Coal-fired power plant load adjusting system and method coupled with compressed steam energy storage

Abstract

The invention discloses a coal-fired power plant load adjusting system and method coupled with compressed steam energy storage, and provides an innovative scheme of cooperative operation of three modes of a low ebb period, a peak period and a mean price period by deeply integrating a coal-fired boiler power generation system and a compressed steam energy storage system. In the electricity consumption trough period, the system introduces low-temperature and low-pressure dead steam at an outlet of a steam turbine into a compression energy storage loop, the low-temperature and low-pressure dead steam is converted into high-pressure water to be stored through multi-stage compression and cooling, and meanwhile a normal-pressure water tank is used for maintaining water balance; in the peak period of power utilization, high-pressure water is released and heated to drive the expansion turbine to generate power, and the power grid load gap is quickly supplemented. And independently operating the coal-fired power generation system in the average price period. Through closed-loop coupling of energy storage and power generation, the load adjusting range and response speed of the coal-fired power plant are remarkably improved, heat efficiency loss of low-load operation is avoided, heat energy gradient utilization is achieved through heat storage circulation, and resource consumption and carbon emission are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal power generation and energy storage, and in particular to a load regulation system and regulation method for a coal-fired power plant coupled with compressed steam energy storage. Background Art

[0002] In recent years, coal-fired power plant technology has continued to advance. Supercritical and ultra-supercritical boiler technologies have increased boiler operating pressures and temperatures, significantly improving thermal efficiency and reducing coal consumption and CO2 emissions. However, as power plant capacity increases, the difference between peak and off-peak loads is also increasing, leading to a wider range of plant load factors. This reduces power generation efficiency at low loads and increases coal consumption. Therefore, there is an urgent need for innovative coal-fired power plant processes to ensure stable peak and off-peak power consumption while maintaining plant efficiency.

[0003] Currently, large-scale energy storage technologies primarily focus on pumped hydro and compressed air storage. However, pumped hydro is limited by geographical conditions and struggles to fully align with the grid's load distribution. Compressed air storage, unlike the working fluid of coal-fired power plants, is often used for grid-side energy storage. Therefore, on the coal-fired power generation side, the optimal energy storage method is to utilize the working fluid water for energy storage, namely compressed steam storage. Therefore, the efficient coupling of coal-fired power plants with compressed steam storage warrants further research. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a load regulation system and regulation method for a coal-fired power plant coupled with compressed steam energy storage, which uses the turbine exhaust steam of the coal-fired boiler power generation system as the working fluid of the compressed energy storage system, thereby improving the flexibility and efficiency of the load regulation of the coal-fired power plant, so that the coal-fired power plant can always maintain a high power generation load operation.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is: a load regulation system for a coal-fired power plant coupled with compressed steam energy storage, comprising a coal-fired boiler power generation cycle loop, a compressed steam energy storage cycle loop, and a heat storage cycle loop; The coal-fired boiler power generation cycle includes a boiler, wherein the boiler outlet is connected to the first steam turbine inlet via a pipeline with a first valve, the first steam turbine outlet is connected to the first condenser inlet via a pipeline with a second valve, the first condenser outlet is connected to the condensate pump inlet via a pipeline with a third valve, the condensate pump outlet is connected to the low-temperature heater inlet via a pipeline with a fourth valve, the low-temperature heater outlet is connected to the deaerator inlet via a pipeline with a fifth valve, the deaerator outlet is connected to the feedwater pump inlet via a pipeline with a sixth valve, the feedwater pump outlet is connected to the high-temperature heater inlet via a pipeline with a seventh valve, and the high-temperature heater outlet is connected to the boiler inlet via a pipeline with an eighth valve; The compressed steam energy storage cycle includes a first steam turbine, wherein the outlet of the first steam turbine is connected to the inlet of the first compressor via a pipeline with a fifteenth valve, the outlet of the first compressor is connected to the inlet of the first cooler via a pipeline with a sixteenth valve, the outlet of the first cooler is connected to the inlet of the second compressor via a pipeline with a seventeenth valve, the outlet of the second compressor is connected to the inlet of the second cooler via a pipeline with an eighteenth valve, the outlet of the second cooler is connected to the inlet of the high-pressure steam-water storage tank via a pipeline with a nineteenth valve, the outlet of the high-pressure steam-water storage tank is connected to the inlet of the first heater via a pipeline with a twentieth valve, the outlet of the first heater is connected to the inlet of the second steam turbine via a pipeline with a twenty-first valve, the outlet of the second steam turbine is connected to the inlet of the second heater via a pipeline with a twenty-second valve, the outlet of the second heater is connected to the inlet of the third steam turbine via a pipeline with a twenty-third valve, the outlet of the third steam turbine is connected to the inlet of the second condenser via a pipeline with a thirty-third valve, the outlet of the second condenser is connected to the inlet of the atmospheric water tank via a pipeline with a thirty-fourth valve, the outlet of the atmospheric water tank is connected to the inlet of the water pump via a pipeline with a thirty-fifth valve, and the outlet of the water pump is connected to the inlet of the low-temperature heater via a valve with a thirty-sixth valve; The heat storage circulation loop includes a low-temperature oil tank and a high-temperature oil tank. The low-temperature oil tank outlet is connected to the first cooler inlet and the second cooler inlet via a pipeline with a twenty-sixth valve and a pipeline with a twenty-seventh valve respectively. The first cooler inlet and the second cooler outlet are connected to the second heater inlet via a pipeline with a twenty-fifth valve and a pipeline with a twenty-fourth valve respectively. The high-temperature oil tank outlet is connected to the first heater and the second heater inlet via a pipeline with a thirty-first valve and a pipeline with a thirty-second valve respectively. The outlets of the first heater and the second heater are connected to the low-temperature oil tank inlet via a pipeline with a thirtieth valve and a pipeline with a twenty-eighth valve respectively.

