Method and device for controlling peak regulation of thermal power generating unit

Abstract

The invention provides a thermal power generating unit peak regulation control method and device, and the method comprises the steps: obtaining the current power generation load of a thermal power generating unit when determining that the thermal power generating unit enters a dry-to-wet critical state; judging whether the current power generation load meets the load reduction requirement of the power grid side or not; if yes, controlling the thermal power generating unit to operate according to the current operation state; and if not, the steam extraction amount entering a high-pressure heater of the thermal power generating unit is controlled to be increased, so that the amount of steam entering a steam turbine of the thermal power generating unit for acting is reduced, and the power generation load is reduced under the condition that the thermal power generating unit keeps running in the dry state. By increasing the steam extraction amount, the temperature of feed water at an inlet of the economizer is increased, heat needed when the feed water is converted into a gas state from a liquid state is reduced, and therefore the coal feeding amount is reduced, the power generation load is reduced, and the dry state can be kept after the load of the boiler is continuously reduced; and the load of the boiler when the thermal power generating unit enters the dry-to-wet critical state is reduced as much as possible.

Description

Technical Field

[0001] The present application relates to thermal power generation technology, and in particular to a peak regulation control method and device for a thermal power unit. Background Art

[0002] With the rapid increase in installed capacity of renewable energy sources such as solar and wind power, their volatility, intermittency and unpredictability have brought huge challenges to the stable and safe operation of the power grid. If no intervention is taken, it will affect the production plan of the units and lead to the phenomenon of abandoned solar and wind power, which will affect the economy of the power system, the cleanliness of power generation and the reliability of power supply. Therefore, the peak and frequency regulation of thermal power units is the main choice for the power grid to solve the problem of new energy consumption.

[0003] However, under deep peak-shaving conditions, ultra-supercritical units inevitably operate in wet mode, and the transition process is long and difficult to control, which seriously limits the deep peak-shaving capability of the units. Summary of the Invention

[0004] The present application provides a peak-shaving control method and device for a thermal power unit to solve the technical problems mentioned in the background technology.

[0005] In a first aspect, the present application provides a peak load control method for a thermal power plant, comprising: When it is determined that the thermal power unit has entered a critical state of transition from dry state to wet state, obtaining a current power generation load of the thermal power unit; Determining whether the current power generation load meets the load reduction demand of the power grid side; If so, controlling the thermal power unit to operate according to the current operating state; If not, the amount of steam extracted from the high-pressure heater of the thermal power unit is controlled to increase so as to reduce the amount of steam entering the steam turbine of the thermal power unit to perform work, thereby reducing the power generation load while the thermal power unit remains in dry operation.

[0006] Optionally, also include: Obtaining the current steam temperature at the outlet of the steam-water separator of the thermal power unit; When the current steam temperature is equal to the critical steam temperature, it is determined that the thermal power unit enters the critical state of dry-to-wet transition, wherein the critical steam temperature is a temperature higher than a preset temperature value of the saturated steam temperature at the outlet of the steam-water separator, and the saturated steam temperature is the saturated temperature corresponding to the current steam pressure at the outlet of the steam-water separator.

[0007] Optionally, before the control increases the amount of steam extracted from the high-pressure heater of the thermal power unit, the control further includes: determining whether the current steam temperature is less than the critical steam temperature; The controlling of increasing the amount of extraction steam entering the high-pressure heater of the thermal power unit comprises: When the current steam temperature is lower than the critical steam temperature, the amount of steam extracted from the high-pressure heater of the thermal power unit is controlled to increase.

[0008] Optionally, the controlling of increasing the amount of extracted steam entering the high-pressure heater of the thermal power unit includes: By increasing the opening of the valve between the high-pressure heater and the steam turbine, the amount of steam extracted from the high-pressure heater of the thermal power unit is controlled to increase.

[0009] Optionally, the increasing the opening of the valve between the high-pressure heater and the steam turbine to control the increase in the amount of extracted steam entering the high-pressure heater of the thermal power unit includes: Controlling the opening of the valve to increase a preset opening, and obtaining an updated steam temperature at the outlet of the steam-water separator after a first preset time period; determining whether the updated steam temperature is still lower than the critical steam temperature; If yes, controlling the opening of the valve again to increase the preset opening, so as to increase the amount of steam extracted into the high-pressure heater of the thermal power unit; If not, the opening of the valve is maintained at the current opening.

[0010] Optionally, the determining whether the updated steam temperature is still lower than the critical steam temperature further includes: Determining whether the updated steam temperature is lower than the steam temperature at the steam-water separator outlet before the preset opening is increased; If so, controlling the valve opening to be the opening when the thermal power unit is in a critical state of transition from dry state to wet state; The determining whether the updated steam temperature is still lower than the critical steam temperature includes: If not, it is determined whether the updated steam temperature is still lower than the critical steam temperature.

[0011] Optionally, also include: When the thermal power unit is in the process of reducing power generation load, an operating parameter combination of the thermal power unit is obtained, where the operating parameter combination includes at least one of the following operating parameters: temperature of the working medium at an economizer outlet, steam flow rate of a low-pressure cylinder of a steam turbine, pressure of a high-pressure heater, water level of the high-pressure heater, and heating rate of the high-pressure heater; When at least one operating parameter of the operating parameter combination does not meet the corresponding safe operating condition, the opening of the valve is controlled to decrease so as to reduce the amount of steam extracted into the high-pressure heater of the thermal power unit.

[0012] Optionally, after controlling the opening of the valve to decrease, the method further includes: After a second preset time period, obtaining an updated operating parameter combination of the thermal power unit; When any target operating parameter in the updated operating parameter combination still does not meet the corresponding safe operating condition, the valve opening is controlled to be the opening before the thermal power unit reduces the power generation load.

