Coal-fired power generation system integrating heat pump heat storage circulation and operation method

Abstract

The invention discloses a coal-fired power generation system integrating heat pump heat storage circulation and an operation method, and belongs to the technical field of coal-fired power generation. According to the coal-fired power generation system integrated with the heat pump heat storage circulation, heat energy of low-temperature flue gas is stored when the load of a power grid is off-peak under the control of a heat storage valve and a heat release valve by coupling a heat pump heat storage system and a heat release system, the heat loss of a coal-fired system is reduced, and the power generation efficiency is improved. The power generation capacity of the coal-fired power generation system is increased by quickly releasing heat storage energy of the high-temperature heat storage tank at the load peak, and the load change requirement can be quickly responded and the peak regulation capacity of the power grid can be improved by flexibly switching the heat storage operation mode and the heat release operation mode.

Description

Technical Field

[0001] The present invention relates to the technical field of coal-fired power generation, and in particular to a coal-fired power generation system integrated with a heat pump heat storage cycle and an operation method thereof. Background Art

[0002] Coal-fired power generation, as a long-term dominant mode of electricity production in history, has inherent operating characteristics and environmental pressures that are particularly prominent in the current context of energy transformation. Coal-fired supercritical water gasification technology uses supercritical water as a medium to efficiently convert coal into hydrogen-rich synthesis gas at extremely high temperatures and pressures, which not only improves the efficiency of hydrogen production, but also makes it easy to deposit and separate harmful elements such as nitrogen and sulfur through a specific chemical reaction pathway, which is convenient for subsequent pollution control treatment. More importantly, this technology also facilitates carbon capture in the coal-fired process, helps reduce greenhouse gas emissions, and is in line with the general trend of global energy low-carbon transformation.

[0003] Although coal-fired supercritical water gasification technology has shown great potential in improving energy conversion efficiency and environmental friendliness, it still faces some challenges in practical applications. In particular, its ability to quickly respond to changes in grid load is relatively limited, especially during the peak load operation phase, where the problem of insufficient flexibility is particularly significant. This not only limits its adaptability in modern power grids, but also exacerbates the difficulty of operating the power system in the face of intermittent and uncertain renewable energy.

[0004] Therefore, how to achieve the flexibility of coal-fired power generation systems has become a technical problem that technical personnel in this field need to solve urgently. Summary of the invention

[0005] The object of the present invention is to provide a coal-fired power generation system and an operation method integrated with a heat pump heat storage cycle, so as to overcome the problem of insufficient flexibility of the coal-fired power generation system in the peak load operation stage in the prior art.

[0006] The present invention solves the above technical problems through the following technical solutions: The present invention provides a coal-fired power generation system with an integrated heat pump heat storage cycle, comprising a heat pump heat storage system, a heat release system and a coal supercritical water gasification power generation system; the heat pump heat storage system comprises a heat storage valve, a heat pump evaporator, a heat pump compressor, a heat storage heat exchanger, a heat pump expansion valve, a low-temperature heat storage tank and a high-temperature heat storage tank; the heat release system comprises a low-temperature heat storage tank, a high-temperature heat storage tank, a heat release valve and a heat release heat exchanger; The low-temperature flue gas of the coal supercritical water gasification power generation system is connected to the cooling inlet of the coal supercritical water gasification power generation system through the heat storage valve and the hot end of the heat pump evaporator in sequence; the cold end outlet of the heat pump evaporator is connected to the heat pump compressor, the hot end of the heat storage heat exchanger, the heat pump expansion valve and the cold end inlet of the heat pump evaporator in sequence, and the outlet of the low-temperature heat storage tank is connected to the inlet of the high-temperature heat storage tank through the cold end of the heat storage heat exchanger; The pressurized gasification feed water of the coal supercritical water gasification power generation system is connected to the oxidation reaction inlet of the coal supercritical water gasification power generation system through the exothermic valve and the cold end of the exothermic heat exchanger in sequence, and the outlet of the high-temperature heat storage tank is connected to the low-temperature heat storage tank through the hot end of the exothermic heat exchanger.