[0006] In a preferred solution, in the coal-fired boiler power generation cycle, the first steam turbine outlet is further connected to the low-temperature heater inlet via a pipeline with a ninth valve.

[0007] In a preferred solution, in the coal-fired boiler power generation cycle, the first steam turbine outlet is further connected to the deaerator inlet via a pipeline with a tenth valve.

[0008] In a preferred solution, in the coal-fired boiler power generation cycle, the first steam turbine outlet is further connected to the high-temperature heater inlet via a pipeline with an eleventh valve.

[0009] In a preferred embodiment, in the coal-fired boiler power generation cycle, the first condenser outlet is connected to the cooling tower inlet via a pipeline with a twelfth valve, the cooling tower outlet is connected to the cooling water pump inlet via a pipeline with a thirteenth valve, and the cooling water pump outlet is connected to the first condenser inlet via a pipeline with a fourteenth valve.

[0010] In a preferred solution, in the compressed steam energy storage circulation loop, the second condenser outlet is connected to the cooling tower inlet and the cooling water pump outlet through a pipeline with a thirty-seventh valve and a pipeline with a thirty-eighth valve, respectively.

[0011] Based on the above-mentioned method for regulating the load regulation system of a coal-fired power plant coupled with compressed steam energy storage, the method includes off-peak operation mode, peak operation mode and parity operation mode by deeply coupling the coal-fired boiler power generation system and the compressed steam energy storage system; Specifically, the off-peak operation mode is as follows: during the off-peak period, the coal-fired boiler power generation system operates normally, while part of the exhaust steam from the first steam turbine flows into the compressed steam energy storage system to drive the first compressor and the second compressor to store excess electricity. The water flow reduced in the power generation cycle is replenished through the atmospheric pressure water tank; Specifically, the peak operation mode is as follows: during peak electricity consumption periods, the coal-fired boiler power generation system operates normally, while the compressed steam energy storage system operates to release high-pressure steam to drive the second and third steam turbines to generate power, thereby filling the load gap of the power generation system; The specific operation mode during the parity period is: during the period of electricity consumption parity, only the coal-fired boiler power generation system is operated, while the compressed steam energy storage system is stationary.

[0012] In a preferred solution, in a coal-fired boiler power generation system when the system is in the off-peak operation mode, the high-temperature and high-pressure steam at the boiler outlet drives the first steam turbine to generate power and then flows through the first condenser. In the first condenser, the exhaust steam at the first steam turbine outlet exchanges heat with the cooling water pressurized by the cooling water pump and is cooled and cooled into water. The water at the first condenser outlet is pressurized by the condensate pump and flows through a low-temperature heater. The cooling water then flows back to the cooling tower, absorbs the low-temperature steam discharged from the first steam turbine in the low-temperature heater to increase the water temperature, and then flows through the deaerator. The tenth valve is opened, and the medium-temperature steam at the outlet of the first steam turbine is used to heat the feed water and remove oxygen from the water. The water at the deaerator outlet is pressurized by the feed water pump and flows through the high-temperature heater, absorbs the heat of the high-temperature steam and increases the temperature of the feed water in the high-temperature heater, thereby increasing its temperature when entering the boiler and improving the steam generation efficiency. In the compressed steam energy storage system, the fifteenth valve is opened to allow the low-temperature, low-pressure exhaust steam at the outlet of the first turbine to flow through the compressed steam energy storage system, driving the energy storage process. The low-pressure steam flows through the first compressor and the second compressor in sequence and is compressed into high-temperature, high-pressure steam. The high-temperature, high-pressure steam at the outlet of the first compressor and the second compressor flows through the first cooler and the second cooler respectively, exchanges heat with the low-temperature heat transfer oil from the low-temperature oil tank and cools it into a steam-water mixture. Finally, it is stored in the high-pressure steam-water storage tank, and the heat transfer oil that absorbs heat and heats up is stored in the high-temperature oil tank. The thirty-fifth valve is opened to release the water in the atmospheric pressure water tank. After being pressurized by the water pump, it is mixed with the water at the outlet of the first condenser and flows into the low-temperature heater to replenish water to the coal-fired boiler power generation cycle.

