Flexible power generation system integrating heat storage and operation method

Abstract

The invention discloses an integrated heat storage flexible power generation system and an operation method, and belongs to the technical field of coal-fired power generation. According to the integrated heat storage flexible power generation system, the heat storage system, the heat release system and the supercritical water gasification technology are deeply coupled, the heat storage and heat release two-way adjusting capacity of the coal supercritical water gasification power generation system is constructed, and the heat storage and heat release of the coal supercritical water gasification power generation system are adjusted by adjusting a first valve and a second valve; high-temperature heat of synthesis gas at an outlet of the supercritical water gasification reactor is recycled to reduce power generation output during load valley, stored heat is released to carbon dioxide at an outlet of a carbon dioxide compressor during load peak, power generation output is increased, load fluctuation can be effectively dealt with, the peak regulation capacity of the system is enhanced, and the requirement for flexible operation of a modern power grid is met; through combination of the heat storage system and the heat release system, energy distribution is optimized, irreversible heat loss is reduced, and therefore the comprehensive energy utilization efficiency of coal-fired power generation is improved.

Description

Technical Field

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

[0002] Coal is the largest primary energy source in China, and its rational use is an important guarantee for China's energy security and sustainable economic and social development. However, the existing coal utilization method, which mainly relies on combustion for power generation, causes atmospheric pollutants and greenhouse gas emissions, causing environmental problems and threatening the stability of the ecological environment and human health. In order to achieve a balance between energy supply and environmental protection, the development of clean coal utilization technology is imminent.

[0003] Coal supercritical water gasification technology is a clean and efficient coal conversion technology. It can convert organic matter in coal into synthesis gas mainly composed of hydrogen and carbon dioxide in a supercritical water atmosphere. Elements such as nitrogen, sulfur, phosphorus, and mercury are deposited in the reactor in the form of inorganic salts, which makes it easy to separate pollutants. It has the advantages of high hydrogen production efficiency, low pollution, and strong raw material adaptability. Thermal power generation is one of the main uses of coal. Coal supercritical water gasification technology can be applied to the power generation field to improve the environmental friendliness of the power generation system. When applying coal supercritical water gasification technology to power generation, the power generation system needs to heat the feed water to a supercritical state by heat exchange to provide reaction raw materials for the gasification reaction.

[0004] However, as the proportion of renewable energy in the power grid continues to rise, the volatility of the power grid load is becoming increasingly severe. The traditional coal supercritical water gasification power generation system is difficult to quickly adapt to frequent changes in load due to the large thermal inertia of the boiler and the slow adjustment response speed, which puts higher requirements on the system's operational flexibility.

[0005] Therefore, how to overcome the problem of two-way regulation of heat storage and heat release in the coal supercritical water gasification power generation system so that it can flexibly respond to fluctuations in the power grid load has become a technical problem that technical personnel in this field urgently need to overcome. Summary of the invention

[0006] The object of the present invention is to provide a flexible power generation system with integrated heat storage and an operation method to overcome the shortcomings of the coal supercritical water gasification power generation system in the prior art in terms of rapid response to changes in grid load.

[0007] The present invention solves the above technical problems through the following technical solutions: A flexible power generation system with integrated heat storage, comprising a coal supercritical water gasification power generation system and a heat storage system and a heat release system coupled therewith; the heat storage system comprises a first valve, a heat storage heat exchanger, a high-temperature heat storage tank, a low-temperature heat storage tank and an auxiliary turbine; the heat release system comprises a second valve, a heat storage heat exchanger, a high-temperature heat storage tank and a low-temperature heat storage tank; the coal supercritical water gasification power generation system comprises a supercritical water gasification reactor, a carbon dioxide compressor and a power generation unit; The first output end of the power generation unit is connected to the supercritical water gasification reactor, and the output end of the supercritical water gasification reactor is divided into two paths, the first path is connected to the first input end of the power generation unit, and the second path is sequentially connected to the first valve, the heat storage heat exchanger, and the auxiliary turbine to the second input end of the power generation unit. When storing heat, the output end of the low-temperature heat storage tank is connected to the input end of the high-temperature heat storage tank through the cold end of the heat storage heat exchanger; The second output end of the power generation unit is connected to the carbon dioxide compressor, the second valve, the heat storage heat exchanger and the third input end of the power generation unit in sequence. When releasing heat, the output end of the high-temperature heat storage tank is connected to the input end of the low-temperature heat storage tank via the hot end of the heat storage heat exchanger.

