate is calculated by integral difference.This application can accurately realize the quantitative calculation of boiler energy storage variation in the process of coal-fired unit variable load, solve the technical problems of low calculation precision of energy storage variation in prior art, restrict the technical problems of unit peak shaving efficiency improvement, provide data support for efficient deep peak shaving operation of unit.

Description

Technical Field

[0001] This invention relates to the field of coal-fired power generation technology, specifically to a method for calculating the change in energy storage of a variable load boiler in a coal-fired power generation unit and related equipment. Background Technology

[0002] Currently, building a new power system based on renewable energy has become the core direction of energy structure transformation. Renewable energy sources such as wind power and photovoltaics have been widely promoted and applied due to their clean and low-carbon advantages. However, the power generation of such renewable energy sources has significant time-varying characteristics and strong volatility. Their output fluctuations can easily cause power imbalances in the power grid, affecting the safe and stable operation of the power grid and power quality. This, in turn, restricts the efficient absorption of new energy power and has become a key problem that urgently needs to be solved in the process of building a new power system.

[0003] To address these challenges, it is necessary to leverage various regulatory resources to mitigate fluctuations in renewable energy output and ensure grid power balance. Coal-fired power generating units, as one of the core regulatory resources in the current power system, possess rapid load regulation capabilities. They can flexibly adjust output to mitigate the volatility of renewable energy, supporting the efficient absorption of new energy power and playing an irreplaceable role in the safe and stable operation of the new power system.

[0004] However, coal-fired power generating units generate additional energy consumption when performing load shifting and peak shaving operations. This additional energy consumption can be divided into two categories: "unavoidable" and "avoidable". Among them, the "unavoidable" additional energy consumption stems from the difference in the heat storage state of the unit under different operating conditions. Specifically, it manifests as the additional energy consumption caused by the difference in heat storage before and after the unit's load shifting transient process. This part of the additional energy consumption is not directly related to the load shifting process itself, but is only caused by the difference in heat storage state.

[0005] Currently, research on the boiler thermal storage characteristics of coal-fired power generating units under variable load scenarios is still insufficient. A complete method for quantifying thermal storage capacity and targeted control optimization strategies have not yet been formed, resulting in the inability to effectively avoid or reduce the aforementioned unavoidable additional energy consumption. This restricts the improvement of peak-shaving efficiency of coal-fired power generating units, makes it difficult to fully exert their peak-shaving support role in the new power system, is not conducive to the low-coal-consumption dispatch optimization of the new power system, and cannot fully take into account the stability and operational economy of the power system.

[0006] Therefore, in-depth research on the boiler heat storage characteristics of coal-fired power generating units under variable load scenarios and accurate quantification of the unit's heat storage capacity provide a reliable reference for optimizing unit control strategies, thereby improving the peak-shaving efficiency of coal-fired power generating units, reducing additional energy consumption, and making them more efficient peak-shaving power sources. This is of great significance for optimizing the low-coal-consumption dispatch of units in new power systems and ensuring the stability and economy of the power system. Summary of the Invention

[0007] In order to overcome the defects of the prior art, the purpose of this invention is to provide a method and related equipment for calculating the change in energy storage of a coal-fired power generating unit under changing load, so as to solve the technical problem that the change in energy storage during the changing load of a coal-fired power generating unit is difficult to calculate accurately and restricts the improvement of the unit's peak-shaving efficiency.

[0008] This invention is achieved through the following technical solution: In a first aspect, the present invention provides a method for calculating the change in energy storage of a variable load boiler in a coal-fired power generating unit, including: A transient model of a coal-fired power generating unit was constructed. Based on the transient model and the unit's structure and operating constraints, the maximum load change rate and load change rate range of the coal-fired power generating unit were determined. Based on the actual operating conditions of the power plant, the load range during the load change process of the unit was determined. Select several variable load rates within the determined variable load rate range, and conduct unit variable operating condition tests in conjunction with the determined load range to calculate the steam heat absorption under each variable load rate. Within the defined load range, select several load points, calculate the heat absorption of the working fluid under steady-state conditions at each load point, and perform fitting optimization on the steady-state heat absorption of the working fluid to obtain the heat absorption function under steady-state conditions. Based on the heat absorption function under steady-state conditions and the heat absorption function of steam under variable conditions, the change in boiler energy storage under strain load rate and within a specified load range is calculated by integration and difference, thus completing the calculation of the change in boiler energy storage under variable load of coal-fired power generating unit.

