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CN-122014371-A - Method, system and control device for switching operation of two machines in one furnace

CN122014371ACN 122014371 ACN122014371 ACN 122014371ACN-122014371-A

Abstract

The invention discloses a method, a system and a control device for switching operation of one boiler and two turbines, wherein the method comprises the steps of S1, determining total electricity load of a power grid, S2, determining total cost of the system meeting the total electricity load in a plurality of operation modes, wherein the plurality of operation modes comprise a first operation mode, a second operation mode and a third operation mode, the coal-fired boiler is communicated with a first turbine unit in the first operation mode, the coal-fired boiler is communicated with a second turbine unit in the second operation mode, the coal-fired boiler is communicated with the first turbine unit and the second turbine unit in the third operation mode, and S3, switching the system from the current mode to a target mode according to the total cost, wherein the target mode is the mode with the lowest total cost among the first operation mode, the second operation mode and the third operation mode. According to the method for switching operation of one furnace and two machines, the peak regulation flexibility and the economic operation level of the thermal power unit under the background of high permeability of new energy can be remarkably improved.

Inventors

  • HE XINRONG
  • TAN RUI
  • ZHANG WENJIE
  • JIANG GUOAN
  • YAN ZHIYUAN
  • HAO FEI

Assignees

  • 国能南京电力试验研究有限公司

Dates

Publication Date
20260512
Application Date
20260122

Claims (10)

