Start-stop optimization control method and system for circulating water pump of thermal power generating unit

Abstract

The invention relates to a thermal power generating unit circulating water pump start-stop optimization control method and system, and the method comprises the steps: carrying out the coupling of an established thermal power generating unit vacuum degree characteristic model, a multi-working-condition circulating water flow calculation model, and a thermal power generating unit generation power change calculation expression caused by the vacuum degree change; a multi-working-condition thermal power generating unit power generation electric energy loss calculation model is obtained; the fire coal cost of the thermal power generating unit is calculated through the multi-working-condition thermal power generating unit power generation electric energy loss calculation model; establishing a thermal power generating unit total operation cost model, wherein the thermal power generating unit total operation cost at least comprises thermal power generating unit fire coal cost; and constructing an optimization problem which takes the minimization of the total operation cost of the thermal power generating unit as an optimization target and meets the operation constraint condition of the thermal power generating unit and the start-stop constraint condition of the multi-working-condition circulating water pump, and solving the optimization problem to obtain an optimal start-stop state sequence of the circulating water pump in the target time period based on the grid-connected power and environment temperature data of the target time period. According to the method, the global economy of thermal power generating unit operation can be optimized.

Description

Technical Field

[0001] This application relates to the field of power system technology, and in particular to a method and system for optimizing the start-up and shutdown of circulating water pumps in thermal power units. Background Technology

[0002] In thermal power units, condenser vacuum is one of the key parameters affecting the thermal economy of the unit, and circulating water pumps are the main equipment for maintaining condenser vacuum. Therefore, the operating mode of the circulating water pumps directly determines the flow rate of circulating cooling water, which in turn affects the condenser vacuum and the coal consumption of the thermal power unit.

[0003] However, existing circulating water pump operation control methods fall into two categories. The first involves keeping a large number of circulating water pumps running at a fixed rate. While this results in higher vacuum levels and greater power output for the thermal power unit, thus saving on coal costs (energy saving), the increased power consumption due to the large number of pumps running also increases plant power costs (electricity consumption). The second method involves keeping a smaller number of circulating water pumps running at a fixed rate. While this reduces plant power consumption and saves on plant power costs (electricity saving), the lower circulating water flow levels result in lower vacuum levels and less power output for the thermal power unit, further increasing coal costs (energy consumption). Therefore, existing circulating water pump operation control methods either result in energy saving but also power consumption, or vice versa, failing to achieve optimal overall economic efficiency for thermal power unit operation. Summary of the Invention

[0004] This application provides a method and system for optimizing the start-up and shutdown of circulating water pumps in thermal power units. By controlling the dynamic start-up and shutdown of circulating water pumps, the overall economic efficiency of thermal power unit operation can be optimized.

[0005] In a first aspect, this application provides a method for optimizing the start-up and shutdown control of circulating water pumps in thermal power units, including: A vacuum degree characteristic model for thermal power units is established to characterize the correlation between the vacuum degree of thermal power units and circulating water flow, grid-connected power, and ambient temperature. Based on the operating conditions of thermal power units and the start-stop state variables of circulating water pumps, a multi-condition circulating water flow calculation model is established. Based on the vacuum degree of thermal power units and the grid-connected power of thermal power units, a calculation expression for the change in power generation of thermal power units caused by changes in vacuum degree is established. The established vacuum degree characteristic model of the thermal power unit, the multi-condition circulating water flow calculation model, and the calculation expression of the power generation change of the thermal power unit caused by the change in vacuum degree are coupled to obtain the multi-condition thermal power unit power generation energy loss calculation model. The coal-fired cost of the thermal power unit is calculated using the multi-condition thermal power unit power generation energy loss calculation model; a total operating cost model of the thermal power unit is established, which includes at least the coal-fired cost of the thermal power unit; operating constraints of the thermal power unit are established; and multi-condition circulating water pump start-up and shutdown constraints are established based on the operating conditions of the thermal power unit and the start-up and shutdown state variables of the circulating water pump. An optimization problem is constructed with the goal of minimizing the total operating cost of the thermal power unit and satisfying the operating constraints of the thermal power unit and the start-stop constraints of the multi-condition circulating water pump. Based on the grid-connected power and ambient temperature data for the target period, the optimal start-stop state sequence of the circulating water pump for the target period is obtained by solving the optimization problem.

[0006] Secondly, this application provides an optimized start-stop control system for circulating water pumps in thermal power units, comprising: The basic calculation model construction module is used to: establish a vacuum degree characteristic model for thermal power units to characterize the correlation between the vacuum degree of thermal power units and circulating water flow, grid-connected power, and ambient temperature; establish a multi-condition circulating water flow calculation model based on the operating conditions of thermal power units and the start-stop state variables of circulating water pumps; and establish a calculation expression for the change in power generation of thermal power units caused by changes in vacuum degree based on the vacuum degree and grid-connected power of thermal power units. The integrated calculation model coupling module is used to couple the established thermal power unit vacuum degree characteristic model, the multi-condition circulating water flow calculation model, and the calculation expression of the thermal power unit power generation power change caused by the vacuum degree change to obtain the multi-condition thermal power unit power generation energy loss calculation model. The optimization problem definition module is used to: calculate the coal cost of the thermal power unit through the multi-condition thermal power unit power generation energy loss calculation model; establish a total operating cost model of the thermal power unit, wherein the total operating cost of the thermal power unit includes at least the coal cost of the thermal power unit; establish operating constraints of the thermal power unit; and establish multi-condition circulating water pump start-up and shutdown constraints based on the operating conditions of the thermal power unit and the start-up and shutdown state variables of the circulating water pump. The optimization problem construction and solution module is used to: construct an optimization problem with the goal of minimizing the total operating cost of the thermal power unit and satisfying the operating constraints of the thermal power unit and the start-stop constraints of the multi-condition circulating water pump; and solve the optimization problem based on the grid-connected power and ambient temperature data of the target period to obtain the optimal start-stop state sequence of the circulating water pump during the target period.

[0007] Thirdly, this application provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the optimized start-stop control method for circulating water pumps in thermal power units provided in the first aspect.

[0008] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, it implements the steps of the optimized start-stop control method for the circulating water pump of a thermal power unit provided in the first aspect.

[0009] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the optimized start-stop control method for the circulating water pump of a thermal power unit provided in the first aspect.

[0010] The optimized start-stop control method for circulating water pumps in thermal power units provided in this application controls the dynamic start-stop of circulating water pumps and dynamically adjusts the condenser vacuum. This unifies two opposing objectives—increasing vacuum to reduce coal costs and reducing circulating water pump power consumption to reduce plant power costs—into a global optimization problem. By dynamically seeking the optimal economic balance between the two, an economic balance is achieved between increasing condenser vacuum (energy saving) and reducing circulating water pump power consumption (power saving). In other words, an economic balance is achieved between increasing the work capacity of thermal power units (energy saving) and reducing plant power consumption (power saving), thereby achieving energy and power savings and ultimately achieving the optimal global economic performance of thermal power unit operation. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0013] Figure 1 This is a flowchart illustrating an optimized start-stop control method for a circulating water pump in a thermal power unit, as provided in an embodiment of this application.

[0014] Figure 2 The graphs show the day-ahead grid-connected power and temperature as input data under single-unit operating conditions.

[0015] Figure 3 The graphs show the day-ahead grid-connected power and temperature as input data under dual-machine operation conditions.

[0016] Figure 4A The power generation losses of thermal power units in Example 1, Comparative Example 1, and Comparative Example 3 are shown.

[0017] Figure 4BThe absolute pressure values ​​of the thermal power units in Example 1, Comparative Example 1, and Comparative Example 3 are given.

[0018] Figure 5A The power generation loss of thermal power unit #1 in Example 2, Comparative Example 2, and Comparative Example 4 is shown.

[0019] Figure 5B The absolute pressure values ​​of thermal power unit #1 in Example 2, Comparative Example 2, and Comparative Example 4 are given.

[0020] Figure 6A The power generation loss of thermal power unit #2 in Example 2, Comparative Example 2, and Comparative Example 4 is shown.