[0009] Preferably, the transient model of the coal-fired power generation unit is a coal-fired power generation unit model, which includes a boiler, superheater, reheater, turbine, deaerator, condenser, high-pressure heater, low-pressure heater, and water storage tank; the coal-fired power generation unit model adopts a structure of condensate-driven gravity-flow reheating and intermediate-pressure cylinder exhaust steam supply for heating; the coal-fired power generation unit model is equipped with a logic control system, which includes coal feeding control, water feeding control, air volume control, and steam temperature control.

[0010] Preferably, the unit structure includes the characteristics of the unit pipe materials, boiler thermal stress, and maximum flow velocity in the pipes; wherein the operating constraints are that if material thermal stress is not considered when building the transient model, the maximum load change rate of the unit is determined based on the actual operating conditions of the power plant.

[0011] Preferably, the load range during the defined unit load change process includes 100% THA load to the lowest load at which the power plant is operating.

[0012] Preferably, the formula for calculating the steam heat absorption under varying load rates and operating conditions is as follows:

[0013] in, The heat absorbed by steam per unit time during the variable load process is expressed in kJ / s. The water supply flow rate is expressed in kg / s. The reheat steam flow rate is kg / s; These are the enthalpy values ​​of feedwater, main steam, and reheat steam inlet and outlet, respectively, in kJ / kg. The feedwater flow rate, each enthalpy value, and the reheat steam flow rate were all obtained through variable operating condition testing.

[0014] The preferred expression for the steady-state heat absorption function is as follows:

[0015] in, The heat absorbed by steam per unit time under steady-state conditions is expressed in kJ / s and L. i is the coefficient; t is time, s; C is a constant; j is the exponent of each parameter.

[0016] Preferably, the formula for calculating the change in boiler energy storage is as follows:

[0017] In the formula, This represents the change in boiler energy storage. This represents the heat absorbed by steam per unit time under steady-state operating conditions. This refers to the heat absorbed by steam per unit time during a variable load process. The load change time is s; when the unit increases load, the steady-state heat absorption minus the transient heat absorption is used for calculation; when the unit decreases load, the transient heat absorption minus the steady-state heat absorption is used for calculation; the calculation accuracy can be optimized by adjusting the exponent values ​​of each parameter in the steady-state heat absorption function. The larger the exponent value, the higher the calculation accuracy.

[0018] Secondly, the present invention also provides a calculation system for the change in energy storage of a coal-fired power generation unit under varying loads, comprising: The model operating condition processing module is used to build a transient model of the coal-fired power generation unit. Based on the transient model of the coal-fired power generation unit and combined with the unit structure and operating constraints, the maximum load change rate and load change rate range of the coal-fired power generation unit are determined. Based on the actual operating conditions of the power plant, the load range during the load change process of the unit is determined. The heat absorption calculation module is used to select several variable load rates within the determined variable load rate range, and conduct unit variable operating condition tests in conjunction with the determined load range to calculate the steam heat absorption under each variable load rate and variable operating condition. The function fitting module is used to select several load points within the determined load range, calculate the heat absorption of the working fluid under steady-state conditions at each load point, and perform fitting optimization on the steady-state heat absorption of the working fluid to obtain the heat absorption function under steady-state conditions. The energy storage calculation module is used to calculate the change in boiler energy storage under a specified load range at a given load rate by integrating and subtracting the heat absorption function under steady-state conditions and the heat absorption function of steam under variable conditions, thus completing the calculation of the change in boiler energy storage under variable load of coal-fired power generating units.

[0019] Thirdly, the present invention also provides a mobile terminal, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the method for calculating the change in energy storage of a coal-fired power generation unit under varying loads as described above.

[0020] Fourthly, the present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method for calculating the change in energy storage of a variable-load boiler in a coal-fired power generation unit as described above.