[0013] In a second aspect, the present application provides a peak-shaving control device for a thermal power unit, comprising: an acquisition module, configured to acquire the current power generation load of the thermal power unit when it is determined that the thermal power unit has entered a critical state of transition from dry state to wet state; A judgment module, configured to judge whether the current power generation load meets the load reduction requirement of the power grid side; If so, the first control module is used to control the thermal power unit to operate according to the current operating state; If not, the second control module is used to control the increase in the amount of steam extraction entering the high-pressure heater of the thermal power unit to reduce the amount of steam entering the turbine of the thermal power unit to do work, so as to reduce the power generation load while the thermal power unit remains in dry operation.

[0014] Optionally, the method further includes: a determination module configured to: Get the current steam temperature at the outlet of the steam-water separator of the thermal power unit; When the current steam temperature is equal to the critical steam temperature, it is determined that the thermal power unit enters the critical state of dry-to-wet transition, where the critical steam temperature is a temperature higher than a preset temperature value of the saturated steam temperature at the outlet of the steam-water separator, and the saturated steam temperature is the saturated temperature corresponding to the current steam pressure at the outlet of the steam-water separator.

[0015] Optionally, the system further includes: a second judgment module, configured to: before the second control module controls the increase of the extraction steam amount entering the high-pressure heater of the thermal power unit, further configured to: judge whether the current steam temperature is less than the critical steam temperature; The second control module controls the increase of the steam extraction amount of the high-pressure heater entering the thermal power unit, specifically for: controlling the increase of the steam extraction amount of the high-pressure heater entering the thermal power unit when the current steam temperature is lower than the critical steam temperature.

[0016] Optionally, the second control module controls the increase of the extraction steam flow into the high-pressure heater of the thermal power unit, specifically for: By increasing the opening of the valve between the high-pressure heater and the steam turbine, the amount of steam extracted from the high-pressure heater of the thermal power unit is controlled to increase.

[0017] Optionally, the second control module controls the increase in the amount of steam extracted from the high-pressure heater of the thermal power unit by increasing the opening of the valve between the high-pressure heater and the steam turbine, specifically for: The opening of the control valve is increased by a preset opening, and after a first preset time period, an updated steam temperature at the steam-water separator outlet is obtained; The second judgment module judges whether the updated steam temperature is still lower than the critical steam temperature; If yes, the second control module controls the valve opening again to increase the preset opening, so as to increase the extraction steam amount entering the high-pressure heater of the thermal power unit; If not, the second control module maintains the valve opening at the current opening.

[0018] Optionally, before the second judgment module judges whether the updated steam temperature is still lower than the critical steam temperature, it is further configured to: Determine whether the updated steam temperature is lower than the steam temperature at the steam-water separator outlet before the preset opening is increased; If so, the second control module controls the valve opening to be the opening when the thermal power unit is in a critical state of transition from dry state to wet state; The second judgment module judges whether the updated steam temperature is still lower than the critical steam temperature, and is specifically used to: If not, it is determined whether the updated steam temperature is still less than the critical steam temperature.

[0019] Optionally, the acquisition module is further configured to: when the thermal power unit is in the process of reducing power generation load, acquire an operating parameter combination of the thermal power unit, the operating parameter combination including at least one of the following operating parameters: temperature of the working medium at the economizer outlet, steam flow rate of the low-pressure cylinder of the steam turbine, pressure of the high-pressure heater, water level of the high-pressure heater, and heating rate of the high-pressure heater; When at least one operating parameter of the operating parameter combination does not meet the corresponding safe operating condition, the second control module is used to control the valve opening to decrease so as to reduce the amount of steam extraction entering the high-pressure heater of the thermal power unit.

[0020] Optionally, after the second control module controls the valve opening to decrease, the acquisition module is further configured to: acquire an updated operating parameter combination of the thermal power unit after a second preset time period; When any target operating parameter in the updated operating parameter combination still does not meet the corresponding safe operating condition, the second control module is used to control the valve opening to be the opening before the thermal power unit reduces the power generation load.

[0021] In a third aspect, the present application provides an electronic device, comprising: a processor and a memory; Memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory, so that the processor performs the method as described in any one of the first aspects.

[0022] In a fourth aspect, an embodiment of the present application provides a readable storage medium, including a program or instruction. When the program or instruction runs on a computer, the method described in any one of the above-mentioned first aspects is executed.

[0023] In a fifth aspect, an embodiment of the present application provides a computer program product, comprising a computer program, which, when executed by a processor, implements the method as described in any one of the first aspects.

[0024] The present application provides a method and device for peak-shaving control of a thermal power unit, which obtains the current power generation load of the thermal power unit when determining that the thermal power unit has entered a critical state of transition from dry to wet state; determines whether the current power generation load meets the load reduction demand on the power grid side; if so, controls the thermal power unit to operate according to the current operating state; if not, controls the steam extraction amount of the high-pressure heater entering the thermal power unit to increase, so as to reduce the amount of steam entering the steam turbine of the thermal power unit to do work, thereby reducing the power generation load while the thermal power unit remains in dry state operation. It is achieved that when the thermal power unit cooperates with the power grid's load reduction demand, but the coal supply is difficult to meet the power grid's load reduction demand, by increasing the steam extraction volume, not only can the steam entering the turbine be reduced, thereby reducing the power generation load on the power grid side, but the feed water temperature at the economizer inlet can also be increased, reducing the heat required for the feed water to be converted from liquid to gaseous steam, reducing the required coal supply, and thus reducing the coal supply, so that the boiler load continues to decrease. At this time, the boiler should be switched to wet operation, but due to the increase in steam extraction volume, the steam temperature at the steam-water separator outlet can still reach the saturation temperature of dry operation under the corresponding pressure, so that the boiler can still operate in a dry state, and ultimately the boiler load can be reduced as much as possible while maintaining dry operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0026] Figure 1 A schematic diagram of the structure of a peak-shaving control system for a thermal power plant provided in one embodiment of the present application; Figure 2 A flow chart of a peak-shaving control method for a thermal power plant provided in one embodiment of the present application; Figure 3 A flow chart of a peak-shaving control method for a thermal power plant provided in another embodiment of the present application; Figure 4 A schematic structural diagram of a peak-shaving control device for a thermal power plant provided in one embodiment of the present application; Figure 5 A schematic diagram of the structure of an electronic device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0027] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application are clearly and completely described below. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts also fall within the scope of protection of this application.

