A heat pump-based integrated system for electricity storage and electrothermal utilization, coupled with low-grade heat recovery and medium-low temperature flue gas carbon capture.

Abstract

This invention discloses a heat pump-powered energy storage and electrothermal integrated utilization system for medium- and low-temperature flue gas carbon capture coupled with low-grade heat recovery. The carbon capture cycle includes an adsorption process and a desorption process. The adsorption process captures carbon dioxide from the medium- and low-temperature flue gas and uses the waste heat of the flue gas and the heat released during the adsorption process as a low-grade heat source for the heat pump cycle. The desorption process heats and regenerates the saturated adsorbent material, enabling its recycling, and uses the generated high-purity carbon dioxide as a raw material for production. The heat pump cycle recovers the heat output from the carbon capture cycle and uses electricity to drive the heat pump cycle to increase the grade of the low-grade heat source, outputting high-temperature heat. The heat storage cycle stores the high-temperature heat output from the heat pump cycle and supplies the heat energy to the desorption process and the organic Rankine cycle. The organic Rankine cycle converts the heat energy stored in the heat storage cycle into electricity. This invention achieves low-cost, high-density, and long-term storage of electrical energy, realizing integrated electrothermal utilization.

Description

Technical Field

[0001] This invention relates to energy storage and carbon capture technology, and in particular to a heat pump energy storage and electrothermal integrated utilization system that couples low-temperature flue gas carbon capture with low-grade heat recovery. Background Technology

[0002] Currently, the proportion of renewable energy generation is continuously increasing, but its intermittent and fluctuating nature makes it difficult to absorb and utilize renewable energy. Furthermore, the mismatch between power generation and load poses new challenges to grid peak shaving and frequency regulation. Energy storage technology, especially electricity storage technology, is key to solving this problem.

[0003] Currently, pumped hydro storage is the most widely used energy storage technology globally and nationally, accounting for approximately 86% of the total installed capacity. Pumped hydro storage boasts high efficiency, long lifespan, large capacity, and low cost per kilowatt-hour, but suffers from long construction periods, high investment costs, significant environmental impact, and stringent requirements regarding geographical and geological conditions. Lithium-ion batteries account for approximately 11% of the total installed capacity. They offer high energy storage efficiency, short construction periods, high energy density, and fast response speed, but also suffer from high cost per kilowatt-hour, short lifespan, and significant safety risks. Other emerging energy storage technologies, such as sodium-sulfur batteries, flow batteries, compressed air energy storage, liquid air energy storage, and molten salt thermal energy storage, are currently in the research and demonstration stages and have not yet achieved large-scale commercial application, failing to simultaneously meet the demands for high density, low cost, and long-duration operation.

[0004] Heat pump energy storage, as an emerging energy storage technology, uses heat storage as an intermediate process to achieve "electricity-heat-electricity" storage and conversion. This technology is not limited by geographical conditions, is safe and reliable, and combines the advantages of low cost and long-term operation of heat storage. The round-trip efficiency of a heat pump energy storage system depends on the efficiency of the heat pump cycle, the efficiency of heat storage, and the efficiency of power generation. Among these, the temperature of the low-grade heat source in the heat pump cycle has a significant impact on the system efficiency. If only heat is extracted from the environment, and the power generation side expands to the ambient temperature, its theoretical system efficiency will be lower than that of pumped hydro storage. Therefore, finding a suitable low-grade heat source is key to improving the efficiency of heat pump energy storage and promoting its application. How to solve the problem of sourcing low-grade heat sources for heat pump energy storage systems and achieve a significant improvement in the overall energy utilization efficiency of the entire system is an urgent problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide a heat pump energy storage and electrothermal integrated utilization system for medium and low temperature flue gas carbon capture coupled with low-grade heat recovery, so as to effectively solve the problems of new energy consumption, power grid peak shaving and frequency regulation, and efficient carbon capture.

[0006] Technical solution: The present invention provides a heat pump energy storage and electrothermal integrated utilization system for medium- and low-temperature flue gas carbon capture coupled with low-grade heat recovery, comprising:

[0007] The carbon capture cycle includes a first tank, a first evaporator, a second tank, and a high-temperature storage tank. Both the first and second tanks are equipped with flue gas inlets and outlets and working fluid inlets and outlets. Low-temperature flue gas enters the first tank through the flue gas inlet. The adsorption medium in the first tank captures carbon dioxide from the flue gas. Simultaneously, the waste heat from the flue gas and the heat released during the adsorption process are transferred to the first working fluid flowing through the first tank. The heat-carrying first working fluid then transfers its heat to the second working fluid in the heat pump cycle via the first evaporator. The first working fluid, after releasing its heat, flows back to the first tank. The heat-carrying second working fluid then transfers its heat to the third working fluid in the heat storage cycle. The third working fluid in the heat storage cycle transfers its heat to the heat storage medium in the high-temperature storage tank. The first working fluid absorbs high-temperature heat from the heat storage medium and then enters the second tank, heating the saturated adsorption medium in the second tank to desorb and regenerate it. The first working fluid, after releasing its high-temperature heat, flows back to the high-temperature storage tank. In this process, the first tank is the adsorption process, and the second tank is the desorption process. The process is as follows: When the adsorption medium in the first tank is saturated, medium- and low-temperature flue gas enters the second tank through the flue gas inlet. The adsorption medium in the second tank captures carbon dioxide in the flue gas. At the same time, the waste heat of the flue gas and the heat released during the adsorption process are transferred to the first working fluid flowing through the second tank. The first working fluid carrying heat transfers the heat to the second working fluid in the heat pump cycle through the first evaporator. Simultaneously, the first working fluid, after releasing heat, flows back to the second tank. The second working fluid carrying heat transfers the heat to the third working fluid in the heat storage cycle. The third working fluid in the heat storage cycle transfers the heat it carries to the heat storage medium in the high-temperature storage tank. The first working fluid absorbs high-temperature heat from the heat storage medium and then enters the first tank, heating the saturated adsorption medium in the first tank to desorb and regenerate it. The first working fluid, after releasing high-temperature heat, flows back to the high-temperature storage tank. During this process, the first tank is in the desorption process, and the second tank is in the adsorption process. The adsorption and desorption functions of the first and second tanks are switched to achieve continuous adsorption and desorption.