[0021] Compared with the prior art, the present invention has the following beneficial technical effects: This invention provides a method for calculating the change in boiler energy storage in a coal-fired power generating unit under varying load conditions. It involves constructing a transient model of the coal-fired power generating unit, determining the maximum load change rate and the load change rate range based on the unit's structure and operating constraints, and clarifying the load range during the load change process according to the actual operating conditions of the power plant. Subsequently, several rates are selected within the load change rate range, and unit-specific operating condition tests are conducted within the load range to calculate the steam heat absorption at each rate. Simultaneously, several load points are selected within the load range, and the working fluid heat absorption under steady-state conditions at each point is calculated. The steady-state heat absorption function is then obtained through fitting and optimization. Ultimately, based on this function and the steam heat absorption under varying operating conditions, the change in boiler energy storage within a specified load range under varying load rates is calculated through integration and subtraction. This solves the technical problem in existing technologies where the change in energy storage during load changes in coal-fired units is difficult to calculate accurately, thus hindering the improvement of peak-shaving efficiency. This method fully considers the "unavoidable" energy consumption generated by boiler heat storage during load changes in coal-fired units. The proposed method for calculating the change in boiler energy storage can provide a reliable reference for low-coal-consumption scheduling optimization of new power system units, helping to improve the rationality and economy of power system scheduling. The difference method used in the calculation process of this invention can effectively avoid transient and steady-state errors caused by the model itself, further improving the accuracy of the energy storage change calculation results and solving the pain point of large errors in traditional calculation methods, providing technical support for improving the peak-shaving efficiency of units. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the method for calculating the change in energy storage of a coal-fired power generating unit under varying loads in an embodiment of the present invention. Figure 2This is a model diagram of a coal-fired power generation unit in an embodiment of the present invention; Figure 3 This is a schematic diagram of the steam heat absorption curve of a 670MW unit under varying loads in an embodiment of the present invention; Figure 4 This is a schematic diagram of the calculation system for the change in energy storage of a coal-fired power generating unit under varying loads in an embodiment of the present invention. In the diagram: 1. Model working condition processing module; 2. Heat absorption calculation module; 3. Function fitting module; 4. Energy storage calculation module. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0024] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0025] The purpose of this invention is to provide a method and related equipment for calculating the change in energy storage of a coal-fired power generating unit under varying load, so as to solve the technical problem in the prior art that it is difficult to accurately calculate the change in energy storage during the load change process of a coal-fired power generating unit, which restricts the improvement of the unit's peak-shaving efficiency.

[0026] The present invention will now be described in further detail with reference to the accompanying drawings: See Figure 1 In one embodiment of the present invention, taking a 670MW unit as an example, a method for calculating the change in boiler energy storage of a coal-fired power generating unit under varying loads is provided, including: Step 1: Construct a transient model of the coal-fired power generating unit. Based on the transient model and the unit's structure and operating constraints, determine the maximum load change rate and load change rate range of the coal-fired power generating unit. Then, based on the actual operating conditions of the power plant, determine the load range during the load change process. , ]; Specifically, the transient model of the coal-fired power generation unit is a coal-fired power generation unit model, which includes a boiler, superheater, reheater, turbine, deaerator, condenser, high-pressure heater, low-pressure heater, and water storage tank; the coal-fired power generation unit model adopts a structure of condensate-driven gravity-flow reheating and intermediate-pressure cylinder exhaust steam supply for heating; the coal-fired power generation unit model is equipped with a logic control system, which includes coal feeding control, water feeding control, air volume control, and steam temperature control.

[0027] Specifically, the unit structure includes the characteristics of the unit pipe materials, boiler thermal stress, and maximum flow velocity in the pipes; among which, the operating constraints are that if the thermal stress of the materials is not considered when building the transient model, the maximum load change rate of the unit is determined based on the actual operating conditions of the power plant.

[0028] When the maximum load change rate of the unit is determined to be A0, the load change rate range is: A=(0, A0) In the formula, A is the load change rate of the coal-fired power generation unit, MW / min; A0 is the maximum load change rate of the coal-fired power generation unit, MW / min.

[0029] Specifically, the load range during the determined unit load change process includes the load from 100% THA to the lowest load at which the power plant operates, and the selected load operating range is from 50% THA to 100% THA.

[0030] In this embodiment, the maximum load change rate of the unit is determined to be 4% based on the actual operating conditions of the power plant, and a load change rate of 3% is selected.