[0013] In a preferred solution, the coal-fired boiler power generation system operates normally when the system is in the peak operation mode. The high-temperature and high-pressure steam at the boiler outlet drives the first steam turbine to generate power and then flows through the first condenser. In the first condenser, the exhaust steam exchanges heat with the cooling water pressurized by the cooling water pump and is cooled and cooled into water. The water at the outlet of the first condenser is pressurized by the condensate pump and flows through the low-temperature heater. The cooling water then flows back to the cooling tower, absorbs the heat of the low-temperature steam discharged by the first steam turbine in the low-temperature heater, and then flows through the deaerator. The tenth valve is opened, and the medium-temperature steam at the outlet of the first steam turbine is used to heat the feed water and remove oxygen from the water. The water at the outlet of the deaerator is pressurized by the feed water pump and flows through the high-temperature heater. In the high-temperature heater, the water absorbs the heat of the high-temperature steam to further increase the temperature of the feed water and finally flows back to the boiler. In the compressed steam energy storage system, the fifteenth valve and the thirty-fifth valve are closed, and the energy release process is operated. The high-pressure water at the outlet of the high-pressure steam-water storage tank is first heated and heated by the first heater, and then expanded in the second turbine and the third turbine in turn to generate power. During this period, it is heated and heated again by the second heater. In the heater, the high-pressure water exchanges heat with the heat transfer oil from the high-temperature oil tank to increase the work capacity. After cooling and cooling in the second condenser, it is stored in the atmospheric pressure water tank, and the heat transfer oil after releasing heat and cooling is stored in the low-temperature oil tank. The cooling water after absorbing heat and heating in the second condenser flows back to the cooling tower.

[0014] In the preferred scheme, when the system is in the parity period operation mode, only the coal-fired boiler power generation system is operated. The high-temperature and high-pressure steam at the boiler outlet drives the first steam turbine to generate power and then flows through the first condenser. In the first condenser, the exhaust steam exchanges heat with the cooling water pressurized by the cooling water pump and is cooled into water. The water at the outlet of the first condenser is pressurized by the condensate pump and flows through the low-temperature heater. The cooling water flows back to the cooling tower and absorbs the heat of the low-temperature steam discharged from the first steam turbine in the low-temperature heater. It then flows through the deaerator and opens the tenth valve. The medium-temperature steam at the outlet of the first steam turbine is used to heat the feed water to remove oxygen from the water. The water at the outlet of the deaerator is pressurized by the feed water pump and flows through the high-temperature heater. It absorbs the heat of the high-temperature steam in the high-temperature heater to further increase the temperature of the feed water and finally flows back to the boiler.

[0015] The present invention provides a load regulation system and method for a coal-fired power plant coupled with compressed steam energy storage. By adopting the above structure and method, the system has the following beneficial effects: (1) By deeply integrating coal-fired power plants with compressed steam energy storage systems, efficient response to grid load demand at different times is achieved. During low-power periods, the system converts excess steam generated by coal-fired power plants into compressed energy storage, avoiding the efficiency drop caused by low-load operation of traditional coal-fired units. During peak power periods, the energy storage system quickly releases high-pressure steam to supplement power generation, significantly improving the power plant's ability to adapt to peak and valley fluctuations in the power grid. This dynamic regulation mechanism not only significantly shortens the load response time, but also breaks through the limitations of the peak-shaving range of traditional coal-fired power plants, providing reliable support for the stable operation of the power grid. (2) By optimizing the coordinated operation of coal-fired power generation and energy storage systems, the problem of energy waste under low-load conditions is effectively solved. The system uses the power plant's own working fluid to store and release energy, avoiding the resource consumption of introducing external working fluids. At the same time, the waste heat in the compressor cooling process is recovered through the heat storage cycle and used for steam reheating in the energy release stage, forming a closed-loop utilization of heat energy. This design significantly reduces the heat loss caused by frequent load changes in traditional coal-fired power plants, enabling the units to maintain high-efficiency operation for a long time, and the overall energy utilization rate is systematically improved; (3) The system reduces coal consumption and carbon emissions per unit of power generation by reducing the low-load operation time of coal-fired units. At the same time, it uses energy storage to participate in the peak regulation of the power grid to realize the difference in peak and valley electricity prices, forming a virtuous cycle of environment and economy. In addition, the energy storage system replaces part of the coal-fired power generation demand, further alleviating the environmental pressure of the power plant. It also provides a transformation and upgrading solution with low transformation cost and high return rate for traditional coal-fired power plants, which has broad industrial application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1It is a schematic diagram of the overall structure of the present invention.