[0021] Figure 6B The absolute pressure values ​​of thermal power unit #2 in Example 2, Comparative Example 2, and Comparative Example 4 are given.

[0022] Figure 7 This is a schematic diagram of the structure of the thermal power unit circulating water pump start-stop optimization control system provided in the embodiments of this application.

[0023] Figure 8 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0025] Figure 1 This is a flowchart illustrating an optimized start-stop control method for a thermal power unit's circulating water pump, as provided in an embodiment of this application. Please refer to... Figure 1 The optimized start-stop control method for circulating water pumps of thermal power units provided in this application includes steps 110 to 140, which will be described in detail below.

[0026] Step 110: Establish a vacuum degree characteristic model for thermal power units to characterize the correlation between vacuum degree of thermal power units and circulating water flow, grid-connected power, and ambient temperature; establish a multi-condition circulating water flow calculation model based on the operating conditions of thermal power units and the start-stop state variables of circulating water pumps; establish a calculation expression for the change in power generation of thermal power units caused by changes in vacuum degree based on the vacuum degree of thermal power units and the grid-connected power of thermal power units. Step 120: Couple the established vacuum degree characteristic model of the thermal power unit, the multi-condition circulating water flow calculation model, and the calculation expression of the power generation change of the thermal power unit caused by the change in vacuum degree to obtain the multi-condition thermal power unit power generation energy loss calculation model. Step 130: Calculate the coal cost of the thermal power unit using the multi-condition thermal power unit power generation energy loss calculation model; establish a total operating cost model for the thermal power unit, wherein the total operating cost of the thermal power unit includes at least the coal cost of the thermal power unit; establish operating constraints for the thermal power unit; and establish multi-condition circulating water pump start-up and shutdown constraints based on the operating conditions of the thermal power unit and the start-up and shutdown state variables of the circulating water pump. Step 140: Construct an optimization problem with the goal of minimizing the total operating cost of the thermal power unit and satisfying the operating constraints of the thermal power unit and the start-stop constraints of the multi-condition circulating water pump. Based on the grid-connected power and ambient temperature data of the target period, solve the optimization problem to obtain the optimal start-stop state sequence of the circulating water pump during the target period.

[0027] It is understood that the multi-condition thermal power unit power generation energy loss calculation model is used to characterize the relationship between the power generation energy loss of each thermal power unit under any condition and the grid-connected power, ambient temperature, and circulating water pump start-up and shutdown state variables.

[0028] The target time period refers to a future time period, such as the next dispatch cycle in power dispatching. The grid-connected power data for the target time period refers to the power curve or power sequence that thermal power units need to supply to the grid during the target time period. In this application, the grid-connected power data for the target time period is equal to the dispatch load data for the target time period.

[0029] Energy loss during power generation by thermal power units; energy consumed by auxiliary equipment of thermal power units during power generation.

[0030] The optimized start-stop control method for circulating water pumps in thermal power units provided in this application controls the dynamic start-stop of circulating water pumps and dynamically adjusts the condenser vacuum. This unifies two opposing objectives—increasing vacuum to reduce coal costs and reducing circulating water pump power consumption to reduce plant power costs—into a global optimization problem. By dynamically seeking the optimal economic balance between the two, an economic balance is achieved between increasing condenser vacuum (energy saving) and reducing circulating water pump power consumption (power saving). In other words, an economic balance is achieved between increasing the work capacity of thermal power units (energy saving) and reducing plant power consumption (power saving), thereby achieving energy and power savings and ultimately achieving the optimal global economic performance of thermal power unit operation.

[0031] The following description Figure 1 Further optional specific embodiments for each step in the optimized start-up and shutdown control of circulating water pumps in thermal power units, as described in the example.

[0032] Step 110: Establish a vacuum degree characteristic model for thermal power units to characterize the correlation between the vacuum degree of thermal power units and circulating water flow, grid-connected power, and ambient temperature; establish a multi-condition circulating water flow calculation model based on the operating conditions of thermal power units and the start-stop state variables of circulating water pumps; and establish a calculation expression for the change in power generation of thermal power units caused by changes in vacuum degree based on the vacuum degree and grid-connected power of thermal power units.

[0033] In some embodiments, in the step of establishing a vacuum characteristic model for thermal power units to characterize the correlation between the vacuum degree of thermal power units and circulating water flow, grid-connected power, and ambient temperature, the expression of the vacuum characteristic model for thermal power units is: ; in, The absolute pressure of the condenser during time period t; Let be the grid-connected power of the thermal power unit in time period t; The absolute pressure design reference value for the condenser; The circulating water flow rate input to the condenser during time period t; An ambient temperature correction factor related to vacuum level; The measured ambient temperature during time period t; denoted as the design ambient temperature of the condenser; 'a' is a coefficient that can be obtained by fitting operating data of thermal power units.

[0034] It is understood that the vacuum characteristic model of the thermal power unit is applicable to every thermal power unit participating in operation; the grid-connected power mentioned in the model refers to the grid-connected power of each thermal power unit.

[0035] It should be noted that in the following embodiments of this application, T and t are interpreted in the same way as follows: T refers to dividing a scheduling period into T time periods of equal length, and t refers to the t-th time period within a scheduling period, where t = 1, 2, 3…T. The value of T can be determined according to requirements, thereby controlling the duration of each time period.

[0036] For example, when a 24-hour scheduling period is divided into 24 equal time periods, T=24, t=1,2,3…24. When a 24-hour scheduling period is divided into 48 equal time periods, T=48, t=1,2,3…48. When a 24-hour scheduling period is divided into 1440 equal time periods, T=1440, t=1,2,3…1440. 24 hours contains 1440 minutes.

[0037] As we can understand, vacuum level is used to measure the degree to which the gas pressure in a space is lower than normal atmospheric pressure. Vacuum level can be expressed in terms of absolute pressure. Absolute pressure refers to the pressure calculated from absolute zero pressure, or ideal vacuum, and the unit of absolute pressure can be Pascal (Pa). The higher the absolute pressure, the lower the vacuum level; the lower the absolute pressure, the higher the vacuum level.

[0038] In some embodiments, the operating conditions of the thermal power unit include a first operating condition and a second operating condition; The first operating condition is: a single thermal power unit operates, that is, one thermal power unit participates in operation, one standby circulating water pump and at least one commonly used circulating water pump participate in operation; the standby circulating water pump is the first standby circulating water pump; under the first operating condition, the start-stop state variable of the circulating water pump is the start-stop state variable of the first standby circulating water pump. The second operating condition is: dual-unit operation of thermal power units, that is, two thermal power units are in operation, two standby circulating water pumps and at least two main circulating water pumps are in operation, the two standby circulating water pumps are the second standby circulating water pump and the third standby circulating water pump; under the second operating condition, the starting and stopping status variables of the circulating water pumps include the starting and stopping status variables of the second standby circulating water pump and the starting and stopping status variables of the third standby circulating water pump.

[0039] It is understood that single-unit operation of a thermal power plant refers to only one thermal power unit operating to supply power to the grid. Dual-unit operation of a thermal power plant refers to two thermal power units operating in parallel to jointly supply power to the grid. The commonly used circulating water pump can be simply referred to as the commonly used pump, and the standby circulating water pump can be simply referred to as the standby pump. The commonly used circulating water pump is configured to be continuously operating when the thermal power unit is in operation. The standby circulating water pump is configured to switch between start-up and shutdown states as needed when the thermal power unit is in operation. Multiple thermal power units in the power plant share a circulating water supply system, meaning that multiple circulating water pumps supply circulating water to the circulating water supply system, which then delivers it to the condensers of each thermal power unit.

