Integrated heat storage flexible power generation system and operation method

Abstract

The application discloses a kind of integrated heat storage flexible power generation system and operating method, belong to coal-fired power generation technical field.The integrated heat storage flexible power generation system provided by the present application, by coupling heat storage system, heat releasing system and supercritical water gasification technology deeply, build the two-way regulation ability of heat storage and heat release of coal supercritical water gasification power generation system, by adjusting first valve and second valve, recover the high-temperature heat of synthesis gas at the outlet of supercritical water gasification reactor to reduce power output at load low point, release stored heat to carbon dioxide at the outlet of carbon dioxide compressor at load peak, increase power output, can effectively respond to load fluctuation, enhance the peak shaving capability of system, meet the flexible operation demand of modern power grid;By the combination of heat storage system and heat releasing system, optimize energy distribution, reduce irreversible heat loss, to improve the comprehensive energy utilization efficiency of coal-fired power generation.

Description

TECHNICAL FIELD

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

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

[0003] Coal supercritical water gasification technology is a kind of coal clean and efficient conversion technology, which can convert the organic matter in coal into synthesis gas mainly composed of hydrogen and carbon dioxide in a supercritical water atmosphere, and nitrogen, sulfur, phosphorus, mercury and other elements are deposited in the reactor in the form of inorganic salts, which is easy to realize the separation of pollutants, 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, and coal supercritical water gasification technology can be applied to the field of power generation to improve the environmental protection of the power generation system. When coal supercritical water gasification technology is applied to power generation, the power generation system needs to heat the feed water to a supercritical state in a heat exchange manner to provide reaction raw materials for the gasification reaction.

[0004] However, with the increasing proportion of renewable energy in the power grid, the volatility of power grid load is increasing. The traditional coal supercritical water gasification power generation system has large boiler thermal inertia and slow regulation response speed, and it is difficult to quickly adapt to the frequent changes of load, which puts higher requirements on the operation flexibility of the system.

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

[0006] The purpose of the present application is to provide a flexible power generation system integrated with heat storage and an operation method thereof, in order to overcome the deficiencies of the existing coal supercritical water gasification power generation system in quickly responding to the changes of power grid load.

[0007] The present application solves the above technical problems by the following technical solutions:

[0008] The application discloses a flexible power generation system integrated with heat storage, which comprises a coal supercritical water gasification power generation system and a heat storage system and a heat release system coupled with the coal supercritical water gasification power generation system; 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, the heat storage heat exchanger, the high-temperature heat storage tank and the 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.

[0009] The first output end of the power generation unit is connected with the supercritical water gasification reactor, and the output end of the supercritical water gasification reactor is divided into two paths, one of which is connected with the first input end of the power generation unit, and the other of which is connected with the first valve, the heat storage heat exchanger, the auxiliary turbine and the second input end of the power generation unit in sequence; during heat storage, the output end of the low-temperature heat storage tank is connected with the input end of the high-temperature heat storage tank through the cold end of the heat storage heat exchanger.

[0010] The second output end of the power generation unit is connected with the carbon dioxide compressor, the second valve, the heat storage heat exchanger and the third input end of the power generation unit in sequence, and during heat release, the output end of the high-temperature heat storage tank is connected with the input end of the low-temperature heat storage tank through the hot end of the heat storage heat exchanger.

[0011] The application further improves that the power generation unit comprises a supercritical turbine, a first cooler, a first gas-liquid separator, a synthetic gas compressor, a burner, a gas turbine, a feed water heat exchanger, a second cooler, a second gas-liquid separator and a water pump.

[0012] The supercritical water gasification reactor is connected with the supercritical turbine, the first cooler and the first gas-liquid separator in sequence, the output end of the first gas-liquid separator is divided into two paths, one of which is connected with the first input end of the feed water heat exchanger through the water pump, and the other of which is connected with the synthetic gas compressor, the burner and the gas turbine and the second input end of the feed water heat exchanger in sequence; the output end of the feed water heat exchanger is divided into two paths, one of which is the first output end of the power generation unit, and the other of which is connected with the second cooler and the second gas-liquid separator in sequence, and the output end of the second gas-liquid separator is the second output end of the power generation unit.

