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

Abstract

The invention 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, and the reheating boiler system is used for receiving a first working medium of the power generation assembly; the first working medium is heated to obtain 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 and conducting energy conversion treatment on the second working medium to obtain a third working medium, and the power generation assembly is used for receiving the third working medium and conducting circulating power generation operation on the third working medium. And the energy storage system is used for receiving the waste heat working medium and carrying out working medium energy storage. The technical problems that when an existing system generates power, smoke in a boiler is directly exhausted, waste heat is not utilized, and the power generation efficiency of the power generation system is reduced are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal power generation, and in particular to a coal-fired power generation system based on supercritical carbon dioxide energy storage. Background Art

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

[0003] At present, supercritical carbon dioxide cycle can be integrated with coal-fired boilers to replace steam turbine systems to form a power generation system with higher power generation efficiency. However, when the system is generating electricity, the flue gas in the boiler is directly discharged, and the waste heat is not utilized, which reduces the power generation efficiency of the power generation system. Summary of the invention

[0004] The present invention provides a coal-fired power generation system based on supercritical carbon dioxide energy storage, which solves the technical problem that the existing technology integrates supercritical carbon dioxide circulation with coal-fired boilers to replace the steam turbine system to form a power generation system with higher power generation efficiency. However, when the system is generating electricity, the flue gas in the boiler is directly discharged, lacking the use of waste heat, which reduces the power generation efficiency of the power generation system.

[0005] The present invention provides a coal-fired power generation system based on supercritical carbon dioxide energy storage, comprising a reheat boiler system, a coal-fired power generation system and an energy storage system;

[0006] The reheat boiler system is connected to the coal-fired power generation system and the energy storage system respectively;

[0007] The coal-fired power generation system comprises a power generation component and a turbine component;

[0008] The reheat boiler system is used to receive the first working fluid of the power generation component and heat the first working fluid to obtain a second working fluid;

[0009] The power generation assembly is respectively connected to the turbine assembly, the energy storage system and the reheat boiler system;

[0010] The turbine assembly is used to receive the second working fluid and perform energy conversion on the second working fluid to obtain a third working fluid;

[0011] The power generation component is used to receive the third working fluid and perform a cyclic power generation operation on the third working fluid to obtain a waste heat working fluid and a first working fluid;

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

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

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

[0015] The first port of the working medium heat exchanger is connected to the power generation component through the second heat exchange pipe;

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

[0017] The third heat exchange pipeline is connected to the energy storage system, and the second turbine is connected to the power generation component.

[0018] Optionally, the power generation assembly includes 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 to the first port of the working medium 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;

[0020] 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;

[0021] 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;

[0022] 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.

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

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

[0025] 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 medium tank;

[0026] 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;

[0027] 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 medium storage chamber.

[0028] Optionally, 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;

[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 to one end of the third turbine through the third heat exchange pipe;

[0031] 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 medium storage chamber;

[0032] The other end of the working medium 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 assembly.

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

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

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

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

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

[0038] It can be seen from the above technical solutions that the present invention has the following advantages:

[0039] The present invention couples a reheat boiler system, a coal-fired power generation system and an energy storage system. The coal-fired power generation system includes a power generation component and a turbine component. The power generation component is used to perform a cyclic power generation operation on the third working fluid to obtain a waste heat working fluid and a first working fluid. The waste heat working fluid and the first working fluid are then sent to the energy storage system and the reheat boiler system, respectively, thereby realizing the recycling of waste heat and improving the power generation performance of the system. Compared with the traditional power generation system, the technical problem that the flue gas in the existing system is directly discharged during power generation, lacks the utilization of waste heat, and reduces the power generation efficiency of the power generation system is overcome. The reheat boiler system is connected to the coal-fired power generation system and the energy storage system respectively, and the waste heat is utilized by the energy storage system, thereby improving the power generation efficiency of the power generation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0041] Figure 1 A schematic diagram of the structure of a coal-fired power generation system based on supercritical carbon dioxide energy storage provided by an embodiment of the present invention;

[0042] The reference numerals are as follows:

[0043] 1. furnace; 2. working fluid 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 fluid storage chamber; 217. third compressor; 218. TES heat exchange assembly; 219. first heat exchanger; 220. liquid working fluid storage chamber; 221. second heat exchanger; 222. high-temperature heat exchange working fluid tank; 223. low-temperature heat exchange working fluid tank; 224. third turbine; 225. third heat exchanger. DETAILED DESCRIPTION

[0044] The embodiment of the present invention provides a coal-fired power generation system based on supercritical carbon dioxide energy storage, which is used to solve the technical problem that the existing technology integrates supercritical carbon dioxide circulation with coal-fired boilers to replace the steam turbine system to form a power generation system with higher power generation efficiency. However, when the system is generating electricity, the flue gas in the boiler is directly discharged, and there is a lack of waste heat utilization, which reduces the power generation efficiency of the power generation system.