[0028] In recent years, the installed capacity of renewable energy sources such as solar and wind power has increased rapidly, and the power grid's ability to absorb new energy has also increased accordingly. However, renewable energy is volatile, intermittent and unpredictable, making it difficult to use for power grid peak regulation. Therefore, solving the problem of new energy absorption through peak regulation of thermal power units is the current main choice for the power grid.

[0029] Thermal power plant boilers operate in two different states at different loads. When the boiler load is above 25%-35%, the boiler operates in a dry state, where the steam flow exceeds the feedwater flow and the separator is free of water. When the boiler load is below 25%-35%, the boiler operates in a wet state, where the steam flow is less than the feedwater flow and the separator contains water. Therefore, during peak and frequency regulation, the boiler may transition from a dry state to a wet state. However, the transition from dry to wet state is a unique phase in the peak regulation process, transitioning between circulating flow and primary forced flow. During this transition, key parameters such as the boiler's main steam pressure, steam temperature, and superheat will all change. Failure to achieve this transition can result in unstable operating conditions, such as significant fluctuations in main steam temperature and drastic fluctuations in the water tank liquid level. This can severely limit the unit's deep peak regulation capabilities and even seriously impact its operational safety.

[0030] In the existing technology, when the power grid requires load reduction, the load of the thermal power unit is generally reduced by reducing the coal supply. However, at present, the boiler load can be reduced to 25% under ideal circumstances by the coal supply. However, when the boiler load is reduced to 25%, it still does not meet the power grid's load reduction requirements. It is necessary to further reduce the coal supply to reduce the boiler load. In this way, the boiler will switch from a dry state to a wet state, and there may be a possibility of failure in the state conversion, thereby increasing the safety risks of the boiler.

[0031] Therefore, in order to solve the technical problems existing in the prior art, the present application proposes a peak-shaving control method and device for a thermal power unit. When the power grid reduces its load, after the boiler load is reduced by overfeeding, the thermal power unit enters a critical state of dry-to-wet transition. If it is still difficult to meet the power grid load reduction demand, by increasing the extraction volume of the high-pressure heater, not only can the steam entering the turbine be reduced, thereby reducing the power generation load on the power grid side, but the steam has energy, which can increase the feed water temperature at the economizer inlet. The increase in the feed water temperature reduces the heat required for the conversion from liquid to gaseous steam, and the required coal feed will be reduced, thereby continuing to reduce the boiler load. At this time, the boiler should be converted to wet operation, but due to the increase in the extraction volume, the steam temperature at the steam-water separator outlet can still reach the saturation temperature during dry operation at the corresponding pressure, thereby allowing the boiler to maintain dry operation under a lower load, thereby minimizing the load of the boiler when the thermal power unit enters the critical state of dry-to-wet transition.

[0032] Figure 1 This is a schematic diagram of the structure of a thermal power plant peak load regulation control system provided in one embodiment of the present application. Figure 1 As shown, the peak-shaving control system of the thermal power unit includes: a boiler 1, a high-pressure cylinder of a steam turbine 2, a low-pressure cylinder of a steam turbine 3, a condenser 4, a low-pressure heater 5, a deaerator 6, a high-pressure heater 7, an economizer 8, a steam-water separator 9, a numerical monitoring system 10, a first temperature measuring device 11, a steam flow meter 12, a pressure gauge 13, a water level gauge 14, a temperature rise rate meter 15, a second temperature measuring device 16, and a valve 17.

[0033] In the figure, the solid line represents the flow path of the fluid (steam), and the dotted line represents the signal transmission path.

[0034] Figure 2 This is a flow chart of a peak load control method for a thermal power plant provided in one embodiment of the present application. Figure 1 The structural diagram of the peak load regulation control system of the thermal power unit is shown in FIG. Figure 2 The executive body is Figure 1 Numerical monitoring system in 10. Figure 2 As shown, the method includes: S201. When it is determined that the thermal power unit has entered a critical state of transitioning from a dry state to a wet state, the current power generation load of the thermal power unit is obtained.

[0035] In this step, the boiler is operating in a dry state. When the power grid requires load reduction, the generating load of the thermal power unit is reduced to meet the grid load reduction requirement. At this time, the boiler load can be reduced by adjusting the coal supply. When the boiler load drops to the critical state where the boiler enters the dry-to-wet state, further reduction in the boiler load will cause the boiler to undergo a dry-to-wet state transition, potentially posing a safety hazard. Therefore, this embodiment minimizes this dry-to-wet transition by delaying the time the boiler enters the wet state.

[0036] At this time, the current power generation load of the thermal power unit is obtained.

[0037] Optional, before S201, also includes: S21. Obtain the current steam temperature at the outlet of the steam-water separator of the thermal power unit.

