Coal-fired power generation system based on supercritical carbon dioxide energy storage

Abstract

The application discloses a coal-fired power generation system based on supercritical carbon dioxide energy storage, and relates to the technical field of thermal power generation. The system comprises a reheating boiler system, a coal-fired power generation system and an energy storage system. The coal-fired power generation system comprises a power generation assembly and a turbine assembly. The reheating boiler system is used for receiving a first working medium of the power generation assembly, heating and treating the first working medium, and obtaining a second working medium. The power generation assembly is connected with the turbine assembly, the energy storage system and the reheating boiler system. The turbine assembly is used for receiving the second working medium, performing energy conversion treatment on the second working medium, and obtaining a third working medium. The power generation assembly is used for receiving the third working medium, performing cyclic power generation operation on the third working medium, obtaining a waste heat working medium and the first working medium. The energy storage system is used for receiving the waste heat working medium and performing working medium energy storage. The application solves the technical problem that, in the prior art, flue gas in a boiler is directly discharged, the waste heat is not utilized, and the power generation efficiency of the power generation system is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of thermal power generation technology, and particularly relates to a coal-fired power generation system based on supercritical carbon dioxide energy storage. BACKGROUND

[0002] In recent years, supercritical carbon dioxide cycle technology has developed rapidly, and key technologies have made breakthroughs. The supercritical carbon dioxide cycle system is simplified, compact, high-efficiency, air-cooled, and can be combined with various heat sources to form a power generation system. Therefore, the supercritical carbon dioxide cycle has good application prospects in the field of thermal power generation.

[0003] At present, the supercritical carbon dioxide cycle can be integrated with a coal-fired boiler to replace the steam turbine system to form a power generation system with higher power generation efficiency. However, when the system generates power, the flue gas in the boiler is directly discharged, lacking the use of waste heat and reducing the power generation efficiency of the power generation system. SUMMARY

[0004] The present application provides a coal-fired power generation system based on supercritical carbon dioxide energy storage, which solves the technical problem that the prior art integrates supercritical carbon dioxide cycle with a coal-fired boiler to replace the steam turbine system to form a power generation system with higher power generation efficiency. However, when the system generates power, the flue gas in the boiler is directly discharged, lacking the use of waste heat and reducing the power generation efficiency of the power generation system.

[0005] The present application provides a coal-fired power generation system based on supercritical carbon dioxide energy storage, which includes a reheating boiler system, a coal-fired power generation system, and an energy storage system.

[0006] The reheating boiler system is connected to the coal-fired power generation system and the energy storage system.

[0007] The coal-fired power generation system includes a power generation assembly and a turbine assembly.

[0008] The reheating boiler system is used to receive the first working medium of the power generation assembly, heat treat the first working medium, and obtain the second working medium.

[0009] The power generation assembly is connected to the turbine assembly, the energy storage system, and the reheating boiler system.

[0010] The turbine assembly is used to receive the second working medium and perform energy conversion treatment on the second working medium to obtain the third working medium.

[0011] The power generation assembly is used to receive the third working medium and perform cyclic power generation operation on the third working medium to obtain the waste heat working medium and the first working medium.

[0012] The energy storage system is used to receive the waste heat working medium and perform working medium energy storage.

[0013] Optionally, the reheat boiler system comprises a working fluid heat exchanger, a first heat exchange pipe, a second heat exchange pipe and a third heat exchange pipe;

[0014] The turbine assembly comprises a first turbine and a second turbine;

[0015] The first port of the working fluid heat exchanger is connected with the power generation assembly through the second heat exchange pipe;

[0016] The second port of the working fluid heat exchanger is connected with the first turbine, and the first turbine is connected with the second turbine through the first heat exchange pipe;

[0017] The third heat exchange pipe is connected with the energy storage system, and the second turbine is connected with the power generation assembly.