[0008] The heat pump cycle is used to increase the grade of the low-grade heat source output by the carbon capture cycle through electric power, and output high-temperature heat to be stored in a high-temperature storage tank.

[0009] The heat storage cycle includes a low-temperature storage tank and a high-temperature storage tank. The high-temperature storage tank supplies the stored high-temperature heat to the desorption process and the organic Rankine cycle. The third working fluid in the high-temperature storage tank releases high-temperature heat again through the organic Rankine cycle and is then stored in the low-temperature storage tank. The low-temperature third working fluid in the low-temperature storage tank absorbs the heat of the second working fluid in the heat pump cycle and then flows back to the high-temperature storage tank.

[0010] The organic Rankine cycle is used to convert thermal energy in a thermal storage cycle into electrical energy, and the thermal storage cycle is used to achieve the continuity of the electro-thermal-electric conversion.

[0011] Preferably, the carbon capture cycle also includes a regenerator. The first working fluid, after releasing heat from the first evaporator, transfers its waste heat to the organic Rankine cycle via the regenerator to preheat the fourth working fluid in the organic Rankine cycle. At the same time, the first working fluid, after recovering waste heat via the regenerator, flows back to the first tank or the second tank.

[0012] Preferably, the carbon capture cycle further includes a first heat exchange tube and a second heat exchange tube respectively disposed in the second tank and the first tank. The adsorption medium or saturated adsorption medium is attached to the surface of the first heat exchange tube or the second heat exchange tube. A first working fluid flows in the second heat exchange tube and the first heat exchange tube. The first heat exchange tube and the second heat exchange tube are used to realize the exchange of heat between the first working fluid in the tube and the waste heat of the flue gas outside the tube and the heat released during the adsorption process or the heat of the saturated adsorption medium.

[0013] Preferably, valve No. 2 and valve No. 4 are respectively installed between the working fluid outlets of the first tank and the second tank and the hot side inlet of the first evaporator; valve No. 1 and valve No. 7 are respectively installed between the hot side outlet of the first evaporator and the working fluid inlets of the first tank and the second tank; valve No. 3 and valve No. 5 are respectively installed between the working fluid outlets of the first tank and the second tank and the first inlet of the high-temperature storage tank; and valve No. 8 and valve No. 6 are respectively installed between the first outlet of the high-temperature storage tank and the working fluid inlets of the first tank and the second tank.

[0014] When valves 1, 2, 5, and 6 are opened, and valves 3, 4, 7, and 8 are closed, the first tank undergoes an adsorption process, and the second tank undergoes a desorption process.

[0015] Preferably, the heat pump cycle includes a first evaporator, a throttling valve, a first condenser, and a compressor; the cold-side inlet of the first evaporator is connected to the outlet of the throttling valve, the inlet of the throttling valve is connected to the hot-side outlet of the first condenser, the hot-side inlet of the first condenser is connected to the outlet of the compressor, and the inlet of the compressor is connected to the cold-side outlet of the first evaporator.

[0016] Preferably, the thermal storage cycle further includes a first condenser and a second evaporator; the cold-side inlet of the first condenser is connected to the outlet of the low-temperature storage tank, the inlet of the low-temperature storage tank is connected to the hot-side outlet of the second evaporator, the hot-side inlet of the second evaporator is connected to the second outlet of the high-temperature storage tank, and the second inlet of the high-temperature storage tank is connected to the cold-side outlet of the first condenser.

[0017] Preferably, the organic Rankine cycle includes a second evaporator, a pump, a second condenser, and an expander; the cold-side inlet of the second evaporator is connected to the pump outlet, the pump inlet is connected to the hot-side outlet of the second condenser, the hot-side inlet of the second condenser is connected to the expander outlet, and the expander inlet is connected to the cold-side outlet of the second evaporator.

[0018] Preferably, the organic Rankine cycle further includes a regenerator disposed between the second evaporator and the pump, wherein the cold-side inlet of the second evaporator is connected to the cold-side outlet of the regenerator, and the cold-side inlet of the regenerator is connected to the pump outlet.

[0019] Preferably, the adsorption medium in the carbon capture cycle is a polyamine solid adsorption material with an adsorption temperature of 60-70℃ and a regeneration temperature of 110-120℃; an internal cooling / internal heating heat exchange structure is adopted to enhance the adsorption and desorption processes.