[0040] In some embodiments, the step of establishing a multi-condition circulating water flow calculation model based on the operating conditions of the thermal power unit and the start-stop state variables of the circulating water pump includes: Based on the first operating condition and the start / stop state variables of the first circulating water pump, a circulating water flow calculation model is established under the first operating condition; the expression for the circulating water flow calculation model under the first operating condition is: ; ; in, The circulating water flow rate input to the condenser under the first operating condition in time period t; The circulating water flow rate input to the condenser when the first standby circulating water pump stops operating during time period t; For the first The flow rate of circulating water input to the condenser when the first standby circulating water pump is started and running during the time period; is a binary variable representing the start / stop status of the first standby circulating water pump in time period t. It takes a value of 1 when the first standby circulating water pump is running and a value of 0 when the first standby circulating water pump is stopped. h is a coefficient obtained by fitting the operating data of the thermal power unit. Based on the second operating condition and the start-stop state variables of the second and third circulating water pumps, a calculation model for the circulating water flow rate under the second operating condition is established; the expression for the calculation model of the circulating water flow rate under the second operating condition is: ; ; in, The circulating water flow rate input to the condenser of each thermal power unit under the second operating condition in time period t; The circulating water flow rate input to the condenser during time period t is when the second and third standby circulating water pumps are both stopped. For the first The second and third standby circulating water pumps during the time period are both started and running, and the circulating water flow rate input to the condenser is as follows: is a binary variable representing the start / stop status of the second standby circulating water pump in time period t. It takes the value 1 when the second standby circulating water pump is running and takes the value 0 when the second standby circulating water pump is stopped. is a binary variable representing the start / stop status of the third standby circulating water pump in time period t. It takes a value of 1 when the third standby circulating water pump is running and a value of 0 when the third standby circulating water pump is stopped. o and v are both coefficients that can be obtained by fitting the operating data of the thermal power unit. Based on the circulating water flow calculation model under the first operating condition and the circulating water flow calculation model under the second operating condition, the multi-operating-condition circulating water flow calculation model is obtained; the expression of the multi-operating-condition circulating water flow calculation model is: ; in, The circulating water flow rate input to the condenser during time period t.

[0041] It should be noted that the first, second, and third terms in this application are for ease of description and should not be regarded as limitations on the technical features.

[0042] It is understandable that, Let $\frac{t}{t}$ be the circulating water flow rate input to the condenser of each thermal power unit under the second operating condition in time period $t$. In other words, the circulating water flow rate input to the condenser of each thermal power unit under the second operating condition in time period $t$ is the same. Considering the risks associated with circulating water flow regulation, the impact of starting and stopping the circulating water pumps on the flow of both thermal power units under dual-unit operation will be consistent.

[0043] In some embodiments, in the step of establishing a calculation expression for the change in power generation of the thermal power unit caused by the change in vacuum degree based on the vacuum degree and grid-connected power of the thermal power unit, the calculation expression for the change in power generation of the thermal power unit caused by the change in vacuum degree is: ; in, The change in power generation of thermal power units caused by the change in vacuum level during time period t; Let be the grid-connected power of the thermal power unit in time period t; The absolute pressure change of the condenser in time period t+1 compared to time period t is caused by the start-up and shutdown of the circulating water pump. Let be the absolute pressure of the condenser during time period t.

[0044] It is understandable that the absolute pressure change in the condenser represents the change in the condenser's vacuum level. The calculation model for the change in power generation of the thermal power unit caused by the change in vacuum level was obtained through experiments at an existing thermal power plant.

[0045] In the above embodiments, The method for obtaining this information is described below. The formula for calculating the absolute pressure change of the condenser is established, and its expression is: ; in, The absolute pressure change of the condenser in time period t+1 compared to time period t is caused by the start-up and shutdown of the circulating water pump. The absolute pressure of the condenser during time period t; The absolute pressure of the condenser during time period t; Based on the formula for calculating the absolute pressure change of the condenser, and combined with the coupled model of the operating state of the thermal power unit, a calculation model for the absolute pressure change of the condenser is obtained. The calculation model for the absolute pressure change of the condenser is expressed as follows: ; in, The absolute pressure change of the condenser in time period t+1 compared to time period t is caused by the start-up and shutdown of the circulating water pump. Let be the grid-connected power of the thermal power unit in time period t; Let be the power generation capacity of the thermal power unit in time period t; The circulating water flow rate input to the condenser during time period t; This represents the grid-connected power of the thermal power unit in the (t+1)th time period; is the circulating water flow rate input to the condenser in the (t+1)th time period; 'a' is the fitted data, which can be obtained based on actual operating data.

[0046] It's also understandable that a thermal power unit includes core equipment and auxiliary equipment. The core equipment generates electricity. The auxiliary equipment supports the core equipment in generating electricity more efficiently. The core equipment includes the boiler, turbine, and generator. The auxiliary equipment includes a series of devices such as circulating water pumps and condensers. The circulating water pumps provide circulating cooling water to the condenser, which uses this circulating cooling water to establish a vacuum. The vacuum established by the condenser acts as the cold end of the turbine, reducing the turbine's exhaust pressure, thereby increasing the turbine's work capacity and ultimately improving the power generation efficiency of the thermal power unit.

[0047] Step 120: Couple the established vacuum degree characteristic model of the thermal power unit, the multi-condition circulating water flow calculation model, and the calculation expression of the power generation change of the thermal power unit caused by the change in vacuum degree to obtain the multi-condition thermal power unit power generation energy loss calculation model.

[0048] In some embodiments, the step of coupling the vacuum degree characteristic model of the thermal power unit, the multi-condition circulating water flow calculation model, and the calculation expression for the change in power generation of the thermal power unit caused by the change in vacuum degree to obtain the multi-condition thermal power unit power generation energy loss calculation model includes: By coupling the vacuum degree characteristic model of the thermal power unit, the circulating water flow calculation model under the first operating condition, and the power generation change calculation formula of the thermal power unit under vacuum change, a power generation loss calculation model for the thermal power unit under the first operating condition is obtained; the expression for the power generation loss calculation model of the thermal power unit under the first operating condition is: ; in, Let be the power generation loss of the thermal power unit in time period t; Let be the grid-connected power of the thermal power unit in time period t; The circulating water flow rate input to the condenser when the first standby circulating water pump stops operating during time period t; for The flow rate of circulating water input to the condenser when the first standby circulating water pump starts and runs; is a binary variable representing the start / stop status of the first standby circulating water pump in time period t. It takes the value 1 when the first standby circulating water pump is running and takes the value 0 when the first standby circulating water pump is stopped. The absolute pressure design reference value for the condenser; Let t be the ambient temperature at time t. The design ambient temperature of the condenser; m, n, z, and h are all coefficients that can be obtained by fitting operating data of thermal power units; The vacuum degree characteristic model of the thermal power unit, the circulating water flow calculation model under the second operating condition, and the calculation expression for the change in power generation of the thermal power unit caused by the change in vacuum degree are coupled to obtain the power generation loss calculation model of the thermal power unit under the second operating condition; the expression for the power generation loss calculation model of the thermal power unit under the second operating condition is: ; in, Let i be the power generation loss of the i-th thermal power unit in the t-th time period, where i=1 represents the first thermal power unit and i=2 represents the second thermal power unit. Let i be the grid-connected power of the i-th thermal power unit in time period t; The circulating water flow rate input to the condenser during time period t is when the second and third standby circulating water pumps are both stopped. For the first The second and third standby circulating water pumps during the time period are both started and running, and the circulating water flow rate input to the condenser is as follows: is a binary variable representing the start / stop status of the second standby circulating water pump in time period t. It takes the value 1 when the second standby circulating water pump is running and takes the value 0 when the second standby circulating water pump is stopped. is a binary variable representing the start / stop status of the third standby circulating water pump in time period t. It takes the value 1 when the third standby circulating water pump is running and takes the value 0 when the third standby circulating water pump is stopped. The absolute pressure design reference value for the condenser; Let t be the ambient temperature at time t. The design ambient temperature of the condenser; m, n, z, and h are all coefficients that can be obtained by fitting operating data of thermal power units; Based on the power loss calculation model of the thermal power unit under the first operating condition and the power loss calculation model of the thermal power unit under the second operating condition, the power loss calculation model of the multi-operating-condition thermal power unit is obtained.

[0049] It is understandable that the design ambient temperature of the condenser is a design parameter of the condenser, which is a fixed temperature value determined during the design and manufacturing stages of the condenser.

[0050] Step 130: Calculate the coal cost of the thermal power unit using the multi-condition thermal power unit power generation energy loss calculation model; establish a total operating cost model for the thermal power unit, wherein the total operating cost of the thermal power unit includes at least the coal cost of the thermal power unit; establish operating constraints for the thermal power unit; and establish multi-condition circulating water pump start-up and shutdown constraints based on the operating conditions of the thermal power unit and the start-up and shutdown state variables of the circulating water pump.