[0018] Optionally, the power generation assembly comprises a high-temperature heat exchanger, a low-temperature heat exchanger, a cooler, a first compressor and a second compressor;

[0019] The first cold side of the high-temperature heat exchanger is connected with the first port of the working fluid heat exchanger through the second heat exchange pipe, and the first hot side of the high-temperature heat exchanger is connected with the second turbine;

[0020] The second hot side of the high-temperature heat exchanger is connected with the first hot side of the low-temperature heat exchanger, and the second hot side of the low-temperature heat exchanger is connected with the first end of the second compressor and the first hot side of the cooler respectively;

[0021] The second hot side of the cooler is connected with the first end of the first compressor, and the second end of the first compressor is connected with the first cold side of the low-temperature heat exchanger;

[0022] The second end of the second compressor is connected with the second cold side of the low-temperature heat exchanger and the second cold side of the high-temperature heat exchanger respectively.

[0023] Optionally, the energy storage system comprises a first heat exchanger, a liquid working fluid storage chamber, a second heat exchanger, a high-temperature heat exchanger working fluid tank, a low-temperature heat exchanger working fluid tank and an energy storage module;

[0024] The liquid working fluid storage chamber is connected with the power generation assembly, and the first end of the liquid working fluid storage chamber is connected with the first cold side of the second heat exchanger;

[0025] The second cold side of the second heat exchanger is connected with the first end of the energy storage module, and the first hot side of the second heat exchanger is connected with the first cold side of the first heat exchanger through the low-temperature heat exchanger working fluid tank;

[0026] The second cold side of the first heat exchanger is connected with the second hot side of the second heat exchanger through the high-temperature heat exchanger working fluid tank.

[0027] The second end of the energy storage module is connected with the first hot side of the first heat exchanger, and the second hot side of the first heat exchanger is connected with the second end of the liquid working medium storage chamber.

[0028] Optionally, the energy storage module comprises a working medium storage chamber, a third compressor, a TES heat exchange assembly, a third turbine and a third heat exchanger.

[0029] The first cold side of the TES heat exchange assembly serves as the first end of the energy storage module, and the first hot side of the TES heat exchange assembly serves as the second end of the energy storage module.

[0030] The second cold side of the TES heat exchange assembly is connected with one end of the third turbine through the third heat exchange pipeline.

[0031] The other end of the third turbine is connected with the first end of the third heat exchanger, and the second end of the third heat exchanger is connected with one end of the working medium storage chamber.

[0032] The other end of the working medium storage chamber is connected with one end of the third compressor, and the other end of the third compressor is connected with the second hot side of the TES assembly.

[0033] Optionally, the first cold side and the second cold side of the cooler are connected with the energy storage system.

[0034] Optionally, the first working medium is carbon dioxide.

[0035] Optionally, the energy release pressure of the energy storage system is 6-8 MPa.

[0036] Optionally, an air preheater is arranged inside the furnace.

[0037] Optionally, a flue is arranged inside the furnace, and the flue is used for conveying flue gas in the furnace to the air preheater and the energy storage system.

[0038] From the above technical solutions, the present application has the following advantages:

[0039] The application couples a reheat boiler system, a coal-fired power generation system and an energy storage system, the coal-fired power generation system comprising a power generation assembly and a turbine assembly, the power generation assembly being used to perform a cyclic power generation operation on a third working medium to obtain a waste heat working medium and a first working medium, and the waste heat working medium and the first working medium being sent to the energy storage system and the reheat boiler system respectively, so as to realize waste heat recycling and improve the power generation performance of the system. Compared with the conventional power generation system, the application overcomes the technical problem of the prior art that the flue gas in the boiler is directly discharged during power generation, and the waste heat is not utilized, thereby reducing the power generation efficiency of the power generation system. The reheat boiler system is connected with the coal-fired power generation system and the energy storage system respectively, the waste heat is utilized by the energy storage system, and the power generation efficiency of the power generation system is improved. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0041] Figure 1 A structure schematic diagram of a coal-fired power generation system based on supercritical carbon dioxide energy storage is provided for the embodiments of the present application.