[0007] The present invention is further improved in that: the coal supercritical water gasification power generation system includes a supercritical water gasification reactor, a burner, a gas turbine, a feed water heat exchanger, a cooler, a gas-liquid separator, a feed water pump and an organic Rankine cycle system; The supercritical water gasification reactor is sequentially connected to a burner, a gas turbine, a hot end of a feed water heat exchanger, a hot end of an organic Rankine cycle system, a cooler, a gas-liquid separator, a feed water pump and a cold end of a feed water heat exchanger, and the cold end outlet of the feed water heat exchanger is respectively connected to the inlet of the supercritical water gasification reactor and the burner.

[0008] A further improvement of the present invention is that the organic Rankine cycle system includes an organic working fluid heat exchanger, an organic working fluid turbine, a condenser and an organic working fluid pump, wherein the cold end outlet of the organic working fluid heat exchanger is connected to the organic working fluid turbine, the condenser, the organic working fluid pump in sequence to the cold end inlet of the organic working fluid heat exchanger, and the hot end of the organic working fluid heat exchanger is the hot end of the organic Rankine cycle system.

[0009] A further improvement of the present invention is that the inlet temperature of the gas turbine is 700°C to 1500°C.

[0010] A further improvement of the present invention is that the outlet temperature of the cooler is 20°C to 35°C.

[0011] A further improvement of the present invention is that the operating temperature of the supercritical water gasification reactor is 600°C to 700°C.

[0012] A further improvement of the present invention is that the operating pressure of the supercritical water gasification reactor is 25 MPa to 30 MPa.

[0013] A further improvement of the present invention is that the heat storage medium of the heat pump heat storage system and the heat release system adopts molten salt.

[0014] The present invention also provides an operation method of a coal-fired power generation system with an integrated heat pump heat storage cycle, wherein the coal-fired power generation system with an integrated heat pump heat storage cycle as described above is adopted, the heat storage valve is opened, the heat release valve is closed, the coal-fired power generation system is in a heat pump heat storage operation mode, the low-temperature flue gas of the coal supercritical water gasification power generation system enters the hot end inlet of the heat pump evaporator through the heat storage valve, the cold end outlet of the heat pump evaporator enters the hot end inlet of the heat storage heat exchanger after being pressurized by the heat pump compressor, the hot end outlet of the heat storage heat exchanger enters the cold end inlet of the heat pump evaporator after being depressurized by the heat pump expansion valve, and the heat storage working fluid at the outlet of the low-temperature heat storage tank enters the high-temperature heat storage tank after being heated by the cold end of the heat storage heat exchanger; Open the heat release valve and close the heat storage valve. The coal-fired power generation system is in the heat release operation mode. The pressurized gasification feed water of the coal supercritical water gasification power generation system enters the oxidation reaction inlet of the coal supercritical water gasification power generation system through the heat release valve and the cold end of the heat release heat exchanger in turn; the heat storage working fluid at the outlet of the high-temperature heat storage tank releases heat through the hot end of the heat release heat exchanger and then enters the low-temperature heat storage tank.

[0015] A further improvement of the present invention is that when the coal-fired power generation system is in a heat pump heat storage operation mode, the power generation of the coal supercritical water gasification power generation system is reduced by recovering the low-temperature thermal energy of the low-temperature flue gas, and the low-temperature thermal energy is converted into high-temperature thermal energy and stored in a high-temperature heat storage tank; when the coal-fired power generation system is in a heat release operation mode, the power generation of the coal supercritical water gasification power generation system is increased by releasing the thermal energy stored in the high-temperature heat storage tank to the pressurized gasification water supply.

[0016] Compared with the prior art, the positive and progressive effects of the present invention are: The coal-fired power generation system with integrated heat pump heat storage cycle provided by the present invention achieves storage of thermal energy of low-temperature flue gas when the power grid load is low, under the control of the heat storage valve and the heat release valve, thereby reducing the heat loss of the coal-fired power generation system, and increasing the power generation of the coal-fired power generation system by quickly releasing the stored heat energy of the high-temperature heat storage tank when the load is peak. By flexibly switching between the heat storage operation mode and the heat release operation mode, it can quickly respond to load change demands and improve the peak-shaving capacity of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings in the specification are used to provide further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0018] Figure 1 A connection diagram of a coal-fired power generation system with an integrated heat pump heat storage cycle according to the present invention; Figure 2 This is a connection diagram of the heat pump heat storage operation mode; Figure 3 It is a connection diagram of the heat release operation mode; 1 is a supercritical water gasification reactor, 2 is a burner, 3 is a gas turbine, 4 is a feed water heat exchanger, 5 is an organic working fluid heat exchanger, 6 is a cooler, 7 is a gas-liquid separator, 8 is a feed water pump, 9 is an organic working fluid turbine, 10 is a condenser, 11 is an organic working fluid pump, 12 is a heat storage valve, 13 is a heat pump evaporator, 14 is a heat pump compressor, 15 is a heat storage heat exchanger, 16 is a heat pump expansion valve, 17 is a low-temperature heat storage tank, 18 is a high-temperature heat storage tank, 19 is a heat release valve, and 20 is a heat release heat exchanger. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0022] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0023] In addition, it should be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments, which are intended to explain the present invention rather than to limit it.