[0017] Figure 2 This is a schematic structural diagram of the compression cooling unit of the present invention.

[0018] Figure 3 It is a schematic structural diagram of the expansion and reheating unit of the present invention.

[0019] In the figure: boiler 1, first valve 2, first steam turbine 3, second valve 4, first condenser 5, third valve 6, condensate pump 7, fourth valve 8, low-temperature heater 9, fifth valve 10, deaerator 11, sixth valve 12, feed water pump 13, seventh valve 14, high-temperature heater 15, eighth valve 16, ninth valve 17, tenth valve 18, eleventh valve 19, twelfth valve 20, cooling tower 21, thirteenth valve 22, cooling water pump 23, fourteenth valve 24, fifteenth valve 25, first compressor 26, sixteenth valve 27, first cooler 28, seventeenth valve 29, second compressor 30, eighteenth valve 31, second cooler 32, nineteenth valve 33, high-pressure steam-water storage tank 34 , twentieth valve 35, first heater 36, twenty-first valve 37, second steam turbine 38, twenty-second valve 39, second heater 40, twenty-third valve 41, third steam turbine 42, high-temperature oil tank 43, twenty-fourth valve 44, twenty-fifth valve 45, twenty-sixth valve 46, twenty-seventh valve 47, low-temperature oil tank 48, twenty-eighth valve 49, thirtieth valve 50, thirty-first valve 51, thirty-second valve 52, thirty-third valve 53, second condenser 54, thirty-fourth valve 55, atmospheric water tank 56, thirty-fifth valve 57, water pump 58, thirty-sixth valve 59, thirty-seventh valve 60, thirty-eighth valve 61, compression cooling unit 62, expansion reheat unit 63. DETAILED DESCRIPTION

[0020] Example 1: like Figure 1 A load regulation system for a coal-fired power plant coupled with compressed steam energy storage includes a coal-fired boiler power generation cycle loop, a compressed steam energy storage cycle loop, and a heat storage cycle loop; The coal-fired boiler power generation cycle includes a boiler 1, the boiler 1 outlet is connected to the first steam turbine 3 inlet via a pipeline with a first valve 2, the first steam turbine 3 outlet is connected to the first condenser 5 inlet via a pipeline with a second valve 4, the first condenser 5 outlet is connected to the condensate pump 7 inlet via a pipeline with a third valve 6, the condensate pump 7 outlet is connected to the low-temperature heater 9 inlet via a pipeline with a fourth valve 8, the low-temperature heater 9 outlet is connected to the deaerator 11 inlet via a pipeline with a fifth valve 10, the deaerator 11 outlet is connected to the feedwater pump 13 inlet via a pipeline with a sixth valve 12, the feedwater pump 13 outlet is connected to the high-temperature heater 15 inlet via a pipeline with a seventh valve 14, and the high-temperature heater 15 outlet is connected to the boiler 1 inlet via a pipeline with an eighth valve 16; The compressed steam energy storage cycle includes a first steam turbine 3, the outlet of the first steam turbine 3 is connected to the inlet of the first compressor 26 via a pipeline with a fifteenth valve 25, the outlet of the first compressor 26 is connected to the inlet of the first cooler 28 via a pipeline with a sixteenth valve 27, the outlet of the first cooler 28 is connected to the inlet of the second compressor 30 via a pipeline with a seventeenth valve 29, the outlet of the second compressor 30 is connected to the inlet of the second cooler 32 via a pipeline with an eighteenth valve 31, the outlet of the second cooler 32 is connected to the inlet of the high-pressure steam-water storage tank 34 via a pipeline with a nineteenth valve 33, the outlet of the high-pressure steam-water storage tank 34 is connected to the inlet of the first heater 36 via a pipeline with a twentieth valve 35, and the first heater The outlet of steam turbine 36 is connected to the inlet of second steam turbine 38 via a pipeline with a twenty-first valve 37, the outlet of second steam turbine 38 is connected to the inlet of second heater 40 via a pipeline with a twenty-second valve 39, the outlet of second heater 40 is connected to the inlet of third steam turbine 42 via a pipeline with a twenty-third valve 41, the outlet of third steam turbine 42 is connected to the inlet of second condenser 54 via a pipeline with a thirty-third valve 53, the outlet of second condenser 54 is connected to the inlet of atmospheric water tank 56 via a pipeline with a thirty-fourth valve 55, the outlet of atmospheric water tank 56 is connected to the inlet of water pump 58 via a pipeline with a thirty-fifth valve 57, the outlet of water pump 58 is connected to the inlet of low-temperature heater 9 via a valve with a thirty-sixth valve 59; The heat storage circulation loop includes a low-temperature oil tank 48 and a high-temperature oil tank 43. The outlet of the low-temperature oil tank 48 is connected to the inlet of the first cooler 28 and the inlet of the second cooler 32 via a pipeline with a twenty-sixth valve 46 and a pipeline with a twenty-seventh valve 47 respectively. The inlet of the first cooler 28 and the outlet of the second cooler 32 are connected to the inlet of the second heater 40 via a pipeline with a twenty-fifth valve 45 and a pipeline with a twenty-fourth valve 44 respectively. The outlet of the high-temperature oil tank 43 is connected to the inlet of the first heater 36 and the second heater 40 via a pipeline with a thirty-first valve 51 and a pipeline with a thirty-second valve 52 respectively. The outlets of the first heater 36 and the second heater 40 are connected to the inlet of the low-temperature oil tank 48 via a pipeline with a thirtieth valve 50 and a pipeline with a twenty-eighth valve 49 respectively.