[0042] In the drawings, the reference signs are as follows:

[0043] 1, furnace; 2, working medium heat exchanger; 3, first heat exchange pipeline; 4, first turbine; 5, second turbine; 6, second heat exchange pipeline; 7, third heat exchange pipeline; 8, air preheater; 9, flue; 10, second compressor; 11, high-temperature heat exchanger; 12, low-temperature heat exchanger; 13, cooler; 14, first compressor; 216, working medium storage room; 217, third compressor; 218, TES heat exchange assembly; 219, first heat exchanger; 220, liquid working medium storage room; 221, second heat exchanger; 222, high-temperature heat exchange working medium tank; 223, low-temperature heat exchange working medium tank; 224, third turbine; 225, third heat exchanger. DETAILED DESCRIPTION

[0044] The embodiments of the present application provide a coal-fired power generation system based on supercritical carbon dioxide energy storage, which is used to solve the technical problem of the prior art that the supercritical carbon dioxide cycle is integrated with the coal-fired boiler to replace the steam turbine system, thereby forming a power generation system with higher power generation efficiency. However, during power generation, the flue gas in the boiler is directly discharged, the waste heat is not utilized, and the power generation efficiency of the power generation system is reduced.

[0045] In order to make the application purposes, features and advantages of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the embodiments described below are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0046] For the convenience of understanding, please refer to Figure 1 A coal-fired power generation system based on supercritical carbon dioxide energy storage, comprising a reheating boiler system, a coal-fired power generation system and an energy storage system;

[0047] The reheating boiler system is connected with the coal-fired power generation system and the energy storage system respectively;

[0048] The coal-fired power generation system comprises a power generation assembly and a turbine assembly;

[0049] The reheating boiler system is used for receiving a first working medium of the power generation assembly, heating the first working medium to obtain a second working medium;

[0050] The power generation assembly is connected with the turbine assembly, the energy storage system and the reheating boiler system respectively;

[0051] The turbine assembly is used for receiving the second working medium and performing energy conversion processing on the second working medium to obtain a third working medium;

[0052] The power generation assembly is used for receiving the third working medium and performing cyclic power generation operation on the third working medium to obtain a waste heat working medium and the first working medium;

[0053] The energy storage system is used for receiving the waste heat working medium and performing working medium energy storage.

[0054] In the embodiment of the present application, the coal-fired power generation system based on supercritical carbon dioxide energy storage comprises a reheating boiler system, a coal-fired power generation system and an energy storage system. The reheating boiler system is arranged inside the furnace 1, and is connected with the coal-fired power generation system and the energy storage system respectively. The reheating boiler system is used for receiving the first working medium of the power generation assembly. When the coal is burned in the furnace 1, the first working medium (i.e. the carbon dioxide working medium) is heated, so as to obtain the second working medium (i.e. the first working medium after heat absorption), and the second working medium is delivered to the coal-fired power generation system. The coal-fired power generation system comprises a power generation assembly and a turbine assembly, and the power generation assembly is connected with the turbine assembly, the energy storage system and the reheating boiler system respectively. When the second working medium enters the turbine assembly, the continuous energy conversion operation is performed through the turbine assembly, so as to obtain the third working medium. The high and low temperature heat recovery and power generation operation are performed on the third working medium through the power generation assembly, so as to obtain the waste heat working medium and the first working medium. The energy storage system is used for receiving the waste heat working medium, and the waste heat working medium is subjected to working medium energy storage. The energy utilization of the reheating process is optimized, and the working medium energy utilization rate is improved. The connection between the components in the system makes the circulation of the working medium more smooth, the energy transmission and conversion between different components are more coordinated, and the operation stability of the whole system is improved.

[0055] Referring to Figure 1 As shown in the figure, the reheating boiler system comprises a working medium heat exchanger 2, a first heat exchange pipeline 3, a second heat exchange pipeline 6 and a third heat exchange pipeline 7; the turbine assembly comprises a first turbine 4 and a second turbine 5; the first port of the working medium heat exchanger 2 is connected with the power generation assembly through the second heat exchange pipeline 6; the second port of the working medium heat exchanger 2 is connected with the first turbine 4, and the first turbine 4 is connected with the second turbine 5 through the first heat exchange pipeline 3; the third heat exchange pipeline 7 is connected with the energy storage system, and the second turbine 5 is connected with the power generation assembly.