[0008] A further improvement of the present invention is that the power generation unit includes a supercritical turbine, a No. 1 cooler, a No. 1 gas-liquid separator, a synthesis gas compressor, a burner, a gas turbine, a feedwater heat exchanger, a No. 2 cooler, a No. 2 gas-liquid separator and a water pump; The supercritical water gasification reactor is connected to the supercritical turbine, the No. 1 cooler and the No. 1 gas-liquid separator in sequence. The output end of the No. 1 gas-liquid separator is divided into two paths. The first path is connected to the first input end of the feed water heat exchanger through a water pump, and the second path is connected to the synthesis gas compressor, the burner, and the gas turbine in sequence to the second input end of the feed water heat exchanger; the output end of the feed water heat exchanger is divided into two paths, the first path is the first output end of the power generation unit; the second path is connected to the No. 2 cooler and the No. 2 gas-liquid separator in sequence, and the output end of the No. 2 gas-liquid separator is the second output end of the power generation unit; The input end of the supercritical turbine is the first input end of the power generation unit, the input end of the No. 1 cooler is the second input end of the power generation unit, and the input end of the burner is the third input end of the power generation unit.

[0009] A further improvement of the present invention is that the inlet temperature of the gas turbine is 1100°C to 1500°C, and the inlet pressure is 1.5 MPa to 3 MPa.

[0010] A further improvement of the present invention is that the power generation unit further comprises a third valve, and the supercritical water gasification reactor is connected to the supercritical turbine via the third valve.

[0011] A further improvement of the present invention is that the outlet temperatures of the No. 1 cooler and the No. 2 cooler are 20°C to 40°C.

[0012] A further improvement of the present invention is that the operating temperature of the supercritical water gasification reactor is 500° C. to 800° C., and the operating pressure is 25 MPa to 30 MPa.

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

[0014] The present invention also provides an operation method of a flexible power generation system with integrated heat storage, using the above-mentioned flexible power generation system with integrated heat storage, when the coal supercritical water gasification power generation system is in a load valley, the first valve is opened and the second valve is closed, the synthesis gas at the outlet of the supercritical water gasification reactor enters the hot end inlet of the heat storage heat exchanger through the first valve, and the hot end outlet of the heat storage heat exchanger enters the second input end of the power generation unit after pressure relief by the auxiliary turbine; at this time, the heat storage working fluid at the outlet of the low-temperature heat storage tank enters the high-temperature heat storage tank through the cold end of the heat storage heat exchanger, and the power generation of the power generation unit is reduced by recovering the high-temperature heat of the synthesis gas at the outlet of the supercritical water gasification reactor; When the coal supercritical water gasification power generation system is at its peak load, the first valve is closed and the second valve is opened. The carbon dioxide at the outlet of the carbon dioxide compressor enters the third input end of the power generation unit through the second valve and the heat storage heat exchanger. At this time, the heat storage working fluid at the outlet of the high-temperature heat storage tank enters the low-temperature heat storage tank through the hot end of the heat storage heat exchanger, and releases the stored heat to the carbon dioxide at the outlet of the carbon dioxide compressor, thereby increasing the power generation of the power generation unit.

[0015] A further improvement of the present invention is that the load peak is a time period when the load value of the coal supercritical water gasification power generation system exceeds 80% of the rated load.

[0016] A further improvement of the present invention is that the load valley is a time period when the load value of the coal supercritical water gasification power generation system is lower than 30% of the rated load.

[0017] Compared with the prior art, the positive and progressive effects of the present invention are: The present invention provides a flexible power generation system with integrated heat storage. By deeply coupling a heat storage system, a heat release system and a supercritical water gasification technology, a two-way regulation capability of heat storage and heat release of a coal supercritical water gasification power generation system is constructed. By adjusting a first valve and a second valve, the high-temperature heat of the synthesis gas at the outlet of the supercritical water gasification reactor is recovered to reduce the power generation output when the load is low, and the stored heat is released to the carbon dioxide at the outlet of the carbon dioxide compressor when the load is peak, so as to increase the power generation output. The system can effectively cope with load fluctuations, enhance the peak-shaving capability of the system and meet the flexible operation requirements of modern power grids. By combining the heat storage system with the heat release system, energy distribution is optimized, and irreversible heat loss is reduced, thereby improving the comprehensive energy utilization efficiency of coal-fired power generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] 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.