[0051] In some embodiments, the step of calculating the coal-fired cost of a thermal power unit using the multi-condition thermal power unit power generation energy loss calculation model includes: Based on the multi-condition thermal power unit power generation energy loss calculation model, the correlation between the power generation energy loss of each thermal power unit and the grid-connected power, ambient temperature, and circulating water pump start-stop state variables under the first or second condition is obtained. Based on the fact that the power generation of a thermal power unit is equal to the sum of the grid-connected power and the power generation loss, the correlation between the power generation of each thermal power unit and the grid-connected power, ambient temperature, and the start-stop state variables of the circulating water pump under the first or second operating conditions can be obtained. Establish a relationship between the coal cost of thermal power units and the power generation of thermal power units. Based on this relationship, obtain the correlation between the coal cost of each thermal power unit and the grid-connected power, ambient temperature, and the start-stop state variables of the circulating water pump under the first or second operating conditions.

[0052] In this embodiment of the application, under the second operating condition, the grid-connected power of each of the two thermal power units is obtained according to step 140.

[0053] In some embodiments, the relationship between the coal cost of the thermal power unit and the power generation capacity of the thermal power unit is expressed as follows:

[0054] In the formula: Let a1, b1, and c1 represent the coal consumption cost of the thermal power unit, respectively. Let T be the power generation of the thermal power unit in the t-th time period; T refers to dividing a scheduling cycle into T time periods of equal length, and t refers to the t-th time period within a scheduling cycle, t=1,2,3…T.

[0055] The generating power of the thermal power unit is equal to the sum of the grid-connected power and the generated power loss, expressed as: ; in, Let t be the power generation capacity of the thermal power unit in time period t; Let be the grid-connected power of the thermal power unit in time period t; Let t be the power generation energy loss of the thermal power unit in time period t; power generation energy loss refers to the energy loss generated by a single thermal power unit when generating electricity.

[0056] It is understandable that the power generation of each thermal power unit is equal to the sum of the grid-connected power of that thermal power unit and the power generation loss of that thermal power unit.

[0057] It is understandable that the power generation loss cost and grid connection cost of thermal power units are included in the coal-fired cost of thermal power units. The total operating cost of thermal power units refers to the total power generation cost of the generating units.

[0058] In some embodiments, the step of establishing a total operating cost model for thermal power units includes at least the coal cost of thermal power units, the start-up and shutdown cost of thermal power units, the deep peak-shaving life loss cost of thermal power units, the oil injection cost of thermal power units, the environmental cost of thermal power units, and the carbon trading cost of thermal power units.

[0059] In some embodiments, the total operating cost model for thermal power units is expressed as follows:

[0060] In the formula, This represents the total operating cost of the thermal power unit. For the cost of coal for thermal power units, Costs associated with starting and stopping thermal power units. Cost of lifespan loss for deep peak shaving in thermal power units. For the cost of fuel injection for thermal power units, For the environmental cost of thermal power units, This refers to the carbon trading costs for thermal power units.

[0061] In some embodiments, the formula for calculating the coal-fired cost of the thermal power unit, that is, the relationship between the coal-fired cost and the power generation capacity of the thermal power unit, is expressed as:

[0062] In the formula: Let a1, b1, and c1 represent the coal consumption cost of the thermal power unit, respectively. Let T be the power generation of the thermal power unit in the t-th time period; T refers to dividing a scheduling cycle into T time periods of equal length, and t refers to the t-th time period within a scheduling cycle, t=1,2,3…T.

[0063] In some embodiments, the start-up and shutdown costs of the thermal power unit The expression is:

[0064] In the formula: Costs associated with the start-up and shutdown of thermal power units; The operating state of the thermal power unit in time period t is represented by a binary variable. The value can be 0 or 1. A value of 0 indicates a stopped state. A value of 1 indicates the start state; S The cost of starting up a thermal power unit once.

[0065] In some embodiments, the deep peak-shaving lifespan loss cost of thermal power units The expression is: , In the formula: c represents the life loss cost of deep peak shaving thermal power units; c represents the purchase cost of thermal power units. Let be the power generation of the thermal power unit in time period t; For rotor cracking cycles, Rotor cracking cycles With thermal power unit power The functional relationship is as follows: τ1 is the wear coefficient of the non-oil-operated thermal power unit; τ2 is the wear coefficient of the oil-operated thermal power unit. This refers to the upper limit of oil injection for peak shaving in thermal power units; This is the lower limit for oil injection for peak shaving in thermal power units; This represents the maximum power generation of the thermal power unit. This represents the minimum power generation capacity of a thermal power unit.

[0066] In some embodiments, the cost of fuel injection for the thermal power unit The expression is: , In the formula: For the cost of fuel injection into thermal power units; This refers to the upper limit of oil injection for peak shaving in thermal power units; This is the lower limit for oil injection for peak shaving in thermal power units; This represents the maximum power generation of the thermal power unit. P oil The price of oil in the current season; This represents the fuel consumption of the thermal power unit during the peak-shaving phase of the oil injection depth in time period t. Let t be the power generation of the thermal power unit in time period t.

[0067] In some embodiments, the environmental cost of the thermal power unit The expression is: , In the formula: Environmental costs of thermal power units; j For the first jVarious pollutants; J The types of taxable pollutants; K The amount of tax payable per pollution equivalent; The first generation produced per unit of coal combustion j Quality of various pollutants; This refers to the environmental protection devices configured for thermal power units that remove the first... j The efficiency of pollutant selection; For the first j Pollution equivalent of each pollutant; Let be the coal consumption of the thermal power unit in time period t.

[0068] In some embodiments, the carbon trading cost of the thermal power unit The calculation formula is: , In the formula: denoted as , where c is the carbon trading cost for thermal power units; α is the carbon trading benchmark price; α is the carbon trading price growth rate; and d is the carbon emission range step size. , Carbon trading volume for thermal power units. This represents the actual carbon emissions of thermal power units. This is the initial carbon emission allowance for thermal power units.

[0069] The actual carbon emissions of the thermal power units The calculation formula is:

[0070] In the formula: This represents the actual carbon emissions of thermal power units. Carbon emission intensity of thermal power units; Let t be the power generation capacity of the thermal power unit in time period t; These are the parameters for the stable combustion state of the thermal power unit during time period t. The value can be 0 or 1, where 0 means not entering the fuel injection and stable combustion state, and 1 means entering the fuel injection and stable combustion state. This represents the fuel consumption of thermal power units during the t-th period of the peak-shaving phase of the oil injection depth.

[0071] The initial carbon emission quota of the thermal power unit The calculation formula is:

[0072] In the formula: The initial carbon emission allowance for thermal power units; This is the power supply benchmark value for thermal power units.

[0073] In some embodiments, the step of establishing operating constraints for thermal power units includes output limit constraints and ramp rate constraints for thermal power units.

[0074] In some embodiments, the output constraint condition of the thermal power unit is expressed as: , In the formula: This represents the maximum power generation of the thermal power unit. This is the lower limit for oil injection for peak shaving in thermal power units; is the operating status parameter of the thermal power unit in time period t, with a value of 0 or 1, where 0 represents the stopped state and 1 represents the running state; Let T be the power generation of the thermal power unit in the t-th time period; T refers to dividing a scheduling cycle into T time periods of equal length, and t refers to the t-th time period within a scheduling cycle, t=1,2,3…T.

[0075] In some embodiments, the climbing rate constraint condition of the thermal power unit is expressed as follows:

[0076] In the formula: This is the upper limit of the ramp rate for thermal power units. This is the lower limit of the downhill ramp rate for thermal power units. Let be the power generation of the thermal power unit in time period t; This represents the power generation of the thermal power unit during the (t-1)th time period.

