A solar-coal dual-heat source energy storage complementary flexible power generation system and operation method

Abstract

The present invention discloses a solar-fired coal-fired dual-heat source energy storage complementary flexible power generation system and an operation method, the system comprises a coal-fired thermal power generation system and a solar-fired coal-fired dual-heat source heat storage system consisting of a cold salt tank, an oil-salt heat exchanger, a brine heat exchanger, a steam molten salt heat exchanger, a hot salt tank, a solar collector, and an oil-water heat exchanger; the oil-water heat exchanger is connected in parallel with the oil-salt heat exchanger and the brine heat exchanger respectively; the oil-salt heat exchanger and the steam molten salt heat exchanger are connected in series to achieve simultaneous storage of solar energy and main / reheat steam heat; the power generation stability when the light suddenly changes is controlled by adjusting the heat transfer oil regulating valve, the speed of the cold / hot salt pump, the solar water supply regulating valve and the No. 1 water supply regulating valve; the unit can achieve rapid and efficient load change by adjusting the main / reheat steam regulating valve, the speed of the cold / hot salt pump, the molten salt regulating valve, the water supply pump and the No. 2 water supply regulating valve; the present invention can realize solar-fired coal-fired dual-heat source heat storage, flexible coupling of light and coal storage and energy utilization across time and space, thereby improving the efficient and flexible operation capability of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of multi-energy complementary power generation, and in particular to a solar-coal dual-heat source energy storage complementary flexible power generation system and an operation method thereof. Background Art

[0002] my country is developing a large amount of renewable energy. However, due to the strong intermittent nature of wind and solar power, the integration of large-scale photovoltaic and wind power generation into the grid has exacerbated grid voltage and frequency fluctuations, necessitating further improvements in the grid's peak-shaving capacity. This requires greater flexibility in coal-fired and solar thermal power generation systems to meet the grid's peak-shaving and frequency-regulating needs. This also requires addressing the high initial investment in CSP and the high coal consumption of coal-fired power plants. Coupling solar power with coal-fired power generation can improve CSP efficiency and reduce coal consumption in coal-fired units. However, there is currently no reasonable solar-coal coupling solution that allows the system to meet the grid's rapid and frequent peak-shaving and frequency-regulating requirements while operating efficiently and flexibly. A safer, more efficient, and more flexible solar-coal coupling solution is needed to ensure that solar and coal-fired power generation can coordinate with each other under varying solar radiation intensity and grid load commands, improving the system's load-shaving rate and ensuring accurate and rapid follow-up of grid commands under varying solar radiation intensities, ensuring efficient and flexible operation. Summary of the Invention

[0003] In order to solve the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a solar-coal dual-heat source energy storage complementary flexible power generation system and an operation method. The system realizes the flexible coupling of coal-fired power generation and solar thermal power generation. The heat storage device can simultaneously store the heat of the solar system and the main steam, quickly offset the impact of light changes on the operating stability of the coal-fired thermal power generation system, realize the decoupling of the machine and the boiler, and enable the solar-coal dual-heat source energy storage complementary flexible power generation system under different light conditions to quickly and significantly change the load, and can also smoothly cope with the impact of light on the output power stability, while reducing the amount of coal and improving economy.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A solar-coal dual heat source energy storage complementary flexible power generation system, comprising a coal-fired thermal power generation system and a solar-coal dual heat source energy storage system: wherein,