[0025] See also Figure 1A coal-fired power generation system with an integrated heat pump heat storage cycle includes a heat pump heat storage system, a heat release system and a coal supercritical water gasification power generation system; the heat pump heat storage system includes a heat storage valve 12, a heat pump evaporator 13, a heat pump compressor 14, a heat storage heat exchanger 15, a heat pump expansion valve 16, a low-temperature heat storage tank 17 and a high-temperature heat storage tank 18; the heat release system includes a low-temperature heat storage tank 17, a high-temperature heat storage tank 18, a heat release valve 19 and a heat release heat exchanger 20; The low-temperature flue gas of the coal supercritical water gasification power generation system is connected to the cooling inlet of the coal supercritical water gasification power generation system through the heat storage valve 12 and the hot end of the heat pump evaporator 13 in sequence; the cold end outlet of the heat pump evaporator 13 is connected to the heat pump compressor 14, the hot end of the heat storage heat exchanger 15, and the heat pump expansion valve 16 to the cold end inlet of the heat pump evaporator 13 in sequence, and the outlet of the low-temperature heat storage tank 17 is connected to the inlet of the high-temperature heat storage tank 18 through the cold end of the heat storage heat exchanger 15; The pressurized gasification feed water of the coal supercritical water gasification power generation system is connected to the oxidation reaction inlet of the coal supercritical water gasification power generation system through the heat release valve 19 and the cold end of the heat release heat exchanger 20 in sequence, and the outlet of the high-temperature heat storage tank 18 is connected to the low-temperature heat storage tank 17 through the hot end of the heat release heat exchanger 20.

[0026] Specifically, the coal supercritical water gasification power generation system includes a supercritical water gasification reactor 1, a burner 2, a gas turbine 3, a feed water heat exchanger 4, a cooler 6, a gas-liquid separator 7, a feed water pump 8 and an organic Rankine cycle system; The supercritical water gasification reactor 1 is connected in sequence to the burner 2, the gas turbine 3, the hot end of the feed water heat exchanger 4, the hot end of the organic Rankine cycle system, the cooler 6, the gas-liquid separator 7, the feed water pump 8 to the cold end of the feed water heat exchanger 4, and the cold end outlet of the feed water heat exchanger 4 is connected to the inlet of the supercritical water gasification reactor 1 and the burner 2 respectively.

[0027] Specifically, the organic Rankine cycle system includes an organic working fluid heat exchanger 5, an organic working fluid turbine 9, a condenser 10 and an organic working fluid pump 11, wherein the cold end outlet of the organic working fluid heat exchanger 5 is connected to the organic working fluid turbine 9, the condenser 10, the organic working fluid pump 11 in sequence to the cold end inlet of the organic working fluid heat exchanger 5, and the hot end of the organic working fluid heat exchanger 5 is the hot end of the organic Rankine cycle system.

[0028] Specifically, the inlet temperature of the gas turbine 3 is 700°C to 1500°C.

[0029] Specifically, the outlet temperature of the cooler 6 is 20°C to 35°C.

[0030] Specifically, the operating temperature of the supercritical water gasification reactor 1 is 600°C to 700°C.

[0031] Specifically, the operating pressure of the supercritical water gasification reactor 1 is 25 MPa-30 MPa.

[0032] Specifically, the heat storage medium of the heat pump heat storage system and the heat release system adopts molten salt.