  1. 1. A method of switching operation of a furnace to a machine, the method being applied to a system (100) of switching operation of a furnace to a machine, the system (100) comprising a coal-fired boiler (10), a first turbine group (20) and a second turbine group (30), the rated power of the first turbine group (20) being greater than the rated power of the second turbine group (30), the method comprising: step S1, determining the total power load of a power grid; Step S2, determining a total cost of the system (100) to meet the total electrical load in a plurality of operating modes, wherein the plurality of operating modes includes a first operating mode in which the coal-fired boiler (10) is in communication with the first turbine group (20), a second operating mode in which the coal-fired boiler (10) is in communication with the second turbine group (30), and a third operating mode in which the coal-fired boiler (10) is in communication with both the first turbine group (20) and the second turbine group (30), The total cost includes coal cost, equipment loss cost and switching cost, The coal cost includes the coal consumption of the coal-fired boiler (10) when a plurality of the operation modes respectively satisfy the total electric load, The equipment loss costs include a life loss at the start-up of the first turbine group (20) and/or the second turbine group (30) when the system (100) switches from the current operating mode to the other operating mode, the life loss being determined based on a rotor temperature difference of the first turbine group (20) and/or the second turbine group (30), The switching costs include steam consumption costs and electrical energy consumption costs when the system (100) switches from the current operating mode to another of the operating modes; And step S3, switching the system (100) from a current mode to a target mode according to the total cost, wherein the target mode is the mode with the lowest total cost among the first operation mode, the second operation mode and the third operation mode.
  2. 2. A method for switching operation of a furnace according to claim 1, wherein the first turbine group (20) comprises a first high pressure cylinder (21) and a first medium pressure cylinder (22), the second turbine group (30) comprises a second high pressure cylinder (31), The system (100) further comprises a first pipeline (41), a second pipeline (42), a third pipeline (43), a mechanical vapor recompression system (44), a mixing header (45), a reheater (46), a first control valve (47) and a second control valve (48), wherein the first pipeline (41) is connected between the vapor outlet of the first high-pressure cylinder (21) and the vapor inlet of the mixing header (45), the first pipeline (41) comprises a first sub-pipeline (411) and a second sub-pipeline (412), the pipe diameter and the length of the first sub-pipeline (411) are different from those of the second sub-pipeline (412), the first control valve (47) is arranged on the first pipeline (41) and is configured to enable the vapor outlet of the first high-pressure cylinder (21) to be selectively communicated with the first sub-pipeline (411) or the second sub-pipeline (412), the second pipeline (42) is connected between the second high-pressure cylinder (31) and the vapor outlet of the reheating header (45) and the first pipeline (46) of the mechanical vapor compressor (46), the steam outlet of the first high-pressure cylinder (21) is connected with the steam inlet of the first medium-pressure cylinder (22) through the third pipeline (43), the second control valve (48) is connected on the third pipeline (43) and used for controlling the on-off of the third pipeline (43) and adjusting the flow of the third pipeline (43), The method further comprises the steps of: Step S40, confirming that the target mode is the third operation mode; Step S50, monitoring the temperature and the pressure of the steam outlet of the first high-pressure cylinder (21) and the steam outlet of the second high-pressure cylinder (31) in real time; Inputting the temperatures and pressures of the steam outlet of the first high pressure cylinder (21) and the steam outlet of the second high pressure cylinder (31) into a pre-trained neural network model to obtain a plurality of control parameters, wherein the plurality of control parameters comprise the steam flow parameter of the third pipeline (43), the communication condition of the first sub-pipeline (411) and the second sub-pipeline (412) and the compressor rotating speed parameter of the mechanical steam recompression system (44), Wherein the neural network model is pre-trained with the aim of minimizing the temperature and pressure differences of the first and second pipelines (41, 42); and step S60, adjusting the first control valve (47), the second control valve (48) and the rotating speed of the compressor based on a plurality of control parameters so that the pressure and the temperature of the steam outlet of the first pipeline (41) and the pressure and the temperature of the second pipeline (42) reach preset targets.
  3. 3. The method for switching operation of a boiler according to claim 2, wherein the system (100) further comprises a fourth pipeline, a fifth pipeline, an air supply pipeline, a combustion air pipeline, a first air preheater and a second air preheater, wherein one end of each of the fourth pipeline and the fifth pipeline is communicated with a main steam pipe (34) of the second steam turbine unit (30), one end of each of the air supply pipeline and the combustion air pipeline is communicated with the coal-fired boiler (10), the first air preheater is provided with a first flow passage and a second flow passage which are mutually heat-exchanged, the first flow passage is connected in series with the air supply pipeline, the other end of the fourth pipeline is connected with an inlet end of the second flow passage, the second air preheater is provided with a third flow passage and a fourth flow passage which are mutually heat-exchanged, the third flow passage is connected in series with the air supply pipeline, the other end of the fifth pipeline is connected with an inlet end of the fourth flow passage, The method further comprises the steps of: Step S41, confirming that the target mode is the first operation mode; and S51, confirming that the total power load is lower than a preset threshold, and communicating the fourth pipeline and/or the fifth pipeline, wherein the preset threshold is smaller than or equal to the total output of the system (100) when the coal-fired boiler (10) operates at the lowest steady burning load in the first operation mode.
  4. 4. A method of switching operation of a furnace and a machine according to claim 3, wherein step S51 comprises: step S511, confirming that the total power load is lower than the preset threshold; Step S512, determining flow control information based on the total power load, the output power of the second turbine unit (30) and the steam pressure of a main steam pipe (34) of the second turbine unit (30), wherein the flow control information comprises a steam flow path, flow, temperature and pressure; step S513 of communicating the fourth pipe and/or the fifth pipe based on the flow control information and controlling the flow rate, the temperature, and the pressure of the fourth pipe and/or the fifth pipe.
  5. 5. A method of switching operation of a furnace according to claim 3, wherein the outlet end of the second flow path and/or the fourth flow path is in communication with the steam inlet of the reheater (46).
  6. 6. The method of one-furnace two-machine switching operation according to any one of claims 1 to 5, wherein when the current mode is a first operation mode or a second operation mode, the target mode is a third operation mode, or when the current mode is a first operation mode, the target mode is a second operation mode, or when the current mode is a second operation mode, the target mode is a first operation mode, the switching the system (100) from the current mode to the target mode according to the total cost comprises: Determining a first load change curve of a currently operated turbine unit and a second load change curve of the turbine unit to be started according to the target mode, the total power load, the current main steam pressure of the system (100), the real-time rotating speed and the load of the currently operated turbine unit, wherein the first load change curve and the second load change curve are obtained by performing closed-loop control with the minimum total output power of the system (100) changed to be the highest priority; Slowly reducing the power of the currently running turbine unit according to the first load change curve, and starting the turbine unit to be started according to the second load change curve; the power of the first turbine group (20) and the second turbine group (30) is adjusted to match the total power load.
  7. 7. The method of switching operation of one or two machines according to any of claims 1-5, wherein when the current mode is a third operation mode and the target mode is the first operation mode or the second operation mode, the switching the system (100) from the current mode to the target mode according to the total cost comprises: Determining a third load change curve and a fourth load change curve according to the target mode, the total power load, the current main steam pressure of the system (100), the real-time rotating speeds and loads of the first turbine unit (20) and the second turbine unit (30), wherein the third load change curve is the total power change curve of the system (100), the change rate of the total power is in a preset range, and the fourth load change curve is the power change curve of the turbine unit to be stopped and the end point is 0; And adjusting the power of another turbine unit other than the turbine unit to be shut down according to a fifth load profile for counteracting the third load profile and causing the total power of the system (100) to follow the third load profile.
  8. 8. The method for switching operation of one or two furnaces according to any one of claims 1 to 5, wherein step S1 includes predicting the total power load after a preset time based on historical load data, grid scheduling plan, weather forecast, and an expected mode switching time point; Step S3 comprises switching the system (100) to the target mode at the mode switching time point.
  9. 9. A system (100) for switching operation of one furnace and two turbines, characterized by comprising a coal-fired boiler (10), a first turbine unit (20) and a second turbine unit (30), the rated power of the first turbine unit (20) being greater than the rated power of the second turbine unit (30), the system (100) being for use in a method according to any of claims 1-8.
  10. 10. A control device (200) for a two-in-one switching, characterized in that the control device (200) is applied to a system (100) for a two-in-one switching operation according to claim 9, the control device (200) comprising a processor (201), a memory (202) and a computer program (203) stored in the memory (202) and executable on the processor (201), the processor (201) executing the computer program (203) causing the control device (200) to implement a method for a two-in-one switching operation according to any one of claims 1-8.