[0031] Step 2: Select several variable load rates within the determined variable load rate range, and conduct unit variable operating condition tests in conjunction with the determined load range to calculate the steam heat absorption under each variable load rate. In this embodiment, within the selected load range, several variable load rates (0 < A' ≤ A0, A1, A2, A3, A4, ...) are selected within the interval (0, A0). The unit is then subjected to variable operating condition processing using the selected variable load rates to obtain the feedwater flow rate under a certain variable load rate. enthalpy value Enthalpy of main steam reheat steam flow rate Enthalpy values ​​at entrance and exit , The heat absorption curve of the working fluid was calculated.

[0032] Specifically, the formulas for calculating the steam heat absorption under varying load rates and operating conditions are as follows:

[0033] in, The heat absorbed by steam per unit time during the variable load process is expressed in kJ / s. The water supply flow rate is expressed in kg / s. The reheat steam flow rate is kg / s; These are the enthalpy values ​​of feedwater, main steam, and reheat steam inlet and outlet, respectively, in kJ / kg. The feedwater flow rate, each enthalpy value, and the reheat steam flow rate were all obtained through variable operating condition testing.

[0034] Step 3: Select several load points within the determined load range, calculate the heat absorption of the working fluid under steady-state conditions at each load point, and perform fitting optimization on the steady-state heat absorption of the working fluid to obtain the heat absorption function under steady-state conditions. In this embodiment, several load points are selected within the load range. The computer group is under load Water supply flow rate enthalpy of water supply Enthalpy of main steam reheat steam flow rate Enthalpy values ​​at entrance and exit , Then, the heat absorption of the working fluid under steady-state conditions is calculated, and the heat absorption of the working fluid is fitted and optimized to obtain the heat absorption of the working fluid under steady-state conditions. .

[0035] Specifically, the expression for the heat absorption function under steady-state conditions is as follows:

[0036] in, The heat absorbed by steam per unit time under steady-state conditions is expressed in kJ / s and L. i is the coefficient; t is time, s; C is a constant; j is the exponent of each parameter.

[0037] The formula for calculating the steam heat absorption of a coal-fired power generation unit under steady-state operating conditions. , , .

[0038] Step 4: Based on the heat absorption function under steady-state conditions and the heat absorption function of steam under variable conditions, the change in boiler energy storage under the strain load rate and within the specified load range is calculated by integration and difference, thus completing the calculation of the change in boiler energy storage under variable load of coal-fired power generation unit.

[0039] In this embodiment, within a selected load range, the coal consumption curve under variable load conditions is calculated at a certain variable load rate, and compared with the heat absorption curve under steady-state conditions. The difference is then calculated and integrated to obtain the unit load at a variable load rate of A. arrive Changes in boiler energy storage during the process .

[0040] Specifically, the formula for calculating the change in boiler energy storage is as follows:

[0041] In the formula, This represents the change in boiler energy storage. This represents the heat absorbed by steam per unit time under steady-state operating conditions. This refers to the heat absorbed by steam per unit time during a variable load process. The load change time is s; when the unit increases load, the steady-state heat absorption minus the transient heat absorption is used for calculation; when the unit decreases load, the transient heat absorption minus the steady-state heat absorption is used for calculation; the calculation accuracy can be optimized by adjusting the exponent values ​​of each parameter in the steady-state heat absorption function. The larger the exponent value, the higher the calculation accuracy.

[0042] When the unit increases load, the steady-state heat absorption is used to subtract the transient heat absorption; when the load decreases, the transient heat absorption is used to subtract the steady-state heat absorption.

[0043] The data collected from APROS during the unit's load change process from 75% THA to 100% THA are shown in Table 1.

[0044] Table 1. Key parameters of a 670MW coal-fired power generating unit under load variation from 50% THA to 100% THA.

[0045] according to Figure 3 As shown, the heat absorbed by the steam under varying operating conditions and steady-state fitting is illustrated. During the load increase process, the boiler's heat storage increases during the transient load increase, which reduces the heat absorption of the steam. Later, due to the excessively rapid increase in pulverized coal speed, the heat absorption rises rapidly. The difference between the steady-state steam heat absorption and the transient steam heat absorption is the change in the boiler's heat storage during the load change process. That is, the difference between the shaded area on the left half and the shaded area on the right half in Figure 3 represents the change in the boiler's energy storage during the load change process from 75% THA to 100% THA. The calculated change in boiler energy storage during this load change process is 7099.36 MJ.