[0033] Based on the same inventive concept, the present invention provides an operation method of a coal-fired power generation system with an integrated heat pump heat storage cycle, using the above-mentioned coal-fired power generation system with an integrated heat pump heat storage cycle, see Figure 2 , open the heat storage valve 12, close the heat release valve 19, the coal-fired power generation system is in the heat pump heat storage operation mode, the low-temperature flue gas of the coal supercritical water gasification power generation system enters the hot end inlet of the heat pump evaporator 13 through the heat storage valve 12, the cold end outlet of the heat pump evaporator 13 enters the hot end inlet of the heat storage heat exchanger 15 after being pressurized by the heat pump compressor 14, the hot end outlet of the heat storage heat exchanger 15 enters the cold end inlet of the heat pump evaporator 13 after being depressurized by the heat pump expansion valve 16, and the heat storage working fluid at the outlet of the low-temperature heat storage tank 17 enters the high-temperature heat storage tank 18 after being heated at the cold end of the heat storage heat exchanger 15; See also Figure 3 , open the heat release valve 19, close the heat storage valve 12, the coal-fired power generation system is in the heat release operation mode, and the pressurized gasification feed water of the coal supercritical water gasification power generation system enters the oxidation reaction inlet of the coal supercritical water gasification power generation system through the heat release valve 19 and the cold end of the heat release heat exchanger 20 in sequence; the heat storage working fluid at the outlet of the high-temperature heat storage tank 18 enters the low-temperature heat storage tank 17 after heat release at the hot end of the heat release heat exchanger 20.

[0034] Specifically, when the coal-fired power generation system is in the heat pump heat storage operation mode, the power generation of the coal supercritical water gasification power generation system is reduced by recovering the low-temperature thermal energy of the low-temperature flue gas, and the low-temperature thermal energy is converted into high-temperature thermal energy and stored in the high-temperature heat storage tank 18; when the coal-fired power generation system is in the heat release operation mode, the power generation of the coal supercritical water gasification power generation system is increased by releasing the thermal energy stored in the high-temperature heat storage tank 18 to the pressurized gasification water supply.

[0035] Embodiment 1 A coal-fired power generation system with integrated heat pump heat storage cycle, comprising a coal supercritical water gasification power generation system, a heat pump heat storage system and a heat release system; The coal supercritical water gasification power generation system comprises a supercritical water gasification reactor 1, a burner 2, a gas turbine 3, a feed water heat exchanger 4, an organic working fluid heat exchanger 5, a cooler 6, a gas-liquid separator 7, a feed water pump 8, an organic working fluid turbine 9, a condenser 10 and an organic working fluid pump 11; the cold end outlets of the coal and oxygen and feed water heat exchangers 4 are respectively connected to the inlet of the supercritical water gasification reactor 1, and the ash is discharged from the outlet of the supercritical water gasification reactor 1; the outlet of the supercritical water gasification reactor 1 is connected to the burner 2 inlet, the burner 2 outlet is connected to the gas turbine 3 inlet; the gas turbine 3 outlet is connected to the hot end inlet of the feed water heat exchanger 4, the hot end outlet of the feed water heat exchanger 4 is connected to the hot end inlet of the organic working fluid heat exchanger 5, and the hot end outlet of the organic working fluid heat exchanger 5 is connected to the inlet of the gas-liquid separator 7 through the cooler 6; the liquid phase outlet of the gas-liquid separator 7 and the make-up water are connected to the cold end inlet of the feed water heat exchanger 4 through the feed water pump 8, and the cold end outlet of the feed water heat exchanger 4 is respectively connected to the supercritical water gasification reactor 1 and the burner 2 inlet; The heat pump heat storage system is based on the coal supercritical water gasification power generation system and also includes a heat storage valve 12, a heat pump evaporator 13, a heat pump compressor 14, a heat storage heat exchanger 15, a heat pump expansion valve 16, a low-temperature heat storage tank 17 and a high-temperature heat storage tank 18; the hot end outlet of the feed water heat exchanger 4 is partially diverted through the heat storage valve 12 to be connected to the hot end inlet of the heat pump evaporator 13, and the hot end outlet of the heat pump evaporator 13 and the hot end outlet of the organic working fluid heat exchanger 5 are mixed and connected to the inlet of the cooler 6; the cold end outlet of the heat pump evaporator 13 is connected to the inlet of the heat pump compressor 14, and the outlet of the heat pump compressor 14 is connected to the hot end inlet of the heat storage heat exchanger 15, and the hot end outlet of the heat storage heat exchanger 15 is connected to the cold end inlet of the heat pump evaporator 13 through the heat pump expansion valve 16; the outlet of the low-temperature heat storage tank 17 is connected to the inlet of the high-temperature heat storage tank 18 through the cold end of the heat storage heat exchanger 15; Based on the coal supercritical water gasification power generation system, the heat release system also includes a low-temperature heat storage tank 17, a high-temperature heat storage tank 18, a heat release valve 19 and a heat release heat exchanger 20; the outlet of the water supply pump 8 is partially diverted through the heat release valve 19 to be connected to the cold end inlet of the heat release heat exchanger 20, and the cold end outlet of the heat release heat exchanger 20 is connected to the inlet of the burner 2; the outlet of the high-temperature heat storage tank 18 is connected to the inlet of the low-temperature heat storage tank 17 through the hot end of the heat release heat exchanger 20.