[0013] The input end of the supercritical turbine is the first input end of the power generation unit, the input end of the first 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.

[0014] The application further improves that the inlet temperature of the gas turbine is 1100-1500 DEG C, and the inlet pressure is 1.5-3 MPa.

[0015] The application further improves that the power generation unit further comprises a third valve, and the supercritical water gasification reactor is connected with the supercritical turbine through the third valve.

[0016] The further improvement of the present application is that the outlet temperature of the first cooler and the second cooler is 20-40 DEG C.

[0017] The further improvement of the present application is that the operation temperature of the supercritical water gasification reactor is 500-800 DEG C, and the operation pressure is 25-30 MPa.

[0018] The further improvement of the present application is that the heat storage medium of the heat storage system and the heat release system is molten salt.

[0019] The present application also provides a running method of the integrated heat storage flexible power generation system, and the integrated heat storage flexible power generation system is used, when the coal supercritical water gasification power generation system is in a load valley, the first valve is opened, the second valve is closed, the synthesis gas at the outlet of the supercritical water gasification reactor enters the heat storage heat exchanger hot end inlet through the first valve, and the heat storage heat exchanger hot end outlet enters the second input end of the power generation unit after being discharged by the auxiliary turbine; at this time, the heat storage working medium at the outlet of the low-temperature heat storage tank enters the high-temperature heat storage tank through the heat storage heat exchanger cold end, the high-temperature heat of the synthesis gas at the outlet of the supercritical water gasification reactor is recovered, and the power generation capacity of the power generation unit is reduced.

[0020] When the coal supercritical water gasification power generation system is in a load peak, the first valve is closed, 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 medium at the outlet of the high-temperature heat storage tank enters the low-temperature heat storage tank through the heat storage heat exchanger hot end, the stored heat is released to the carbon dioxide at the outlet of the carbon dioxide compressor, and the power generation capacity of the power generation unit is increased.

[0021] The further improvement of the present application is that the load peak is a time period in which the load value of the coal supercritical water gasification power generation system exceeds 80% of the rated load.

[0022] The further improvement of the present application is that the load valley is a time period in which the load value of the coal supercritical water gasification power generation system is less than 30% of the rated load.

[0023] Compared with the prior art, the positive progress effect of the present application is that:

[0024] The application provides a flexible power generation system integrated with heat storage, which is capable of effectively responding to load fluctuation, enhancing the peak shaving capacity of the system and meeting the flexible operation requirement of a modern power grid by deeply coupling a heat storage system, a heat release system and a supercritical water gasification technology, constructing the bidirectional regulation capacity of heat storage and heat release of the coal supercritical water gasification power generation system, recovering the high-temperature heat of synthesis gas at the outlet of the supercritical water gasification reactor to reduce power generation output when the load is low by adjusting the first valve and the second valve, releasing the stored heat to carbon dioxide at the outlet of the carbon dioxide compressor to increase the power generation output when the load is high, optimizing energy distribution, reducing irreversible heat loss and thereby improving the comprehensive energy utilization efficiency of coal-fired power generation by the combination of the heat storage system and the heat release system. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings are included to provide a further understanding of the application, and are incorporated in and constitute a part of this application, illustrate embodiments of the application and serve to explain the principles of the application, and are not intended to limit the application.

[0026] Figure 1 It is a connection schematic diagram of the flexible power generation system integrated with heat storage of the application;

[0027] Figure 2 It is a connection schematic diagram of the coal supercritical water gasification power generation system;

[0028] Figure 3 It is a connection schematic diagram of the flexible power generation system integrated with heat storage when heat storage;

[0029] Figure 4 It is a connection schematic diagram of the flexible power generation system integrated with heat storage when heat release;

[0030] 1 is a supercritical water gasification reactor, 2 is a third valve, 3 is a supercritical turbine, 4 is a first cooler, 5 is a first gas-liquid separator, 6 is a synthesis gas compressor, 7 is a combustor, 8 is a gas turbine, 9 is a feedwater heat exchanger, 10 is a second cooler, 11 is a second 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

[0031] To make the objects, technical solutions and advantages of the embodiments of the application clearer, the technical solutions in the embodiments of the application will be described below in connection with the drawings in the embodiments of the application. Obviously, the described embodiments are only some of the embodiments of the application, rather than all the embodiments of the application. The components of the embodiments of the application described and shown in the drawings can be arranged and designed in various different configurations.