[0077] In some embodiments, the step of establishing multi-condition circulating water pump start-up and shutdown constraints based on the operating conditions of the thermal power unit and the start-up and shutdown state variables of the circulating water pump includes: When a thermal power unit is running alone, the starting and stopping constraints for the circulating water pump include: the sum of the number of times a standby circulating water pump is started and stopped within each scheduling cycle is less than or equal to two. When a thermal power unit is operating with two units, the starting and stopping constraints for the circulating water pumps include: the sum of the number of starts and stops for each standby circulating water pump in each scheduling cycle is less than or equal to two, and the sum of the total number of starts and stops for the two standby circulating water pumps in each scheduling cycle is less than or equal to three.

[0078] In some embodiments, the step of establishing multi-condition circulating water pump start-up and shutdown constraints based on the operating conditions of the thermal power unit and the start-up and shutdown state variables of the circulating water pump includes: Based on the first operating condition and the start / stop state variables of the first circulating water pump, start / stop constraints for the standby circulating water pump under the first operating condition are established; the expression for the start / stop constraints for the standby circulating water pump under the first operating condition is: ; In the formula: is a binary variable representing the start / stop status of the first standby circulating water pump in time period t. It takes the value 1 when the first standby circulating water pump is running and takes the value 0 when the first standby circulating water pump is stopped. T refers to dividing a scheduling cycle into T time periods of equal length, and t refers to the t-th time period in a scheduling cycle, t=1,2,3…T; Based on the second operating condition and the start-stop state variables of the second and third circulating water pumps, start-stop constraints for the standby circulating water pump under the second operating condition are established; the expression for the start-stop constraints for the standby circulating water pump under the second operating condition is: ; In the formula: is a binary variable representing the start / stop status of the second standby circulating water pump in time period t. It takes the value 1 when the second standby circulating water pump is running and takes the value 0 when the second standby circulating water pump is stopped. This is a binary variable representing the start / stop status of the second standby circulating water pump during the (t-1)th time period. The value is 1 when the second standby circulating water pump is running and 0 when the second standby circulating water pump is stopped. is a binary variable representing the start / stop status of the third standby circulating water pump in time period t. It takes the value 1 when the third standby circulating water pump is running and takes the value 0 when the third standby circulating water pump is stopped. This is a binary variable representing the start / stop status of the third standby circulating water pump during the (t-1)th time period. The value is 1 when the third standby circulating water pump is running and 0 when the third standby circulating water pump is stopped.

[0079] Step 140: Construct an optimization problem with the goal of minimizing the total operating cost of the thermal power unit and satisfying the operating constraints of the thermal power unit and the start-stop constraints of the multi-condition circulating water pump. Based on the grid-connected power and ambient temperature data of the target period, solve the optimization problem to obtain the optimal start-stop state sequence of the circulating water pump during the target period.

[0080] Understandably, in the first operating condition, that is, when the thermal power unit is running alone, the optimal start-stop state sequence of the first standby circulating water pump is obtained within the target time period; in the second operating condition, that is, when the thermal power unit is running with two units, the optimal start-stop state sequence of the second standby circulating water pump and the optimal start-stop state sequence of the third standby circulating water pump within the target time period are obtained.

[0081] In some embodiments, before the step of solving the optimization problem to obtain the optimal start-stop state sequence of the circulating water pump, the method further includes acquiring thermal power unit operating data. The thermal power unit operating data includes data such as grid-connected power, ambient temperature, circulating water flow rate, vacuum degree, and thermal power unit coal consumption. The thermal power unit operating data can be collected in real time through the power plant's SIS system. The step of solving the optimization problem to obtain the optimal start-stop state sequence of the circulating water pump includes: based on the acquired thermal power unit operating data, solving the constructed optimization problem to obtain the optimal start-stop state sequence of the circulating water pump.

[0082] To verify the effectiveness of the optimized start-stop control method for circulating water pumps of thermal power units provided in this application embodiment, a typical 600MW supercritical coal-fired power generating unit in China was selected as the thermal power unit in this application embodiment. The actual operating parameter data of the thermal power unit on a typical peak-shaving day were used for simulation testing and comparative analysis.

[0083] 1. Test environment and parameter settings: Hardware platform: Simulation tests were conducted on a workstation equipped with an Intel Xeon processor to ensure that the optimization problem could be solved quickly.

[0084] Software environment: The model and constraints in steps 110 to 130 are constructed in MATLAB R2021a; and the Gurobi optimization solver is called to solve the mixed integer linear programming problem to complete the solution steps in step 140.

[0085] Operational data: All operational data, including grid-connected power, ambient temperature, circulating water flow, vacuum degree, coal consumption, etc., are sourced from the power plant’s plant-level monitoring information system (SIS).

[0086] Key operating parameters: By regression analysis of the historical operating data of the thermal power unit over a year, the key operating parameters involved in the embodiments of this application are obtained, and the specific values ​​are shown in Table 1.

[0087] Table 1 Key Operating Parameters of Thermal Power Units

[0088] 2. Comparison of Scheme Designs: The operation methods of circulating water pumps include: The first method is the start-stop optimization control method for the circulating water pump of a thermal power unit provided in the embodiments of this application, which is referred to as the start-stop optimization control method. The second method is to start the standby pump: This is an existing method for operating circulating water pumps. When a single thermal power unit is running, one main circulating water pump is in operation, while a standby circulating water pump is started to maintain operation. When two thermal power units are running, two main circulating water pumps are in operation, while two standby circulating water pumps are started to maintain operation. The third method is to not start the standby pump: This is an existing method of operating circulating water pumps. When a single thermal power unit is running, one main circulating water pump is in operation, while the standby circulating water pump is not in operation. When two thermal power units are running, both main circulating water pumps are in operation, while the standby circulating water pump is not in operation.

[0089] Based on the single-unit operation and dual-unit operation of thermal power units, as well as three different operating methods of circulating water pumps, the following six comparative schemes are designed: Example 1: A single thermal power unit operates, and the circulating water pump adopts the start-stop optimization control method provided in the embodiment of this application; Example 2: The thermal power unit operates with two units, and the circulating water pump adopts the start-stop optimization control method provided in the embodiment of this application; Comparative Example 1: A single thermal power unit operates, and the circulating water pump adopts the existing method of starting up the standby pump; Comparative Example 2: The thermal power unit operates with two units running, and the circulating water pump adopts the existing method of starting the standby pump; Comparative Example 3: The thermal power unit operates as a single unit, and the circulating water pump adopts the existing method of not starting the standby pump; Comparative Example 4: The thermal power unit operates with two units running, and the circulating water pump adopts the existing method of not starting the standby pump.

[0090] 3. Test Result Analysis: Based on the above six sets of comparison schemes, grid-connected power data and ambient temperature data were input, and tests were conducted to obtain test results.

[0091] Please refer to the input grid-connected power data and ambient temperature data. Figure 2 and Figure 3 .

[0092] Figure 2 This section presents the day-ahead grid-connected power and temperature line graphs as input data under single-unit operating conditions. Specifically, it shows the grid-connected power and temperature line graphs for the next dispatch cycle, i.e., the next 24 hours, in power dispatching.

[0093] Figure 3 This section presents the day-ahead grid-connected power and temperature line graphs, which serve as input data under dual-machine operation conditions. Specifically, it shows the grid-connected power and temperature line graphs for the next dispatch cycle, i.e., the next 24 hours, in power dispatching.

[0094] During the testing process, single-unit operation was implemented, specifically the independent operation of a single 600MW thermal power unit; dual-unit operation was implemented, specifically the parallel operation of two 600MW thermal power units. Inputting grid-connected power data and ambient temperature data, the test results yielded the total operating cost and cost breakdown for a 24-hour dispatch cycle. The design ambient temperature of the condenser was also considered. The value is set to 15℃.

[0095] The test results for Example 1, Comparative Example 1, and Comparative Example 3 are shown in Table 2, where total cost refers to the total operating cost of the thermal power unit. According to Table 2, Example 1 (total cost of RMB 3,142,100) has the lowest total cost, saving RMB 4,500 compared to Comparative Example 1 (total cost of RMB 3,146,600) and RMB 2,500 compared to Comparative Example 3 (total cost of RMB 3,144,600). Therefore, replacing the existing methods of starting and not starting the standby pump with the start-stop optimization control method provided in this application can generate economic benefits of RMB 2,500 to RMB 4,500 savings within 24 hours, and RMB 900,000 to RMB 1,650,000 savings annually in terms of the total operating cost of the thermal power unit. According to Table 2, the carbon emissions of Example 1 (10,671 tons)... ), compared to the carbon emissions of Comparison 1 (10,689 tons) Carbon emissions of Comparative Example 2 (10,681 tons) The requirements are all lower. Therefore, compared with existing methods of starting a standby pump and methods of not starting a standby pump, the start-stop optimization control method provided in this application embodiment is more environmentally friendly.