[0020] Based on the same inventive concept, the present invention provides a method for integrated utilization of heat pump electricity storage and electrothermal energy through medium- and low-temperature flue gas carbon capture coupled with low-grade heat recovery, comprising a continuous adsorption and desorption process, and an electro-thermal-electro-conversion process, specifically as follows:

[0021] In the process, low-temperature flue gas enters the first tank through the flue gas inlet. The adsorption medium in the first tank captures carbon dioxide from the flue gas. Simultaneously, the waste heat from the flue gas and the heat released during the adsorption process are transferred to the first working fluid flowing through the first tank. Driven by electricity, the first working fluid, carrying heat, transfers this heat to the second working fluid in the heat pump cycle. The first working fluid, after releasing heat, returns to the first tank. The second working fluid, carrying heat, transfers this heat to the third working fluid in the heat storage cycle, achieving electro-thermal conversion. The third working fluid in the heat storage cycle transfers its heat to the heat storage medium in the high-temperature storage tank. The first working fluid absorbs high-temperature heat from the heat storage medium and then enters the second tank, heating the saturated adsorption medium in the second tank, causing it to desorb and regenerate. The first working fluid, after releasing high-temperature heat, returns to the high-temperature storage tank. During this process, the first tank is the adsorption process, and the second tank is the desorption process. When the adsorption medium in the first tank becomes saturated, the low-temperature flue gas... The flue gas enters the second tank through the flue gas inlet. The adsorption medium in the second tank captures carbon dioxide in the flue gas. Simultaneously, the waste heat of the flue gas and the heat released during the adsorption process are transferred to the first working fluid flowing through the second tank. The first working fluid, carrying heat, transfers the heat to the second working fluid in the heat pump cycle via the first evaporator. After releasing heat, the first working fluid returns to the second tank. The second working fluid, carrying heat, transfers the heat to the third working fluid in the heat storage cycle, achieving electro-thermal conversion. The third working fluid in the heat storage cycle transfers the heat it carries to the heat storage medium in the high-temperature storage tank. The first working fluid absorbs high-temperature heat from the heat storage medium and then enters the first tank, heating the saturated adsorption medium in the first tank to desorb and regenerate it. After releasing high-temperature heat, the first working fluid returns to the high-temperature storage tank. During this process, the first tank is in the desorption process, and the second tank is in the adsorption process. The adsorption and desorption functions of the first and second tanks are switched to achieve continuous adsorption and desorption.

[0022] The low-grade heat source output from the carbon capture cycle is upgraded by an electrically driven heat pump cycle, and the high-temperature heat is stored in a high-temperature storage tank. The third working fluid, after releasing high-temperature heat in the high-temperature storage tank, releases heat again through an organic Rankine cycle and is then stored in a low-temperature storage tank. The low-temperature working fluid in the low-temperature storage tank absorbs heat from the second working fluid in the heat pump cycle and then flows back to the high-temperature storage tank. The organic Rankine cycle converts the heat energy stored in the high-temperature storage tank into electrical energy, realizing heat-to-electricity conversion.

[0023] Beneficial effects: Compared with the prior art, the significant technical effects of the present invention are as follows:

[0024] (1) By using thermal storage as an intermediate process, low-cost, high-density and long-term storage of electrical energy is achieved, which effectively solves the problems of new energy consumption and power grid peak regulation and frequency regulation.

[0025] (2) The coupling carbon capture system solves the problem of low heat source in the heat pump energy storage system, greatly improves the system conversion efficiency of electricity-heat-electricity, and recovers the waste heat and adsorption heat of flue gas. The stored heat is used to drive the desorption process, realizing the comprehensive utilization of electricity and heat and improving the overall energy utilization efficiency of the whole system. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the system structure of the present invention;

[0027] In the diagram: 1. First tank; 2. First evaporator; 3. Throttling valve; 4. First condenser; 5. Compressor; 6. Second tank; 7. Low-temperature storage tank; 8. High-temperature storage tank; 9. Second evaporator; 10. Regenerator; 11. Pump; 12. Second condenser; 13. Expander; 14. First heat exchange tube; 15. Second heat exchange tube; 16. Valve No. 1; 17. Valve No. 2; 18. Valve No. 3; 19. Valve No. 4; 20. Valve No. 5; 21. Valve No. 6; 22. Valve No. 7; 23. Valve No. 8. Detailed Implementation

[0028] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] The heat from medium- and low-temperature flue gas cannot be used for work, making its heat energy recovery and utilization difficult. However, it can serve as a low-grade heat source for heat pump energy storage systems. After heat pump enhancement and efficiency improvement, it can be used for heat energy storage and thermoelectric conversion. Furthermore, the high carbon dioxide content in medium- and low-temperature flue gas makes it a target for efficient carbon capture. The widely used adsorption and absorption processes are mostly heat dissipation processes, while the regeneration process of the adsorption and absorption materials is a heat utilization process. This not only provides a low-grade heat source for heat pump energy storage systems but also comprehensively utilizes the stored heat, greatly improving the overall energy efficiency of the system.