[0056] In the embodiment of the present application, the reheat boiler system comprises a working medium heat exchanger 2 (i.e. a CO2 working medium heat exchanger 2), a first heat exchange pipeline 3, a second heat exchange pipeline 6 and a third heat exchange pipeline 7. The turbine assembly comprises a first turbine 4 and a second turbine 5. The first port of the working medium heat exchanger 2 is connected with the power generation assembly through the second heat exchange pipeline 6, and the first working medium obtained after the power generation assembly circulates the power generation process is returned to the working medium heat exchanger 2 through the second heat exchange pipeline 6. The second port of the working medium heat exchanger 2 is connected with the first turbine 4, and the first turbine 4 is connected with the second turbine 5 through the first heat exchange pipeline 3. The first working medium is heated in the working medium heat exchanger 2 and then transmitted to the first turbine 4 for turbine, and the second working medium after turbine is transmitted to the second turbine 5 for secondary turbine, so as to obtain the third working medium and transmit it to the power generation assembly. By arranging the first turbine 4 and the second turbine 5, the multi-stage turbine can improve the energy conversion efficiency of the entire turbine assembly compared with the single-stage turbine, so as to improve the power generation efficiency of the entire system. The third heat exchange pipeline 7 is connected with the energy storage system, and the second turbine 5 is connected with the power generation assembly. Part of the waste heat is transmitted to the energy storage system through the third heat exchange pipeline 7.

[0057] It is worth mentioning that in the traditional power generation system, the waste heat after power generation is often directly discarded, causing energy waste. By recycling and storing part of the waste heat through the third heat exchange pipeline 7 and the energy storage system, the energy can be reused when needed. For example, during the power consumption peak or other energy supplement needs, the energy in the energy storage system can be put back into the system, improving the comprehensive utilization efficiency of the energy of the entire system.

[0058] Referring to Figure 1 As shown in the figure, the power generation assembly comprises a high-temperature heat exchanger 11, a low-temperature heat exchanger 12, a cooler 13, a first compressor 14 and a second compressor 10; the first cold side of the high-temperature heat exchanger 11 is connected with the first port of the working medium heat exchanger 2 through the second heat exchange pipeline 6, and the first hot side of the high-temperature heat exchanger 11 is connected with the second turbine 5; the second hot side of the high-temperature heat exchanger 11 is connected with the first hot side of the low-temperature heat exchanger 12, and the second hot side of the low-temperature heat exchanger 12 is connected with the first end of the second compressor 10 and the first hot side of the cooler 13 respectively; the second hot side of the cooler 13 is connected with the first end of the first compressor 14, and the second end of the first compressor 14 is connected with the first cold side of the low-temperature heat exchanger 12; the second end of the second compressor 10 is connected with the second cold side of the low-temperature heat exchanger 12 and the second cold side of the high-temperature heat exchanger 11 respectively.

[0059] In this embodiment of the invention, the power generation assembly includes a high-temperature heat exchanger 11, a low-temperature heat exchanger 12, a cooler 13, a first compressor 14, and a second compressor 10. The first cold side of the high-temperature heat exchanger 11 is connected to the first port of the working fluid heat exchanger 2 via a second heat exchange pipe 6, and the first hot side of the high-temperature heat exchanger 11 is connected to the second turbine 5. The second hot side of the high-temperature heat exchanger 11 is connected to the first hot side of the low-temperature heat exchanger 12, and the second hot side of the low-temperature heat exchanger 12 is connected to the first end of the second compressor 10 and the first hot side of the cooler 13, respectively. The second hot side of the cooler 13 is connected to the first end of the first compressor 14, and the second end of the first compressor 14 is connected to the first cold side of the low-temperature heat exchanger 12. The second end of the second compressor 10 is connected to the second cold side of the low-temperature heat exchanger 12 and the second cold side of the high-temperature heat exchanger 11, respectively. The third working fluid after turbine flow sequentially passes through the high-temperature heat exchanger 11 and the low-temperature heat exchanger 12 for diversion processing, and the diverted third working fluid undergoes multi-stage compression through the first compressor 14 and the second compressor 10, respectively. It has higher efficiency compared to a single regenerative cycle system.