[0038] In this embodiment, Figure 1 As shown, a first temperature measuring device 11 is installed at the outlet of the steam-water separator 9 for monitoring the steam temperature at the outlet of the steam-water separator 9. Therefore, the current steam temperature at the outlet of the steam-water separator 9 can be obtained through the first temperature measuring device 11 and transmitted to the numerical monitoring system 10.

[0039] S22. When the current steam temperature is equal to the critical steam temperature, determine that the thermal power unit enters the critical state of transition from dry state to wet state, wherein the critical steam temperature is a temperature higher than a preset temperature value of the saturated steam temperature at the outlet of the steam-water separator, and the saturated steam temperature is the saturated temperature corresponding to the current steam pressure at the outlet of the steam-water separator.

[0040] In this embodiment, the steam temperature at the steam separator outlet can be used to determine whether the boiler is operating in a dry or wet state. Since the critical steam temperature is a temperature higher than a preset saturated steam temperature at the steam separator outlet, where the preset temperature may be, for example, 15°C, and the saturated steam temperature is the saturated temperature corresponding to the current steam pressure at the steam separator outlet, when the steam temperature at the steam separator outlet reaches the critical steam temperature, it can be determined that the thermal power unit has entered a critical state of transition from dry to wet. Then, S201 is executed.

[0041] This embodiment determines whether the boiler is in the critical state of transition from dry state to wet state by comparing the current steam temperature with the critical steam temperature, thereby simplifying the process of determining whether the boiler is in the critical state of transition from dry state to wet state. Moreover, since the current steam temperature can reflect the steam volume at the outlet of the steam-water separator, it also has high accuracy.

[0042] S202: Determine whether the current power generation load meets the load reduction demand of the grid side. If so, execute S203; if not, execute S204.

[0043] In this step, when the boiler is in the critical state of transitioning from dry to wet, if the current generating load can meet the grid's load reduction requirements, the boiler does not need to continue to reduce its load. Thus, although the boiler is in the critical state of transitioning from dry to wet, it is still operating in the dry state. If the current generating load cannot meet the grid's load reduction requirements, the thermal power unit needs to continue to reduce its load, which means that the boiler also needs to continue to reduce its load. Therefore, according to the prior art, the boiler needs to undergo a dry-wet transition and enter wet operation. Therefore, a determination is made as to whether the current generating load meets the grid's load reduction requirements, and control is performed based on the determination result.

[0044] S203. Control the thermal power unit to operate according to the current operating status.

[0045] In this step, when the boiler is in the critical state of dry-to-wet transition, if the current power generation load can meet the load reduction demand on the grid side, the thermal power unit is controlled to operate according to the current operating state. At this time, the boiler is in dry operation and does not need to be converted from dry to wet.

[0046] S204. Control the steam extraction amount entering the high-pressure heater of the thermal power unit to increase so as to reduce the amount of steam entering the steam turbine of the thermal power unit to do work, thereby reducing the power generation load while maintaining the thermal power unit in dry state operation.

[0047] In this step, when the boiler is in the critical state of dry-to-wet state, if the current power generation load cannot meet the load reduction demand on the grid side, the steam extraction amount of the high-pressure heater of the thermal power unit is increased, which not only reduces the amount of steam entering the turbine of the thermal power unit to do work, thereby reducing the power generation load, but also the steam has energy, which can increase the feed water temperature at the economizer inlet. The increase in feed water temperature reduces the heat required to convert it from liquid to gaseous steam, and the required coal feed amount will be reduced, so that the boiler load continues to decrease. At this time, by increasing the steam extraction amount, the steam temperature at the outlet of the steam-water separator can still reach the saturation temperature during dry operation under the corresponding pressure, thereby making the boiler run in a dry state and reducing the power generation load.

[0048] Optionally, before executing S204, the process further includes: determining whether the current steam temperature is lower than a critical steam temperature.

[0049] Accordingly, a specific implementation of S204 is: when the current steam temperature is lower than the critical steam temperature, the steam extraction amount entering the high-pressure heater of the thermal power unit is controlled to increase.

[0050] In this embodiment, when the current steam temperature is equal to the critical steam temperature, it indicates that the boiler is in a critical state between dry and wet. If the current steam temperature is lower than the critical steam temperature, it indicates that the boiler is in a wet state. For a thermal power unit, it is not desirable for the boiler to operate in a wet state. Therefore, when the current steam temperature is lower than the critical steam temperature, the steam extraction amount of the high-pressure heater entering the thermal power unit is controlled to increase so that the boiler operates in a dry state.

[0051] Optionally, another specific implementation of S204 is: increasing the opening of a valve between the high-pressure heater and the steam turbine to control the increase in the amount of steam extracted from the high-pressure heater of the thermal power unit.

[0052] In this embodiment, if the amount of steam extraction entering the high-pressure heater of the thermal power unit is to be increased, it can be achieved by controlling and increasing the opening of the valve 17 between the high-pressure heater and the steam turbine. This implementation method is simple and easy to implement, and the valve opening is easy to control, thereby facilitating the control of the increase in the amount of steam extraction.

[0053] In summary, this embodiment obtains the current generating load of the thermal power unit upon determining that the thermal power unit has entered the critical dry-to-wet transition state; determines whether the current generating load meets the load reduction requirements of the power grid; and if so, controls the thermal power unit to operate according to the current operating state. If not, controls the steam extraction rate entering the thermal power unit's high-pressure heater to increase, thereby reducing the amount of steam entering the thermal power unit's steam turbine to perform work, thereby reducing the generating load while the thermal power unit maintains dry operation. This embodiment achieves a solution where, when the thermal power unit is cooperating with the power grid's load reduction requirements but the coal feed rate is insufficient to meet the grid's load reduction requirements, the feedwater temperature at the economizer inlet is increased by increasing the steam extraction rate, reducing the heat required to convert the feedwater from liquid to gaseous steam, thereby reducing the required coal feed rate and thus reducing the generating load of the thermal power unit. Furthermore, the boiler can maintain dry operation even after the load continues to decrease, minimizing the boiler load when the thermal power unit enters the critical dry-to-wet transition state.