[0030] Based on this, the present invention designs a heat pump power storage and electrothermal integrated utilization system for medium- and low-temperature flue gas carbon capture coupled with low-grade heat recovery, including a carbon capture cycle, a heat pump cycle, a heat storage cycle, and an organic Rankine cycle. The carbon capture cycle includes an adsorption process and a desorption process. The adsorption process is used to capture carbon dioxide in medium- and low-temperature flue gas and uses the waste heat of the flue gas and the heat released during the adsorption process as a low-grade heat source for the heat pump cycle. The desorption process is used to heat and regenerate the saturated adsorbent material, realizing the recycling of the adsorbent material and producing high-purity carbon dioxide, which can be used as a raw material for production. At the same time, the carbon capture cycle further recovers the remaining waste heat of the flue gas and the heat released during the adsorption process to preheat the working fluid in the organic Rankine cycle. The heat pump cycle is used to recover the heat output from the carbon capture cycle and uses electricity to drive the heat pump cycle to increase the grade of the low-grade heat source and output high-temperature heat. The heat storage cycle is used to store the high-temperature heat output from the heat pump cycle and supply the heat energy to the desorption process and the organic Rankine cycle. The organic Rankine cycle is used to convert the heat energy stored in the heat storage cycle into electricity.

[0031] This system uses medium- and low-temperature flue gas as both a carbon and heat source, employing adsorption materials to capture carbon dioxide from the flue gas. During charging, the waste heat from the flue gas and the heat released during adsorption (adsorption heat) are recovered as a low-grade heat source for the heat pump cycle. This heat is then used to drive the heat pump cycle with green electricity or surplus electricity to improve the gas's grade and is stored in a high-temperature storage tank. During discharging, an organic Rankine cycle is used to convert the stored heat energy into electricity, while a regenerator further recovers the waste heat from the flue gas and the adsorption heat. The desorption process of the carbon capture cycle is driven by the heat stored in the high-temperature storage tank. This invention uses heat storage as an intermediate process to achieve low-cost, high-density, and long-term storage of electrical energy, effectively addressing the needs of new energy consumption and grid peak shaving and frequency regulation. Coupled with the carbon capture system, it solves the problem of low-grade heat source for the heat pump energy storage system, significantly improving the system's "electricity-heat-electricity" round-trip efficiency. It also recovers the waste heat and adsorption heat from the medium- and low-temperature flue gas, and uses some of the stored heat to drive the desorption process of the adsorption materials, achieving comprehensive utilization of electricity and heat and improving the overall energy efficiency of the entire system.

[0032] Example 1

[0033] like Figure 1 The figure shown is the preferred embodiment of the present invention, a heat pump energy storage and electrothermal integrated utilization system for medium and low temperature flue gas carbon capture coupled with low grade heat recovery, including a carbon capture cycle, a heat pump cycle, a heat storage cycle and an organic Rankine cycle.

[0034] The carbon capture cycle includes a first tank 1, a first evaporator 2, a second tank 6, a high-temperature storage tank 8, a regenerator 10, a first heat exchange tube 14, and a second heat exchange tube 15. Both the first tank 1 and the second tank 6 have flue gas inlet and outlet and working fluid inlet and outlet at their top and bottom, respectively. The first tank 1 contains the second heat exchange tube 15, and the second tank 6 contains the first heat exchange tube 14. The outlets of the second heat exchange tube 15 and the first heat exchange tube 14 are connected to the hot-side inlet of the first evaporator 2 via valve 17 and valve 19, respectively. The hot-side outlet of the first evaporator 2 is connected to the hot-side inlet of the regenerator 10. The hot-side outlet of the regenerator 10 is connected to the inlet of the second heat exchange tube 15 and the inlet of the first heat exchange tube 14 via valve 16 and valve 22, respectively. The outlets of the second heat exchange tube 15 and the first heat exchange tube 14 are connected via valve 18, respectively. Valve 20 is connected to the first inlet of the high-temperature storage tank 8. The first outlet of the high-temperature storage tank 8 is connected to the inlet of the second heat exchange tube 15 and the inlet of the first heat exchange tube 14 via valves 23 and 21, respectively. The functions of the first tank 1 and the second tank 6 can be switched to achieve continuous adsorption and desorption. When valves 16, 17, 20, and 21 are opened, and valves 18, 19, 22, and 23 are closed, the adsorption process occurs in the first tank 1, and the desorption process occurs in the second tank 6. When valves 18, 19, 22, and 23 are opened, and valves 16, 17, 20, and 21 are closed, the desorption process occurs in the first tank 1, and the adsorption process occurs in the second tank 6.

[0035] During the adsorption process, the first tank 1 and the second tank 6 are used to capture carbon dioxide from the low-temperature flue gas. During the desorption process, the first tank 1 and the second tank 6 are used to heat and regenerate the saturated adsorption medium, realizing the recycling of the adsorption medium and generating high-purity carbon dioxide, which can be used as a raw material for production. The first evaporator 2 is used to transfer the waste heat of the flue gas and the heat released during the adsorption process to the heat pump cycle. The high-temperature storage tank 8 is used to store the high-temperature heat output by the heat pump cycle and to provide heat for the desorption process. The regenerator 10 is used to preheat the fourth working fluid in the organic Rankine cycle. During the desorption process, the first heat exchange tube 14 and the second heat exchange tube 15 are used to heat the saturated adsorption medium on the surface of the tubes to promote its regeneration. During the adsorption process, the first heat exchange tube 14 and the second heat exchange tube 15 are used to heat the first working fluid of the carbon capture cycle, providing a low-grade heat source for the heat pump cycle.

