Carbon capture and energy storage and thermal power generation coupled energy comprehensive utilization system

Abstract

The invention discloses a carbon capture and energy storage and thermal power generation coupled energy comprehensive utilization system, which comprises a thermal power generation system, an energy storage system and a carbon capture system, and is characterized in that a compression energy storage unit of the energy storage system is coupled to a feed water heat regeneration unit of the thermal power generation system; an expansion energy release unit of the energy storage system is coupled to a steam turbine generator set of the thermal power generation system, and a steam-water cycle working medium in the thermal power generation system serves as a heat storage and cold storage medium of the carbon dioxide energy storage system. The carbon capture system is coupled between the thermal power generation system and the carbon dioxide energy storage system, captures carbon dioxide gas in the flue gas, inputs the carbon dioxide gas into the carbon dioxide energy storage system to serve as a circulating working medium, and heats the circulating working medium in the expansion energy release unit through waste heat of the flue gas. According to the scheme, the operation efficiency of the thermal power generation system and the operation efficiency of the carbon dioxide energy storage system can be improved, the overall energy utilization efficiency of the system can be improved, and meanwhile the emission amount of gas pollutants is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of comprehensive energy utilization, and in particular to a comprehensive energy utilization system coupling carbon capture and energy storage with thermal power generation. Background Art

[0002] Based on many factors such as the optimization and adjustment of energy structure and strict control of industrial pollutants, increasing the installed capacity and proportion of renewable energy power generation is the main development trend of the energy industry. At the same time, the main function of thermal power generation has also undergone a corresponding change, from the main power supply to participating in and cooperating with the power grid to carry out deep peak regulation. However, due to weather and climate conditions, wind power, solar thermal, photovoltaic and other renewable energy power generation methods are generally intermittent and highly volatile. In order to make up for the reduction in grid stability caused by the integration of renewable energy, thermal power units and energy storage equipment need to undertake heavier peak regulation tasks.

[0003] The energy storage technology based on the gas-liquid phase change cycle of carbon dioxide uses excess electricity or clean energy to compress and condense the gaseous carbon dioxide at room temperature and pressure in the gas storage bin into liquid carbon dioxide and store it in a storage tank during the low-power consumption period, and stores the heat energy generated during the compression process. During the peak power consumption period, the stored heat energy is used to heat the liquid carbon dioxide to a gas state. The gaseous carbon dioxide drives the turbine to drive the generator to generate electricity, and the gaseous carbon dioxide after doing work returns to the gas storage bin for recycling. It has the advantages of simple structure, flexible layout, and high energy storage efficiency, and has gradually attracted widespread attention.

[0004] At present, there is no comprehensive energy utilization system in the industry that deeply couples carbon capture, carbon dioxide storage and thermal power generation. Summary of the invention

[0005] In view of this, the present invention provides an energy comprehensive utilization system that couples carbon capture and energy storage with thermal power generation to solve the problem of how to deeply couple carbon capture, carbon dioxide energy storage and thermal power generation, thereby improving the system's energy comprehensive utilization efficiency and reducing the emission of gaseous pollutants.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: An energy comprehensive utilization system coupling carbon capture and energy storage with thermal power generation, comprising: Thermal power generation system, including coal-fired boiler unit, steam turbine generator set and feedwater heat recovery unit; The energy storage system comprises a compression energy storage unit and an expansion energy release unit; the compression energy storage unit is coupled to the feed water heat recovery unit, condensed water is drawn from the feed water heat recovery unit, the circulating working medium in the compression energy storage unit is cooled and the temperature of the condensed water is increased; the expansion energy release unit is coupled to the steam turbine generator set, steam is drawn from the steam turbine generator set, and the circulating working medium in the expansion energy release unit is heated; A carbon capture system, coupled between the coal-fired boiler unit and the energy storage system, captures carbon dioxide gas in the flue gas of the coal-fired boiler unit and inputs it into the energy storage system as a circulating working fluid; Wherein, the energy storage system further comprises a gas storage unit and a liquid storage unit, and the carbon capture system comprises a carbon dioxide collector, a carbon dioxide compressor, a dryer, a liquefier and a storage container connected in sequence; The carbon dioxide collector is connected to the coal-fired boiler unit via a first connecting pipeline, and the first connecting pipeline is coupled to the expansion energy release unit, and the waste heat of the flue gas is used to heat the circulating working medium in the expansion energy release unit; The dryer is connected to the gas storage unit via a second connecting pipeline, a pressure reducing mechanism is provided on the second connecting pipeline, the carbon dioxide collector captures the carbon dioxide gas in the flue gas, and after being compressed by the carbon dioxide compressor and dried by the dryer, the carbon dioxide gas is input into the gas storage unit via the second connecting pipeline; The liquefier is connected to the liquid storage unit via a third connecting pipeline, and the liquid carbon dioxide liquefied by the liquefier is input into the liquid storage unit via the third connecting pipeline.