[0045] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] For easier understanding, see Figure 1 , a coal-fired power generation system based on supercritical carbon dioxide energy storage, including a reheat boiler system, a coal-fired power generation system and an energy storage system;

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

[0048] The coal-fired power generation system includes a power generation component and a turbine component;

[0049] A reheat boiler system is used to receive a first working fluid of the power generation component and heat the first working fluid to obtain a second working fluid;

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

[0051] The turbine assembly is used to receive the second working fluid and perform energy conversion on the second working fluid to obtain a third working fluid;

[0052] A power generation component, used for receiving a third working fluid and performing a cyclic power generation operation on the third working fluid to obtain a waste heat working fluid and a first working fluid;

[0053] The energy storage system is used to receive waste heat working fluid and store the working fluid energy.

[0054] In an embodiment of the present invention, a coal-fired power generation system based on supercritical carbon dioxide energy storage includes a reheat boiler system, a coal-fired power generation system and an energy storage system. The reheat boiler system is arranged inside the furnace 1, and the reheat boiler system is connected to the coal-fired power generation system and the energy storage system respectively. The reheat boiler system is used to receive the first working fluid of the power generation component. When the coal burns in the furnace 1, the first working fluid (i.e., the carbon dioxide working fluid) is heated to obtain the second working fluid (i.e., the first working fluid after absorbing heat), and the second working fluid is transported to the coal-fired power generation system. The coal-fired power generation system includes a power generation component and a turbine component, and the power generation component is connected to the turbine component, the energy storage system and the reheat boiler system respectively. When the second working fluid enters the turbine component, the turbine component performs continuous energy conversion operations to obtain a third working fluid, and the power generation component performs high and low temperature heat recovery and power generation operations on the third working fluid to obtain a waste heat working fluid and a first working fluid. The energy storage system is used to receive the waste heat working fluid and store the working fluid energy with the waste heat working fluid. The energy utilization of the reheating process is optimized, and the energy utilization rate of the working fluid is improved. Moreover, the connection between the components in the system makes the circulation of the working fluid smoother, and the transfer and conversion of energy between different components more coordinated, thereby improving the operating stability of the entire system.

[0055] See also Figure 1 As shown, the reheat boiler system includes a working fluid heat exchanger 2, a first heat exchange pipe 3, a second heat exchange pipe 6 and a third heat exchange pipe 7; the turbine assembly includes a first turbine 4 and a second turbine 5; the first port of the working fluid heat exchanger 2 is connected to the power generation assembly through the second heat exchange pipe 6; the second port of the working fluid heat exchanger 2 is connected to the first turbine 4, and the first turbine 4 is connected to the second turbine 5 through the first heat exchange pipe 3; the third heat exchange pipe 7 is connected to the energy storage system, and the second turbine 5 is connected to the power generation assembly.

[0056] In the embodiment of the present invention, the reheat boiler system includes a working fluid heat exchanger 2 (i.e., a CO2 working fluid heat exchanger 2), a first heat exchange pipe 3, a second heat exchange pipe 6, and a third heat exchange pipe 7. The turbine assembly includes a first turbine 4 and a second turbine 5. The first port of the working fluid heat exchanger 2 is connected to the power generation assembly through the second heat exchange pipe 6. After the power generation assembly circulates and generates electricity, the first working fluid obtained flows back to the working fluid heat exchanger 2 through the second heat exchange pipe 6. The second port of the working fluid heat exchanger 2 is connected to the first turbine 4, and the first turbine 4 is connected to the second turbine 5 through the first heat exchange pipe 3. After being heated in the working fluid heat exchanger 2, the first working fluid is transported to the first turbine 4 for turbine, and the second working fluid after turbine is then transported to the second turbine 5 through the first heat exchange pipe 3 for secondary turbine to obtain the third working fluid, which is then transported to the power generation assembly. By setting the first turbine 4 and the second turbine 5, a multi-stage turbine is realized compared with a single-stage turbine, which can improve the energy conversion efficiency of the entire turbine assembly, thereby improving the power generation efficiency of the entire system. The third heat exchange pipe 7 is connected to the energy storage system, and the second turbine 5 is connected to the power generation component. Part of the waste heat is transmitted to the energy storage system through the third heat exchange pipe 7.