[0019] Figure 1 A connection diagram of a flexible power generation system with integrated heat storage according to the present invention; Figure 2 This is a connection diagram of a coal supercritical water gasification power generation system; Figure 3 When heat storage is used, a connection diagram of a flexible power generation system with integrated heat storage is shown; Figure 4 Schematic diagram of the connection of a flexible power generation system with integrated thermal storage when releasing heat; Among them, 1 is a supercritical water gasification reactor, 2 is the third valve, 3 is a supercritical turbine, 4 is a No. 1 cooler, 5 is a No. 1 gas-liquid separator, 6 is a synthesis gas compressor, 7 is a burner, 8 is a fuel gas turbine, 9 is a feed water heat exchanger, 10 is a No. 2 cooler, 11 is a No. 2 gas-liquid separator, 12 is a carbon dioxide compressor, 13 is a water pump, 14 is a first valve, 15 is a heat storage heat exchanger, 16 is a low-temperature heat storage tank, 17 is a high-temperature heat storage tank, 18 is an auxiliary turbine, and 19 is a second valve. DETAILED DESCRIPTION

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] A flexible power generation system with integrated heat storage includes a coal supercritical water gasification power generation system and a heat storage system and a heat release system coupled therewith; the heat storage system includes a first valve 14, a heat storage heat exchanger 15, a high-temperature heat storage tank 17, a low-temperature heat storage tank 16 and an auxiliary turbine 18; the heat release system includes a second valve 19, a heat storage heat exchanger 15, a high-temperature heat storage tank 17 and a low-temperature heat storage tank 16; the coal supercritical water gasification power generation system includes a supercritical water gasification reactor 1, a carbon dioxide compressor 12 and a power generation unit; The first output end of the power generation unit is connected to the supercritical water gasification reactor 1. The output end of the supercritical water gasification reactor 1 is divided into two paths. The first path is connected to the first input end of the power generation unit, and the second path is sequentially connected to the first valve 14, the heat storage heat exchanger 15, and the auxiliary turbine 18 to the second input end of the power generation unit. When storing heat, the output end of the low-temperature heat storage tank 16 is connected to the input end of the high-temperature heat storage tank 17 via the cold end of the heat storage heat exchanger 15; The second output end of the power generation unit is connected to the carbon dioxide compressor 12, the second valve 19, the heat storage heat exchanger 15 in sequence to the third input end of the power generation unit. When releasing heat, the output end of the high-temperature heat storage tank 17 is connected to the input end of the low-temperature heat storage tank 16 via the hot end of the heat storage heat exchanger 15.

[0027] By deeply coupling the heat storage system, the heat release system and the supercritical water gasification technology, a two-way regulation capability of heat storage and heat release of the coal supercritical water gasification power generation system is constructed. By adjusting the first valve and the second valve, the high-temperature heat of the synthesis gas at the outlet of the supercritical water gasification reactor is recovered to reduce the power generation output when the load is low, and the stored heat is released to the carbon dioxide at the outlet of the carbon dioxide compressor when the load is peak, so as to increase the power generation output. This can effectively cope with load fluctuations, enhance the peak-shaving capacity of the system, and meet the flexible operation requirements of modern power grids. By combining the heat storage system with the heat release system, energy distribution is optimized and irreversible heat loss is reduced, thereby improving the comprehensive energy utilization efficiency of coal-fired power generation.