[0036] The heat pump cycle includes a first evaporator 2, a throttling valve 3, a first condenser 4, and a compressor 5. The cold-side inlet of the first evaporator 2 is connected to the outlet of the throttling valve 3, the inlet of the throttling valve 3 is connected to the hot-side outlet of the first condenser 4, the hot-side inlet of the first condenser 4 is connected to the outlet of the compressor 5, and the inlet of the compressor 5 is connected to the cold-side outlet of the first evaporator 2. The first evaporator 2 is used to raise the initial temperature of the second working fluid in the heat pump cycle, making it a low-temperature, low-pressure vapor. The throttling valve 3 is used to control the flow rate of the second working fluid in the heat pump cycle, making it a low-temperature, low-pressure wet vapor. The first condenser 4 is used to cool the second working fluid in the heat pump cycle, making it a high-temperature, high-pressure liquid. The compressor 5 is used to compress the second working fluid in the heat pump cycle, making it a high-temperature, high-pressure vapor.

[0037] The thermal storage cycle includes a first condenser 4, a cryogenic storage tank 7, a high-temperature storage tank 8, and a second evaporator 9. The cold-side inlet of the first condenser 4 is connected to the outlet of the cryogenic storage tank 7, the inlet of the cryogenic storage tank 7 is connected to the hot-side outlet of the second evaporator 9, the hot-side inlet of the second evaporator 9 is connected to the second outlet of the high-temperature storage tank 8, and the second inlet of the high-temperature storage tank 8 is connected to the cold-side outlet of the first condenser 4. The first condenser 4 is used to transfer the high-temperature heat generated by the heat pump cycle to the third working fluid in the thermal storage cycle; the cryogenic storage tank 7 is used to store the cryogenic storage medium; the high-temperature storage tank 8 is used to store the high-temperature heat output by the heat pump cycle; and the second evaporator 9 is used to provide high-temperature heat to the organic Rankine cycle.

[0038] The organic Rankine cycle includes a second evaporator 9, a regenerator 10, a pump 11, a second condenser 12, and an expander 13. The cold-side inlet of the second evaporator 9 is connected to the cold-side outlet of the regenerator 10, the cold-side inlet of the regenerator 10 is connected to the outlet of the pump 11, the inlet of the pump 11 is connected to the hot-side outlet of the second condenser 12, the hot-side inlet of the second condenser 12 is connected to the outlet of the expander 13, and the inlet of the expander 13 is connected to the cold-side outlet of the second evaporator 9. The second evaporator 9 provides high-temperature heat to the organic Rankine cycle, making it high-temperature, high-pressure vapor. The regenerator 10 preheats the fourth working fluid within the organic Rankine cycle. The pump 11 compresses the fourth working fluid within the organic Rankine cycle, making it a high-pressure liquid. The second condenser 12 cools the fourth working fluid within the organic Rankine cycle, making it a low-temperature, low-pressure liquid. The expander 13 expands the fluid, converting the high-temperature heat into electricity, and transforms the fourth working fluid into low-temperature, low-pressure vapor.

[0039] In this embodiment, the temperature of the medium-low temperature flue gas is 60-80℃, and the carbon dioxide content is relatively high.

[0040] The adsorption medium in the first tank 1 and the second tank is a polyamine solid adsorption material with an adsorption temperature of 60-70℃ and a regeneration temperature of 110-120℃.

[0041] The adsorption medium in the first tank 1 is attached to or saturated with the adsorption medium on the surface of the second heat exchange tube 15, and the saturated adsorption medium or adsorption medium in the second tank 6 is attached to the surface of the first heat exchange tube 14. The first tank 1 and the second tank 6 are used interchangeably to achieve continuous carbon adsorption and carbon desorption.

[0042] The first tank 1 and the second tank 6 employ an internally cooled / internally heated heat exchange structure to enhance the adsorption and desorption processes. When the first tank 1 is used for adsorption and the second tank 6 is used for desorption: the second heat exchange tube 15 in the first tank 1 is an internally cooled heat exchange structure, converting waste heat from the flue gas and adsorption heat into a low-grade heat source for the heat pump cycle; the first heat exchange tube 14 in the second tank 6 is an internally heated heat exchange structure. The first working fluid exiting the high-temperature storage tank carries high-temperature heat and flows through the first heat exchange tube 14, heating the saturated adsorbent material on the surface of the first heat exchange tube, causing it to desorb and regenerate for recycling. When the first tank 1 is used for desorption and the second tank 6 is used for adsorption, the process is similar.

[0043] The carbon capture process in the first tank 1 or the second tank 6 is an exothermic process, which makes the inlet temperature of the first evaporator 2 reach 60-75℃, which can be used as a low-temperature heat source for the heat pump cycle.

[0044] The hot-side inlet temperature of the regenerator 10 is 45-55℃, which can be used to preheat the fourth working fluid in the organic Rankine cycle.

[0045] The high-temperature storage tank 8 in the thermal storage cycle has a thermal storage temperature of 120-130℃, and the thermal storage medium is pressurized water or phase change material.

[0046] The second working fluid in the heat pump cycle and the fourth working fluid in the organic Rankine cycle are organic working fluids.

[0047] The carbon desorption process in the first tank 1 or the second tank 6 is heated by the high-temperature storage tank 8, and the first working fluid is pressurized water or heat transfer oil.

[0048] The working principle and process of the above system are as follows:

[0049] First, when the system is initially used, one of the first tank 1 or the second tank 6 acts as an adsorption tank to carry out the adsorption process, while the other is temporarily not working. When the initial adsorption process of the first tank 1 or the second tank 6 is completed, the adsorption medium in the first tank 1 or the second tank 6 becomes a saturated adsorption medium. At this time, the first tank 1 or the second tank 6 becomes a desorption tank, and the second tank 6 or the first tank 1 becomes an adsorption tank. At this time, the adsorption process and the desorption process are carried out simultaneously. After the adsorption or desorption is completed, the adsorption and desorption functions of the first tank 1 and the second tank 6 are switched.