[0046] In summary, this embodiment provides a method for calculating the change in boiler energy storage during load changes in coal-fired power generating units. By constructing a transient model of the coal-fired power generating unit, the steam heat absorption at a certain load change rate is calculated. Within the load change range, several steady-state operating conditions are selected, and their steam heat absorption is calculated. Then, the calculation points for the steady-state operating conditions are fitted and the parameters are optimized. Finally, the difference between the steam heat absorption of the transient and steady-state operating conditions yields the change in boiler energy storage during the load change process. Using this method, the change in boiler energy storage during load changes can be quantified, providing reference for unit control strategies. Simultaneously, additional energy consumption can be calculated through the heat storage difference, enabling reasonable electricity dispatch and effective electricity price prediction under the existing electricity spot market. It has the advantages of simple and accurate calculation, flexible and economical operation of power plants, and can also promote energy conservation and emission reduction in coal-fired heating units, contributing to the high-quality development of coal-fired power enterprises, with broad application prospects.

[0047] Example 2 according to Figure 4 As shown, this embodiment also provides a calculation system for the change in energy storage of a coal-fired power generation unit's boiler under varying loads, including: Model operating condition processing module 1 is used to build a transient model of the coal-fired power generation unit. Based on the transient model of the coal-fired power generation unit and combined with the unit structure and operating constraints, the maximum load change rate and load change rate range of the coal-fired power generation unit are determined. Based on the actual operating conditions of the power plant, the load range during the load change process of the unit is determined. The heat absorption calculation module 2 is used to select several variable load rates within the determined variable load rate range, and conduct unit variable operating condition tests in conjunction with the determined load range to calculate the steam heat absorption under each variable load rate and variable operating condition. The function fitting module 3 is used to select several load points within the determined load range, calculate the heat absorption of the working fluid under steady-state conditions at each load point, and perform fitting optimization on the steady-state heat absorption of the working fluid to obtain the heat absorption function under steady-state conditions. The energy storage calculation module 4 is used to calculate the change in boiler energy storage under a specified load range at a given strained load rate by integrating the steady-state heat absorption function and the steam heat absorption function under variable operating conditions, thus completing the calculation of the change in boiler energy storage under variable load in coal-fired power generating units.

[0048] Example 3 The present invention also provides a mobile terminal, including a memory, a processor, and a computer program stored in the memory and executable on the processor, such as a program for calculating the change in energy storage of a coal-fired power generation unit under variable load.

[0049] When the processor executes the computer program, it implements the above-mentioned method for calculating the change in energy storage of the variable load boiler in a coal-fired power generating unit, for example: A transient model of a coal-fired power generating unit was constructed. Based on the transient model and the unit's structure and operating constraints, the maximum load change rate and load change rate range of the coal-fired power generating unit were determined. Based on the actual operating conditions of the power plant, the load range during the load change process of the unit was determined. Select several variable load rates within the determined variable load rate range, and conduct unit variable operating condition tests in conjunction with the determined load range to calculate the steam heat absorption under each variable load rate. Within the defined load range, select several load points, calculate the heat absorption of the working fluid under steady-state conditions at each load point, and perform fitting optimization on the steady-state heat absorption of the working fluid to obtain the heat absorption function under steady-state conditions. Based on the heat absorption function under steady-state conditions and the heat absorption function of steam under variable conditions, the change in boiler energy storage under strain load rate and within a specified load range is calculated by integration and difference, thus completing the calculation of the change in boiler energy storage under variable load of coal-fired power generating unit.

[0050] Alternatively, when the processor executes the computer program, it implements the functions of each module in the above system, for example: Model operating condition processing module 1 is used to build a transient model of the coal-fired power generation unit. Based on the transient model of the coal-fired power generation unit and combined with the unit structure and operating constraints, the maximum load change rate and load change rate range of the coal-fired power generation unit are determined. Based on the actual operating conditions of the power plant, the load range during the load change process of the unit is determined. The heat absorption calculation module 2 is used to select several variable load rates within the determined variable load rate range, and conduct unit variable operating condition tests in conjunction with the determined load range to calculate the steam heat absorption under each variable load rate and variable operating condition. The function fitting module 3 is used to select several load points within the determined load range, calculate the heat absorption of the working fluid under steady-state conditions at each load point, and perform fitting optimization on the steady-state heat absorption of the working fluid to obtain the heat absorption function under steady-state conditions. The energy storage calculation module 4 is used to calculate the change in boiler energy storage under a specified load range at a given strained load rate by integrating the steady-state heat absorption function and the steam heat absorption function under variable operating conditions, thus completing the calculation of the change in boiler energy storage under variable load in coal-fired power generating units.