[0036] The present invention is based on supercritical water gasification technology, which reduces the generation of nitrogen oxides and sulfur oxides and realizes complete carbon capture of carbon dioxide in the system, providing a new technical path for clean, efficient and low-carbon operation of coal-fired power generation; fully utilizes high-temperature thermal energy and flue gas waste heat in the supercritical water gasification process, combines heat pump technology to improve the quality of low-temperature waste heat, realizes multi-level energy ladder utilization, and significantly reduces the heat loss of the coal-fired system. Through the efficient operation of the heat storage system, the waste of high-temperature energy is reduced, and the overall thermal efficiency of the system is improved; through the integration of heat pump heat storage cycle and heat release cycle, flue gas waste heat and low-grade thermal energy are stored when the power grid load is low, and the stored heat energy is quickly released at peak load to increase the system's power generation. Through the flexible switching of conventional operation, heat storage operation and heat release operation modes, the system can quickly respond to load changes and greatly improve the peak-shaving capacity of the power grid.

[0037] Embodiment 2 An operation method of a coal-fired power generation system with an integrated heat pump heat storage cycle is as follows: the coal-fired power generation system includes a conventional operation mode, a heat pump heat storage operation mode and a heat release operation mode; in the conventional operation mode, coal, oxygen and gasified feed water at the outlet of a feed water heat exchanger 4 enter a supercritical water gasification reactor 1 to undergo a supercritical water gasification reaction, ash is discharged from the outlet of the supercritical water gasification reactor 1, synthesis gas enters a burner 2 from the outlet of the supercritical water gasification reactor 1 to undergo a complete oxidation reaction with oxygen, and part of the gasified feed water at the outlet of the feed water heat exchanger 4 enters the inlet of the burner 2 to adjust the inlet temperature of the gas turbine 3; the flue gas at the outlet of the burner 2 enters the gas turbine 3; The exhaust gas of the gas turbine 3 enters the hot end of the feed water heat exchanger 4 to preheat the gasified feed water, and the outlet of the hot end of the feed water heat exchanger 4 enters the hot end of the organic working fluid heat exchanger 5 to heat the organic working fluid; the outlet of the cold end of the organic working fluid heat exchanger 5 enters the organic working fluid turbine 9 to expand and generate electricity, and the outlet of the organic working fluid turbine 9 enters the cold end inlet of the organic working fluid heat exchanger 5 after passing through the condenser 10 and the organic working fluid pump 11; the hot end outlet of the organic working fluid heat exchanger 5 enters the gas-liquid separator 7 after being cooled by the cooler 6, and the gas phase outlet of the gas-liquid separator 7 is completely carbon captured, and the liquid phase outlet is mixed with the make-up water and pressurized by the feed water pump 8 before entering the cold end inlet of the feed water heat exchanger 4; See also Figure 2 , heat pump heat storage operation mode: on the basis of the conventional operation mode, open the heat storage valve 12, and part of the flue gas at the hot end outlet of the water supply heat exchanger 4 enters the hot end inlet of the heat pump evaporator 13 through the heat storage valve 12, and the hot end outlet of the heat pump evaporator 13 is mixed with the hot end outlet of the organic working medium heat exchanger 5 and then enters the inlet of the cooler 6; in the heat pump cycle, the cold end outlet of the heat pump evaporator 13 enters the hot end inlet of the heat storage heat exchanger 15 after being pressurized by the heat pump compressor 14, and the hot end outlet of the heat storage heat exchanger 15 enters the cold end inlet of the heat pump evaporator 13 after being depressurized by the heat pump expansion valve 16; the heat storage working medium at the outlet of the low-temperature heat storage tank 17 enters the high-temperature heat storage tank 18 after being heated at the cold end of the heat storage heat exchanger 15; See also Figure 3 , heat release operation mode: on the basis of the conventional operation mode, open the heat release valve 19, and part of the vaporized feed water at the outlet of the feed water pump 8 enters the cold end inlet of the heat release heat exchanger 20 through the heat release valve 19, and the cold end outlet of the heat release heat exchanger 20 enters the inlet of the burner 2; the heat storage medium at the outlet of the high-temperature heat storage tank 18 releases heat at the hot end of the heat release heat exchanger 20 and then enters the low-temperature heat storage tank 17.