[0007] In a specific embodiment, the thermal power generation system also includes a feedwater heater connected between the coal-fired boiler unit and the feedwater heat recovery unit, and the carbon dioxide compressor is coupled to the feedwater heater. The heat generated by the carbon dioxide compressor compressing the carbon dioxide gas is transmitted to the feedwater heater, and the boiler feed water output from the feedwater heat recovery unit is heated before being transmitted to the coal-fired boiler unit.

[0008] In a specific scheme, the feed water heat recovery unit includes a low-pressure heater, a deaerator and a feed water pump connected in sequence; the condensed water is drawn out from the inlet end of the low-pressure heater, cools the circulating working fluid in the compression energy storage unit and increases the temperature, and then is transported to the outlet end of the low-pressure heater.

[0009] In a specific scheme, the compressed energy storage unit includes a first-stage compressor, a first-stage heat exchanger, a second-stage compressor and a second-stage heat exchanger connected in sequence; the condensed water drawn out from the inlet end of the low-pressure heater is respectively transported to the first-stage heat exchanger and the second-stage heat exchanger to cool the circulating working fluid in the first-stage heat exchanger and the second-stage heat exchanger and increase the temperature.

[0010] In a specific embodiment, the compression energy storage unit further includes a preheater connected to an inlet end of the first-stage compressor and a condenser connected to an outlet end of the second-stage heat exchanger.

[0011] In a specific embodiment, the steam turbine generator set includes a steam turbine and a condenser which are connected to each other; the steam is drawn from the steam turbine, heats the circulating working fluid in the expansion energy release unit, and is then transported to the condenser.

[0012] In a specific embodiment, the expansion energy release unit includes a third-stage heat exchanger, a first-stage turbine, a fourth-stage heat exchanger and a second-stage turbine connected in sequence; the steam drawn out from the steam turbine is respectively transported to the third-stage heat exchanger and the fourth-stage heat exchanger to heat the circulating working fluid in the third-stage heat exchanger and the fourth-stage heat exchanger.

[0013] In a specific embodiment, the expansion energy release unit further includes an evaporator connected to the inlet end of the third-stage heat exchanger, and the first connecting pipeline is coupled to the evaporator to heat the circulating working medium in the evaporator using the waste heat of the flue gas.

[0014] An energy comprehensive utilization system that couples carbon capture and energy storage with thermal power generation provided in an embodiment of the present invention deeply couples a thermal power generation system, a carbon dioxide energy storage system, and a carbon capture system. On the one hand, the steam-water cycle working fluid in the thermal power generation system is used as a heat storage and cold storage medium for the carbon dioxide energy storage system, which can not only improve the operating efficiency of the thermal power generation system and the carbon dioxide energy storage system, but also improve the overall energy utilization efficiency of the system; further, the carbon dioxide energy storage system does not need to be equipped with additional heat storage devices and cold storage devices, and the system structure is simplified. On the other hand, the carbon capture system is coupled between the thermal power generation system and the carbon dioxide energy storage system to capture the carbon dioxide gas in the flue gas emitted by the thermal power generation system and input it into the carbon dioxide energy storage system as a circulating working fluid. This not only reduces the emission of gaseous pollutants from the thermal power generation system, but also enables recycling and reuse to increase its added value. Furthermore, in the process of capturing carbon dioxide gas, the carbon capture system couples the waste heat of the flue gas emitted by the thermal power generation system to the carbon dioxide energy storage system, and uses the waste heat of the flue gas to heat the carbon dioxide circulating working fluid in the expansion energy release unit, thereby further improving energy utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of an energy comprehensive utilization system coupling carbon capture and energy storage with thermal power generation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical scheme and advantages of the present invention clearer, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Examples of these preferred embodiments are illustrated in the accompanying drawings. The embodiments of the present invention shown in the accompanying drawings and described according to the accompanying drawings are merely exemplary, and the present invention is not limited to these embodiments.