[0050] During use:

[0051] Low-temperature flue gas enters the first tank 1 through the top inlet. Carbon dioxide is captured by the adsorbent material attached to the surface of the second heat exchange tube 15. Simultaneously, waste heat from the flue gas and heat released during the adsorption process are recovered by the second heat exchange tube 15, preheating the first working fluid within it. This heat-carrying first working fluid then enters the first evaporator 2 through valve 17, transferring heat to the second working fluid in the heat pump cycle. It then enters the regenerator 10 to preheat the fourth working fluid in the organic Rankine cycle, before re-entering the second heat exchange tube 15 through valve 16, and the cycle repeats. Simultaneously, the heat-carrying second working fluid transfers heat to the third working fluid in the heat storage cycle. The third working fluid in the heat storage cycle transfers its heat to the heat storage medium in the high-temperature storage tank 8. The first working fluid absorbs high-temperature heat from the heat storage medium and enters the first heat exchange tube 14 through valve 21, heating the saturated adsorbent material attached to its surface and promoting its desorption and regeneration.

[0052] Furthermore, the functions of the first and second tanks can be switched. The above process describes that the first tank 1 performs the adsorption function, and the adsorption process occurs inside; the second tank 6 performs the desorption function, and the desorption process occurs inside. This process can be achieved by opening valves 16, 17, 20, and 21, and closing valves 18, 19, 22, and 23. When the adsorbent material in the first tank 1 is saturated, a function switch is required. At this time, valves 18, 19, 22, and 23 are opened, and valves 16, 17, 20, and 21 are closed. The medium-low temperature flue gas enters the second tank 6 through the top inlet and captures carbon dioxide in the flue gas through the adsorption medium attached to the surface of the first heat exchange tube 14. At the same time, the waste heat of the flue gas and the heat released during the adsorption process are recovered by the first heat exchange tube 14 to preheat the first working fluid in the first heat exchange tube 14. The first working fluid carrying heat enters the first evaporator 2 through valve 19 and transfers the heat to the second working fluid in the heat pump cycle. Then it enters the regenerator 10 to preheat the fourth working fluid in the organic Rankine cycle. Then it enters the first heat exchange tube 14 again through valve 22, and so on. Meanwhile, the second working fluid carrying heat transfers heat to the third working fluid in the heat storage cycle. The third working fluid in the heat storage cycle transfers the heat it carries to the heat storage medium in the high-temperature storage tank 8. The first working fluid absorbs high-temperature heat from the heat storage medium and enters the second heat exchange tube 15 through valve 23 to heat the saturated adsorbed medium attached to the surface of the second heat exchange tube 15, promoting its desorption and regeneration.

[0053] The second working fluid in the heat pump cycle is heated into low-temperature, low-pressure steam in the first evaporator 2, and then compressed into high-temperature, high-pressure steam in the compressor 5. The steam carrying high-temperature heat transfers heat to the third working fluid in the heat storage cycle in the first condenser 4. The high-temperature, high-pressure steam is cooled into a high-temperature, high-pressure liquid after passing through the first condenser 4. It then flows through the throttling valve 3 to reduce its pressure and become low-temperature, low-pressure wet steam. Finally, it returns to the first evaporator 2 to be heated by a low-grade heat source, and so on.

[0054] The low-temperature working fluid in the heat storage cycle flows out from the low-temperature storage tank 7 and enters the first condenser 4 to absorb the high-temperature heat generated by the heat pump cycle. Then it enters the high-temperature storage tank 8 and stores the high-temperature heat in the high-temperature storage tank 8. Excess heat can be carried by the high-temperature third working fluid to the second evaporator 9 to provide high-temperature heat to the organic Rankine cycle. The cooled low-temperature third working fluid returns to the low-temperature storage tank 7, and so on.

[0055] In the Organic Rankine Cycle, the fourth working fluid is heated into high-temperature, high-pressure steam in the second evaporator 9, and then flows into the expander 13. Through expansion, the high-temperature heat is converted into electricity, turning the fourth working fluid into low-temperature, low-pressure steam. It then enters the second condenser 12 and is cooled by cooling water to become a low-temperature, low-pressure liquid. The low-temperature, low-pressure liquid is then compressed by the pump 11 to become a high-pressure liquid. It then enters the regenerator 10, where the residual heat from the flue gas and the heat released by the adsorption process are used to preheat the fourth working fluid. Finally, it flows back into the second evaporator 9, and the cycle repeats continuously.