[0006] The coal-fired thermal power generation system includes a boiler 1, a steam turbine high-pressure cylinder 2, a steam turbine medium- and low-pressure cylinders 3, a condenser 4, a condensate pump 5, a low-pressure heater 6, a deaerator 7, a feed water pump 8 and a high-pressure heater 9 which are connected in sequence; the superheated steam outlet of the boiler 1 is connected to the inlet of the steam turbine high-pressure cylinder 2; the water working medium inlet of the boiler 1 is connected to the water working medium outlet of the high-pressure heater 9; the steam outlet of the steam turbine high-pressure cylinder 2 is connected to the reheated steam inlet of the boiler 1 through a pipeline, and the extraction steam outlet of the steam turbine high-pressure cylinder 2 is connected to the steam inlet of the high-pressure heater 9 through a pipeline; the reheated steam outlet of the boiler 1 is connected to the steam inlet of the high-pressure heater 9 through a pipeline The steam outlet is connected to the steam inlet of the medium and low pressure cylinders 3 of the steam turbine; the first stage extraction steam outlet of the medium and low pressure cylinders 3 of the steam turbine is connected to the steam inlet of the deaerator 7 through a pipeline, and the second stage extraction steam outlet is connected to the steam inlet of the low pressure heater 6 through a pipeline; the water working medium outlet of the deaerator 7 is connected to the high pressure heater 9 through the feed water pump 8; the steam outlet of the medium and low pressure cylinders 3 of the steam turbine is connected to the steam inlet of the condenser 4; the water working medium outlet of the condenser 4 is connected to the water working medium inlet of the low pressure heater 6 through the condensate pump 5; the water working medium outlet of the low pressure heater 6 is connected to the water working medium inlet of the deaerator 7;

[0007] The solar-coal-fired dual-heat source heat storage system includes a cold salt tank 18, a cold salt pump 19, an oil-salt heat exchanger 13, a steam molten salt heat exchanger 14, a hot salt tank 15, a hot salt pump 16 and a brine heat exchanger group 17 connected in sequence; it also includes a solar collector 11 and an oil-water heat exchanger 12; the water working medium inlet of the oil-water heat exchanger 12 is connected to the outlet of the water pump 8 through a solar water supply regulating valve 10, the water working medium outlet is connected to the water supply inlet of the boiler 1 through a pipeline, the heat transfer oil inlet is connected to the heat transfer oil outlet of the solar collector 11 through a pipeline, and the heat transfer oil outlet is connected to the heat transfer oil inlet of the solar collector 11 through a pipeline; the heat transfer oil inlet of the oil-salt heat exchanger 13 is connected to the heat transfer oil outlet of the solar collector 11 through a heat transfer oil regulating valve 23, the heat transfer oil outlet is connected to the heat transfer oil inlet of the solar collector 11 through a pipeline, and the molten salt inlet is connected to the cold salt The pump 19 is connected to the molten salt outlet of the cold salt tank 18, and the molten salt outlet is connected to the molten salt inlet of the steam molten salt heat exchanger 14 through a pipeline; the steam inlet of the steam molten salt heat exchanger 14 is connected to the main steam outlet of the boiler 1 through the main steam regulating valve 20, the steam inlet is connected to the reheat steam outlet of the boiler 1 through the reheat steam regulating valve 24, the steam outlet is connected to the cold reheat steam inlet of the boiler 1 through a pipeline, and the molten salt outlet is connected to the molten salt inlet of the hot salt tank 15 through a pipeline; the molten salt inlet of the brine heat exchanger group 17 is connected to the molten salt outlet of the hot salt tank 15 through the hot salt pump 16, the molten salt outlet is connected to the molten salt inlet of the cold salt tank 18 through a pipeline, the water working medium inlet is connected to the water working medium outlet of the feed water pump 8 through a pipeline, the water working medium outlet is connected to the water working medium inlet of the boiler 1 through a pipeline, and the steam outlet is connected to the steam inlets of the medium and low pressure cylinders 3 of the steam turbine through pipelines.

[0008] The brine heat exchanger group 17 includes a brine heat exchanger 171 and a brine steam generator 172; the molten salt inlet of the brine heat exchanger 171 is connected to the hot salt tank 15 through the hot salt pump 16, the molten salt outlet is connected to the molten salt inlet of the cold salt tank 18 through a pipeline, the water working medium inlet is connected to the water working medium outlet of the feed water pump 8 through the No. 1 feed water regulating valve 21, and the water working medium outlet is connected to the feed water working medium inlet of the boiler 1 through a pipeline; the molten salt inlet of the brine steam generator 172 is connected to the molten salt inlet of the brine heat exchanger 171 through the molten salt regulating valve 173, the molten salt outlet is connected to the molten salt outlet of the brine heat exchanger 171 through a pipeline, the water working medium inlet is connected to the water working medium outlet of the feed water pump 8 through the No. 2 feed water regulating valve 22, and the steam outlet is connected to the medium and low pressure cylinders 3 of the steam turbine through pipelines.