[0017] It should be noted that the same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limitations on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0018] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions according to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0019] The embodiment of the present invention provides an energy comprehensive utilization system coupling carbon capture and energy storage with thermal power generation, see Figure 1 The comprehensive energy utilization system includes a deeply coupled thermal power generation system 1, an energy storage system 2 and a carbon capture system 3.

[0020] Among them, Figure 1 As shown, the thermal power generation system 1 includes a coal-fired boiler unit 11, a steam turbine generator set 12 and a feed water heat recovery unit 13. The coal-fired boiler unit 11 heats water to evaporate water to form steam, which is then transported to the steam turbine generator set 12. The steam turbine generator set 12 generates electricity using steam. The steam releases energy through the steam turbine generator set 12 and is condensed to form condensed water, which is then transported to the feed water heat recovery unit 13. The feed water heat recovery unit 13 heats the condensed water and then transports it to the coal-fired boiler unit 11.

[0021] As a specific example, in this embodiment, Figure 1As shown, the coal-fired boiler unit 11 includes a coal-fired boiler 111 and a chimney 112. The feedwater heat recovery unit 13 heats the condensed water and then transports it to the coal-fired boiler 111 for heating and evaporation. The flue gas generated by the coal-fired boiler 111 is discharged through the chimney 112. The steam turbine generator set 12 includes a steam turbine 121 and a condenser 122 that are connected to each other. The steam generated by the coal-fired boiler unit 11 is transported to the steam turbine 121. The steam turbine 121 drives the corresponding generator to generate electricity. The steam releases energy through the steam turbine 121 and then is transported to the condenser 122. The steam is condensed by the condenser 122 to form condensed water and then transported to the feedwater heat recovery unit 13. The feed water heat recovery unit 13 includes a low-pressure heater 131, a deaerator 132 and a feed water pump 133 which are connected in sequence. The condensed water output from the condenser 122 is heated by the low-pressure heater 131, deoxygenated by the deaerator 132, and then transported to the coal-fired boiler unit 11 by the feed water pump 133.

[0022] Among them, the energy storage system 2 is a carbon dioxide energy storage system, and the energy storage system 2 mainly includes a gas storage unit 21, a compression energy storage unit 22, a liquid storage unit 23 and an expansion energy release unit 24 which are connected in a closed loop in sequence. The gas storage unit 21 is used to store gaseous carbon dioxide at normal pressure, and the liquid storage unit 23 is used to store liquid carbon dioxide. The gaseous carbon dioxide flowing out of the gas storage unit 21 is converted into liquid carbon dioxide with a preset energy storage pressure through the compression energy storage unit 22, and flows into the liquid storage unit 23, and energy storage is completed in this process. The liquid carbon dioxide output from the liquid storage unit 23 releases energy through the expansion energy release unit 24 and is converted into gaseous carbon dioxide at normal pressure, and flows into the gas storage unit 21, and energy release and application are completed in this process. Typically, the compression energy storage unit 22 compresses gaseous carbon dioxide into liquid carbon dioxide and stores it in the liquid storage unit 23 during off-peak hours or when wind and solar power is abandoned, converting the energy into compression energy and thermal energy for storage; during peak hours, the expansion energy release unit 24 vaporizes and expands the liquid carbon dioxide to do work, releasing the stored energy and converting it into electrical energy for use.

[0023] Among them, the specific composition structures of the gas storage unit 21, the compression energy storage unit 22, the liquid storage unit 23 and the expansion energy release unit 24 can be realized by referring to existing technologies, such as the technical solutions disclosed in the existing patent documents CN116221616A, CN117628836A, and CN116857027A.