[0056] Example 2

[0057] In this embodiment, the carbon capture cycle includes a first tank 1, a first evaporator 2, a second tank 6, and a high-temperature storage tank 8. Both the first tank 1 and the second tank 6 are equipped with flue gas inlets and outlets and working fluid inlets and outlets. Low-temperature flue gas enters the first tank 1 through the flue gas inlet. The adsorption medium inside the first tank 1 captures carbon dioxide from the flue gas. Simultaneously, the waste heat of the flue gas and the heat released during the adsorption process are transferred to the first working fluid flowing through the first tank 1. The heat-carrying first working fluid then transfers the heat to the second working fluid within the heat pump cycle via the first evaporator 2, while simultaneously releasing heat... After releasing heat, the first working fluid returns to the first tank 1. The second working fluid, carrying heat, transfers the heat to the third working fluid in the heat storage cycle. The third working fluid in the heat storage cycle transfers the heat it carries to the heat storage medium in the high-temperature storage tank 8. The first working fluid absorbs high-temperature heat from the heat storage medium and then enters the second tank 6, heating the saturated adsorption medium in the second tank 6 to desorb and regenerate it. After releasing high-temperature heat, the first working fluid returns to the high-temperature storage tank 8. During this process, the first tank 1 is the adsorption process, and the second tank 6 is the desorption process. When the adsorption medium in the first tank 1 is saturated, medium- and low-temperature flue gas enters the second tank 6 through the flue gas inlet. The adsorption medium in the second tank 6 captures carbon dioxide in the flue gas, and the waste heat of the flue gas and the heat released during the adsorption process are transferred to the first working fluid flowing through the second tank 6. The first working fluid, carrying heat, transfers the heat to the second working fluid in the heat pump cycle via the first evaporator 2. At the same time, the first working fluid, after releasing heat, returns to the second tank 6, and the second working fluid, carrying heat, transfers the heat to the third working fluid in the heat storage cycle. The three working fluids are: the third working fluid in the heat storage cycle transfers the heat it carries to the heat storage medium in the high-temperature storage tank 8; the first working fluid absorbs high-temperature heat from the heat storage medium and then enters the first tank 1 to heat the saturated adsorption medium in the first tank 1, causing it to desorb and regenerate; the first working fluid, after releasing high-temperature heat, flows back into the high-temperature storage tank 8; during this process, the first tank 1 is the desorption process and the second tank 6 is the adsorption process; the adsorption and desorption functions of the first tank 1 and the second tank 6 are switched to achieve continuous adsorption and desorption.

[0058] The heat pump cycle structure and the heat storage cycle structure are the same as in Example 1.

[0059] The organic Rankine cycle includes a second evaporator 9, a pump 11, a second condenser 12, and an expander 13; the cold-side inlet of the second evaporator 9 is connected to the outlet of the pump 11, the inlet of the pump 11 is connected to the hot-side outlet of the second condenser 12, the hot-side inlet of the second condenser 12 is connected to the outlet of the expander 13, and the inlet of the expander 13 is connected to the cold-side outlet of the second evaporator 9.

[0060] The working principle and process of the system are similar to those in Example 1. The difference is that no heat exchange tubes are installed in the first tank 1 and the second tank 6. In addition, there is no regenerator 10. Therefore, the first working fluid, after releasing heat in the first evaporator 2, flows back to the first tank 1 or the second tank 6. At the same time, the fourth working fluid in the organic Rankine cycle cannot be preheated. The fourth working fluid processed by the pump 11 directly enters the second evaporator 9.

[0061] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A heat pump electricity storage and electric heat comprehensive utilization system coupled with low-grade heat recovery of medium-low temperature flue gas carbon capture, characterized in that, Comprise: Carbon capture cycle, comprising a first tank (1), a first evaporator (2), a second tank (6) and a high-temperature storage tank (8), the first tank (1) and the second tank (6) are provided with flue gas inlet and outlet and working fluid inlet and outlet; When the medium and low temperature flue gas enters the first tank (1) from the flue gas inlet of the first tank (1), the adsorption medium in the first tank (1) captures the carbon dioxide in the flue gas, and the flue gas waste heat and the heat released in the adsorption process are transferred to the first working fluid flowing through the first tank (1), the first working fluid carrying heat transfers heat to the second working fluid in the heat pump cycle through the first evaporator (2), and the first working fluid releases heat after releasing heat and flows back to the first tank (1), the second working fluid carrying heat transfers heat to the third working fluid in the heat storage cycle, and the third working fluid in the heat storage cycle transfers the heat it carries to the heat storage medium in the high-temperature storage tank (8), the first working fluid absorbs high-temperature heat from the heat storage medium, then enters the second tank (6), heats the saturated adsorption medium in the second tank (6) to make it desorb and regenerate, and the first working fluid releases high-temperature heat after releasing heat and flows back to the high-temperature storage tank (8); In this process, the first tank (1) is an adsorption process, and the second tank (6) is a desorption process; When the adsorption medium in the first tank (1) is saturated, the medium and low temperature flue gas enters the second tank (6) from the flue gas inlet of the second tank (6), the adsorption medium in the second tank (6) captures the carbon dioxide in the flue gas, and the flue gas waste heat and the heat released in the adsorption process are transferred to the first working fluid flowing through the second tank (6), the first working fluid carrying heat transfers heat to the second working fluid in the heat pump cycle through the first evaporator (2), and the first working fluid releases heat after releasing heat and flows back to the second tank (6), the second working fluid carrying heat transfers heat to the third working fluid in the heat storage cycle, and the third working fluid in the heat storage cycle transfers the heat it carries to the heat storage medium in the high-temperature storage tank (8), the first working fluid absorbs high-temperature heat from the heat storage medium, then enters the first tank (1), heats the saturated adsorption medium in the first tank (1) to make it desorb and regenerate, and the first working fluid releases high-temperature heat after releasing heat and flows back to the high-temperature storage tank (8); In this process, the first tank (1) is a desorption process, and the second tank (6) is an adsorption process; The adsorption and desorption functions of the first tank (1) and the second tank (6) are switched to realize continuous adsorption and desorption; Heat pump cycle, for upgrading the low-grade heat source grade output by the carbon capture cycle through the electrically driven heat pump cycle, and outputting high-temperature heat to store in the high-temperature storage tank (8); The heat storage cycle includes a low-temperature storage tank (7) and a high-temperature storage tank (8), the high-temperature storage tank (8) supplies stored high-temperature heat to the desorption process and the organic Rankine cycle, the third working fluid after releasing high-temperature heat in the high-temperature storage tank (8) is stored in the low-temperature storage tank (7) after releasing heat again by the organic Rankine cycle, and the low-temperature third working fluid in the low-temperature storage tank (7) absorbs heat of the second working fluid in the heat pump cycle and returns to the high-temperature storage tank (8); The organic Rankine cycle is used to convert heat energy in the heat storage cycle into electric energy, and the heat storage cycle is used to realize the continuity of electric-heat-electric conversion.