[0032] The following detailed description of embodiments of the application in conjunction with the appended drawings is intended as a description of selected embodiments of the application solely and is not intended to limit the scope of the application, as described in the claims.

[0033] It should be noted that like reference numerals and letters refer to like items in the following drawings and thus, once an item is defined in one drawing, it is not necessary to further define and explain it in the subsequent drawings.

[0034] In the description of the embodiments of the application, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "horizontal", "inner", and the like, is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the application is usually placed, and is only for the convenience of describing the application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. In addition, the terms "first", "second", and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0035] In addition, it should be noted that, unless otherwise explicitly specified and limited, the terms "provided", "mounted", "connected", "linked", and the like should be broadly understood, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, can be electrically connected; can be directly connected, or indirectly connected through an intermediate medium; can be internal communication of two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0036] The application will be further described in detail below in conjunction with the drawings and specific embodiments, which are an explanation of the application rather than a limitation.

[0037] The integrated heat storage flexible power generation system comprises 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 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, the heat storage heat exchanger 15, the high-temperature heat storage tank 17, and the 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;

[0038] The first output end of the power generation unit is connected with 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 with the first input end of the power generation unit, and the second path is connected with the first valve 14, the heat storage heat exchanger 15, the auxiliary turbine 18 to the second input end of the power generation unit in sequence; when heat storage, the output end of the low-temperature heat storage tank 16 is connected with the input end of the high-temperature heat storage tank 17 through the cold end of the heat storage heat exchanger 15.

[0039] The second output end of the power generation unit is connected with the carbon dioxide compressor 12, the second valve 19, the heat storage heat exchanger 15 to the third input end of the power generation unit in sequence, and when heat release, the output end of the high-temperature heat storage tank 17 is connected with the input end of the low-temperature heat storage tank 16 through the hot end of the heat storage heat exchanger 15.

[0040] By deeply coupling the heat storage system, the heat release system and the supercritical water gasification technology, the bidirectional adjustment ability of the coal supercritical water gasification power generation system for heat storage and heat release is constructed, the first valve and the second valve are adjusted, the high-temperature heat of the synthesis gas at the outlet of the supercritical water gasification reactor is recovered at the load valley to reduce the power generation output, and the stored heat is released to the carbon dioxide at the outlet of the carbon dioxide compressor at the load peak to increase the power generation output, so that the load fluctuation can be effectively coped with, the peak shaving ability of the system is enhanced, the modern power grid flexibility operation demand is met, the energy distribution is optimized through the combination of the heat storage system and the heat release system, the irreversible heat loss is reduced, and therefore the comprehensive energy utilization efficiency of the coal-fired power generation is improved.

[0041] Specifically, the power generation unit comprises a supercritical turbine 3, a first cooler 4, a first gas-liquid separator 5, a synthesis gas compressor 6, a combustor 7, a gas turbine 8, a feedwater heat exchanger 9, a second cooler 10, a second gas-liquid separator 11 and a water pump 13.

[0042] The supercritical water gasification reactor is connected with the supercritical turbine 3, the first cooler 4 and the first gas-liquid separator 5 in sequence, the output end of the first gas-liquid separator 5 is divided into two paths, the first path is connected with the first input end of the feedwater heat exchanger 9 through the water pump 13, and the second path is connected with the synthesis gas compressor 6, the combustor 7 and the gas turbine 8 to the second input end of the feedwater heat exchanger 9 in sequence; the output end of the feedwater heat exchanger 9 is divided into two paths, the first path is the first output end of the power generation unit, and the second path is connected with the second cooler 10 and the second gas-liquid separator 11 in sequence, and the output end of the second gas-liquid separator 11 is the second output end of the power generation unit.