[0009] The operating temperature of the molten salt is 150°C to 580°C.

[0010] The operating temperature of the heat transfer oil is 180°C to 390°C.

[0011] The heat transfer medium in the hot salt tank 15 and the cold salt tank 18 is ternary salt, 20% LiNO3+52% KNO3+28% NaNO3.

[0012] The solar heat collector 11 is composed of a plurality of solar heat collecting tubes 111 which are first connected in series and then in parallel.

[0013] The above-mentioned method for operating a solar-fired coal-fired dual-heat source energy storage complementary flexible power generation system is as follows: when the solar radiation intensity suddenly increases, the opening of the solar water supply regulating valve 10 is increased to adjust the water flow entering the oil-water heat exchanger 12, and the opening of the thermal oil regulating valve 23 is increased to adjust the thermal oil flow entering the oil-salt heat exchanger 13. At the same time, the speed of the cold salt pump 19 is adjusted to adjust the molten salt flow entering the oil-salt heat exchanger 13. The adjustment target is to keep the outlet temperature of the water medium of the oil-water heat exchanger 12 consistent with the outlet temperature of the high-pressure heater 9. , maintain the stable power generation power of the coal-fired thermal power generation system; when the solar radiation intensity drops suddenly, reduce the opening of the solar water supply regulating valve 10 to adjust the water flow entering the oil-water heat exchanger 12, open and increase the opening of the No. 1 water supply regulating valve 21 to adjust the water flow entering the brine heat exchanger 171, and at the same time adjust the speed of the hot salt pump 16 to adjust the hot molten salt flow entering the brine heat exchanger 171. The adjustment target is to keep the water temperature entering the boiler 1 unchanged and maintain the power of the coal-fired thermal power generation system stable; when the coal-fired thermal power generation system When the load needs to be reduced quickly, the opening of the main steam regulating valve 20 and the reheat steam regulating valve 24 is increased, and the molten salt flow entering the steam molten salt heat exchanger 14 is adjusted by adjusting the speed of the cold salt pump 19. At the same time, the opening of the solar water supply regulating valve 10 is adjusted. The adjustment target is to quickly reduce the main steam flow entering the high-pressure cylinder 2 of the steam turbine and the reheat steam flow entering the medium and low-pressure cylinders 3 of the steam turbine. The power reduction rate of the coal-fired thermal power generation system meets the requirements of the power grid and is highly efficient. When the coal-fired thermal power generation system needs to increase the load quickly, increase the hot salt pump 19. The speed of pump 16 adjusts the molten salt flow entering the brine heat exchanger group 17, and the opening of the molten salt regulating valve 173 is increased to adjust the hot molten salt flow entering the brine steam generator 172. At the same time, the speed of the feed water pump 8 is increased and the opening of the No. 2 feed water regulating valve 22 is increased to increase the water flow entering the brine steam generator 172. The adjustment target is that the steam flow rate at which the brine steam generator 172 generates steam and enters the medium and low pressure cylinders 3 of the steam turbine to perform work can meet the load increase rate requirements of the coal-fired thermal power generation system, thereby achieving rapid and efficient load increase.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] (1) The present invention connects an oil-salt heat exchanger in series with a steam molten salt heat exchanger, and connects the oil-salt heat exchanger in parallel with an oil-water heat exchanger, so that the energy of the dual heat sources of solar energy and main steam can be stored in a hot salt tank at the same time under the conditions of load reduction or high solar radiation intensity. The water working medium is then heated by heat exchange through a salt water steam generator and a salt water heat exchanger to generate high-temperature steam or water, which is then returned to the coal-fired thermal power generation system, so that the heat in the hot molten salt can be supplemented to the coal-fired thermal power generation system to quickly increase the load or cope with changes in the reduction of solar radiation intensity, which is conducive to realizing the cascade utilization of energy of the complementary system and meeting the needs of rapid load change of the power grid when the solar radiation intensity changes.