[0096] Understandably, Tables 2 and 3 determine that thermal power units will not start or stop based on the input grid-connected power data, meaning that the start-up and shutdown costs of thermal power units are zero.

[0097] Table 2 Costs of different circulating water pump operation methods under single-unit operating conditions.

[0098] The test results for Example 2, Comparative Example 2, and Comparative Example 4 are shown in Table 3. The total cost refers to the total operating cost of the thermal power unit. The two thermal power units operating in parallel are Thermal Power Unit #1 and Thermal Power Unit #2. According to Table 3, Example 2 (total cost of RMB 6,208,200) has the lowest total cost, saving RMB 8,400 compared to Comparative Example 2 (total cost of RMB 6,216,600) and RMB 3,700 compared to Comparative Example 4 (total cost of RMB 6,211,900). Therefore, replacing the existing methods of starting and not starting the standby pump with the start-stop optimization control method provided in this application can generate economic benefits of RMB 3,700 to RMB 8,400 in 24 hours and RMB 1,350,000 to RMB 3,070,000 annually in terms of the total operating cost of the thermal power unit. According to Table 3, the carbon emissions of Example 2 (10,504 + 10,655 tons) ), compared to the carbon emissions of Comparison Example 2 (10502 + 10689 tons) The carbon emissions of Comparative Example 4 (10492 + 10681 tons) The requirements are all lower. Therefore, compared with existing methods of starting a standby pump and methods of not starting a standby pump, the start-stop optimization control method provided in this application embodiment is more environmentally friendly.

[0099] Therefore, the start-stop optimization control method provided in this application achieves optimal total operating cost and better environmental benefits for thermal power units by finely balancing the coal cost, start-stop cost, deep peak-shaving life loss cost, oil injection cost, environmental cost, and carbon trading cost of thermal power units.

[0100] Table 3. Costs of different circulating water pump operation methods under dual-machine operation conditions.

[0101] The impact of different circulating water pump operation methods on the total cost, as shown in Tables 2 and 3, is analyzed as follows: When using the existing method of not starting the standby pump, the standby pump remains inactive, relying solely on the main pump to provide circulating water. This results in a lower circulating water flow rate into the condenser, leading to a lower condenser vacuum, reduced work capacity of the thermal power unit, increased coal consumption, and consequently, a higher total cost. When using the existing method of starting the standby pump, the standby pump is constantly running, and the circulating water is supplied jointly by the standby and main pumps. This results in a higher circulating water flow rate into the condenser, leading to a higher condenser vacuum and enhanced work capacity of the thermal power unit. However, the standby pump operation consumes a large amount of electrical energy, which also increases coal consumption, further increasing the total cost. The start-stop optimization control method provided in this application obtains the optimal start-stop state sequence of the circulating water pump. The standby circulating water pump is operated according to this start-stop state sequence, and the dynamic start-stop of the circulating water pump is controlled. The condenser vacuum is dynamically adjusted, and the two opposing objectives—increasing the vacuum to reduce coal costs and reducing the power consumption of the circulating water pump to reduce plant power costs—are unified into a global optimization problem. By dynamically seeking the best economic balance point between the two, an economic balance is achieved between increasing the condenser vacuum (energy saving) and reducing the power consumption of the circulating water pump (power saving). In other words, an economic balance is achieved between increasing the work capacity of the thermal power unit (energy saving) and reducing the power consumption of the plant (power saving), so as to achieve energy saving and power saving, and thus achieve the global economic optimization of the thermal power unit operation.

[0102] For both simple single-machine operation and complex dual-machine operation, the start-stop optimization control method provided in this application can solve for a more economical start-stop state sequence of the circulating water pump through global optimization.

[0103] Please see Figure 4A and Figure 4B , Figure 4A The power generation losses of thermal power units in Example 1, Comparative Example 1, and Comparative Example 3 are shown. Figure 4B The absolute pressure values ​​of the thermal power units in Example 1, Comparative Example 1, and Comparative Example 3 are given.

[0104] Please see Figure 5A and Figure 5B , Figure 5A The power generation losses of thermal power unit #1 in Example 2, Comparative Example 2, and Comparative Example 4 are shown. Figure 5B The absolute pressure values ​​of thermal power unit #1 in Example 2, Comparative Example 2, and Comparative Example 4 are given.

[0105] Please see Figure 6A and Figure 6B , Figure 6A The power generation loss of thermal power unit #2 in Example 2, Comparative Example 2, and Comparative Example 4 is shown. Figure 6BThe absolute pressure values ​​of thermal power unit #2 in Example 2, Comparative Example 2, and Comparative Example 4 are given.

[0106] Figure 4A and Figure 4B It is clearly shown that, compared with Comparative Examples 1 and 3, the absolute pressure value of the thermal power unit in Example 1 is more dynamic and reasonable. Specifically, in Example 1, when the power generation loss is high, a higher vacuum level is maintained (that is, a lower absolute pressure value is maintained) to ensure economy; when the power generation loss is low, the vacuum level is allowed to decrease (that is, the absolute pressure value is allowed to increase) to save energy; in Comparative Example 1 (starting the standby pump), the vacuum level is always high (that is, the absolute pressure value is always low), and in Comparative Example 3 (not starting the standby pump), the vacuum level is always low (that is, the absolute pressure value is always high).

[0107] Figure 5A and Figure 5B ,as well as Figure 6A and Figure 6B It is clearly shown that, compared with Comparative Examples 2 and 4, the absolute pressure value of the thermal power unit in Example 2 is more dynamic and reasonable. Specifically, in Example 2, when the power generation loss is high, a higher vacuum level is maintained (that is, a lower absolute pressure value is maintained) to ensure economy; when the power generation loss is low, the vacuum level is allowed to decrease (that is, the absolute pressure value is allowed to increase) to save energy; in Comparative Example 2 (starting the standby pump), the vacuum level is always high (that is, the absolute pressure value is always low), and in Comparative Example 4 (not starting the standby pump), the vacuum level is always low (that is, the absolute pressure value is always high).

[0108] Figure 7 This is a schematic diagram of the structure of the thermal power unit circulating water pump start-stop optimization control system provided in the embodiments of this application. Please refer to... Figure 7 The optimized control system for the start-stop of the circulating water pump in this thermal power unit may include a basic calculation model construction module 701, a comprehensive calculation model coupling module 702, an optimization problem definition module 703, and an optimization problem construction and solution module 704. Among them: The basic calculation model construction module 701 is used to: establish a characteristic model of the vacuum degree of thermal power units to characterize the correlation between the vacuum degree of thermal power units and circulating water flow, grid-connected power, and ambient temperature; establish a multi-condition circulating water flow calculation model based on the operating conditions of thermal power units and the start-stop state variables of circulating water pumps; and establish a calculation expression for the change in power generation of thermal power units caused by changes in vacuum degree based on the vacuum degree and grid-connected power of thermal power units. The integrated calculation model coupling module 702 is used to couple the established thermal power unit vacuum degree characteristic model, the multi-condition circulating water flow calculation model, and the calculation expression of the thermal power unit power generation power change caused by the vacuum degree change to obtain the multi-condition thermal power unit power generation energy loss calculation model. The optimization problem definition module 703 is used to: calculate the coal cost of the thermal power unit through the multi-condition thermal power unit power generation energy loss calculation model; establish a total operating cost model of the thermal power unit, wherein the total operating cost of the thermal power unit includes at least the coal cost of the thermal power unit; establish operating constraints of the thermal power unit; and establish multi-condition circulating water pump start-up and shutdown constraints based on the operating conditions of the thermal power unit and the start-up and shutdown state variables of the circulating water pump. The optimization problem construction and solution module 704 is used to: construct an optimization problem with the goal of minimizing the total operating cost of the thermal power unit and satisfying the operating constraints of the thermal power unit and the start-stop constraints of the multi-condition circulating water pump; and solve the optimization problem based on the grid-connected power and ambient temperature data of the target period to obtain the optimal start-stop state sequence of the circulating water pump in the target period.