[0038] During off-peak load, the heat storage valve 12 is opened to divert part of the flue gas at the hot end outlet of the feed water heat exchanger 4, and the power generation of the organic working fluid turbine 9 is reduced by recovering part of the low-temperature thermal energy of the flue gas. Through the integrated heat pump heat storage cycle, the low-grade thermal energy is converted into high-grade thermal energy and stored in the heat storage tank, so as to further absorb the surplus power of the power grid or renewable energy power. During peak load, the heat release valve 19 is opened to release the heat stored in the heat storage tank to part of the gasified feed water at the outlet of the feed water pump 8, thereby increasing the power generation of the gas turbine 3 and the organic working fluid turbine 9.

[0039] Finally, it should be noted that the above-listed embodiments exist only as one or more specific forms of expression of the technical solution of the present invention. Their purpose is to clearly explain the concept, principle and application of the present invention through specific examples, and it is by no means intended to limit the protection scope of the present invention to these specific embodiments. In fact, the real value of the present invention lies in the technical ideas and innovations it proposes, rather than its form of expression or means of implementation.

[0040] For ordinary technicians in the relevant technical field, after in-depth reading and understanding of the technical solution of the present invention, they are fully capable of making various forms of changes, modifications or equivalent substitutions to the specific implementation methods of the invention based on their own professional knowledge and skills. These changes may include but are not limited to: adjusting the value range of technical parameters, optimizing algorithm processes to improve efficiency, replacing some technical components to achieve better compatibility or reduce costs, etc. As long as these changed technical solutions still substantially maintain the technical features claimed for protection by the original invention, that is, they can still achieve the core functions and effects of the present invention, then these changes should be deemed to fall within the scope of protection of the pending claims of the present invention.

[0041] In addition, with the continuous progress and development of technology, new technical means and methods continue to emerge, which also provides broad space for further improvement and perfection of the present invention. Therefore, the protection scope of the present invention should also include those reasonably foreseeable improvements and extensions based on the existing technology. As long as these improvements and extensions do not deviate from the basic principles and core concepts of the present invention, they should be regarded as equivalents of the present invention and are also protected by patent rights.

Claims

1. A coal-fired power generation system with integrated heat pump heat storage cycle, characterized in that: It comprises a heat pump heat storage system, a heat release system and a coal supercritical water gasification power generation system; the heat pump heat storage system comprises a heat storage valve (12), a heat pump evaporator (13), a heat pump compressor (14), a heat storage heat exchanger (15), a heat pump expansion valve (16), a low-temperature heat storage tank (17) and a high-temperature heat storage tank (18); the heat release system comprises a low-temperature heat storage tank (17), a high-temperature heat storage tank (18), a heat release valve (19) and a heat release heat exchanger (20); The low-temperature flue gas of the coal supercritical water gasification power generation system is connected to the cooling inlet of the coal supercritical water gasification power generation system via the heat storage valve (12) and the hot end of the heat pump evaporator (13) in sequence; the cold end outlet of the heat pump evaporator (13) is connected to the heat pump compressor (14), the hot end of the heat storage heat exchanger (15), the heat pump expansion valve (16) and the cold end inlet of the heat pump evaporator (13) in sequence, and the outlet of the low-temperature heat storage tank (17) is connected to the inlet of the high-temperature heat storage tank (18) via the cold end of the heat storage heat exchanger (15); The pressurized gasification feed water of the coal supercritical water gasification power generation system is connected to the oxidation reaction inlet of the coal supercritical water gasification power generation system via the heat release valve (19) and the cold end of the heat release heat exchanger (20) in sequence, and the outlet of the high-temperature heat storage tank (18) is connected to the low-temperature heat storage tank (17) via the hot end of the heat release heat exchanger (20).