[0016] (2) The present invention controls the ratio of the thermal oil used to heat the water working medium and the molten salt working medium by adjusting the valve opening of the thermal oil regulating valve, which is beneficial to maintaining the operational stability of the coal-fired thermal power generation system when the intensity of solar radiation changes; and controls the ratio of the molten salt and thermal oil used to heat the water working medium by adjusting the opening of the No. 1 feed water regulating valve, which is beneficial to maintaining the safe and stable operation of the coal-fired thermal power generation system when the intensity of solar radiation suddenly decreases.

[0017] (3) The present invention adjusts the steam flow entering the high-pressure cylinder of the steam turbine by adjusting the opening of the main steam regulating valve (20), and adjusts the flow entering the steam molten salt heat exchanger by matching the speed of the cold salt pump, thereby achieving rapid load reduction, and at the same time storing the heat of the main steam to achieve cross-temporal and spatial energy utilization; by adjusting the opening of the molten salt regulating valve and the No. 2 feed water regulating valve, the flow and rate of steam generated by the molten salt heating water working medium are controlled, thereby increasing the flow of working steam entering the medium and low-pressure cylinders of the steam turbine, achieving rapid load increase, meeting the needs of rapid and efficient peak and frequency regulation of the power grid, and operating efficiently and flexibly. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the solar-coal dual heat source energy storage complementary flexible power generation system of the present invention. DETAILED DESCRIPTION

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] like Figure 1 As shown, the present invention provides a solar-coal dual heat source energy storage complementary flexible power generation system, including a coal-fired thermal power generation system and a solar-coal dual heat source heat storage system: wherein,

[0021] The coal-fired thermal power generation system includes a boiler 1, a steam turbine high-pressure cylinder 2, a steam turbine medium- and low-pressure cylinders 3, a condenser 4, a condensate pump 5, a low-pressure heater 6, a deaerator 7, a feed water pump 8, and a high-pressure heater 9, which are connected in sequence; the superheated steam outlet of the boiler 1 is connected to the inlet of the steam turbine high-pressure cylinder 2; the water working medium inlet of the boiler 1 is connected to the water working medium outlet of the high-pressure heater 9; the steam outlet of the steam turbine high-pressure cylinder 2 is connected to the reheated steam inlet of the boiler 1 through a pipeline, and the extraction steam outlet of the steam turbine high-pressure cylinder 2 is connected to the steam inlet of the high-pressure heater 9 through a pipeline; the reheated steam outlet of the boiler 1 is connected to the steam inlet of the high-pressure heater 9 through a pipeline The steam outlet is connected to the steam inlet of the medium and low pressure cylinders 3 of the steam turbine; the first stage extraction steam outlet of the medium and low pressure cylinders 3 of the steam turbine is connected to the steam inlet of the deaerator 7 through a pipeline, and the second stage extraction steam outlet is connected to the steam inlet of the low pressure heater 6 through a pipeline; the water working medium outlet of the deaerator 7 is connected to the high pressure heater 9 through the feed water pump 8; the steam outlet of the medium and low pressure cylinders 3 of the steam turbine is connected to the steam inlet of the condenser 4; the water working medium outlet of the condenser 4 is connected to the water working medium inlet of the low pressure heater 6 through the condensate pump 5; the water working medium outlet of the low pressure heater 6 is connected to the water working medium inlet of the deaerator 7;