[0060] It is worth mentioning that the characteristic of coal-fired power generation systems is that they recycle supercritical CO2 as the working medium and use S-CO2 as the working fluid for cyclic power generation.

[0061] See Figure 1 As shown, the energy storage system includes a first heat exchanger 219, a liquid working fluid storage chamber 220216, a second heat exchanger 221, a high-temperature heat exchange fluid tank 222, a low-temperature heat exchange fluid tank 223, and an energy storage module. The liquid working fluid storage chamber 220216 is connected to the power generation components, and its first end is connected to the first cold side of the second heat exchanger 221. The second cold side of the second heat exchanger 221 is connected to the first end of the energy storage module, and its first hot side is connected to the first cold side of the first heat exchanger 219 via the low-temperature heat exchange fluid tank 223. The second cold side of the first heat exchanger 219 is connected to the second hot side of the second heat exchanger 221 via the high-temperature heat exchange fluid tank 222. The second end of the energy storage module is connected to the first hot side of the first heat exchanger 219, and the second hot side of the first heat exchanger 219 is connected to the second end of the liquid working fluid storage chamber 220216.

[0062] In the embodiment of the application, the energy storage system comprises a first heat exchanger 219, a liquid working medium storage chamber 220216 (i.e. a liquid CO2 storage chamber), a second heat exchanger 221, a high-temperature heat exchange working medium tank 222, a low-temperature heat exchange working medium tank 223 and an energy storage module. The liquid working medium storage chamber 220216 is connected to the power generation assembly, and a first end of the liquid working medium storage chamber 220216 is connected to a first cold side of the second heat exchanger 221. A second cold side of the second heat exchanger 221 is connected to a first end of the energy storage module, and a first hot side of the second heat exchanger 221 is connected to a first cold side of the first heat exchanger 219 through the low-temperature heat exchange working medium tank 223. When the energy storage system is in a power generation condition, the liquid working medium storage chamber 220216 releases liquid CO2. The liquid CO2 working medium is transmitted to the second heat exchanger 221. The working medium is evaporated in the second heat exchanger 221 and is transmitted from a second cold side of the second heat exchanger 221 to the energy storage module. A second cold side of the first heat exchanger 219 is connected to a second hot side of the second heat exchanger 221 through the high-temperature heat exchange working medium tank 222. A second end of the energy storage module is connected to a first hot side of the first heat exchanger 219, and a second hot side of the first heat exchanger 219 is connected to a second end of the liquid working medium storage chamber 220216. When the energy storage system is in an energy storage condition, the waste heat working medium is cooled and heat-exchanged by the energy storage module, and the processed working medium is transported to the first heat exchanger 219 for cooling treatment to obtain cooled working medium, and then the cooled working medium is transported to the liquid working medium storage chamber 220216 for energy storage. The liquid working medium storage chamber 220216 is heated by the waste heat of the power generation assembly to maintain the pressure stable during the release of carbon dioxide, thereby improving the working capacity of the system.

[0063] Referring to Figure 1 As shown in FIG. 6, the energy storage module comprises a working medium storage chamber 216, a third compressor 217, a TES heat exchange assembly 218, a third turbine 224 and a third heat exchanger 225. A first cold side of the TES heat exchange assembly 218 serves as a first end of the energy storage module, and a first hot side of the TES heat exchange assembly 218 serves as a second end of the energy storage module. A second cold side of the TES heat exchange assembly 218 is connected to one end of the third turbine 224 through a third heat exchange pipeline 7. The other end of the third turbine 224 is connected to a first end of the third heat exchanger 225, and a second end of the third heat exchanger 225 is connected to one end of the working medium storage chamber 216. The other end of the working medium storage chamber 216 is connected to one end of the third compressor 217, and the other end of the third compressor 217 is connected to the second hot side of the TES assembly.