[0021] In a preferred solution, in the coal-fired boiler power generation cycle, the outlet of the first steam turbine 3 is further connected to the inlet of the low-temperature heater 9 via a pipeline with a ninth valve 17 .

[0022] In a preferred solution, in the coal-fired boiler power generation cycle, the outlet of the first steam turbine 3 is further connected to the inlet of the deaerator 11 via a pipeline with a tenth valve 18 .

[0023] In a preferred solution, in the coal-fired boiler power generation cycle, the outlet of the first steam turbine 3 is further connected to the inlet of the high-temperature heater 15 via a pipeline with an eleventh valve 19 .

[0024] In a preferred embodiment, in the coal-fired boiler power generation cycle, the outlet of the first condenser 5 is connected to the inlet of the cooling tower 21 via a pipeline with a twelfth valve 20, the outlet of the cooling tower 21 is connected to the inlet of the cooling water pump 23 via a pipeline with a thirteenth valve 22, and the outlet of the cooling water pump 23 is connected to the inlet of the first condenser 5 via a pipeline with a fourteenth valve 24.

[0025] In a preferred embodiment, in the compressed steam energy storage circulation loop, the outlet of the second condenser 54 is connected to the inlet of the cooling tower 21 and the outlet of the cooling water pump 23 through a pipeline with a thirty-seventh valve 60 and a pipeline with a thirty-eighth valve 61 respectively.

[0026] Example 2: The method for regulating a load regulation system of a coal-fired power plant coupled with compressed steam energy storage described in Example 1 includes a low-peak operation mode, a peak operation mode, and a parity operation mode by deeply coupling the coal-fired boiler power generation system and the compressed steam energy storage system; The off-peak operation mode is as follows: during the off-peak period, the coal-fired boiler power generation system operates normally, and at the same time, part of the exhaust steam from the first steam turbine 3 flows into the compressed steam energy storage system to drive the first compressor 26 and the second compressor 30 to store excess electricity, and the water flow reduced in the power generation cycle is replenished through the atmospheric pressure water tank 56; Specifically, the peak operation mode is as follows: during peak electricity consumption periods, the coal-fired boiler power generation system operates normally, while the compressed steam energy storage system operates to release high-pressure steam to drive the second steam turbine 38 and the third steam turbine 42 to generate power, thereby making up for the load gap of the power generation system; The specific operation mode during the parity period is: during the period of electricity consumption parity, only the coal-fired boiler power generation system is operated, while the compressed steam energy storage system is stationary.

[0027] Example 3: Based on Example 2, in a coal-fired boiler power generation system when the system is in the off-peak operation mode, the high-temperature and high-pressure steam at the outlet of the boiler 1 drives the first steam turbine 3 to generate power and then flows through the first condenser 5. In the first condenser 5, the exhaust steam at the outlet of the first steam turbine 3 exchanges heat with the cooling water pressurized by the cooling water pump 23, and is cooled and cooled into water. The water at the outlet of the first condenser 5 is pressurized by the condensate pump 7 and flows through the low-temperature heater 9. The cooling water then flows back to the cooling tower 21. In the low-temperature heater 9, it absorbs the low-temperature steam discharged from the first steam turbine 3 to increase the water temperature. Then, it flows through the deaerator 11, and the tenth valve 18 is opened. The medium-temperature steam at the outlet of the first steam turbine 3 is used to heat the feed water and remove oxygen from the water. The water at the outlet of the deaerator 11 is pressurized by the feed water pump 13 and flows through the high-temperature heater 15. In the high-temperature heater 15, it absorbs the heat of the high-temperature steam and increases the temperature of the feed water, thereby increasing its temperature when entering the boiler 1 and improving the steam generation efficiency. In the compressed steam energy storage system, the fifteenth valve 25 is opened to allow the low-temperature, low-pressure exhaust steam at the outlet of the first steam turbine 3 to flow through the compressed steam energy storage system, driving the energy storage process. The low-pressure steam flows through the first compressor 26 and the second compressor 30 in sequence and is compressed into high-temperature, high-pressure steam. The high-temperature, high-pressure steam at the outlets of the first compressor 26 and the second compressor 30 flows through the first cooler 28 and the second cooler 32 respectively, exchanges heat with the low-temperature heat transfer oil from the low-temperature oil tank 48 and cools it into a steam-water mixture, and is finally stored in the high-pressure steam-water storage tank 34. The heat transfer oil that absorbs heat and heats up is stored in the high-temperature oil tank 43. The thirty-fifth valve 57 is opened to release the water in the atmospheric pressure water tank 56. After being pressurized by the water pump 58, it is mixed with the water at the outlet of the first condenser 5 and flows into the low-temperature heater 9 to replenish water for the coal-fired boiler power generation cycle.