[0022] The solar-coal-fired dual-heat source heat storage system includes a cold molten salt tank 18, a cold salt pump 19, an oil-salt heat exchanger 13, a steam molten salt heat exchanger 14, a hot salt tank 15, a hot salt pump 16, and a brine heat exchanger group 17, which are connected in sequence; it also includes a solar collector 11 and an oil-water heat exchanger 12; the water working medium inlet of the oil-water heat exchanger 12 is connected to the outlet of the water pump 8 through a solar water supply regulating valve 10, the water working medium outlet is connected to the water supply inlet of the boiler 1 through a pipeline, the heat transfer oil inlet is connected to the heat transfer oil outlet of the solar collector 11 through a pipeline, and the heat transfer oil The oil outlet is connected to the heat transfer oil inlet of the solar thermal collector 11 through a pipeline, which can realize the use of solar energy heat to heat the feed water, replacing part of the steam extraction of the high-pressure cylinder 2 of the steam turbine, which helps the system save coal consumption and improve power; the heat transfer oil inlet of the oil-salt heat exchanger 13 is connected to the heat transfer oil outlet of the solar thermal collector 11 through a heat transfer oil regulating valve 23, the heat transfer oil outlet is connected to the heat transfer oil inlet of the solar thermal collector 11 through a pipeline, the molten salt inlet is connected to the molten salt outlet of the cold salt tank 18 through the cold salt pump 19, and the molten salt outlet is connected to the steam molten salt exchanger The molten salt inlet of the heat exchanger 14 is connected through a pipeline; the oil-salt heat exchanger 13 is arranged in parallel with the oil-water heat exchanger 12, which helps to flexibly control the heat of the solar-collected water, while storing excess solar energy and improving energy utilization efficiency; the steam inlet of the steam molten salt heat exchanger 14 is connected to the main steam outlet of the boiler 1 through the main steam regulating valve 20, the steam inlet is connected to the reheat steam outlet of the boiler 1 through the reheat steam regulating valve 24, the steam outlet is connected to the cold reheat steam inlet of the boiler 1 through a pipeline, and the molten salt outlet is connected to the molten salt inlet of the hot salt tank 15 The molten salt inlet of the brine heat exchanger group 17 is connected to the molten salt outlet of the hot salt tank 15 through the hot salt pump 16, the molten salt outlet is connected to the molten salt inlet of the cold salt tank 18 through a pipe, the water working medium inlet is connected to the water working medium outlet of the feed water pump 8 through a pipe, the water working medium outlet is connected to the water working medium inlet of the boiler 1 through a pipe, and the steam outlet is connected to the steam inlet of the medium and low pressure cylinder 3 of the steam turbine through a pipe; the steam molten salt heat exchanger and the oil-salt heat exchanger are arranged in series to increase the temperature zone for heat storage of solar energy and main steam reheat steam, thereby improving energy utilization.

[0023] As a preferred embodiment of the present invention, the brine heat exchanger group 17 includes a brine heat exchanger 171 and a brine steam generator 172; the molten salt inlet of the brine heat exchanger 171 is connected to the hot salt tank 15 through the hot salt pump 16, the molten salt outlet is connected to the molten salt inlet of the cold salt tank 18 through a pipeline, the water working medium inlet is connected to the water working medium outlet of the feed water pump 8 through the No. 1 feed water regulating valve 21, and the water working medium outlet is connected to the feed water working medium inlet of the boiler 1 through a pipeline; the molten salt inlet of the brine steam generator 172 is connected to the molten salt inlet of the brine heat exchanger 171 through the molten salt regulating valve 173, the molten salt outlet is connected to the molten salt outlet of the brine heat exchanger 171 through a pipeline, the water working medium inlet is connected to the water working medium outlet of the feed water pump 8 through the No. 2 feed water regulating valve 22, and the steam outlet is connected to the medium and low pressure cylinders 3 of the turbine through pipelines.

[0024] As a preferred embodiment of the present invention, the operating temperature of the molten salt is 150°C to 580°C, which is between the maximum steam temperature in the coal-fired unit and the operating temperature of the thermal oil. It can effectively store the thermal energy of solar energy, main steam and reheated steam.

[0025] As a preferred embodiment of the present invention, the operating temperature of the heat transfer oil is 180° C. to 390° C., ensuring that the operating temperature of the heat transfer oil can safely meet the requirements for heating water supply.