[0028] Specifically, the power generation unit includes a supercritical turbine 3, a No. 1 cooler 4, a No. 1 gas-liquid separator 5, a synthesis gas compressor 6, a burner 7, a gas turbine 8, a feed water heat exchanger 9, a No. 2 cooler 10, a No. 2 gas-liquid separator 11 and a water pump 13; The supercritical water gasification reactor is sequentially connected to the supercritical turbine 3, the No. 1 cooler 4 and the No. 1 gas-liquid separator 5. The output end of the No. 1 gas-liquid separator 5 is divided into two paths. The first path is connected to the first input end of the feed water heat exchanger 9 through the water pump 13, and the second path is sequentially connected to the synthesis gas compressor 6, the burner 7, and the gas turbine 8 to the second input end of the feed water heat exchanger 9; the output end of the feed water heat exchanger 9 is divided into two paths, the first path is the first output end of the power generation unit; the second path is sequentially connected to the No. 2 cooler 10 and the No. 2 gas-liquid separator 11, and the output end of the No. 2 gas-liquid separator 11 is the second output end of the power generation unit; The input end of the supercritical turbine 3 is the first input end of the power generation unit, the input end of the No. 1 cooler 4 is the second input end of the power generation unit, and the input end of the burner 7 is the third input end of the power generation unit.

[0029] Specifically, the inlet temperature of the gas turbine 8 is 1100° C. to 1500° C., and the inlet pressure is 1.5 MPa to 3 MPa.

[0030] Specifically, the power generation unit further includes a third valve 2 , and the supercritical water gasification reactor is connected to the supercritical turbine 3 via the third valve 2 .

[0031] Specifically, the outlet temperatures of the No. 1 cooler 4 and the No. 2 cooler 10 are 20°C to 40°C.

[0032] Specifically, the operating temperature of the supercritical water gasification reactor 1 is 500° C. to 800° C., and the operating pressure is 25 MPa to 30 MPa.

[0033] Specifically, the heat storage medium of the heat storage system and the heat release system is molten salt.

[0034] Based on the same inventive concept, the present invention also provides an operation method of a flexible power generation system with integrated heat storage, using the flexible power generation system with integrated heat storage as described above, see Figure 3 When the coal supercritical water gasification power generation system is at a low load, the first valve 14 is opened and the second valve 19 is closed. The synthesis gas at the outlet of the supercritical water gasification reactor 1 enters the hot end inlet of the heat storage heat exchanger 15 through the first valve 14, and the hot end outlet of the heat storage heat exchanger 15 enters the second input end of the power generation unit after being depressurized by the auxiliary turbine 18; at this time, the heat storage medium at the outlet of the low-temperature heat storage tank 16 enters the high-temperature heat storage tank 17 through the cold end of the heat storage heat exchanger 15, and the power generation of the power generation unit is reduced by recovering the high-temperature heat of the synthesis gas at the outlet of the supercritical water gasification reactor 1; See also Figure 4 When the coal supercritical water gasification power generation system is at a peak load, the first valve 14 is closed and the second valve 19 is opened. The carbon dioxide at the outlet of the carbon dioxide compressor 12 enters the third input end of the power generation unit through the second valve 19 and the heat storage heat exchanger 15. At this time, the heat storage medium at the outlet of the high-temperature heat storage tank 17 enters the low-temperature heat storage tank 16 through the hot end of the heat storage heat exchanger 15, and releases the stored heat to the carbon dioxide at the outlet of the carbon dioxide compressor 12, thereby increasing the power generation of the power generation unit.

[0035] Specifically, the load peak is the time period when the load value of the coal supercritical water gasification power generation system exceeds 80% of the rated load, generally the time period from 8:00 to 11:00 and the time period from 18:00 to 21:00 every day.

[0036] Specifically, the load valley refers to the time when the load value of the coal supercritical water gasification power generation system is lower than 30% of the rated load, generally from 2:00 to 5:00 every day.