[0057] It is worth mentioning that in traditional power generation systems, the waste heat after power generation is often directly discarded, resulting in energy waste. However, this part of the waste heat is recovered and stored through the third heat exchange pipe 7 and the energy storage system, and can be reused when needed. For example, during peak power consumption or other times when energy needs to be supplemented, the energy in the energy storage system can be re-invested in the system, thereby improving the comprehensive utilization efficiency of the energy of the entire system.

[0058] See also Figure 1 As shown, the power generation component 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 medium heat exchanger 2 through the 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 respectively connected to the first end of the second compressor 10 and the first hot side of the cooler 13; 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 respectively 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.

[0059] In the embodiment of the present invention, the power generation component 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 medium heat exchanger 2 through the 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 respectively connected to the first end of the second compressor 10 and the first hot side of the cooler 13. 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 respectively 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. The third working medium after the turbine is sequentially diverted through the high-temperature heat exchanger 11 and the low-temperature heat exchanger 12, and the diverted third working medium is respectively compressed in multiple stages through the first compressor 14 and the second compressor 10. Compared with the single reheat process circulation system, it has higher efficiency.

[0060] It is worth mentioning that the coal-fired power generation system is characterized by the recycling of supercritical CO2 as a working medium and the use of S-CO2 as a working fluid for cyclic power generation.

[0061] See also 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 working fluid tank 222, a low-temperature heat exchange working fluid tank 223 and an energy storage module; the liquid working fluid storage chamber 220216 is connected to the power generation component, and the first end of the liquid working fluid storage chamber 220216 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 the first hot side of the second heat exchanger 221 is connected to the first cold side of the first heat exchanger 219 through the low-temperature heat exchange working 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 through the high-temperature heat exchange working 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 an embodiment of the present invention, the energy storage system includes 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 the first end of the liquid working medium storage chamber 220216 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 the first hot side of the second heat exchanger 221 is connected to the 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 state, the liquid working medium storage chamber 220216 releases liquid CO2. And the liquid CO2 working medium is transferred to the second heat exchanger 221. The working medium evaporates in the second heat exchanger 221 and is transferred to the energy storage module from the second cold side of the second heat exchanger 221. The second cold side of the first heat exchanger 219 is connected to the second hot side of the second heat exchanger 221 through the high-temperature heat exchange working medium 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 medium storage chamber 220216. When the energy storage system is in the energy storage state, the waste heat working medium is cooled and heat-exchanged by the energy storage module, and the treated working medium is transported to the first heat exchanger 219 for cooling treatment to obtain cooling working medium, and then the cooling working medium is transported to the liquid working medium storage chamber 220216 for energy storage. By using the waste heat of the power generation component to heat the liquid working medium storage chamber 220216 to maintain the pressure stability during the release of carbon dioxide, the ability of the system working medium to do work is improved.

[0063] See also Figure 1 As shown, the energy storage module includes a working fluid storage chamber 216, a third compressor 217, a TES heat exchange component 218, a third turbine 224 and a third heat exchanger 225; the first cold side of the TES heat exchange component 218 serves as the first end of the energy storage module, and the first hot side of the TES heat exchange component 218 serves as the second end of the energy storage module; the second cold side of the TES heat exchange component 218 is connected to one end of the third turbine 224 through the third heat exchange pipe 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 fluid storage chamber 216; the other end of the working fluid 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 component.

[0064] In an embodiment of the present invention, the energy storage module includes a working fluid 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 the third heat exchange pipe 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 fluid storage chamber 216. The other end of the working fluid 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 fluid is heated by the TES heat exchange assembly 218, and the heated working fluid is transmitted to the third turbine 224 through the third heat exchange pipe 7. The working medium is processed to generate electricity through the third turbine 224 , and then the working medium after the processing to generate electricity is cooled through the third heat exchanger 225 and flows back to the working medium storage chamber 216 .