[0028] In addition, when the system power load changes, combined with Figure 2 , the number of stages of the compression cooling unit 62 can be adjusted to meet the system requirements.

[0029] During these low periods, coal-fired units maintain full load operation to prevent efficiency degradation. Meanwhile, the energy storage system converts a certain percentage of exhaust steam into high-pressure water for storage, providing energy reserves for peak periods.

[0030] Example 4: Based on Example 2, the coal-fired boiler power generation system operates normally when the system is in the peak operation mode. The high-temperature and high-pressure steam at the outlet of the boiler 1 drives the first steam turbine 3 to generate power and then flows through the first condenser 5. In the first condenser 5, the exhaust steam exchanges heat with the cooling water pressurized by the cooling water pump 23 and is cooled into water. The water at the outlet of the first condenser 5 is pressurized by the condensate pump 7 and flows through the low-temperature heater 9. The cooling water then flows back to the cooling tower 21, absorbs the heat of the low-temperature steam discharged from the first steam turbine 3 in the low-temperature heater 9, and then flows through the deaerator 11. The tenth valve 18 is opened, and the medium-temperature steam at the outlet of the first steam turbine 3 is used to heat the feed water and remove oxygen from the water. The water at the outlet of the deaerator 11 is pressurized by the feed water pump 13 and flows through the high-temperature heater 15. In the high-temperature heater 15, the heat of the high-temperature steam is absorbed to further increase the temperature of the feed water, and finally flows back to the boiler 1. In the compressed steam energy storage system, the fifteenth valve 25 and the thirty-fifth valve 57 are closed, and the energy release process is operated. The high-pressure water at the outlet of the high-pressure steam-water storage tank 34 is first heated and heated by the first heater 36, and then expanded in the second steam turbine 38 and the third steam turbine 42 in turn to generate power. During this period, it is heated and heated again by the second heater 40. In the heater, the high-pressure water exchanges heat with the heat transfer oil from the high-temperature oil tank 43 to increase the work capacity. After cooling and cooling in the second condenser 54, it is stored in the atmospheric water tank 56, and the heat transfer oil after releasing heat and cooling is stored in the low-temperature oil tank 48. The cooling water after absorbing heat and heating in the second condenser 54 flows back to the cooling tower 21.

[0031] In addition, when the system power load changes, combined with Figure 3 , the system requirements can be met by adjusting the number of expansion and reheating units 63.

[0032] During the above-mentioned peak period, the total output power of coal-fired units was effectively improved, and was able to quickly respond to grid demand.

[0033] In addition, the heat storage system realizes the cascade utilization of thermal energy, reducing the additional energy consumption of steam reheating.

[0034] Example 5: Based on Example 2, when the system is in the parity period operation mode, only the coal-fired boiler power generation system is operated. The high-temperature and high-pressure steam at the outlet of the boiler 1 drives the first steam turbine 3 to generate power and then flows through the first condenser 5. In the first condenser 5, the exhaust steam exchanges heat with the cooling water pressurized by the cooling water pump 23, and is cooled and cooled into water. The water at the outlet of the first condenser 5 is pressurized by the condensate pump 7 and flows through the low-temperature heater 9. The cooling water then flows back to the cooling tower 21, absorbs the heat of the low-temperature steam discharged from the first steam turbine 3 in the low-temperature heater 9, and then flows through the deaerator 11. The tenth valve 18 is opened, and the medium-temperature steam at the outlet of the first steam turbine 3 is used to heat the feed water to remove oxygen in the water. The water at the outlet of the deaerator 11 is pressurized by the feed water pump 13 and flows through the high-temperature heater 15. In the high-temperature heater 15, the heat of the high-temperature steam is absorbed to further increase the temperature of the feed water, and finally flows back to the boiler 1.