[0043] 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 combustor 7 is the third input end of the power generation unit.

[0044] Specifically, the inlet temperature of the gas turbine 8 is 1100℃-1500℃, and the inlet pressure is 1.5 MPa-3 Mpa.

[0045] Specifically, the power generation unit further comprises a third valve 2, and the supercritical water gasification reactor is connected with the supercritical turbine 3 through the third valve 2.

[0046] Specifically, the outlet temperature of the first cooler 4 and the second cooler 10 is 20-40℃.

[0047] Specifically, the operation temperature of the supercritical water gasification reactor 1 is 500-800℃, and the operation pressure is 25-30 MPa.

[0048] Specifically, the heat storage medium of the heat storage system and the heat release system is molten salt.

[0049] Based on the same inventive concept, the application further provides a running method of the integrated heat storage flexible power generation system, which adopts the integrated heat storage flexible power generation system as described above, and the running method is described below with reference to Figure 3 When the coal supercritical water gasification power generation system is in a load valley, the first valve 14 is opened, 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 outlet of the hot end 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 working 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, the high-temperature heat of the synthesis gas at the outlet of the supercritical water gasification reactor 1 is recovered, and the power generation capacity of the power generation unit is reduced.

[0050] Referring to Figure 4 When the coal supercritical water gasification power generation system is in a load peak, the first valve 14 is closed, 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 working 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, the stored heat is released to the carbon dioxide at the outlet of the carbon dioxide compressor 12, and the power generation capacity of the power generation unit is increased.

[0051] Specifically, the load peak is a time period in which the load value of the coal supercritical water gasification power generation system exceeds 80% of the rated load, generally a time period of 8:00-11:00 every day and a time period of 18:00-21:00 every day.

[0052] Specifically, the load valley is a time in which the load value of the coal supercritical water gasification power generation system is lower than 30% of the rated load, generally a time period of 2:00-5:00 every day.

[0053] Example 1

[0054] Referring to Figure 1 and Figure 2The application discloses a flexible power generation system integrated with heat storage.

[0055] The coal supercritical water gasification power generation system comprises a supercritical water gasification reactor 1, a third valve 2, a supercritical turbine 3, a first cooler 4, a first gas-liquid separator 5, a synthetic gas compressor 6, a burner 7, a gas turbine 8, a feed water heat exchanger 9, a second cooler 10, a second gas-liquid separator 11, a carbon dioxide compressor 12 and a water pump 13; coal, oxygen and the cold end outlet of the feed water heat exchanger 9 are respectively connected to the inlet of the supercritical water gasification reactor 1, and ash is discharged from the outlet of the supercritical water gasification reactor 1; synthetic gas is connected to the inlet of the supercritical turbine 3 through the third valve 2 from the outlet of the supercritical water gasification reactor 1; the outlet of the supercritical turbine 3 is connected to the inlet of the first gas-liquid separator 5 through the first cooler 4; the liquid phase outlet and make-up water of the first gas-liquid separator 5 are connected to the cold end inlet of the feed water heat exchanger 9 through the water pump 13; 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 first gas-liquid separator 5 is connected to the inlet of the burner 7 through the synthetic gas compressor 6; the outlets of the oxygen and carbon dioxide compressors 12 are also respectively connected to the inlet of the burner 7; the outlet of the burner 7 is connected to the inlet of the gas turbine 8; 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 second gas-liquid separator 11 through the second cooler 10; the liquid phase water of the second gas-liquid separator 11 is discharged through a system; the gas phase carbon dioxide is partially discharged through a system, and part of the gas phase carbon dioxide is connected to the inlet of the burner 7 through the carbon dioxide compressor 12;

[0056] Referring to Figure 3 The heat storage system further comprises 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 synthetic gas from 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.