[0054] Figure 3 This is a flow chart of a peak load control method for a thermal power plant provided in another embodiment of the present application. Figure 3 As shown, based on the above embodiment, the method of this embodiment includes: S301. When it is determined that the thermal power unit has entered a critical state of transitioning from a dry state to a wet state, the current power generation load of the thermal power unit is obtained.

[0055] In this step, the specific implementation of S301 can refer to S201 and will not be repeated here.

[0056] S302: Determine whether the current power generation load meets the load reduction demand of the grid side. If so, execute S303; if not, execute S304.

[0057] In this step, the specific implementation of S302 can refer to S202 and will not be repeated here.

[0058] S303. Control the thermal power unit to operate according to the current operating status.

[0059] In this step, the specific implementation of S303 can refer to S203 and will not be repeated here.

[0060] S304: Increase the opening of the control valve by a preset opening, and obtain the updated steam temperature at the steam-water separator outlet after a first preset time period; In this step, when the current power generation load does not meet the load reduction demand on the grid side and the boiler is in a critical state between dry and wet states, it is necessary to increase the opening of valve 17. When increasing the opening of valve 17, in order to avoid a situation where the valve opening increases too much at one time, resulting in a sharp decrease in the amount of steam used to do work in the turbine, the valve opening is increased by a preset opening each time, wherein the preset opening can be, for example, 5% of the fully open state.

[0061] Each time the valve opening increases by a preset opening, the steam at the outlet of the steam-water separator 9 fluctuates. Therefore, it is necessary to collect the updated steam temperature at the outlet of the steam-water separator 9 using the first temperature measuring device 11 after the steam at the outlet of the steam-water separator 9 stabilizes. Therefore, in this step, the updated steam temperature at the outlet of the steam-water separator is obtained after a first preset time period, which may be 5 minutes.

[0062] S305: Determine whether the updated steam temperature is still lower than the critical steam temperature. If so, execute S304; if not, execute S306.

[0063] In this step, the valve opening is increased by the preset opening, and the updated steam temperature obtained after the first preset time period will rise. The updated steam temperature is compared with the critical steam temperature again to determine whether the boiler is still in the critical state of dry-wet state conversion after the valve opening is increased by the preset opening and the steam extraction amount of the high-pressure heater 7 is increased, so as to perform the next step of operation based on the judgment result.

[0064] Optionally, if the first temperature measuring device 11 fails, or the signal transmission route fails, the steam temperature at the outlet of the steam-water separator 9 received by the numerical monitoring system 10 will be abnormal. For example, after the opening of the valve 17 increases, the steam temperature at the outlet of the steam-water separator 9 continues to decrease. Therefore, it is necessary to eliminate the erroneous judgment of the numerical monitoring system 10 caused by the failure of the first temperature measuring device 11 or the failure of the signal transmission route, that is, when the boiler has not entered the critical dry-wet state, it is determined that the boiler has entered the critical dry-wet state.

[0065] Therefore, before executing S307, the method further includes: S31. Determine whether the updated steam temperature is lower than the steam temperature at the steam-water separator outlet before the preset opening is increased. If so, execute S32; if not, execute S305.

[0066] In this embodiment, if the first temperature measuring device 11 does not fail, or the signal transmission path does not fail, that is, Figure 1 If the system shown is operating normally, then after the opening of valve 17 is increased, the updated steam temperature should be greater than the steam temperature at the steam separator outlet before the preset opening increase. Therefore, it is necessary to determine whether the updated steam temperature is still less than the steam temperature at the steam separator outlet before the preset opening increase, and then proceed to the next step based on the determination result.

[0067] If the updated steam temperature is greater than or equal to the steam temperature at the outlet of the steam-water separator before the preset opening is increased, it means Figure 1 The system shown is operating normally, and at this time, S S305 is executed.

[0068] S32. The opening of the control valve is the opening when the thermal power unit is in the critical state of transition from dry state to wet state.

[0069] In this embodiment, if the updated steam temperature is still lower than the steam temperature at the steam-water separator outlet before the preset opening was increased, this indicates that the first temperature measuring device 11 is not faulty, the signal transmission path is not faulty, or some other fault exists. In this case, the numerical monitoring system 10's determination that the boiler has entered the critical dry-wet state is a false positive, meaning that the boiler has not actually entered the critical dry-wet state. Therefore, the control valve opening is the opening at which the thermal power unit is at the critical dry-to-wet transition state.

[0070] S306: Maintain the valve opening at the current opening.

[0071] In this step, when the updated steam temperature is greater than or equal to the critical steam temperature, it means that the valve increases the preset opening, and after the steam extraction amount of the high-pressure heater 7 is increased, the boiler is still in a dry operation state. Moreover, after the first preset time, the updated steam temperature is greater than or equal to the critical steam temperature, which also means that the power generation load of the thermal power unit can meet the load reduction demand of the power grid. At this time, the valve opening can be controlled to be the opening after the preset opening is increased. Until the thermal power unit reduces the power generation load due to the load reduction of the power grid, causing the boiler to be in the dry-wet critical state again, execute S304.