[0035] During the above-mentioned parity period, coal-fired units flexibly adjust their load as needed without any additional energy storage consumption.

Claims

1. A load regulation system for a coal-fired power plant coupled with compressed steam energy storage, characterized by: It includes a coal-fired boiler power generation cycle, a compressed steam energy storage cycle, and a heat storage cycle; The coal-fired boiler power generation cycle includes a boiler, the boiler outlet is connected to the first steam turbine inlet, the first steam turbine outlet is connected to the first condenser inlet, the first condenser outlet is connected to the condensate pump inlet, the condensate pump outlet is connected to the low-temperature heater inlet, the low-temperature heater outlet is connected to the deaerator inlet, the deaerator outlet is connected to the feedwater pump inlet, the feedwater pump outlet is connected to the high-temperature heater inlet, and the high-temperature heater outlet is connected to the boiler inlet; The compressed steam energy storage cycle includes a first steam turbine, the first steam turbine outlet is connected to the first compressor inlet, the first compressor outlet is connected to the first cooler inlet, the first cooler outlet is connected to the second compressor inlet, the second compressor outlet is connected to the second cooler inlet, the second cooler outlet is connected to the high-pressure steam-water storage tank inlet, the high-pressure steam-water storage tank outlet is connected to the first heater inlet, the first heater outlet is connected to the second steam turbine inlet, the second steam turbine outlet is connected to the second heater inlet, the second heater outlet is connected to the third steam turbine inlet, the third steam turbine outlet is connected to the second condenser inlet, the second condenser outlet is connected to the atmospheric water tank inlet, the atmospheric water tank outlet is connected to the water pump inlet, and the water pump outlet is connected to the low-temperature heater inlet; The heat storage circulation loop includes a low-temperature oil tank and a high-temperature oil tank, the low-temperature oil tank outlet is respectively connected to the first cooler inlet and the second cooler inlet, the first cooler inlet and the second cooler outlet are respectively connected to the second heater inlet, the high-temperature oil tank outlet is respectively connected to the first heater and the second heater inlet, and the first heater and the second heater outlet are respectively connected to the low-temperature oil tank inlet.

2. A load regulation system for a coal-fired power plant coupled with compressed steam energy storage according to claim 1, characterized in that: In the coal-fired boiler power generation cycle, the first steam turbine outlet is also connected to the low-temperature heater inlet.

3. The load regulation system for a coal-fired power plant coupled with compressed steam energy storage according to claim 1, characterized in that: In the coal-fired boiler power generation cycle, the first steam turbine outlet is also connected to the deaerator inlet.

4. The load regulation system for a coal-fired power plant coupled with compressed steam energy storage according to claim 1, characterized in that: In the coal-fired boiler power generation cycle, the first steam turbine outlet is also connected to the high-temperature heater inlet.

5. The load regulation system for a coal-fired power plant coupled with compressed steam energy storage according to claim 1, characterized in that: In the coal-fired boiler power generation cycle, the first condenser outlet is connected to the cooling tower inlet, the cooling tower outlet is connected to the cooling water pump inlet, and the cooling water pump outlet is connected to the first condenser inlet.

6. The load regulation system for a coal-fired power plant coupled with compressed steam energy storage according to claim 1, characterized in that: In the compressed steam energy storage circulation loop, the outlet of the second condenser is connected to the inlet of the cooling tower and the outlet of the cooling water pump respectively.

7. A method for regulating a load regulation system of a coal-fired power plant coupled with compressed steam energy storage according to any one of claims 1 to 6, characterized in that: By deeply coupling the coal-fired boiler power generation system and the compressed steam energy storage system, including off-peak operation mode, peak operation mode and parity operation mode; Specifically, the off-peak operation mode is as follows: during the off-peak period, the coal-fired boiler power generation system operates normally, while part of the exhaust steam from the first steam turbine flows into the compressed steam energy storage system to drive the first compressor and the second compressor to store excess electricity. The water flow reduced in the power generation cycle is replenished through the atmospheric pressure water tank; Specifically, the peak operation mode is as follows: during peak electricity consumption periods, the coal-fired boiler power generation system operates normally, while the compressed steam energy storage system operates to release high-pressure steam to drive the second and third steam turbines to generate power, thereby filling the load gap of the power generation system; The specific operation mode during the parity period is: during the period of electricity consumption parity, only the coal-fired boiler power generation system is operated, while the compressed steam energy storage system is stationary.