[0057] Referring to Figure 4, the heat releasing system further comprises a second valve 19, a heat storage and heat exchange device 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 and heat exchange device 15 through the second valve 19, the cold end outlet of the heat storage and heat exchange device 15 is connected to the inlet of the combustor 7; the outlet of the high-temperature heat storage tank 17 is connected to the hot end inlet of the heat storage and heat exchange device 15, and the hot end outlet of the heat storage and heat exchange device 15 is connected to the inlet of the low-temperature heat storage tank 16.

[0058] Example two

[0059] A method for operating a flexible power generation system integrated with heat storage, which uses the flexible power generation system integrated with heat storage as described in Example one, and includes a normal operation mode, a heat storage operation mode and a heat releasing operation mode.

[0060] The third valve 2 is opened, and the first valve 14 and the second valve 19 are closed to form the normal operation mode. At this time, coal, oxygen and gasification feed water at the cold end outlet of the feed water heat exchanger 9 enter the supercritical water gasification reactor 1 to generate a supercritical water gasification reaction, thereby generating 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 to expand and generate power, and the synthesis gas at the outlet of the supercritical turbine 3 enters the first cooler 4 to be separated into gas and liquid in the first gas-liquid separator 5. The water at the liquid phase outlet of the first gas-liquid separator 5 is mixed with make-up water, pressurized by the water pump 13, and then enters the cold end inlet of the feed water heat exchanger 9 to be preheated. The synthesis gas at the gas phase outlet of the first gas-liquid separator 5 is pressurized by the synthesis gas compressor 6, and then enters the combustor 7 to have a complete oxidation reaction with oxygen. The carbon dioxide at the outlet of the carbon dioxide compressor 12 enters the combustor 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 gasification feed water, and then enters the second gas-liquid separator 11 after being cooled by the second cooler 10. The liquid phase water of the second gas-liquid separator 11 is discharged from the system, and part of the gas phase carbon dioxide is circulated to the system by the carbon dioxide compressor 12, and the remaining carbon dioxide is completely captured.

[0061] On the basis of the normal operation mode, the first valve 14 is opened to form the heat storage operation mode. This mode is suitable for the coal supercritical water gasification power generation system at a low load valley. 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 and heat exchange device 15 through the first valve 14, the hot end outlet of the heat storage and heat exchange device 15 is depressurized by the auxiliary turbine 18, and then mixed with the outlet of the supercritical turbine 3 to enter the first 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 and heat exchange device 15.

[0062] On the basis of the normal operation mode, the second valve 19 is opened to form a heat releasing operation mode, which is suitable for the coal supercritical water gasification power generation system in a load peak period. At this time, part of the carbon dioxide at the outlet of the carbon dioxide compressor 12 enters the combustor 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.

[0063] Part of the carbon dioxide at the gas phase outlet of the second gas-liquid separator 11 is pressurized by the carbon dioxide compressor 12 and then connected in circulation to the inlet of the combustor 7. By adjusting the circulation flow rate of the carbon dioxide working medium into the combustor 7, the inlet temperature of the gas turbine 8 can be set to a desired value.

[0064] At a load valley period, the high-temperature heat of part of the synthesis gas at the outlet of the supercritical water gasification reactor 1 is recovered by a heat storage cycle, thereby reducing the power generation capacity of the supercritical turbine 3. At a load peak period, the stored heat is released to part of the carbon dioxide working medium at the outlet of the carbon dioxide compressor 12, thereby increasing the inlet flow rate of the gas turbine 8 and thus increasing the power generation capacity of the gas turbine 8.

[0065] Finally, it should be noted that the above-mentioned embodiments are only one or more specific forms of the technical solutions of the present application, and their purpose is to clearly explain the concept, principle and application mode of the present application through specific examples, and are not intended to limit the protection scope of the present application to these specific embodiments. In fact, the true value of the present application lies in its proposed technical ideas and innovative points, not its forms or implementation methods.

[0066] For ordinary skilled persons in the art, after thoroughly reading and understanding the technical solutions of the present application, they can certainly make various forms of changes, modifications or equivalent replacements to the specific embodiments of the present application 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 the algorithm flow to improve efficiency, replacing part of the technical components to achieve better compatibility or reduce costs, etc. As long as the technical solutions after these changes still maintain the technical features required by the original application, i.e. still can realize the core functions and effects of the present application, these changes should be considered as falling within the protection scope of the claims of the present application.