[0037] Embodiment 1 See also Figure 1 and Figure 2 , a flexible power generation system with integrated heat storage, including a coal supercritical water gasification power generation system, a heat storage system and a heat release system; The coal supercritical water gasification power generation system comprises a supercritical water gasification reactor 1, a third valve 2, a supercritical turbine 3, a No. 1 cooler 4, a No. 1 gas-liquid separator 5, a synthesis gas compressor 6, a burner 7, a gas turbine 8, a feed water heat exchanger 9, a No. 2 cooler 10, a No. 2 gas-liquid separator 11, a carbon dioxide compressor 12 and a water pump 13; the cold end outlets of the coal and oxygen and the feed water heat exchanger 9 are respectively connected to the inlet of the supercritical water gasification reactor 1, the ash is discharged from the outlet of the supercritical water gasification reactor 1, and the synthesis gas is connected from the outlet of the supercritical water gasification reactor 1 to the inlet of the supercritical turbine 3 through the third valve 2; the outlet of the supercritical turbine 3 is connected to the inlet of the No. 1 gas-liquid separator 5 through the No. 1 cooler 4, and the No. 1 gas-liquid separator 5 The liquid phase outlet and make-up water are connected to the cold end inlet of the feed water heat exchanger 9 through the water pump 13, and the cold end outlet of the feed water heat exchanger 9 is connected to the inlet of the supercritical water gasification reactor 1; the gas phase outlet of the No. 1 gas-liquid separator 5 is connected to the inlet of the burner 7 through the synthesis gas compressor 6, and the outlets of the oxygen and carbon dioxide compressors 12 are also connected to the inlet of the burner 7 respectively; the burner 7 outlet is connected to the inlet of the gas turbine 8, and the outlet of the gas turbine 8 is connected to the hot end inlet of the feed water heat exchanger 9; the hot end outlet of the feed water heat exchanger 9 is connected to the inlet of the No. 2 gas-liquid separator 11 through the No. 2 cooler 10, the liquid phase water of the No. 2 gas-liquid separator 11 is discharged from the system, and the gas phase carbon dioxide is partially discharged from the system, and part of it is connected to the inlet of the burner 7 through the carbon dioxide compressor 12; See also Figure 3 , the heat storage system further includes a first valve 14, a heat storage heat exchanger 15, a low-temperature heat storage tank 16, a high-temperature heat storage tank 17 and an auxiliary turbine 18 on the basis of the coal supercritical water gasification power generation system; part of the synthesis gas at the outlet of the supercritical water gasification reactor 1 is connected to the hot end inlet of the heat storage heat exchanger 15 through the first valve 14, the hot end outlet of the heat storage heat exchanger 15 is connected to the inlet of the auxiliary turbine 18, the outlet of the auxiliary turbine 18 is mixed with the outlet of the supercritical turbine 3 and connected to the inlet of the first cooler 4; the outlet of the low-temperature heat storage tank 16 is connected to the cold end inlet of the heat exchanger 15, and the cold end outlet of the heat exchanger 15 is connected to the inlet of the high-temperature heat storage tank 17; See also Figure 4 The heat release system further includes a second valve 19, a heat storage heat exchanger 15, a low-temperature heat storage tank 16 and a high-temperature heat storage tank 17 on the basis of the coal supercritical water gasification power generation system; part of the carbon dioxide at the outlet of the carbon dioxide compressor 12 is connected to the cold end inlet of the heat storage heat exchanger 15 through the second valve 19, and the cold end outlet of the heat storage heat exchanger 15 is connected to the inlet of the burner 7; the outlet of the high-temperature heat storage tank 17 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 inlet of the low-temperature heat storage tank 16.