[0026] As a preferred embodiment of the present invention, the heat transfer medium in the hot salt tank 15 and the cold salt tank 18 is ternary salt, 20% LiNO3+52% KNO3+28% NaNO3, which has a wide operating temperature range and low cost, and is suitable for storing solar energy, main steam heat energy and reheat steam heat energy.

[0027] As a preferred embodiment of the present invention, the solar thermal collector 11 is composed of a plurality of solar thermal collecting tubes 111 connected in series and then in parallel, which is conducive to fully absorbing solar heat.

[0028] like Figure 1As shown, the operating method of the solar-coal dual heat source energy storage complementary flexible power generation system of the present invention is that when the solar radiation intensity suddenly increases, the opening of the solar water supply regulating valve 10 is increased to regulate the water flow entering the oil-water heat exchanger 12, and the opening of the thermal oil regulating valve 23 is increased to regulate the thermal oil flow entering the oil-salt heat exchanger 13. At the same time, the speed of the cold salt pump 19 is adjusted to regulate the molten salt flow entering the oil-salt heat exchanger 13. The adjustment target is to keep the water outlet temperature of the oil-water heat exchanger 12 and the outlet temperature of the high-pressure heater 9 The power generation capacity of the coal-fired thermal power generation system is kept stable; when the solar radiation intensity drops suddenly, the opening of the solar water supply regulating valve 10 is reduced to adjust the water flow entering the oil-water heat exchanger 12, and the opening of the No. 1 water supply regulating valve 21 is opened and increased to adjust the water flow entering the brine heat exchanger 171. At the same time, the speed of the hot salt pump 16 is adjusted to adjust the hot molten salt flow entering the brine heat exchanger 171. The adjustment target is to keep the water temperature entering the boiler 1 unchanged and maintain the power of the coal-fired thermal power generation system stable; when the coal-fired thermal power generation system When the system needs to reduce the load quickly, increase the opening of the main steam regulating valve 20 and the reheat steam regulating valve 24, adjust the molten salt flow entering the steam molten salt heat exchanger 14 by adjusting the speed of the cold salt pump 19, and adjust the opening of the solar water supply regulating valve 10 at the same time. The adjustment target is to quickly reduce the main steam flow entering the high-pressure cylinder 2 of the steam turbine and the reheat steam flow entering the medium and low-pressure cylinders 3 of the steam turbine. The power reduction rate of the coal-fired thermal power generation system meets the requirements of the power grid and is highly efficient. When the coal-fired thermal power generation system needs to increase the load quickly, increase the heat The speed of the salt pump 16 adjusts the molten salt flow entering the brine heat exchanger group 17, and the opening of the molten salt regulating valve 173 is increased to adjust the hot molten salt flow entering the brine steam generator 172. At the same time, the speed of the feed water pump 8 is increased and the opening of the No. 2 feed water regulating valve 22 is increased to increase the water flow entering the brine steam generator 172. The adjustment target is that the steam flow rate at which the brine steam generator 172 generates steam and enters the medium and low pressure cylinders 3 of the steam turbine to perform work can meet the load increase rate requirements of the coal-fired thermal power generation system, thereby achieving rapid and efficient load increase.

[0029] This invention utilizes a solar-coal dual-source heat storage system and a coal-fired thermal power generation system to achieve cascaded and trans-temporal energy utilization. By storing heat from both solar and coal-fired generator sets, the system can be used to increase the variable load rate of the coal-fired thermal power generation system under varying variable load rate requirements, achieving efficient and flexible operation. Furthermore, heat storage can be used to mitigate the impact of solar energy fluctuations on the power generation output of the coal-fired thermal power generation system. This invention addresses the issues of insufficient economic efficiency and flexibility in the operation of both CSP and coal-fired units.