[0064] In the embodiment of the present application, the energy storage module comprises a working medium storage chamber 216, a third compressor 217, a TES heat exchange assembly 218, a third turbine 224 and a third heat exchanger 225. The first cold side of the TES heat exchange assembly 218 serves as the first end of the energy storage module, and the first hot side of the TES heat exchange assembly 218 serves as the second end of the energy storage module. The second cold side of the TES heat exchange assembly 218 is connected to one end of the third turbine 224 through a third heat exchange pipeline 7. The other end of the third turbine 224 is connected to the first end of the third heat exchanger 225, and the second end of the third heat exchanger 225 is connected to one end of the working medium storage chamber 216. The other end of the working medium storage chamber 216 is connected to one end of the third compressor 217, and the other end of the third compressor 217 is connected to the second hot side of the TES assembly. The working medium is heated by the TES heat exchange assembly 218, and the heated working medium is transmitted to the third turbine 224 through the third heat exchange pipeline 7. The working medium is generated by the third turbine 224, and then the generated working medium is cooled by the third heat exchanger 225 and returned to the working medium storage chamber 216.

[0065] It is worth mentioning that the system performance index of the energy storage system before coupling shows a rapid downward trend within a certain time from 76.59% due to the release of carbon dioxide, while the system performance of the reheat boiler system and the coal-fired power generation system after coupling can be maintained at about 77% for a long time, which greatly improves the energy release of the system.

[0066] Referring to Figure 1 As shown in the figure, the first cold side and the second cold side of the cooler 13 are connected to the energy storage system.

[0067] In the embodiment of the present application, the first cold side and the second cold side of the cooler 13 are connected to the energy storage system. Thus, the waste heat working medium is transmitted to the energy storage system.

[0068] It should be noted that the first working medium is carbon dioxide.

[0069] In the embodiment of the present application, the first working medium is carbon dioxide. Since the critical temperature of carbon dioxide is relatively low, carbon dioxide can be used as a working medium to effectively occupy storage space and store energy under certain conditions. Carbon dioxide can change phase under different temperature and pressure conditions, such as from liquid to gas. This phase change process is accompanied by energy absorption and release, which can be effectively utilized in the energy storage system and the power generation assembly. Thus, the energy conversion efficiency of the system is improved.

[0070] It should be noted that the energy release pressure of the energy storage system is 7 MPa.

[0071] Referring to Figure 1 As shown in the figure, the air preheater 8 is arranged in the furnace 1.

[0072] In the embodiment of the present application, the air preheater 8 is arranged inside the furnace 1. The waste heat of the flue gas in the reheating boiler system can be reused through the air preheater 8, thereby improving the utilization rate of the waste heat.

[0073] Referring to Figure 1 As shown in the figure, the furnace 1 is internally provided with the flue 9, and the flue 9 is used to transport the flue gas in the furnace 1 to the air preheater 8 and the energy storage system.

[0074] In the embodiment of the present application, the furnace 1 is internally provided with the flue 9, and the flue 9 divides the flue gas in the reheating boiler system into two streams which are respectively transported to the air preheater 8 and the third turbine 224 inlet of the energy storage system.

[0075] In another embodiment, the working process of the coal-fired power generation system based on supercritical carbon dioxide energy storage is as follows: the carbon dioxide working medium absorbs heat in the boiler, first enters the second heat exchange pipeline 6 to be preheated, and then enters the furnace working medium heat exchanger 22 to absorb heat. The working medium after heat absorption enters the first turbine 4 to perform turbine work. The working medium after the first turbine work enters the third heat exchange pipeline 7 to absorb heat again, and then enters the second turbine 5 to perform turbine work. At this time, the working medium leaves the reheating boiler system (at this time, the state of the working medium is 465.85°C, 8.5MPa). At this time, the working medium enters the hot side of the high-temperature heat exchanger 11 and the low-temperature heat exchanger 12 to be cooled. The cooled working medium (at this time, the state of the working medium is 76.85°C, 8.2MPa) needs to be divided into two streams. One stream flows through the cooler 13 to be cooled (at this time, the state of the working medium is 31.85°C, 8.1MPa) and enters the first compressor 14 to be compressed. The working medium after compression (at this time, the state of the working medium is 66.85°C, 27.77MPa) absorbs heat through the low-temperature heat exchanger 12. The other stream of working medium is directly compressed through the second compressor. At this time, the two streams of working medium are mixed (at this time, the state of the working medium is 204.85°C, 27.66MPa). The mixed working medium absorbs heat through the high-temperature heat exchanger 11 (at this time, the state of the working medium is 423.85°C, 27.5MPa) and returns to the reheating boiler system to form a cycle.