Description

Method, system and control device for switching operation of two machines in one furnace Technical Field The invention relates to the technical field of thermal power generation, in particular to a method, a system and a control device for switching operation of two machines in one furnace. Background The permeability of intermittent new energy sources such as wind power, photovoltaic and the like in an electric power system is continuously improved, and the randomness and fluctuation of the output form a serious challenge for the real-time power balance of a power grid. Under the background, the roles of the thermal power plant which traditionally bears the tasks of basic load and conventional peak regulation are fundamentally transformed, and the thermal power plant needs to be transformed into a flexible regulating power supply for guaranteeing the stable operation of a power grid. In order to effectively eliminate new energy power and avoid the phenomenon of wind and light abandoning in the load valley period, the thermal power generating unit must break through the traditional operation lower limit and carry out deep peak shaving, namely, maintain operation under the working condition far lower than rated load. The power generation device aims to make enough internet surfing space for new energy power generation, and can quickly respond to the new energy power generation device when the power output suddenly drops, so that a power gap is filled. However, deep peak shaving of thermal power generating units faces a series of key technical bottlenecks such as difficulty in stabilizing combustion of low load of boilers, remarkable reduction of unit efficiency, aggravation of equipment loss and the like. Therefore, the deep peak regulation capability of the thermal power generating unit is researched and improved, and the deep peak regulation capability of the thermal power generating unit becomes one of the core technical requirements for constructing a novel power system and supporting clean transformation of an energy structure. Disclosure of Invention The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the invention provides a method for switching operation of two machines in one furnace, which can ensure that the system meets the total power load of a power grid and simultaneously gives consideration to the economical efficiency of coal burning, the health condition of equipment and the cost of mode switching, thereby realizing the minimization of the operation cost and the extension of the service life of the equipment, and remarkably improving the peak regulation flexibility and the economic operation level of the thermal power generating unit under the background of high permeability of new energy. The method for switching operation of the one-furnace and the two-machine according to the first aspect of the invention is applied to a system for switching operation of the one-furnace and the two-machine, the system comprises a coal-fired boiler, a first turbine set and a second turbine set, the rated power of the first turbine set is larger than that of the second turbine set, and the method comprises the steps of determining the total electricity load of a power grid; determining a total cost of the system to meet the total electrical load in a plurality of operating modes, wherein the plurality of operating modes includes a first operating mode in which the coal-fired boiler communicates with the first turbine unit, a second operating mode in which the coal-fired boiler communicates with the second turbine unit, and a third operating mode in which the coal-fired boiler communicates with both the first turbine unit and the second turbine unit, the total cost including a coal cost, a facility loss cost, and a switching cost, the coal cost including a consumption of the coal-fired boiler when the plurality of operating modes meet the total electrical load, respectively, the facility loss cost including a life loss when the system is switched from a current operating mode to another one of the operating modes, starting the first turbine unit and/or the second turbine unit, the life loss being determined based on a difference in the temperatures of the first turbine unit and/or the second turbine unit, the system being a current cost of steam consumption, the system being determined from the current operating mode to the other one of the operating modes based on the current cost, the target mode is the mode with the lowest total cost among the first operation mode, the second operation mode and the third operation mode. According to the method for switching operation of one furnace and two machines, the two-machine system with different capacity is configured, and the dynamic selection of the operation mode is carried out based on the comprehensive total cost, so that the challenges of high cost, high equipment loss and the like of the traditio