[0109] In practical applications, the above system can be a terminal device or a chip applied to a terminal device. In this application, the system can realize the functions of multiple units through software, hardware, or a combination of software and hardware, enabling the system to execute the steps of the optimized start-up and shutdown control method for circulating water pumps in thermal power units as provided in any of the above embodiments. Furthermore, the technical effects of each technical solution in this system can be referenced to the corresponding technical effects in the optimized start-up and shutdown control method for circulating water pumps in thermal power units, and will not be elaborated upon further in this application.

[0110] Figure 8 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application.

[0111] Based on the hardware implementation of each unit in the above system, embodiments of this application also provide an electronic device, such as... Figure 8 As shown, the electronic device 800 includes a memory 810 and a processor 820. The memory 810 stores a computer program, and the processor 820 executes the computer program to implement the steps of the thermal power unit circulating water pump start-stop optimization control method provided in any of the above embodiments.

[0112] Of course, in practical applications, such as Figure 8 As shown, the various components in the electronic device 800 are coupled together via a bus system 830. It can be understood that the bus system 830 is used to achieve communication between these components. In addition to a data bus, the bus system 830 also includes a power bus, a control bus, and a status signal bus. However, for clarity, in... Figure 8The general labeled all buses as Bus System 830.

[0113] In practical applications, the aforementioned processor can be at least one of the following: Application-Specific Integrated Circuit (ASIC), Digital Signal Processing Device (DSPD), Programmable Logic Device (PLD), Field-Programmable Gate Array (FPGA), controller, microcontroller, and microprocessor. It is understood that, for different devices, the electronic devices used to implement the functions of the aforementioned processor can also be other types, and the embodiments of this application do not specifically limit this.

[0114] The aforementioned memory can be volatile memory, such as random-access memory (RAM); or non-volatile memory, such as read-only memory (ROM), flash memory, hard disk drive (HDD), or solid-state drive (SSD); or a combination of the above types of memory, and provides instructions and data to the processor.

[0115] The electronic devices described in the embodiments of this application can be terminal devices or chips applied to terminal devices. The terminal devices described in the embodiments of this application can be computers.

[0116] In an exemplary embodiment, this application also provides a computer-readable storage medium, such as a memory including a computer program, which can be executed by a processor of an electronic device to perform the steps of the aforementioned method.

[0117] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the method described in any one of the embodiments of this application.

[0118] Optionally, the computer program product can be applied to the electronic device in the embodiments of this application, and the computer program instructions cause the computer to execute the corresponding processes implemented by the electronic device in the various methods of the embodiments of this application. For the sake of brevity, they will not be described in detail here.

[0119] This application also provides a computer program.

[0120] Optionally, the computer program can be applied to the electronic device in the embodiments of this application. When the computer program is run on a computer, it causes the computer to execute the corresponding processes implemented by the electronic device in the various methods of the embodiments of this application. For the sake of brevity, it will not be described in detail here.

[0121] It should be understood that in the embodiments of this application, data such as user information are involved. When the embodiments of this application are applied to specific products or technologies, user permission or consent is required, and the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0122] It should be understood that the terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items. The expressions “having,” “may have,” “comprising,” and “including,” or “may include” and “may contain” used herein may be used to indicate the presence of a corresponding feature (e.g., an element such as a number, function, operation, or component), but do not exclude the presence of additional features.

[0123] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another, and are not necessarily used to describe a specific order or sequence. For example, without departing from the scope of this invention, first information may also be referred to as second information, and similarly, second information may also be referred to as first information.

[0124] The technical solutions described in the embodiments of this application can be combined arbitrarily without conflict.

[0125] In the several embodiments provided in this application, it should be understood that the disclosed methods, systems, and devices can be implemented in other ways. The embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0126] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0127] In addition, each functional unit in the various embodiments of this application can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the integrated unit can be implemented in hardware or in the form of hardware plus software functional units.

[0128] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A method for optimizing the start-stop control of circulating water pumps of a thermal power unit, characterized in that, The method comprises the following steps: a vacuum degree characteristic model of the thermal power unit is established to represent the correlation between the vacuum degree of the thermal power unit and the circulating water flow, the grid-connected power and the ambient temperature; a multi-condition circulating water flow calculation model is established based on the operating condition of the thermal power unit and the circulating water pump start-stop state variable; a calculation expression of the change of the power generation of the thermal power unit caused by the change of the vacuum degree is established based on the vacuum degree of the thermal power unit and the grid-connected power of the thermal power unit; the vacuum degree characteristic model of the thermal power unit, the multi-condition circulating water flow calculation model and the calculation expression of the change of the power generation of the thermal power unit caused by the change of the vacuum degree are coupled to obtain a multi-condition thermal power unit power generation electric energy loss calculation model; the coal consumption cost of the thermal power unit is calculated through the multi-condition thermal power unit power generation electric energy loss calculation model; and a total operation cost model of the thermal power unit is established, wherein the total operation cost of the thermal power unit at least comprises the coal consumption cost of the thermal power unit; a thermal power unit operation constraint condition is established; a multi-condition circulating water pump start-stop constraint condition is established based on the operating condition of the thermal power unit and the circulating water pump start-stop state variable; an optimization problem with the minimization of the total operation cost of the thermal power unit as an optimization objective and meeting the thermal power unit operation constraint condition and the multi-condition circulating water pump start-stop constraint condition is constructed, and the optimization problem is solved based on the grid-connected power and the ambient temperature data of a target period to obtain an optimal start-stop state sequence of the circulating water pump in the target period.

2. The thermal power unit circulating water pump start-stop optimization control method according to claim 1, wherein an expression of the vacuum degree characteristic model of the thermal power unit is as follows in the step of establishing the vacuum degree characteristic model of the thermal power unit to represent the correlation between the vacuum degree of the thermal power unit and the circulating water flow, the grid-connected power and the ambient temperature. ； wherein, P t is the absolute pressure of the condenser in the t th time period; P grid t is the grid-connected power of the thermal power unit in the t th time period; P design is the design reference value of the absolute pressure of the condenser; Q t is the circulating water flow rate input to the condenser in the t th time period; K t is the ambient temperature correction coefficient related to the vacuum degree; T t is the measured ambient temperature in the t th time period; T design is the design ambient temperature of the condenser;a is a coefficient, which is obtained by fitting the operation data of the thermal power unit.

3. The thermal power unit circulating water pump start-stop optimization control method according to claim 1, wherein the operating condition of the thermal power unit comprises a first condition and a second condition; the first condition is that the thermal power unit is operated alone, that is, one thermal power unit participates in operation, one standby circulating water pump and at least one commonly used circulating water pump participate in operation; the one standby circulating water pump is a first standby circulating water pump; in the first condition, the circulating water pump start-stop state variable is the first standby circulating water pump start-stop state variable; the second condition is that the thermal power unit is operated in double, that is, two thermal power units participate in operation, two standby circulating water pumps and at least two commonly used circulating water pumps participate in operation, the two standby circulating water pumps are a second standby circulating water pump and a third standby circulating water pump; in the second condition, the circulating water pump start-stop state variable comprises a second standby circulating water pump start-stop state variable and a third standby circulating water pump start-stop state variable.