8. The method for regulating a load regulation system of a coal-fired power plant coupled with compressed steam energy storage according to claim 7, characterized in that: In the coal-fired boiler power generation system when the system is in the off-peak operation mode, the high-temperature and high-pressure steam at the boiler outlet drives the first steam turbine to generate power and then flows through the first condenser. In the first condenser, the exhaust steam at the first steam turbine outlet exchanges heat with the cooling water pressurized by the cooling water pump, and is cooled and cooled into water. The water at the first condenser outlet is pressurized by the condensate pump and flows through the low-temperature heater. The cooling water then flows back to the cooling tower, absorbs the low-temperature steam discharged from the first steam turbine in the low-temperature heater to increase the water temperature, and then flows through the deaerator. The valve between the first steam turbine outlet and the deaerator inlet is opened, and the medium-temperature steam at the first steam turbine outlet is used to heat the feed water and remove oxygen from the water. The water at the deaerator outlet is pressurized by the feed water pump and flows through the high-temperature heater, absorbs the heat of the high-temperature steam and increases the temperature of the feed water in the high-temperature heater, thereby increasing its temperature when entering the boiler and improving the steam generation efficiency. In the compressed steam energy storage system, the valve between the first turbine outlet and the first compressor inlet is opened to allow the low-temperature and low-pressure exhaust steam at the first turbine outlet to flow through the compressed steam energy storage system, driving the energy storage process. The low-pressure steam flows through the first compressor and the second compressor in sequence and is compressed into high-temperature and high-pressure steam. The high-temperature and high-pressure steam at the outlets of the first compressor and the second compressor respectively flows through the first cooler and the second cooler, exchanges heat with the low-temperature heat transfer oil from the low-temperature oil tank and cools it into a steam-water mixed state, and is finally stored in the high-pressure steam-water storage tank. The heat transfer oil that absorbs heat and heats up is stored in the high-temperature oil tank. The valve between the atmospheric pressure water tank outlet and the water pump inlet is opened to release the water in the atmospheric pressure water tank. After being pressurized by the water pump, it is mixed with the water at the outlet of the first condenser and flows into the low-temperature heater to replenish water for the coal-fired boiler power generation cycle.

9. The method for regulating a load regulation system of a coal-fired power plant coupled with compressed steam energy storage according to claim 7, characterized in that: The coal-fired boiler power generation system operates normally when the system is in the peak operation mode. The high-temperature and high-pressure steam at the boiler outlet drives the first steam turbine to generate power and then flows through the first condenser. In the first condenser, the exhaust steam exchanges heat with the cooling water pressurized by the cooling water pump and is cooled and cooled into water. The water at the outlet of the first condenser is pressurized by the condensate pump and flows through the low-temperature heater. The cooling water then flows back to the cooling tower and absorbs the heat of the low-temperature steam discharged from the first steam turbine in the low-temperature heater. It then flows through the deaerator, and the valve between the outlet of the first steam turbine and the inlet of the deaerator is opened. The medium-temperature steam at the outlet of the first steam turbine is used to heat the feed water and remove oxygen from the water. The water at the outlet of the deaerator is pressurized by the feed water pump and flows through the high-temperature heater. It absorbs the heat of the high-temperature steam in the high-temperature heater to further increase the temperature of the feed water and finally flows back to the boiler. In the compressed steam energy storage system, the valve between the first turbine outlet and the first compressor inlet, and the valve between the atmospheric pressure water tank outlet and the water pump are closed, and the energy release process is operated. The high-pressure water at the high-pressure steam-water storage tank outlet is first heated and heated by the first heater, and then expanded in the second turbine and the third turbine in turn to generate power. During this period, it is heated and heated again by the second heater. In the heater, the high-pressure water exchanges heat with the heat transfer oil from the high-temperature oil tank to increase the work capacity. After being cooled and cooled by the second condenser, it is stored in the atmospheric pressure water tank, and the heat transfer oil after releasing heat and cooling is stored in the low-temperature oil tank. The cooling water after absorbing heat and heating in the second condenser flows back to the cooling tower.

10. The method for regulating a load regulation system of a coal-fired power plant coupled with compressed steam energy storage according to claim 7, characterized in that: When the system is in the parity period operation mode, only the coal-fired boiler power generation system is operated. The high-temperature and high-pressure steam at the boiler outlet drives the first steam turbine to generate power and then flows through the first condenser. In the first condenser, the exhaust steam exchanges heat with the cooling water pressurized by the cooling water pump and is cooled into water. The water at the outlet of the first condenser is pressurized by the condensate pump and flows through the low-temperature heater. The cooling water flows back to the cooling tower and absorbs the heat of the low-temperature steam discharged from the first steam turbine in the low-temperature heater. It then flows through the deaerator. The valve between the outlet of the first steam turbine and the inlet of the deaerator is opened, and the medium-temperature steam at the outlet of the first steam turbine is used to heat the feed water to remove oxygen from the water. The water at the outlet of the deaerator is pressurized by the feed water pump and flows through the high-temperature heater. It absorbs the heat of the high-temperature steam in the high-temperature heater to further increase the temperature of the feed water and finally flows back to the boiler.

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