[0072] In summary, this embodiment, building on the previous embodiments, controls the valve opening by increasing the preset opening each time. After a first preset period of time, the updated steam temperature at the steam-water separator outlet is obtained, and a determination is made as to whether the updated steam temperature is still below the critical steam temperature. If so, the valve opening is again controlled to increase the preset opening to increase the steam extraction rate entering the thermal power unit's high-pressure heater. If not, the valve opening is maintained at the current opening. This approach avoids large fluctuations in steam extraction rate by controlling the steam extraction rate each time, improves boiler safety, and maintains stable peak load regulation of the thermal power unit.

[0073] Optionally, based on the above embodiment, the method further includes: S41. When the thermal power unit is in the process of reducing power generation load, obtain an operating parameter combination of the thermal power unit.

[0074] The operating parameter combination includes at least one of the following operating parameters: temperature of the working medium at the economizer outlet, steam flow of the low-pressure cylinder of the steam turbine, pressure of the high-pressure heater, water level of the high-pressure heater, and heating rate of the high-pressure heater.

[0075] In this step, when the boiler is in dry operation and the power grid needs to reduce the load, the thermal power unit is in the process of reducing the power generation load. At this time, the thermal power unit may have safety hazards due to the load reduction. Therefore, during the load reduction process of the thermal power unit, the operating parameters of the thermal power unit are monitored.

[0076] Among them, the operating parameters include: the temperature of the working medium at the economizer outlet, the steam flow of the low-pressure cylinder of the turbine, the pressure of the high-pressure heater, the water level of the high-pressure heater, and the heating rate of the high-pressure heater.

[0077] Among them, the temperature of the working fluid at the economizer outlet can be obtained through the second temperature measuring device 16, the steam flow of the turbine low-pressure cylinder can be obtained by monitoring the steam amount in the turbine low-pressure cylinder 3 through the steam flowmeter 12, the pressure of the high-pressure heater can be obtained by monitoring the pressure in the high-pressure heater 7 through the pressure gauge 13, the water level of the high-pressure heater can be obtained by monitoring the water level in the high-pressure heater 7 through the water level gauge 14, and the heating rate of the high-pressure heater can be obtained by monitoring the heating rate in the high-pressure heater 7 through the heating rate meter 15.

[0078] S42. When at least one operating parameter of the operating parameter combination does not meet the corresponding safe operating condition, the opening of the control valve is reduced to reduce the amount of steam extracted into the high-pressure heater of the thermal power unit.

[0079] In this step, the operating parameters are compared with the corresponding safe operating conditions. Specifically, for the temperature of the working fluid at the economizer outlet, a temperature higher than the preset saturation temperature corresponding to the current boiler pressure is set as the safe operating temperature value. The preset temperature here can be, for example, 10°C. When the temperature of the working fluid at the economizer outlet is higher than the safe operating temperature value, the valve opening is controlled to decrease, thereby reducing the amount of steam extracted from the high-pressure heater of the thermal power unit. For the steam flow of the low-pressure cylinder of the steam turbine, the minimum steam flow flowing into the low-pressure cylinder of the steam turbine is set to the safety steam flow limit. If the steam flow of the low-pressure cylinder of the steam turbine is less than the safety steam flow limit, the opening of the control valve is reduced to reduce the steam extraction amount entering the high-pressure heater of the thermal power unit; Regarding the pressure of the high-pressure heater, the maximum pressure that the high-pressure heater can withstand is set as the safety pressure limit. The maximum pressure that the high-pressure heater can withstand is related to the model of the high-pressure heater. When the pressure of the high-pressure heater is greater than the safety pressure limit, the opening of the control valve is reduced to reduce the amount of steam extracted from the high-pressure heater entering the thermal power unit. For the water level of the high-pressure heater, the maximum water level in the high-pressure heater is set to the safety water level limit. When the water level of the high-pressure heater is greater than the safety water level limit, the opening of the control valve is reduced to reduce the amount of steam extracted from the high-pressure heater of the thermal power unit; For the heating rate of the high-pressure heater, generally, a heating rate of 1.5℃ / min is set as the safe heating rate limit. When the heating rate of the high-pressure heater is greater than the safe heating rate limit, the opening of the control valve is reduced to reduce the amount of steam extracted from the high-pressure heater entering the thermal power unit.

[0080] Optional, after S42, also includes: S43. After a second preset time period, obtain an updated operating parameter combination of the thermal power unit.

[0081] In this step, when any of the above-mentioned operating parameters does not meet the corresponding safe operating conditions, the valve opening is controlled to be reduced to reduce the amount of steam extracted from the high-pressure heater of the thermal power unit, and after the valve opening is reduced for a second preset time, for example, the second preset time is 20 seconds, the updated operating parameters are obtained again to form an updated operating parameter combination.

[0082] For example, if the HPH's heating rate exceeds the safe heating rate limit, and the valve opening is reduced to reduce the amount of steam extracted from the HPH to the thermal power unit, the HPH's heating rate is re-obtained 20 seconds after the valve opening is reduced. This is the updated HPH's heating rate. Other operating parameters can also be re-obtained at this time.

[0083] S44. When any target operating parameter in the updated operating parameter combination still does not meet the corresponding safe operating condition, the opening of the control valve is controlled to be the opening before the thermal power unit reduces the power generation load.

[0084] In this step, the target operating parameter is the corresponding operating parameter for reducing the opening of the control valve due to failure to meet the corresponding safe operating conditions. When the valve opening is reduced, the updated target operating parameter is obtained to determine whether the updated operating parameter meets the corresponding safe operating conditions. If it still does not meet the conditions, the reason may be a failure of the equipment for collecting the operating parameter or a failure of the signal transmission line, which indicates that the judgment result of "the target operating parameter does not meet the corresponding safe operating conditions" is incorrect. At this time, the opening of the control valve is the opening before the thermal power unit reduces the power generation load.