[0024] As a specific example, in this embodiment, Figure 1As shown, the compression energy storage unit 22 mainly includes a first-stage compressor 221, a first-stage heat exchanger 222, a second-stage compressor 223, and a second-stage heat exchanger 224, which are sequentially connected between the gas storage unit 21 and the liquid storage unit 23, and also includes a preheater 225 connected to the inlet end of the first-stage compressor 221 and a condenser 226 connected to the outlet end of the second-stage heat exchanger 224. In the compression heat release energy storage loop, the gaseous carbon dioxide is preheated by the preheater 225, and then compressed in two stages by the first-stage compressor 221 and the second-stage compressor 223 in sequence, and then liquefied by the condenser 226 to form liquid carbon dioxide and stored in the liquid storage unit 23.

[0025] As a specific example, in this embodiment, Figure 1 As shown, the expansion energy release unit 24 mainly includes an evaporator 245, a third-stage heat exchanger 241, a first-stage turbine 242, a fourth-stage heat exchanger 243, and a second-stage turbine 244, which are sequentially connected between the liquid storage unit 23 and the gas storage unit 21. In the heat absorption expansion energy release circuit, the liquid carbon dioxide absorbs heat and vaporizes and expands in the evaporator 245, and then sequentially releases energy by performing work (for example, driving the corresponding generator to generate electricity) through the first-stage turbine 242 and the second-stage turbine 244, and is converted into gaseous carbon dioxide at normal pressure and stored in the gas storage unit 21.

[0026] Among them, Figure 1 As shown, the carbon capture system 3 mainly includes a carbon dioxide collector 31, a carbon dioxide compressor 32, a dryer 33, a liquefier 34 and a storage container 35 which are connected in sequence. The carbon dioxide collector 31 captures the carbon dioxide gas in the flue gas discharged by the thermal power generation system 1, and after being compressed by the carbon dioxide compressor 32, dried by the dryer 33 and liquefied by the liquefier 34, the liquid carbon dioxide is obtained and stored in the storage container 35. In the conventional carbon capture system 3, the liquid carbon dioxide stored in the storage container 35 is transported to the outside and sealed in a specific container for application in other industrial fields.

[0027] In this embodiment, Figure 1As shown, the compression energy storage unit 22 is coupled to the feed water heat recovery unit 13, and condensed water is drawn from the feed water heat recovery unit 13 to cool the circulating working fluid in the compression energy storage unit 22 and increase the temperature of the condensed water. The expansion energy release unit 24 is coupled to the steam turbine generator set 12, and steam is drawn from the steam turbine generator set 12 to heat the circulating working fluid in the expansion energy release unit 24. The carbon capture system 3 is coupled between the coal-fired boiler unit 11 and the energy storage system 2, and captures the carbon dioxide gas in the flue gas of the coal-fired boiler unit 11, and inputs it into the energy storage system 2 as a circulating working fluid. Among them, the carbon capture system 3 is connected to the coal-fired boiler unit 11 through a first connecting pipeline 41, and the first connecting pipeline 41 is coupled to the expansion energy release unit 24, and the waste heat of the flue gas is used to heat the circulating working fluid in the expansion energy release unit 24.

[0028] Specifically, the first connecting pipeline 41 is coupled to the evaporator 245, and the waste heat of the flue gas is used to heat the circulating medium in the evaporator 245. Thus, the waste heat of the flue gas discharged by the thermal power generation system 1 can be further utilized to reduce heat loss, realize the utilization of waste heat of low-quality flue gas, reduce the utilization of high-quality heat source in the energy release process of the carbon dioxide energy storage system 2, and improve the energy utilization efficiency of the system.

[0029] As a preferred solution, in this embodiment, Figure 1 As shown, in the carbon capture system 3, the carbon dioxide collector 31 is connected to the chimney 112 in the coal-fired boiler unit 11 through the first connecting pipeline 41, and the output end of the dryer 33 is also connected to the gas storage unit 21 through the second connecting pipeline 42, and a pressure reduction mechanism 51 is provided on the second connecting pipeline 42. The carbon dioxide collector 31 captures the carbon dioxide gas in the flue gas discharged from the chimney 112, and after being compressed by the carbon dioxide compressor 32 and dried by the dryer 33, it is input into the gas storage unit 21 through the second connecting pipeline 42, thereby, the carbon dioxide captured by the carbon capture system 3 is input into the energy storage system 2 in the form of gaseous carbon dioxide as a circulating working medium. Among them, since the pressure of the gaseous carbon dioxide is relatively high after being compressed by the carbon dioxide compressor 32, a pressure reduction mechanism 51 is provided on the second connecting pipeline 42, and the pressure reduction is performed by throttling and reducing pressure through the pressure reduction mechanism 51, so that the gaseous carbon dioxide is converted to normal pressure and then input into the gas storage unit 21 of the energy storage system 2. In a specific case, the pressure reducing mechanism 51 is selected to be a throttle valve.