Claims

1. A solar-coal dual-heat source energy storage complementary flexible power generation system, characterized by: It includes coal-fired thermal power generation system and solar-fired coal-fired dual heat source heat storage system: The coal-fired thermal power generation system comprises a boiler (1), a steam turbine high-pressure cylinder (2), a steam turbine medium- and low-pressure cylinders (3), a condenser (4), a condensate pump (5), a low-pressure heater (6), a deaerator (7), a feedwater pump (8) and a high-pressure heater (9) connected in sequence; the superheated steam outlet of the boiler (1) is connected to the inlet of the steam turbine high-pressure cylinder (2); the water working medium inlet of the boiler (1) is connected to the water working medium outlet of the high-pressure heater (9); the steam outlet of the steam turbine high-pressure cylinder (2) is connected to the reheated steam inlet of the boiler (1) through a pipeline, and the extraction steam outlet of the steam turbine high-pressure cylinder (2) is connected to the steam inlet of the high-pressure heater (9) through a pipeline; the boiler (1) The reheat steam outlet of the steam turbine is connected to the steam inlet of the medium and low pressure cylinders (3); the first stage extraction steam outlet of the medium and low pressure cylinders (3) of the steam turbine is connected to the steam inlet of the deaerator (7) through a pipeline, and the second stage extraction steam outlet is connected to the steam inlet of the low pressure heater (6) through a pipeline; the water working medium outlet of the deaerator (7) is connected to the high pressure heater (9) through the feed water pump (8); the steam outlet of the medium and low pressure cylinders (3) of the steam turbine is connected to the steam inlet of the condenser (4); the water working medium outlet of the condenser (4) is connected to the water working medium inlet of the low pressure heater (6) through the condensate pump (5); the water working medium outlet of the low pressure heater (6) is connected to the water working medium inlet of the deaerator (7); The solar-coal-fired dual-heat source heat storage system comprises a cold salt tank (18), a cold salt pump (19), an oil-salt heat exchanger (13), a steam molten salt heat exchanger (14), a hot salt tank (15), a hot salt pump (16) and a brine heat exchanger group (17) connected in sequence; further comprising a solar collector (11) and an oil-water heat exchanger (12); the water working medium inlet of the oil-water heat exchanger (12) is connected to the outlet of the water pump (8) through a solar water supply regulating valve (10), and the water working medium outlet is connected to the boiler The water working medium inlet of the furnace (1) is connected through a pipeline, the heat transfer oil inlet is connected to the heat transfer oil outlet of the solar collector (11) through a pipeline, and the heat transfer oil outlet is connected to the heat transfer oil inlet of the solar collector (11) through a pipeline; the heat transfer oil inlet of the oil-salt heat exchanger (13) is connected to the heat transfer oil outlet of the solar collector (11) through a heat transfer oil regulating valve (23), and the heat transfer oil outlet is connected to the heat transfer oil inlet of the solar collector (11) through a pipeline, and the molten salt inlet is connected to the heat transfer oil inlet of the solar collector (11). The supercooled salt pump (19) is connected to the molten salt outlet of the cold salt tank (18), and the molten salt outlet is connected to the molten salt inlet of the steam molten salt heat exchanger (14) through a pipeline; the steam inlet of the steam molten salt heat exchanger (14) is connected to the main steam outlet of the boiler (1) through the main steam regulating valve (20), and the steam inlet is also connected to the reheat steam outlet of the boiler (1) through the reheat steam regulating valve (24), and the steam outlet is connected to the reheat steam inlet of the boiler (1) through a pipeline, and the molten salt outlet The molten salt inlet of the hot salt tank (15) is connected to the molten salt inlet of the brine heat exchanger group (17) through a pipeline; the molten salt inlet of the brine heat exchanger group (17) is connected to the molten salt outlet of the hot salt tank (15) through a hot salt pump (16); the molten salt outlet is connected to the molten salt inlet of the cold salt tank (18) through a pipeline; the water working medium inlet is connected to the water working medium outlet of the feed water pump (8) through a pipeline; the water working medium outlet is connected to the water working medium inlet of the boiler (1) through a pipeline; and the steam outlet is connected to the steam inlet of the medium and low pressure cylinders (3) of the steam turbine through a pipeline; The brine heat exchanger group (17) includes a brine heat exchanger (171) and a brine steam generator (172); The operating temperature of molten salt is 150℃~580℃; The operating temperature of the thermal oil is 180℃~390℃; The heat transfer medium in the hot salt tank (15) and the cold salt tank (18) is ternary salt, 20% LiNO3+52% KNO3+28% NaNO3.