[0085] It should be noted that when it is determined that the operating parameter collection equipment or the signal transmission route is faulty, it is necessary to promptly troubleshoot and resolve the fault, and then control the normal operation of the thermal power unit according to the load requirements of the power grid.

[0086] In this embodiment, when the thermal power unit cooperates with the power grid to reduce load, by comparing the operating parameters with the corresponding safe operating conditions, safety hazards of the thermal power unit can be discovered in time, thereby improving the safety of the thermal power unit.

[0087] Figure 4 This is a schematic diagram of the structure of a peak load control device for a thermal power plant provided in one embodiment of the present application. Figure 4 As shown, the peak-shaving control device for a thermal power unit includes: an acquisition module 410 , a first judgment module 420 , a first control module 430 and a second control module 440 .

[0088] Optionally, the peak-shaving control device for a thermal power unit further includes: a determination module 450 .

[0089] Optionally, the peak-shaving control device for a thermal power unit further includes: a second judgment module 460 .

[0090] An acquisition module 410 is configured to acquire the current power generation load of the thermal power unit when it is determined that the thermal power unit has entered a critical state of transition from dry state to wet state; The first judgment module 420 is used to judge whether the current power generation load meets the load reduction demand of the grid side; If so, the first control module 430 is used to control the thermal power unit to operate according to the current operating state; If not, the second control module 440 is used to control the increase in the amount of steam extraction entering the high-pressure heater of the thermal power unit to reduce the amount of steam entering the steam turbine of the thermal power unit to do work, so as to reduce the power generation load while the thermal power unit remains in dry operation.

[0091] Optionally, the determination module 450 is configured to: Get the current steam temperature at the outlet of the steam-water separator of the thermal power unit; When the current steam temperature is equal to the critical steam temperature, it is determined that the thermal power unit enters the critical state of dry-to-wet transition, where the critical steam temperature is a temperature higher than a preset temperature value of the saturated steam temperature at the outlet of the steam-water separator, and the saturated steam temperature is the saturated temperature corresponding to the current steam pressure at the outlet of the steam-water separator.

[0092] Optionally, before the second control module 440 controls the increase of the extraction steam amount of the high-pressure heater of the thermal power unit, the second judgment module 460 is further configured to: judge whether the current steam temperature is less than the critical steam temperature; The second control module 440 controls the increase of the steam extraction amount of the high-pressure heater of the thermal power unit, specifically for: controlling the increase of the steam extraction amount of the high-pressure heater of the thermal power unit when the current steam temperature is lower than the critical steam temperature.

[0093] Optionally, the second control module 440 controls the increase of the extraction steam flow into the high-pressure heater of the thermal power unit, specifically for: By increasing the opening of the valve between the high-pressure heater and the steam turbine, the amount of steam extracted from the high-pressure heater of the thermal power unit is controlled to increase.

[0094] Optionally, the second control module 440 controls the increase in the amount of steam extracted from the high-pressure heater of the thermal power unit by increasing the opening of the valve between the high-pressure heater and the steam turbine, specifically for: The opening of the control valve is increased by a preset opening, and after a first preset time period, an updated steam temperature at the steam-water separator outlet is obtained; The second determination module 460 determines whether the updated steam temperature is still less than the critical steam temperature; If yes, the second control module 440 controls the valve opening to increase the preset opening again, so as to increase the extraction steam amount entering the high-pressure heater of the thermal power unit; If not, the second control module 440 maintains the valve opening at the current opening.

[0095] Optionally, before the second determination module 460 determines whether the updated steam temperature is still lower than the critical steam temperature, it is further configured to: Determine whether the updated steam temperature is lower than the steam temperature at the steam-water separator outlet before the preset opening is increased; If so, the second control module 440 controls the valve opening to be the opening when the thermal power unit is in a critical state of transition from dry state to wet state; The second judgment module 460 judges whether the updated steam temperature is still lower than the critical steam temperature, specifically for: If not, it is determined whether the updated steam temperature is still less than the critical steam temperature.

[0096] Optionally, the acquisition module 410 is further configured to: when the thermal power unit is in the process of reducing power generation load, acquire an operating parameter combination of the thermal power unit, the operating parameter combination including at least one of the following operating parameters: temperature of the working medium at the economizer outlet, steam flow rate of the low-pressure cylinder of the steam turbine, pressure of the high-pressure heater, water level of the high-pressure heater, and heating rate of the high-pressure heater; When at least one operating parameter of the operating parameter combination does not meet the corresponding safe operating condition, the second control module 440 is used to control the valve opening to decrease so as to reduce the amount of steam extracted into the high-pressure heater of the thermal power unit.

[0097] Optionally, after the second control module 440 controls the valve opening to decrease, the acquisition module 410 is further configured to: acquire an updated operating parameter combination of the thermal power unit after a second preset time period; When any target operating parameter in the updated operating parameter combination still does not meet the corresponding safe operating condition, the second control module 440 is configured to control the valve opening to be the opening before the thermal power unit reduces the power generation load.

[0098] The specific implementation process of the peak-shaving control device for a thermal power unit provided in the embodiment of the present application can be found in the above-mentioned method embodiment. Its implementation principle and technical effects are similar, and will not be repeated here in this embodiment.

[0099] Figure 5 This is a schematic diagram of the structure of an electronic device provided in one embodiment of the present application. Figure 5 As shown, the electronic device includes: a processor 510 and a memory 520.

[0100] The memory 520 stores computer-executable instructions.

[0101] The processor 510 executes the computer-executable instructions stored in the memory 520 , so that the processor 510 performs the method described in any one of the above embodiments.