[0030] As a preferred solution, in this embodiment, Figure 1As shown, the thermal power generation system 1 further includes a feedwater heater 14 connected between the coal-fired boiler unit 11 and the feedwater heat recovery unit 13. Specifically, the feedwater heater 14 is connected between the coal-fired boiler 111 and the feedwater pump 133. The carbon dioxide compressor 32 is coupled to the feedwater heater 14. The heat generated by the carbon dioxide compressor 32 when compressing the carbon dioxide gas is transmitted to the feedwater heater 14, and the boiler feedwater output from the feedwater heat recovery unit 13 is heated before being transmitted to the coal-fired boiler unit 11. Therefore, on the one hand, the compression heat generated in the carbon capture system 3 is used to heat the boiler feedwater, thereby increasing the temperature of the boiler feedwater, reducing the coal consumption in the coal-fired boiler 111, improving the operation efficiency of the thermal power generation system 1, and also improving the energy utilization efficiency of the system; on the other hand, the heat generated by the carbon dioxide compressor 32 can be timely exported, thereby improving the efficiency of the carbon dioxide compressor 32, reducing the power consumption of the carbon dioxide compressor 32, and thus also improving the operation efficiency of the carbon capture system 3.

[0031] As a preferred solution, in this embodiment, Figure 1 As shown, the output end of the liquefier 34 is connected to the liquid storage unit 23 through a third connecting pipeline 43. The liquid carbon dioxide obtained after being compressed by the carbon dioxide compressor 32, dried by the dryer 33, and liquefied by the liquefier 34 can be input into the liquid storage unit 23 through the third connecting pipeline 43. Thus, the carbon dioxide captured by the carbon capture system 3 can be input into the energy storage system 2 in the form of liquid carbon dioxide as a circulating working fluid, that is, in the energy comprehensive utilization system provided in this embodiment, the carbon dioxide captured by the carbon capture system 3 can be input into the energy storage system 2 in the form of gaseous carbon dioxide and / or liquid carbon dioxide as a circulating working fluid according to actual needs. Combined with the storage container 35 in which the carbon capture system 3 itself can store liquid carbon dioxide, the energy comprehensive utilization system is more flexible and perfect for the storage and utilization of carbon dioxide working fluid. In particular, at the initial start-up of the energy storage system 2, a large amount of liquid carbon dioxide can be added to the liquid storage unit 23 through the carbon capture system 3, and energy can be directly released during peak electricity consumption periods, reducing the energy storage process. It can simultaneously achieve system gas replacement and efficient energy utilization, and can give full play to the peak-shaving effect of the combination of thermal power units and energy storage systems on the power grid.

[0032] Specifically, the output end of the liquid storage unit 23 is connected to the evaporator 245 through the fourth connecting pipeline 44, and the booster pump 25 is arranged on the fourth connecting pipeline 44. The first control valve 52 and the second control valve 53 are arranged in sequence on the fourth connecting pipeline 44 at a position between the output end of the liquid storage unit 23 and the booster pump 25, and the third connecting pipeline 43 is connected to the fourth connecting pipeline 44 between the first control valve 52 and the second control valve 53. Therefore, by controlling the opening and closing states of the first control valve 52 and the second control valve 53, the liquid carbon dioxide output from the liquefier 34 through the third connecting pipeline 43 can be input to the liquid storage unit 23 (the first control valve 52 is open, and the second control valve 53 is closed), or can be directly input to the expansion energy release unit 24 through the booster pump 25 (the first control valve 52 is closed, and the second control valve 53 is open).

[0033] Furthermore, in this embodiment, a third control valve 54 is provided on the connection pipeline connecting the condenser 226 to the liquid storage unit 23 .