[0076] In another embodiment, the working process of the energy storage system is as follows: the working medium CO2 flows from the working medium storage chamber 216 (at this time, the state of the working medium is 15°C and 0.1 MPa), first enters the third compressor 217 for compression, and then enters the hot side of the TES heat exchange assembly 218 to release heat to the cold side, and then flows into the first heat exchanger 219 for cooling again, at this time, the cooled working medium is in a liquid state and is sent to the liquid working medium storage chamber 220216 for storage to complete the energy storage process. When the system needs to generate electricity, the liquid CO2 stored in the liquid working medium storage chamber 220216 is released, and the cooler 13 in the power generation cycle is coupled to the liquid working medium storage chamber 220216 to maintain the pressure of the released working medium (at this time, the state of the working medium is 21.9°C and 7 MPa) at about 7 MPa, and then the liquid working medium enters the second heat exchanger 221 to evaporate by absorbing heat, and then flows into the cold side of the TES heat exchange assembly 218 to absorb heat, and then the working medium after absorbing heat in the TES heat exchange assembly 218 is in a high-temperature and high-pressure state (at this time, the state of the working medium is 432.59°C and 5.423 MPa), the working medium is heated again by the flue gas waste heat of the coal-fired power generation system through the third heat exchange pipeline 7, and finally enters the third turbine 224 to generate electricity, and then flows through the third heat exchanger 225 to cool to normal temperature and pressure, and then the CO2 after cooling in the third heat exchanger 225 returns to the working medium storage chamber 216 to complete the energy storage cycle.

[0077] In the embodiment of the present application, the reheating boiler system, the coal-fired power generation system and the energy storage system are coupled, the coal-fired power generation system includes a power generation assembly and a turbine assembly, the third working medium is circulated and operated to generate electricity by the power generation assembly, the waste heat working medium and the first working medium are obtained, and then the waste heat working medium and the first working medium are sent to the energy storage system and the reheating boiler system respectively, so that the waste heat is recycled, and the power generation performance of the system is improved. Compared with the traditional power generation system, the technical problem that the flue gas in the boiler is directly discharged and the waste heat is not utilized, reducing the power generation efficiency of the power generation system, is overcome. The reheating boiler system is connected with the coal-fired power generation system and the energy storage system respectively, the waste heat is utilized by the energy storage system, and the power generation efficiency of the power generation system is improved.

[0078] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system, device and unit described above can refer to the corresponding process in the foregoing method embodiments, which will not be described herein.

[0079] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other manners. For example, the division of the above-described device embodiments is only a logical function division, and there can be another division manner for the actual implementation, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between different units, or the among different units, can be indirect couplings or communication connections through some interfaces, devices or units, and can be in electrical, mechanical or other forms.

[0080] The units described as separated components can or can not be physically separated, and the components displayed as units can or can not be physical units, i.e., can be located in one place, or can be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purposes of the embodiments.