[0102] The specific implementation process of the electronic device provided in the embodiment of the present application can be found in the above-mentioned method embodiment. Its implementation principle and technical effects are similar, and will not be repeated here in this embodiment.

[0103] In the above Figure 5In the illustrated embodiment, it should be understood that the processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the present invention may be directly implemented by a hardware processor or implemented by a combination of hardware and software modules in the processor.

[0104] The memory may include a high-speed RAM memory, and may also include a non-volatile storage NVM, such as at least one disk storage.

[0105] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Buses can be classified as address buses, data buses, and control buses. For ease of illustration, the buses in the drawings of this application are not limited to just one bus or just one type of bus.

[0106] An embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions. When a processor executes the computer-executable instructions, the method shown in the above method embodiment is implemented.

[0107] The computer-readable storage medium mentioned above can be implemented by any type of volatile or non-volatile memory device, or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The computer-readable storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0108] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be an integral part of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processor and the readable storage medium can also exist in a device as discrete components.

[0109] Those skilled in the art will appreciate that all or part of the steps in the above-described method embodiments can be implemented using hardware associated with program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for peak load regulation control of a thermal power plant, characterized in that: include: When it is determined that the thermal power unit has entered a critical state of transition from dry state to wet state, obtaining a current power generation load of the thermal power unit; Determining whether the current power generation load meets the load reduction demand of the power grid side; If so, controlling the thermal power unit to operate according to the current operating state; If not, the amount of steam extracted from the high-pressure heater of the thermal power unit is controlled to increase so as to reduce the amount of steam entering the steam turbine of the thermal power unit to perform work, thereby reducing the power generation load while the thermal power unit remains in dry operation.

2. The method according to claim 1, characterized in that Also includes: Obtaining the current steam temperature at the outlet of the steam-water separator of the thermal power unit; When the current steam temperature is equal to the critical steam temperature, it is determined that the thermal power unit enters the critical state of dry-to-wet transition, wherein the critical steam temperature is a temperature higher than a preset temperature value of the saturated steam temperature at the outlet of the steam-water separator, and the saturated steam temperature is the saturated temperature corresponding to the current steam pressure at the outlet of the steam-water separator.

3. The method according to claim 2, characterized in that Before the control increases the amount of extraction steam entering the high-pressure heater of the thermal power unit, the method further includes: determining whether the current steam temperature is less than the critical steam temperature; The controlling of increasing the amount of extraction steam entering the high-pressure heater of the thermal power unit comprises: When the current steam temperature is lower than the critical steam temperature, the amount of steam extracted from the high-pressure heater of the thermal power unit is controlled to increase.

4. The method according to claim 2 or 3, characterized in that The controlling of increasing the amount of extraction steam entering the high-pressure heater of the thermal power unit comprises: By increasing the opening of the valve between the high-pressure heater and the steam turbine, the amount of steam extracted from the high-pressure heater of the thermal power unit is controlled to increase.

5. The method according to claim 4, characterized in that The method of increasing the opening of the valve between the high-pressure heater and the steam turbine to control the increase in the amount of steam extraction from the high-pressure heater of the thermal power unit comprises: Controlling the opening of the valve to increase a preset opening, and obtaining an updated steam temperature at the outlet of the steam-water separator after a first preset time period; determining whether the updated steam temperature is still lower than the critical steam temperature; If yes, controlling the opening of the valve again to increase the preset opening, so as to increase the amount of steam extracted into the high-pressure heater of the thermal power unit; If not, the opening of the valve is maintained at the current opening.

6. The method according to claim 5, characterized in that Before determining whether the updated steam temperature is still lower than the critical steam temperature, the method further includes: Determining whether the updated steam temperature is lower than the steam temperature at the steam-water separator outlet before the preset opening is increased; If so, controlling the valve opening to be the opening when the thermal power unit is in a critical state of transition from dry state to wet state; The determining whether the updated steam temperature is still lower than the critical steam temperature includes: If not, it is determined whether the updated steam temperature is still lower than the critical steam temperature.

7. The method according to claim 4, characterized in that Also includes: When the thermal power unit is in the process of reducing power generation load, an operating parameter combination of the thermal power unit is obtained, where the operating parameter combination includes at least one of the following operating parameters: temperature of the working medium at an economizer outlet, steam flow rate of a low-pressure cylinder of a steam turbine, pressure of a high-pressure heater, water level of the high-pressure heater, and heating rate of the high-pressure heater; When at least one operating parameter of the operating parameter combination does not meet the corresponding safe operating condition, the opening of the valve is controlled to decrease so as to reduce the amount of steam extracted into the high-pressure heater of the thermal power unit.

8. The method according to claim 7, characterized in that After controlling the opening of the valve to decrease, the method further includes: After a second preset time period, obtaining an updated operating parameter combination of the thermal power unit; When any target operating parameter in the updated operating parameter combination still does not meet the corresponding safe operating condition, the valve opening is controlled to be the opening before the thermal power unit reduces the power generation load.

9. A peak regulation control device for a thermal power unit, characterized in that: include: an acquisition module, configured to acquire the current power generation load of the thermal power unit when it is determined that the thermal power unit has entered a critical state of transition from dry state to wet state; A judgment module, configured to judge whether the current power generation load meets the load reduction requirement of the power grid side; If so, the first control module is used to control the thermal power unit to operate according to the current operating state; If not, the second control module is used to control the increase in the amount of steam extraction entering the high-pressure heater of the thermal power unit to reduce the amount of steam entering the turbine of the thermal power unit to do work, so as to reduce the power generation load while the thermal power unit remains in dry operation.

10. An electronic device, characterized in that: include: processor and memory; Memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory, so that the processor performs the method according to any one of claims 1 to 8.

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