[0067] In addition, with the continuous progress and development of technology, new technical means and methods are constantly emerging, which also provides a broad space for the further improvement and perfection of the present application. Therefore, the protection scope of the present application should also include those reasonable and 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 concept of the present application, they should be considered as the equivalents of the present application and also be protected by the patent right.

Claims

1. A flexible power generation system integrating thermal storage, characterized in that, It includes a coal supercritical water gasification power generation system and a coupled thermal storage system and thermal release system; the thermal storage system includes a first valve (14), a thermal storage heat exchanger (15), a high-temperature thermal storage tank (17), a low-temperature thermal storage tank (16) and an auxiliary turbine (18); the thermal release system includes a second valve (19), a thermal storage heat exchanger (15), a high-temperature thermal storage tank (17) and a low-temperature thermal 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 connected in sequence to the first valve (14), the heat storage heat exchanger (15), the auxiliary turbine (18) to the second input end of the power generation unit. During heat storage, 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) through 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) through the hot end of the heat storage heat exchanger (15). The power generation unit includes a supercritical turbine (3), a first cooler (4), a first gas-liquid separator (5), a syngas compressor (6), a burner (7), a gas turbine (8), a feedwater heat exchanger (9), a second cooler (10), a second gas-liquid separator (11) and a water pump (13). The supercritical water gasification reactor is connected in sequence to the supercritical turbine (3), the first cooler (4), and the first gas-liquid separator (5). The output of the first gas-liquid separator (5) is divided into two paths. The first path is connected to the first input of the feedwater heat exchanger (9) via the water pump (13). The second path is connected in sequence to the synthesis gas compressor (6), the burner (7), and the gas turbine (8) to the second input of the feedwater heat exchanger (9). The output of the feedwater heat exchanger (9) is divided into two paths. The first path is the first output of the power generation unit. The second path is connected in sequence to the second cooler (10) and the second gas-liquid separator (11). The output of the second gas-liquid separator (11) is the second output 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.

2. The flexible power generation system with integrated thermal storage according to claim 1, characterized in that, The inlet temperature of the gas turbine (8) is 1100℃~1500℃ and the inlet pressure is 1.5 MPa~3 Mpa.

3. The flexible power generation system with integrated thermal storage according to claim 1, 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).

4. The flexible power generation system with integrated thermal storage according to claim 1, characterized in that, The outlet temperatures of the No. 1 cooler (4) and the No. 2 cooler (10) are 20℃~40℃.

5. The flexible power generation system with integrated thermal storage according to claim 1, characterized in that, The supercritical water gasification reactor (1) operates at a temperature of 500℃~800℃ and a pressure of 25MPa~30MPa.

6. The flexible power generation system with integrated thermal storage according to claim 1, characterized in that, The heat storage medium for both the heat storage and heat release systems is molten salt.

7. An operation method for a flexible power generation system integrating thermal storage, characterized in that, Using the flexible power generation system with integrated thermal storage as described in any one of claims 1 to 6, 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 syngas from the outlet of the supercritical water gasification reactor (1) enters the hot end inlet of the thermal storage heat exchanger (15) through the first valve (14). The hot end outlet of the thermal 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 thermal storage medium from the outlet of the low-temperature thermal storage tank (16) enters the high-temperature thermal storage tank (17) through the cold end of the thermal storage heat exchanger (15). By recovering the high-temperature heat of the syngas from 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 its peak load, the first valve (14) is closed and the second valve (19) is opened. The carbon dioxide from 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 from 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), releasing the stored heat to the carbon dioxide from the outlet of the carbon dioxide compressor (12), thereby increasing the power generation of the power generation unit.

8. The operation method of the flexible power generation system with integrated thermal storage according to claim 7, characterized in that, The peak load refers to the period during which the load value of the coal supercritical water gasification power generation system exceeds 80% of the rated load.

9. The operation method of the flexible power generation system with integrated thermal storage according to claim 7, characterized in that, The load trough refers to the 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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