2. The solar-coal dual heat source energy storage complementary flexible power generation system according to claim 1 is characterized by: The molten salt inlet of the brine heat exchanger (171) is connected to the hot salt tank (15) through the hot salt pump (16), the molten salt outlet is connected to the molten salt inlet of the cold salt tank (18) through a pipeline, the water working medium inlet is connected to the water working medium outlet of the feed water pump (8) through the No. 1 feed water regulating valve (21), and the water working medium outlet is connected to the water working medium inlet of the boiler (1) through a pipeline; the molten salt inlet of the brine steam generator (172) is connected to the molten salt inlet of the brine heat exchanger (171) through the molten salt regulating valve (173), the molten salt outlet is connected to the molten salt outlet of the brine heat exchanger (171) through a pipeline, the water working medium inlet is connected to the water working medium outlet of the feed water pump (8) through the No. 2 feed water regulating valve (22), and the steam outlet is connected to the medium and low pressure cylinders (3) of the steam turbine through pipelines.

3. The solar-coal dual heat source energy storage complementary flexible power generation system according to claim 1 is characterized by: The solar heat collector (11) is composed of a plurality of solar heat collecting tubes (111) that are first connected in series and then in parallel.

4. The method for operating a solar-coal dual-heat source energy storage complementary flexible power generation system according to any one of claims 1 to 3, wherein when the solar radiation intensity suddenly increases, the opening of the solar water supply regulating valve (10) is increased to regulate the water flow rate entering the oil-water heat exchanger (12), the opening of the thermal oil regulating valve (23) is increased to regulate the thermal oil flow rate entering the oil-salt heat exchanger (13), and at the same time, the speed of the cold salt pump (19) is adjusted to regulate the molten salt flow rate entering the oil-salt heat exchanger (13), and the adjustment target is to adjust the outlet temperature of the water working medium of the oil-water heat exchanger (12) and the high-pressure heater ( 9) outlet temperature remains the same, maintaining the power generation stability of the coal-fired thermal power generation system; when the solar radiation intensity suddenly drops, the opening of the solar water supply regulating valve (10) is reduced to adjust the water flow entering the oil-water heat exchanger (12), the opening of the No. 1 water supply regulating valve (21) is opened and increased to adjust the water flow entering the brine heat exchanger (171), and the speed of the hot salt pump (16) is adjusted to adjust the hot molten salt flow entering the brine heat exchanger (171). The adjustment target is to keep the water temperature entering the boiler (1) unchanged and maintain the power stability of the coal-fired thermal power generation system; when the coal-fired When the thermal power generation system needs to reduce the load quickly, the opening of the main steam regulating valve (20) and the reheat steam regulating valve (24) is increased, and the molten salt flow entering the steam molten salt heat exchanger (14) is adjusted by adjusting the speed of the cold salt pump (19). At the same time, the opening of the solar water supply regulating valve (10) is adjusted. The adjustment target is to quickly reduce the main steam flow entering the high-pressure cylinder (2) of the steam turbine and the reheat steam flow entering the medium and low-pressure cylinders (3) of the steam turbine. The power reduction rate of the coal-fired thermal power generation system meets the requirements of the power grid and is highly efficient. When the coal-fired thermal power generation system needs to increase the load quickly, the thermal power generation system is increased. The rotation speed of the salt pump (16) regulates the flow of molten salt entering the brine heat exchanger group (17), and the opening of the molten salt regulating valve (173) is increased to regulate the flow of hot molten salt entering the brine steam generator (172). At the same time, the rotation speed of the feed water pump (8) is increased and the opening of the second feed water regulating valve (22) is increased to increase the water flow entering the brine steam generator (172). The regulation target is that the steam flow rate of the brine steam generator (172) generating steam and entering the medium and low pressure cylinders (3) of the steam turbine to perform work can meet the load increase rate requirements of the coal-fired thermal power generation system, thereby achieving rapid and efficient load increase.

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