[0051] For example, the computer program can be divided into a model operating condition processing module 1, a heat absorption calculation module 2, a function fitting module 3, and an energy storage calculation module 4; The specific functions of each module are as follows: Model operating condition processing module 1 is used to build a transient model of the coal-fired power generation unit. Based on the transient model of the coal-fired power generation unit and combined with the unit structure and operating constraints, the maximum load change rate and load change rate range of the coal-fired power generation unit are determined. Based on the actual operating conditions of the power plant, the load range during the load change process of the unit is determined. The heat absorption calculation module 2 is used to select several variable load rates within the determined variable load rate range, and conduct unit variable operating condition tests in conjunction with the determined load range to calculate the steam heat absorption under each variable load rate and variable operating condition. The function fitting module 3 is used to select several load points within the determined load range, calculate the heat absorption of the working fluid under steady-state conditions at each load point, and perform fitting optimization on the steady-state heat absorption of the working fluid to obtain the heat absorption function under steady-state conditions. The energy storage calculation module 4 is used to calculate the change in boiler energy storage under a specified load range at a given strained load rate by integrating the steady-state heat absorption function and the steam heat absorption function under variable operating conditions, thus completing the calculation of the change in boiler energy storage under variable load in coal-fired power generating units.

[0052] The mobile terminal can be a computing device such as a desktop computer, laptop, handheld computer, or cloud server. The mobile terminal may include, but is not limited to, a processor and memory.

[0053] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the mobile terminal, connecting various parts of the mobile terminal via various interfaces and lines.

[0054] The memory can be used to store the computer program and / or module. The processor implements various functions of the mobile terminal by running or executing the computer program and / or module stored in the memory and calling the data stored in the memory.

[0055] The memory may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a function (such as sound playback, image playback, etc.); the data storage area may store data created based on the use of the mobile phone (such as audio data, phonebook, etc.). Furthermore, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disks, RAM, plug-in hard disks, SmartMediaCards (SMC), Secure Digital (SD) cards, FlashCards, at least one disk storage device, flash memory device, or other volatile solid-state storage devices.

[0056] Example 4 The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the method for calculating the change in energy storage of a coal-fired power generation unit under variable load.

[0057] If the modules / units integrated in the mobile terminal are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium.

[0058] Based on this understanding, all or part of the processes in the above method can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium. When executed by a processor, the computer program can implement the above-described aggregated reinforcement learning resource scheduling method. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or some intermediate form.

[0059] The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording media, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc.

[0060] It should be noted that the content contained in the computer-readable medium may be appropriately added to or subtracted from the content as required by the legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium may not include electrical carrier signals and telecommunication signals.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for calculating the change in energy storage of a coal-fired power generating unit under varying loads, characterized in that, include: A transient model of a coal-fired power generating unit was constructed. Based on the transient model and the unit's structure and operating constraints, the maximum load change rate and load change rate range of the coal-fired power generating unit were determined. Based on the actual operating conditions of the power plant, the load range during the load change process of the unit was determined. Select several variable load rates within the determined variable load rate range, and conduct unit variable operating condition tests in conjunction with the determined load range to calculate the steam heat absorption under each variable load rate. Within the defined load range, select several load points, calculate the heat absorption of the working fluid under steady-state conditions at each load point, and perform fitting optimization on the steady-state heat absorption of the working fluid to obtain the heat absorption function under steady-state conditions. Based on the heat absorption function under steady-state conditions and the heat absorption function of steam under variable conditions, the change in boiler energy storage under strain load rate and within a specified load range is calculated by integration and difference, thus completing the calculation of the change in boiler energy storage under variable load of coal-fired power generating unit.