[0034] As a preferred solution, in this embodiment, Figure 1 As shown, the compression energy storage unit 22 is coupled to the feed water heat recovery unit 13, and the condensed water is drawn out from the inlet end of the low-pressure heater 131, and after cooling the circulating working medium in the compression energy storage unit 22 and increasing the temperature, it is transported to the outlet end of the low-pressure heater 131. Therefore, on the one hand, the circulating working medium in the compression energy storage unit 22 is cooled by the condensed water with a lower temperature, which can quickly exchange heat, improve the compression efficiency of the compression energy storage unit 22, and thus improve the operation efficiency of the energy storage system 2; on the other hand, after heat exchange, the temperature of the condensed water is greatly increased, which can reduce the amount of air extracted by the feed water heat recovery unit 13 to the steam turbine generator set 12, increase the power generation, and improve the system efficiency of the thermal power generation system 1. The expansion energy release unit 24 is coupled to the steam turbine generator set 12, and the steam is drawn out from the steam turbine 121, and after heating the circulating working medium in the expansion energy release unit 24, it is transported to the condenser 122. By extracting air from the steam turbine 121 in the thermal power generation system 1 (the extraction port is determined according to the thermodynamic balance), the heat required for the energy storage system 2 in the energy release process is provided, thereby increasing the temperature of the main carbon dioxide gas in the energy release process of the energy storage system 2, and further improving the efficiency of the energy storage system 2. Furthermore, the steam-water cycle working fluid in the thermal power generation system 1 is used as the heat storage and cold storage medium of the energy storage system 2, so that the energy storage system 2 does not need to be provided with additional heat storage devices and cold storage devices, and the system structure is simplified.

[0035] As mentioned above, in this embodiment, the compression energy storage unit 22 includes a first-stage compressor 221, a first-stage heat exchanger 222, a second-stage compressor 223, and a second-stage heat exchanger 224 connected in sequence. Figure 1 As shown, the condensed water drawn from the inlet end of the low-pressure heater 131 is respectively delivered to the first-stage heat exchanger 222 and the second-stage heat exchanger 224 to cool the circulating working fluid in the first-stage heat exchanger 222 and the second-stage heat exchanger 224 and to increase the temperature of the condensed water. The condensed water whose temperature is increased by heat exchange in the first-stage heat exchanger 222 and the second-stage heat exchanger 224 is simultaneously delivered to the outlet end of the low-pressure heater 131.

[0036] As mentioned above, in this embodiment, the expansion energy release unit 24 includes a third-stage heat exchanger 241, a first-stage turbine 242, a fourth-stage heat exchanger 243, and a second-stage turbine 244 connected in sequence. The steam drawn from the steam turbine 121 is respectively transported to the third-stage heat exchanger 241 and the fourth-stage heat exchanger 243 to heat the circulating working fluid in the third-stage heat exchanger 241 and the fourth-stage heat exchanger 243. The exhaust water formed by heat exchange in the third-stage heat exchanger 241 and the fourth-stage heat exchanger 243 is simultaneously transported to the condenser 122 to be further condensed into condensed water.

[0037] In summary, the energy comprehensive utilization system provided by the above embodiment of the present invention deeply couples the thermal power generation system, the carbon dioxide energy storage system and the carbon capture system. On the one hand, the steam-water circulating medium in the thermal power generation system is used as the heat storage and cold storage medium of the carbon dioxide energy storage system, which can not only improve the operation efficiency of the thermal power generation system and the carbon dioxide energy storage system, but also improve the overall energy utilization efficiency of the system; further, the carbon dioxide energy storage system does not need to set up additional heat storage devices and cold storage devices, and the system structure is simplified. On the other hand, the carbon capture system is coupled between the thermal power generation system and the carbon dioxide energy storage system, and the carbon dioxide gas in the flue gas emitted by the thermal power generation system is captured and input into the carbon dioxide energy storage system as a circulating medium, thereby not only reducing the emission of gas pollutants in the thermal power generation system, but also being able to be recycled and reused to increase its added value; further, in the process of capturing carbon dioxide gas, the carbon capture system couples the waste heat of the flue gas emitted by the thermal power generation system to the carbon dioxide energy storage system, and uses the waste heat of the flue gas to heat the carbon dioxide circulating medium in the expansion energy release unit, thereby further improving the energy utilization efficiency.