2. A coal-fired power generation system with integrated heat pump heat storage cycle according to claim 1, characterized in that: The coal supercritical water gasification power generation system comprises a supercritical water gasification reactor (1), a burner (2), a gas turbine (3), a feed water heat exchanger (4), a cooler (6), a gas-liquid separator (7), a feed water pump (8) and an organic Rankine cycle system; The supercritical water gasification reactor (1) is connected in sequence to a burner (2), a gas turbine (3), a hot end of a feed water heat exchanger (4), a hot end of an organic Rankine cycle system, a cooler (6), a gas-liquid separator (7), a feed water pump (8) and a cold end of the feed water heat exchanger (4); the cold end outlet of the feed water heat exchanger (4) is respectively connected to the inlet of the supercritical water gasification reactor (1) and the burner (2).

3. A coal-fired power generation system with integrated heat pump heat storage cycle according to claim 2, characterized in that: The organic Rankine cycle system comprises an organic working fluid heat exchanger (5), an organic working fluid turbine (9), a condenser (10) and an organic working fluid pump (11), wherein the cold end outlet of the organic working fluid heat exchanger (5) is connected in sequence to the organic working fluid turbine (9), the condenser (10) and the organic working fluid pump (11) to the cold end inlet of the organic working fluid heat exchanger (5), and the hot end of the organic working fluid heat exchanger (5) is the hot end of the organic Rankine cycle system.

4. A coal-fired power generation system with integrated heat pump thermal storage cycle according to claim 2, characterized in that: The inlet temperature of the gas turbine (3) is 700°C to 1500°C.

5. The coal-fired power generation system with integrated heat pump heat storage cycle according to claim 2, characterized in that: The outlet temperature of the cooler (6) is 20°C to 35°C.

6. The coal-fired power generation system with integrated heat pump heat storage cycle according to claim 1, characterized in that: The operating temperature of the supercritical water gasification reactor (1) is 600°C to 700°C.

7. The coal-fired power generation system with integrated heat pump thermal storage cycle according to claim 1, characterized in that: The operating pressure of the supercritical water gasification reactor (1) is 25 MPa~30 MPa.

8. The coal-fired power generation system with integrated heat pump thermal storage cycle according to claim 1, characterized in that: The heat storage medium of the heat pump heat storage system and heat release system is molten salt.

9. An operating method of a coal-fired power generation system integrated with a heat pump heat storage cycle, characterized in that: A coal-fired power generation system with an integrated heat pump heat storage cycle as described in any one of claims 1 to 8 is adopted, the heat storage valve (12) is opened, the heat release valve (19) is closed, the coal-fired power generation system is in a heat pump heat storage operation mode, the low-temperature flue gas of the coal supercritical water gasification power generation system enters the hot end inlet of the heat pump evaporator (13) through the heat storage valve (12), the cold end outlet of the heat pump evaporator (13) is pressurized by the heat pump compressor (14) and enters the hot end inlet of the heat storage heat exchanger (15), the hot end outlet of the heat storage heat exchanger (15) is depressurized by the heat pump expansion valve (16) and enters the cold end inlet of the heat pump evaporator (13), the heat storage working fluid at the outlet of the low-temperature heat storage tank (17) is heated by the cold end of the heat storage heat exchanger (15) and enters the high-temperature heat storage tank (18); The heat release valve (19) is opened, the heat storage valve (12) is closed, and the coal-fired power generation system is in a heat release operation mode. The pressurized gasification feed water of the coal supercritical water gasification power generation system enters the oxidation reaction inlet of the coal supercritical water gasification power generation system through the heat release valve (19) and the cold end of the heat release heat exchanger (20) in sequence; the heat storage working fluid at the outlet of the high-temperature heat storage tank (18) releases heat through the hot end of the heat release heat exchanger (20) and enters the low-temperature heat storage tank (17).

10. The method for operating a coal-fired power generation system with an integrated heat pump thermal storage cycle according to claim 1, characterized in that: When the coal-fired power generation system is in a heat pump heat storage operation mode, the power generation of the coal supercritical water gasification power generation system is reduced by recovering the low-temperature heat energy of the low-temperature flue gas, and the low-temperature heat energy is converted into high-temperature heat energy and stored in a high-temperature heat storage tank (18); when the coal-fired power generation system is in a heat release operation mode, the power generation of the coal supercritical water gasification power generation system is increased by releasing the heat energy stored in the high-temperature heat storage tank (18) to the pressurized gasification water supply.

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