[0038] Embodiment 2 An operation method of a flexible power generation system with integrated heat storage, using the flexible power generation system with integrated heat storage as described in the first embodiment, including a conventional operation mode, a heat storage operation mode and a heat release operation mode; Open the third valve 2, close the first valve 14 and the second valve 19 for the normal operation mode. At this time, the coal, oxygen and the gasified feed water at the cold end outlet of the feed water heat exchanger 9 enter the supercritical water gasification reactor 1 to undergo a supercritical water gasification reaction to generate high-temperature and high-pressure synthesis gas; the synthesis gas at the outlet of the supercritical water gasification reactor 1 enters the supercritical turbine 3 through the third valve 2 to expand and generate electricity, and the synthesis gas at the outlet of the supercritical turbine 3 enters the first gas-liquid separator 5 through the first cooler 4 for gas-liquid separation; the water at the liquid phase outlet of the first gas-liquid separator 5 is mixed with the make-up water and pressurized by the water pump 13 before entering the cold end inlet of the feed water heat exchanger 9 The synthesis gas at the gas phase outlet of the No. 1 gas-liquid separator 5 is pressurized by the synthesis gas compressor 6 and then enters the burner 7, where it undergoes a complete oxidation reaction with oxygen. The carbon dioxide at the outlet of the carbon dioxide compressor 12 enters the burner 7 to adjust the inlet temperature of the gas turbine 8. The flue gas at the outlet of the gas turbine 8 enters the hot end of the feed water heat exchanger 9 to preheat the gasified feed water, and then enters the No. 2 gas-liquid separator 11 after being cooled by the No. 2 cooler 10. The liquid phase water of the No. 2 gas-liquid separator 11 is discharged from the system, and the gas phase carbon dioxide is partially circulated to the system through the carbon dioxide compressor 12, and the remaining carbon dioxide is completely captured. On the basis of the conventional operation mode, the first valve 14 is opened to enter the heat storage operation mode, which is suitable for the coal supercritical water gasification power generation system when the load is low. At this time, part of the synthesis gas at the outlet of the supercritical water gasification reactor 1 enters the hot end inlet of the heat storage heat exchanger 15 through the first valve 14, and the hot end outlet of the heat storage heat exchanger 15 is depressurized by the auxiliary turbine 18 and then mixed with the outlet of the supercritical turbine 3 to enter the No. 1 cooler 4; the outlet of the low-temperature heat storage tank 16 enters the high-temperature heat storage tank 17 through the cold end of the heat storage heat exchanger 15; On the basis of the conventional operation mode, the second valve 19 is opened to enter the heat release operation mode, which is suitable for the coal supercritical water gasification power generation system when it is at the peak load. At this time, part of the carbon dioxide at the outlet of the carbon dioxide compressor 12 enters the burner 7 through the cold end of the heat storage heat exchanger 15, and the outlet of the high-temperature heat storage tank 17 enters the low-temperature heat storage tank 16 through the hot end of the heat storage heat exchanger 15.

[0039] Among them, the carbon dioxide working medium at the gas phase outlet of the No. 2 gas-liquid separator 11 is pressurized by the carbon dioxide compressor 12 and then circulated to the inlet of the burner 7. By adjusting the circulation flow of the carbon dioxide working medium entering the burner 7, the inlet temperature of the gas turbine 8 reaches the set value.

[0040] When the load is low, the high-temperature heat of part of the synthesis gas at the outlet of the supercritical water gasification reactor 1 is recovered through the heat storage cycle, thereby reducing the power generation of the supercritical turbine 3; when the load is peak, the stored heat is released to part of the carbon dioxide working fluid at the outlet of the carbon dioxide compressor 12 to increase the inlet flow of the gas turbine 8, thereby increasing the power generation of the gas turbine 8.

[0041] 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.

[0042] 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.

[0043] 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 flexible power generation system with integrated thermal storage, characterized in that: The invention comprises a coal supercritical water gasification power generation system and a heat storage system and a heat release system coupled thereto; the heat storage system comprises a first valve (14), a heat storage heat exchanger (15), a high-temperature heat storage tank (17), a low-temperature heat storage tank (16) and an auxiliary turbine (18); the heat release system comprises a second valve (19), a heat storage heat exchanger (15), a high-temperature heat storage tank (17) and a low-temperature heat storage tank (16); the coal supercritical water gasification power generation system comprises a supercritical water gasification reactor (1), a carbon dioxide compressor (12) and a power generation unit; The first output end of the power generation unit is connected to the supercritical water gasification reactor (1), and the output end of the supercritical water gasification reactor (1) is divided into two paths, the first path is connected to the first input end of the power generation unit, and the second path is sequentially connected to the first valve (14), the heat storage heat exchanger (15), and the auxiliary turbine (18) to the second input end of the power generation unit. When storing heat, the output end of the low-temperature heat storage tank (16) is connected to the input end of the high-temperature heat storage tank (17) via the cold end of the heat storage heat exchanger (15); The second output end of the power generation unit is connected in sequence to the carbon dioxide compressor (12), the second valve (19), the heat storage heat exchanger (15) and the third input end of the power generation unit. When releasing heat, the output end of the high-temperature heat storage tank (17) is connected to the input end of the low-temperature heat storage tank (16) via the hot end of the heat storage heat exchanger (15).