[0065] It is worth mentioning that the system performance index of the energy storage system before coupling will show a rapid downward trend from 76.59% within a certain period of time as carbon dioxide is released, while the system after coupling the reheat boiler system and the coal-fired power generation system can maintain performance at around 77% for a long time, which greatly improves the system's continuous energy release.

[0066] See also Figure 1 As shown, 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 invention, the first cold side and the second cold side of the cooler 13 are connected to the energy storage system, so as to transmit the waste heat medium to the energy storage system.

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

[0069] In an embodiment of the present invention, the first working fluid is carbon dioxide. Since the critical temperature of carbon dioxide itself is relatively low, using carbon dioxide as a working fluid can more effectively occupy storage space and store energy under certain conditions. And carbon dioxide can undergo phase changes under different temperature and pressure conditions, such as from liquid to gas. This phase change process is accompanied by the absorption and release of energy, which can be effectively utilized in energy storage systems and power generation components. Thereby improving the energy conversion efficiency of the system.

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

[0071] See also Figure 1 As shown, an air preheater 8 is provided inside the furnace 1.

[0072] In the embodiment of the present invention, an air preheater 8 is provided inside the furnace 1. The air preheater 8 can reuse the waste heat of the flue gas in the reheat boiler system, thereby improving the utilization rate of the waste heat.

[0073] See also Figure 1 As shown, a flue 9 is provided inside the furnace 1, 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 invention, a flue 9 is provided inside the furnace 1, and the flue 9 divides the flue gas in the reheat boiler system into two streams and transmits them to the air preheater 8 and the inlet of the third turbine 224 of the energy storage system respectively.

[0075] In another embodiment, the working process of the coal-fired power generation system based on supercritical carbon dioxide energy storage is specifically as follows: the carbon dioxide working medium absorbs heat in the boiler, first enters the second heat exchange pipe 6 for preheating, and then enters the working medium heat exchanger 22 in the furnace to absorb heat. The working medium after absorbing heat enters the first turbine 4 for turbine work. The working medium after the first turbine work then enters the third heat exchange pipe 7 to absorb heat again, and then enters the second turbine 5 to perform turbine work. At this point, the working medium leaves the reheat boiler system (the state of the working medium at this time is: 465.85°C, 8.5MPa), and at this time the working medium enters the hot side of the high-temperature heat exchanger 11 and the low-temperature heat exchanger 12 for cooling. The cooled working medium (the state of the working medium at this time is: 76 .85°C, 8.2MPa) needs to be split, one of which flows through the cooler 13 for cooling (the state of the working fluid at this time is: 31.85°C, 8.1MPa) and enters the first compressor 14 for compression. The compressed working fluid (the state of the working fluid at this time is: 66.85°C, 27.77MPa) absorbs heat through the low-temperature heat exchanger 12, and the other working fluid is directly compressed through the second compressor. At this time, the two working fluids are mixed (the state of the working fluid at this time is: 204.85°C, 27.66MPa), and the mixed working fluid absorbs heat through the high-temperature heat exchanger 11 (the state of the working fluid at this time is: 423.85°C, 27.5MPa) and returns to the reheat boiler system to form a cycle.

[0076] In another embodiment, the working process of the energy storage system is specifically as follows: the working fluid CO2 starts to flow in from the working fluid storage chamber 216 (at this time the state of the working fluid is: 15°C, 0.1MPa), the CO2 working fluid first enters the third compressor 217 for compression, and the compressed working fluid (at this time the state of the working fluid is: 446.4°C, 6.858MPa) enters the hot side of the TES heat exchange component 218 to release heat to the cold side, and after the working fluid is cooled and heat exchanged in the TES heat exchange component 218 (at this time the state of the working fluid is: 33.18°C, 6.584MPa), it flows into the first heat exchanger 219 for cooling again. At this time, the cooled working fluid is in liquid state and is sent to the liquid working fluid storage chamber 220216 for storage to complete the energy storage process. When the system needs to generate electricity externally, the liquid working medium storage chamber 220216 releases the stored liquid CO2, wherein the heat of the cooler 13 in the power generation cycle is coupled to the liquid working medium storage chamber 220216 to maintain the released working medium (the state of the working medium at this time is: 21.9°C, 7MPa) and the pressure is maintained at about 7MPa, and the liquid working medium then enters the second heat exchanger 221 to absorb heat and evaporate, and after the working medium evaporates in the second heat exchanger 221 (the state of the working medium at this time is: 20.52°C, 5.649MPa), it flows into the TES heat exchange component 2 18 The working fluid passes through the cold side and absorbs heat. After absorbing heat in the TES heat exchange component 218, the working fluid is in a state of high temperature and high pressure (the state of the working fluid at this time is: 432.59°C, 5.423MPa). The working fluid is heated again by the waste heat of the flue gas when passing through the third heat exchange pipeline 7 of the coal-fired power generation system. Finally, the working fluid enters the third turbine 224 and generates electricity in the third turbine 224. After the turbine, the working fluid flows through the third heat exchanger 225 to be cooled to normal temperature and pressure. The CO2 cooled by the third heat exchanger 225 returns to the working fluid storage chamber 216 to complete the energy storage cycle.