4. The thermal power unit circulating water pump start-stop optimization control method according to claim 3, wherein the step of establishing the multi-condition circulating water flow calculation model based on the operating condition of the thermal power unit and the circulating water pump start-stop state variable comprises: ​ ​ establish a first working condition circulating water flow calculation model based on the first working condition and the first circulating water pump start-stop state variable; the first working condition circulating water flow calculation model has an expression as follows: ； wherein, is the circulating water flow rate input to the condenser in the first operating mode in the tth time period; is the circulating water flow rate input to the condenser when the first standby circulating water pump stops running in the tth time period; is the circulating water flow rate input to the condenser when the first standby circulating water pump starts running in the tth time period; is the circulating water flow rate input to the condenser when the first standby circulating water pump starts running in the tth time period; is a binary variable of the start-stop state of the first standby circulating water pump in the tth time period; and h is a coefficient obtained by fitting the operation data of the thermal power generating unit. establish a second working condition circulating water flow calculation model based on the second working condition and the second and third circulating water pump start-stop state variables; the second working condition circulating water flow calculation model has an expression as follows: ； wherein, is the circulating water flow rate input to each thermal power unit condenser in the second operating mode in the tth period; is the circulating water flow rate input to the condenser when both the second and third standby circulating water pumps stop running in the tth period; is the circulating water flow rate input to the condenser in the first operating mode in the tth period; is the circulating water flow rate input to the condenser when both the second and third standby circulating water pumps start running in the tth period; is the binary variable of the start-stop state of the second standby circulating water pump in the tth period; is the binary variable of the start-stop state of the third standby circulating water pump in the tth period; ando and v are coefficients obtained by fitting thermal power unit operation data. obtain the multi-working condition circulating water flow calculation model according to the first working condition circulating water flow calculation model and the second working condition circulating water flow calculation model; the multi-working condition circulating water flow calculation model has an expression as follows: ； wherein, The circulating water flow rate input to the condenser at the tth period.

5. The thermal power unit circulating water pump start-stop optimization control method according to claim 1, characterized in that, in the step of establishing a thermal power unit power generation power change calculation expression caused by vacuum degree change based on the thermal power unit vacuum degree and the thermal power unit grid-connected power, the thermal power unit power generation power change calculation expression caused by vacuum degree change is as follows: ； wherein, is the change of the power generation of the thermal power unit caused by the change of the vacuum degree in the tth period; is the grid-connected power of the thermal power unit in the tth period; is the change of the absolute pressure of the condenser in the t+1th period compared with the tth period caused by the start and stop of the circulating water pump; is the absolute pressure of the condenser in the tth period.

6. The thermal power unit circulating water pump start-stop optimization control method according to claim 3, characterized in that, the step of coupling the thermal power unit vacuum degree characteristic model, the multi-working condition circulating water flow calculation model and the thermal power unit power generation power change calculation expression caused by vacuum degree change to obtain a multi-working condition thermal power unit power generation electric energy loss calculation model comprises: couple the thermal power unit vacuum degree characteristic model, the first working condition circulating water flow calculation model and the thermal power unit power generation power change calculation expression caused by vacuum degree change to obtain a first working condition thermal power unit power generation electric energy loss calculation model; the first working condition thermal power unit power generation electric energy loss calculation model has an expression as follows: ； wherein, is the power generation electric energy loss of the thermal power generating unit in the tth period; is the grid-connected power of the thermal power generating unit in the tth period; is the circulating water flow rate input to the condenser when the first standby circulating water pump stops running in the tth period; is the circulating water flow rate input to the condenser when the first standby circulating water pump starts running in the tth period; is the circulating water flow rate input to the condenser when the first standby circulating water pump starts running in the tth period; is the first standby circulating water pump start-stop state binary variable in the tth period; is the absolute pressure design reference value of the condenser; is the ambient temperature in the tth period; is the design ambient temperature of the condenser; m, n, z, h are all coefficients, which are obtained by fitting the thermal power generating unit operation data; couple the thermal power unit vacuum degree characteristic model, the second working condition circulating water flow calculation model and the thermal power unit power generation power change calculation expression caused by vacuum degree change to obtain a second working condition thermal power unit power generation electric energy loss calculation model; the second working condition thermal power unit power generation electric energy loss calculation model has an expression as follows: ； wherein, is the power generation energy loss of the ith thermal power unit in the tth period, i=1 represents the first thermal power unit, and i=2 represents the second thermal power unit; is the grid-connected power of the ith thermal power unit in the tth period; is the circulating water flow rate input to the condenser when the second and third standby circulating water pumps are both stopped in the tth period; is the circulating water flow rate input to the condenser when the second and third standby circulating water pumps are both started in the tth period; is the circulating water flow rate input to the condenser when the second and third standby circulating water pumps are both started in the tth period; is the start-stop state binary variable of the second standby circulating water pump in the tth period; is the start-stop state binary variable of the third standby circulating water pump in the tth period; is the absolute pressure design reference value of the condenser; is the ambient temperature in the tth period; is the design ambient temperature of the condenser; m, n, z, and h are all coefficients, which are obtained by fitting the thermal power unit operation data; obtain the multi-working condition thermal power unit power generation electric energy loss calculation model according to the first working condition thermal power unit power generation electric energy loss calculation model and the second working condition thermal power unit power generation electric energy loss calculation model.

7. The thermal power unit circulating water pump start-stop optimization control method according to claim 1, characterized in that, in the step of establishing a thermal power unit total operation cost model, the thermal power unit total operation cost at least comprises a thermal power unit coal combustion cost, a thermal power unit start-stop cost, a thermal power unit deep peak regulation life loss cost, a thermal power unit oil injection cost, a thermal power unit environmental cost and a thermal power unit carbon trading cost.

8. The thermal power unit circulating water pump start-stop optimization control method according to claim 1, characterized in that, in the step of establishing a thermal power unit operation constraint condition, the thermal power unit operation constraint condition comprises a thermal power unit output limit constraint condition and a thermal power unit climbing rate constraint condition.

9. The thermal power unit circulating water pump start-stop optimization control method according to claim 3, characterized in that, The step of establishing the multi-working condition circulating water pump start-stop constraint condition based on the thermal power generating unit working condition and the circulating water pump start-stop state variable comprises: The standby circulating water pump start-stop constraint condition under the first working condition is expressed as: ； In the formula: is the start-stop state binary variable of the first standby circulating water pump in the t period; T means that a scheduling period is divided into T time periods of the same length, t means the t period in a scheduling period, t = 1, 2, 3…T; The standby circulating water pump start-stop constraint condition under the second working condition is established based on the second working condition and the second and third circulating water pump start-stop state variables, and an expression of the standby circulating water pump start-stop constraint condition under the second working condition is as follows: ； In the formula: is a binary variable of the start-stop state of the second standby circulating water pump in the tth period; is a binary variable of the start-stop state of the second standby circulating water pump in the t-1th period; is a binary variable of the start-stop state of the third standby circulating water pump in the tth period; is a binary variable of the start-stop state of the third standby circulating water pump in the t-1th period.

10. A thermal power unit circulating water pump start-stop optimization control system, characterized in that, Comprise: The basic calculation model construction module is configured to: establish a thermal power generating unit vacuum degree characteristic model for representing the correlation between the thermal power generating unit vacuum degree and the circulating water flow, the grid-connected power and the ambient temperature; establish a multi-working condition circulating water flow calculation model based on the thermal power generating unit working condition and the circulating water pump start-stop state variable; and establish a calculation expression of the change of the thermal power generating unit power caused by the change of the vacuum degree based on the thermal power generating unit vacuum degree and the grid-connected power of the thermal power generating unit; The comprehensive calculation model coupling module is configured to: couple the established thermal power generating unit vacuum degree characteristic model, the multi-working condition circulating water flow calculation model and the calculation expression of the change of the thermal power generating unit power caused by the change of the vacuum degree to obtain a multi-working condition thermal power generating unit power loss calculation model; The optimization problem definition module is configured to: calculate the thermal power generating unit coal consumption by using the multi-working condition thermal power generating unit power loss calculation model; establish a thermal power generating unit total operation cost model, wherein the thermal power generating unit total operation cost at least comprises the thermal power generating unit coal consumption; and establish a thermal power generating unit operation constraint condition; The step of establishing the multi-working condition circulating water pump start-stop constraint condition based on the thermal power generating unit working condition and the circulating water pump start-stop state variable comprises: The optimization problem construction and solution module is configured to: construct an optimization problem with the minimization of the thermal power generating unit total operation cost as an optimization objective and with the thermal power generating unit operation constraint condition and the multi-working condition circulating water pump start-stop constraint condition being satisfied; and solve the optimization problem based on the grid-connected power and the ambient temperature data of a target period to obtain an optimal circulating water pump start-stop state sequence of the target period.

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