2. A flexible power generation system with integrated thermal storage according to claim 1, characterized in that: The power generation unit includes a supercritical turbine (3), a No. 1 cooler (4), a No. 1 gas-liquid separator (5), a synthesis gas compressor (6), a burner (7), a gas turbine (8), a feed water heat exchanger (9), a No. 2 cooler (10), a No. 2 gas-liquid separator (11) and a water pump (13); The supercritical water gasification reactor is sequentially connected to a supercritical turbine (3), a No. 1 cooler (4) and a No. 1 gas-liquid separator (5); the output end of the No. 1 gas-liquid separator (5) is divided into two paths, the first path is connected to the first input end of a feed water heat exchanger (9) via a water pump (13), and the second path is sequentially connected to a synthesis gas compressor (6), a burner (7), and a gas turbine (8) to the second input end of the feed water heat exchanger (9); the output end of the feed water heat exchanger (9) is divided into two paths, the first path is the first output end of a power generation unit; the second path is sequentially connected to a No. 2 cooler (10) and a No. 2 gas-liquid separator (11), and the output end of the No. 2 gas-liquid separator (11) is the second output end of the power generation unit; The input end of the supercritical turbine (3) is the first input end of the power generation unit, the input end of the first cooler (4) is the second input end of the power generation unit, and the input end of the burner (7) is the third input end of the power generation unit.

3. A flexible power generation system with integrated thermal storage according to claim 2, characterized in that: The inlet temperature of the gas turbine (8) is 1100°C~1500°C, and the inlet pressure is 1.5 MPa~3 MPa.

4. A flexible power generation system with integrated thermal storage according to claim 2, characterized in that: The power generation unit also includes a third valve (2), and the supercritical water gasification reactor is connected to the supercritical turbine (3) via the third valve (2).

5. A flexible power generation system with integrated thermal storage according to claim 2, characterized in that: The outlet temperatures of the first cooler (4) and the second cooler (10) are 20°C to 40°C.

6. A flexible power generation system with integrated thermal storage according to claim 1, characterized in that: The operating temperature of the supercritical water gasification reactor (1) is 500°C to 800°C, and the operating pressure is 25MPa to 30MPa.

7. A flexible power generation system with integrated thermal storage according to claim 1, characterized in that: The heat storage medium of the heat storage system and the heat release system is molten salt.

8. A method for operating a flexible power generation system with integrated thermal storage, characterized in that: A flexible power generation system with integrated heat storage as described in any one of claims 1 to 7 is used. When the coal supercritical water gasification power generation system is in a low load valley, the first valve (14) is opened and the second valve (19) is closed. The synthesis gas at the outlet of the supercritical water gasification reactor (1) enters the hot end inlet of the heat storage heat exchanger (15) through the first valve (14). The hot end outlet of the heat storage heat exchanger (15) enters the second input end of the power generation unit after pressure relief through the auxiliary turbine (18). At this time, the heat storage medium at the outlet of the low-temperature heat storage tank (16) enters the high-temperature heat storage tank (17) through the cold end of the heat storage heat exchanger (15). By recovering the high-temperature heat of the synthesis gas at the outlet of the supercritical water gasification reactor (1), the power generation of the power generation unit is reduced. When the coal supercritical water gasification power generation system is at a peak load, the first valve (14) is closed and the second valve (19) is opened, and the carbon dioxide at the outlet of the carbon dioxide compressor (12) enters the third input end of the power generation unit through the second valve (19) and the heat storage heat exchanger (15). At this time, the heat storage working fluid at the outlet of the high-temperature heat storage tank (17) enters the low-temperature heat storage tank (16) through the hot end of the heat storage heat exchanger (15), and releases the stored heat to the carbon dioxide at the outlet of the carbon dioxide compressor (12), thereby increasing the power generation of the power generation unit.

9. The method for operating a flexible power generation system with integrated thermal storage according to claim 8, characterized in that: The load peak is the time period when the load value of the coal supercritical water gasification power generation system exceeds 80% of the rated load.

10. The method for operating a flexible power generation system with integrated thermal storage according to claim 8, characterized in that: The load valley is a time period when the load value of the coal supercritical water gasification power generation system is lower than 30% of the rated load.

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