[0077] In an embodiment of the present invention, by coupling a reheat boiler system, a coal-fired power generation system and an energy storage system, the coal-fired power generation system includes a power generation component and a turbine component, and the power generation component is used to perform a cyclic power generation operation on the third working fluid to obtain a waste heat working fluid and a first working fluid, and then the waste heat working fluid and the first working fluid are sent to the energy storage system and the reheat boiler system respectively, thereby realizing the recycling of waste heat and improving the power generation performance of the system. Compared with the traditional power generation system, the technical problem that the flue gas in the existing system is directly discharged during power generation, lacks the utilization of waste heat, and reduces the power generation efficiency of the power generation system is overcome. The reheat boiler system is connected to the coal-fired power generation system and the energy storage system respectively, and the waste heat is utilized by the energy storage system, thereby improving the power generation efficiency of the power generation system.

[0078] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0079] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of units is only a logical function division. There may be other division methods in 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. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0080] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0081] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A coal-fired power generation system based on supercritical carbon dioxide energy storage, characterized in that: Includes reheat boiler system, coal-fired power generation system and energy storage system; 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 comprises a power generation component and a turbine component; The reheat boiler system is used to receive the first working fluid of the power generation component and heat the first working fluid to obtain a second working fluid; The power generation assembly is respectively connected to the turbine assembly, the energy storage system and the reheat boiler system; The turbine assembly is used to receive the second working fluid and perform energy conversion on the second working fluid to obtain a third working fluid; The power generation component is used to receive the third working fluid and perform a cyclic power generation operation on the third working fluid to obtain a waste heat working fluid and a first working fluid; The energy storage system is used to receive the waste heat working medium and store working medium energy.

2. The coal-fired power generation system based on supercritical carbon dioxide energy storage according to claim 1 is characterized in that: The reheat boiler system includes a working medium heat exchanger, a first heat exchange pipeline, a second heat exchange pipeline and a third heat exchange pipeline; The turbine assembly includes a first turbine and a second turbine; The first port of the working medium heat exchanger is connected to the power generation component through the second heat exchange pipe; The second port of the working medium 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 pipeline is connected to the energy storage system, and the second turbine is connected to the power generation component.

3. The coal-fired power generation system based on supercritical carbon dioxide energy storage according to claim 2 is characterized in that: 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 medium 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.

4. The coal-fired power generation system based on supercritical carbon dioxide energy storage according to claim 3 is characterized in that: The energy storage system includes a first heat exchanger, a liquid working medium storage chamber, a second heat exchanger, a high-temperature heat exchange working medium tank, a low-temperature heat exchange working medium tank and an energy storage module; The liquid working medium storage chamber is connected to the power generation assembly, and the first end of the liquid working medium 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 medium 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 medium storage chamber.

5. The coal-fired power generation system based on supercritical carbon dioxide energy storage according to claim 4 is characterized in that: The energy storage module includes a working medium storage chamber, a third compressor, a TES heat exchange component, a third turbine and a third heat exchanger; 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; The second cold side of the TES heat exchange assembly is connected to one end of the third turbine through 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 medium storage chamber; The other end of the working medium 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 assembly.

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

7. The coal-fired power generation system based on supercritical carbon dioxide energy storage according to claims 1-6, characterized in that: The first working fluid is carbon dioxide.

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

9. The coal-fired power generation system based on supercritical carbon dioxide energy storage according to claims 1-6, characterized in that: An air preheater is arranged inside the furnace.

10. The coal-fired power generation system based on supercritical carbon dioxide energy storage according to claim 9, characterized in that: A flue is provided inside the furnace, and the flue is used to transport the flue gas in the furnace to the air preheater and the energy storage system.

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