[0081] The above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalent ones; and these modifications or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A coal-fired power generation system based on supercritical carbon dioxide energy storage, characterized in that, This includes reheat boiler systems, coal-fired power generation systems, and energy storage systems; The reheat boiler system is connected to the coal-fired power generation system and the energy storage system, respectively; The coal-fired power generation system includes power generation components and turbine components; The reheat boiler system is used to receive the first working fluid from the power generation component, heat the first working fluid to obtain the second working fluid; The power generation components are respectively connected to the turbine components, the energy storage system, and the reheat boiler system; The turbine assembly is used to receive the second working fluid and perform energy conversion processing on the second working fluid to obtain the third working fluid; The power generation component is used to receive the third working fluid and perform a cycle power generation operation on the third working fluid to obtain waste heat working fluid and the first working fluid; The energy storage system is used to receive the waste heat working fluid and store the working fluid energy. The reheat boiler system includes a working fluid heat exchanger, a first heat exchange pipe, a second heat exchange pipe, and a third heat exchange pipe. The turbine assembly includes a first turbine and a second turbine; The first port of the working fluid heat exchanger is connected to the power generation component through the second heat exchange pipe; The second port of the working fluid heat exchanger is connected to the first turbine, and the first turbine is connected to the second turbine through the first heat exchange pipe; The third heat exchange pipe is connected to the energy storage system, and the second turbine is connected to the power generation component; The power generation assembly includes a high-temperature heat exchanger, a low-temperature heat exchanger, a cooler, a first compressor, and a second compressor; The first cold side of the high-temperature heat exchanger is connected to the first port of the working fluid heat exchanger through the second heat exchange pipe, and the first hot side of the high-temperature heat exchanger is connected to the second turbine. The second hot side of the high-temperature heat exchanger is connected to the first hot side of the low-temperature heat exchanger, and the second hot side of the low-temperature heat exchanger is connected to the first end of the second compressor and the first hot side of the cooler, respectively. The second hot side of the cooler is connected to the first end of the first compressor, and the second end of the first compressor is connected to the first cold side of the low-temperature heat exchanger. The second end of the second compressor is connected to the second cold side of the low-temperature heat exchanger and the second cold side of the high-temperature heat exchanger, respectively. The energy storage system includes a first heat exchanger, a liquid working fluid storage chamber, a second heat exchanger, a high-temperature heat exchange working fluid tank, a low-temperature heat exchange working fluid tank, and an energy storage module. The liquid working fluid storage chamber is connected to the power generation component, and the first end of the liquid working fluid storage chamber is connected to the first cold side of the second heat exchanger. The second cold side of the second heat exchanger is connected to the first end of the energy storage module, and the first hot side of the second heat exchanger is connected to the first cold side of the first heat exchanger through the low-temperature heat exchange working fluid tank. The second cold side of the first heat exchanger is connected to the second hot side of the second heat exchanger through the high-temperature heat exchange medium tank; The second end of the energy storage module is connected to the first hot side of the first heat exchanger, and the second hot side of the first heat exchanger is connected to the second end of the liquid working fluid storage chamber.

2. The coal-fired power generation system based on supercritical carbon dioxide energy storage according to claim 1, characterized in that, The energy storage module includes a working fluid storage chamber, a third compressor, a TES heat exchange assembly, a third turbine, and a third heat exchanger. The first cold side of the TES heat exchanger serves as the first end of the energy storage module, and the first hot side of the TES heat exchanger serves as the second end of the energy storage module. The second cold side of the TES heat exchanger assembly is connected to one end of the third turbine via the third heat exchange pipe. The other end of the third turbine is connected to the first end of the third heat exchanger, and the second end of the third heat exchanger is connected to one end of the working fluid storage chamber. The other end of the working fluid storage chamber is connected to one end of the third compressor, and the other end of the third compressor is connected to the second hot side of the TES heat exchange assembly.

3. The coal-fired power generation system based on supercritical carbon dioxide energy storage according to claim 1, characterized in that, The first and second cold sides of the cooler are connected to the energy storage system.

4. The coal-fired power generation system based on supercritical carbon dioxide energy storage according to any one of claims 1-3, characterized in that, The first working medium is carbon dioxide.

5. The coal-fired power generation system based on supercritical carbon dioxide energy storage according to any one of claims 1-3, characterized in that, The energy release pressure of the energy storage system is 6-8 MPa.

6. The coal-fired power generation system based on supercritical carbon dioxide energy storage according to any one of claims 1-3, characterized in that, An air preheater is installed inside the boiler furnace.

7. The coal-fired power generation system based on supercritical carbon dioxide energy storage according to claim 6, characterized in that, The furnace is equipped with a flue, which is used to transport the flue gas in the furnace to the air preheater and the energy storage system.

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