2. The method for calculating the change in energy storage of a variable-load boiler in a coal-fired power generating unit according to claim 1, characterized in that, The transient model of the coal-fired power generation unit is a coal-fired power generation unit model, which includes a boiler, superheater, reheater, turbine, deaerator, condenser, high-pressure heater, low-pressure heater, and water storage tank. The coal-fired power generation unit model adopts a structure of condensate-driven gravity-flow reheating and intermediate-pressure cylinder exhaust steam supply for heating. The coal-fired power generation unit model is equipped with a logic control system, which includes coal feeding control, water feeding control, air volume control, and steam temperature control.

3. The method for calculating the change in energy storage of a coal-fired power generation unit under varying loads according to claim 1, characterized in that, The unit structure includes the characteristics of the unit pipe materials, boiler thermal stress, and maximum flow velocity in the pipes; among which, the operating constraints are that if the thermal stress of the materials is not considered when building the transient model, the maximum load change rate of the unit is determined based on the actual operating conditions of the power plant.

4. The method for calculating the change in energy storage of a variable-load boiler in a coal-fired power generating unit according to claim 1, characterized in that, The defined load range during the unit load change process includes the range from 100% THA load to the lowest load at which the power plant is operating.

5. The method for calculating the change in energy storage of a variable-load boiler in a coal-fired power generating unit according to claim 1, characterized in that, The formulas for calculating the steam heat absorption under varying load rates and operating conditions are as follows: in, The heat absorbed by steam per unit time during the variable load process is expressed in kJ / s. The water supply flow rate is expressed in kg / s. The reheat steam flow rate is kg / s; These are the enthalpy values ​​of feedwater, main steam, and reheat steam inlet and outlet, respectively, in kJ / kg. The feedwater flow rate, each enthalpy value, and the reheat steam flow rate were all obtained through variable operating condition testing.

6. The method for calculating the change in energy storage of a variable-load boiler in a coal-fired power generating unit according to claim 1, characterized in that, The expression for the heat absorption function under steady-state conditions is as follows: in, The heat absorbed by steam per unit time under steady-state conditions is expressed in kJ / s and L. i is the coefficient; t is time, s; C is a constant; j is the exponent of each parameter.

7. The method for calculating the change in energy storage of a variable-load boiler in a coal-fired power generating unit according to claim 1, characterized in that, The formula for calculating the change in energy storage of the boiler is as follows: In the formula, This represents the change in boiler energy storage. This represents the heat absorbed by steam per unit time under steady-state operating conditions. This refers to the heat absorbed by steam per unit time during a variable load process. For the variable load time, in seconds; When the unit increases load, the steady-state heat absorption is subtracted from the transient heat absorption for calculation; when the unit decreases load, the transient heat absorption is subtracted from the steady-state heat absorption for calculation. The accuracy of the calculation can be optimized by adjusting the exponent values ​​of each parameter in the steady-state heat absorption function. The larger the exponent value, the higher the calculation accuracy.

8. A calculation system for the change in energy storage of a coal-fired power generating unit under varying loads, characterized in that, include: The model operating condition processing module is used to build a transient model of the coal-fired power generation unit. Based on the transient model of the coal-fired power generation unit and combined with the unit structure and operating constraints, the maximum load change rate and load change rate range of the coal-fired power generation unit are determined. Based on the actual operating conditions of the power plant, the load range during the load change process of the unit is determined. The heat absorption calculation module is used to select several variable load rates within the determined variable load rate range, and conduct unit variable operating condition tests in conjunction with the determined load range to calculate the steam heat absorption under each variable load rate and variable operating condition. The function fitting module is used to select several load points within the determined load range, calculate the heat absorption of the working fluid under steady-state conditions at each load point, and perform fitting optimization on the steady-state heat absorption of the working fluid to obtain the heat absorption function under steady-state conditions. The energy storage calculation module is used to calculate the change in boiler energy storage under a specified load range at a given load rate by integrating and subtracting the heat absorption function under steady-state conditions and the heat absorption function of steam under variable conditions, thus completing the calculation of the change in boiler energy storage under variable load of coal-fired power generating units.

9. A mobile terminal, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method for calculating the change in energy storage of the variable load boiler of the coal-fired power generation unit as described in any one of claims 1-7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the method for calculating the change in energy storage of the variable load boiler of the coal-fired power generation unit as described in any one of claims 1-7.

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