[0038] The above is only a specific implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. An energy comprehensive utilization system coupling carbon capture and energy storage with thermal power generation, characterized in that: include: Thermal power generation system, including coal-fired boiler unit, steam turbine generator set and feedwater heat recovery unit; The energy storage system comprises a compression energy storage unit and an expansion energy release unit; the compression energy storage unit is coupled to the feed water heat recovery unit, condensed water is drawn from the feed water heat recovery unit, the circulating working medium in the compression energy storage unit is cooled and the temperature of the condensed water is increased; the expansion energy release unit is coupled to the steam turbine generator set, steam is drawn from the steam turbine generator set, and the circulating working medium in the expansion energy release unit is heated; A carbon capture system, coupled between the coal-fired boiler unit and the energy storage system, captures carbon dioxide gas in the flue gas of the coal-fired boiler unit and inputs it into the energy storage system as a circulating working fluid; Wherein, the energy storage system further comprises a gas storage unit and a liquid storage unit, and the carbon capture system comprises a carbon dioxide collector, a carbon dioxide compressor, a dryer, a liquefier and a storage container connected in sequence; The carbon dioxide collector is connected to the coal-fired boiler unit via a first connecting pipeline, and the first connecting pipeline is coupled to the expansion energy release unit, and the waste heat of the flue gas is used to heat the circulating working medium in the expansion energy release unit; The dryer is connected to the gas storage unit via a second connecting pipeline, a pressure reducing mechanism is provided on the second connecting pipeline, the carbon dioxide collector captures the carbon dioxide gas in the flue gas, and after being compressed by the carbon dioxide compressor and dried by the dryer, the carbon dioxide gas is input into the gas storage unit via the second connecting pipeline; The liquefier is connected to the liquid storage unit via a third connecting pipeline, and the liquid carbon dioxide liquefied by the liquefier is input into the liquid storage unit via the third connecting pipeline.

2. The energy comprehensive utilization system according to claim 1, characterized in that: The thermal power generation system also includes a feedwater heater connected between the coal-fired boiler unit and the feedwater heat recovery unit. The carbon dioxide compressor is coupled to the feedwater heater. The heat generated by compressing the carbon dioxide gas by the carbon dioxide compressor is transmitted to the feedwater heater, and the boiler feed water output from the feedwater heat recovery unit is heated before being transmitted to the coal-fired boiler unit.

3. The energy comprehensive utilization system according to claim 1 or 2, characterized in that: The feed water heat recovery unit includes a low-pressure heater, a deaerator and a feed water pump which are connected in sequence; the condensed water is drawn out from the inlet end of the low-pressure heater, cools the circulating working fluid in the compressed energy storage unit and increases the temperature, and then is transported to the outlet end of the low-pressure heater.

4. The energy comprehensive utilization system according to claim 3, characterized in that: The compressed energy storage unit includes a first-stage compressor, a first-stage heat exchanger, a second-stage compressor and a second-stage heat exchanger connected in sequence; the condensed water drawn out from the inlet end of the low-pressure heater is respectively transported to the first-stage heat exchanger and the second-stage heat exchanger to cool the circulating working fluid in the first-stage heat exchanger and the second-stage heat exchanger and increase the temperature.

5. The energy comprehensive utilization system according to claim 4, characterized in that: The compression energy storage unit further includes a preheater connected to an inlet end of the first stage compressor and a condenser connected to an outlet end of the second stage heat exchanger.

6. The energy comprehensive utilization system according to claim 1 or 2, characterized in that: The steam turbine generator set comprises a steam turbine and a condenser connected to each other; the steam is drawn from the steam turbine, heats the circulating working medium in the expansion energy release unit, and is then transported to the condenser.

7. The energy comprehensive utilization system according to claim 6, characterized in that: The expansion energy release unit includes a third-stage heat exchanger, a first-stage turbine, a fourth-stage heat exchanger and a second-stage turbine connected in sequence; the steam drawn out from the steam turbine is respectively transported to the third-stage heat exchanger and the fourth-stage heat exchanger to heat the circulating working fluid in the third-stage heat exchanger and the fourth-stage heat exchanger.

8. The energy comprehensive utilization system according to claim 7, characterized in that: The expansion energy release unit further includes an evaporator connected to the inlet end of the third-stage heat exchanger, the first connecting pipeline is coupled to the evaporator, and the waste heat of the flue gas is used to heat the circulating working medium in the evaporator.

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