2. The heat pump electricity storage and electric-thermal comprehensive utilization system coupled with low-grade heat recovery of a low-medium temperature flue gas carbon capture according to claim 1, characterized in that, The carbon capture cycle further includes a regenerator (10), the first working fluid after releasing heat by the first evaporator (2) further transfers residual heat to the organic Rankine cycle by the regenerator (10) to preheat the fourth working fluid in the organic Rankine cycle, and at the same time, the first working fluid after recovering residual heat by the regenerator (10) returns to the first tank (1) or the second tank (6).

3. The system of claim 1, wherein, The carbon capture cycle further includes a first heat exchange tube (14) and a second heat exchange tube (15) respectively arranged in the second tank (6) and the first tank (1), an adsorption medium or a saturated adsorption medium is attached to the surface of the first heat exchange tube (14) or the second heat exchange tube (15), the first working fluid flows in the second heat exchange tube (15) and the first heat exchange tube (14), and the first heat exchange tube (14) and the second heat exchange tube (15) are used to realize the heat exchange between the first working fluid in the tube and the residual heat of flue gas and the heat of the adsorption process or the heat of the saturated adsorption medium outside the tube.

4. The system of claim 1, wherein, The first tank (1) and the second tank (6) are respectively provided with a second valve (17) and a fourth valve (19) between the working fluid outlet and the hot side inlet of the first evaporator (2), the first evaporator (2) is respectively provided with a first valve (16) and a seventh valve (22) between the hot side outlet and the working fluid inlet of the first tank (1) and the second tank (6), the first tank (1) and the second tank (6) are respectively provided with a third valve (18) and a fifth valve (20) between the working fluid outlet and the first inlet of the high-temperature storage tank (8), and the high-temperature storage tank (8) is respectively provided with an eighth valve (23) and a sixth valve (21) between the first outlet and the working fluid inlet of the first tank (1) and the second tank (6); When the first valve (16), the second valve (17), the fifth valve (20) and the sixth valve (21) are opened, and the third valve (18), the fourth valve (19), the seventh valve (22) and the eighth valve (23) are closed, the first tank (1) is the adsorption process, and the second tank (6) is the desorption process; when the third valve (18), the fourth valve (19), the seventh valve (22) and the eighth valve (23) are opened, and the first valve (16), the second valve (17), the fifth valve (20) and the sixth valve (21) are closed, the first tank (1) is the desorption process, and the second tank (6) is the adsorption process.

5. The system of claim 1, wherein, The heat pump cycle comprises a first evaporator (2), a throttle valve (3), a first condenser (4) and a compressor (5); the cold side inlet of the first evaporator (2) is connected with the outlet of the throttle valve (3), the inlet of the throttle valve (3) is connected with the hot side outlet of the first condenser (4), the hot side inlet of the first condenser (4) is connected with the outlet of the compressor (5), and the inlet of the compressor (5) is connected with the cold side outlet of the first evaporator (2).

6. The system of claim 1, wherein, The heat pump cycle further comprises a first condenser (4) and a second evaporator (9); the cold side inlet of the first condenser (4) is connected with the outlet of a low-temperature storage tank (7), the inlet of the low-temperature storage tank (7) is connected with the hot side outlet of the second evaporator (9), the hot side inlet of the second evaporator (9) is connected with the second outlet of a high-temperature storage tank (8), and the second inlet of the high-temperature storage tank (8) is connected with the cold side outlet of the first condenser (4).

7. The system of claim 1, wherein, The organic Rankine cycle comprises a second evaporator (9), a pump (11), a second condenser (12) and an expander (13); the cold side inlet of the second evaporator (9) is connected with the outlet of the pump (11), the inlet of the pump (11) is connected with the hot side outlet of the second condenser (12), the hot side inlet of the second condenser (12) is connected with the outlet of the expander (13), and the inlet of the expander (13) is connected with the cold side outlet of the second evaporator (9).

8. The heat pump electricity storage and electric-thermal comprehensive utilization system coupled with low-grade heat recovery of a low-medium temperature flue gas carbon capture according to claim 7, characterized in that, The organic Rankine cycle further comprises a regenerator (10) arranged between the second evaporator (9) and the pump (11), the cold side inlet of the second evaporator (9) is connected with the cold side outlet of the regenerator (10), and the cold side inlet of the regenerator (10) is connected with the outlet of the pump (11).

9. The system of claim 1, wherein, The adsorption medium in the carbon capture cycle is a polyamine solid adsorption material, the adsorption temperature of the material is 60-70℃, and the regeneration temperature is 110-120℃; an internal cooling / heat exchange structure is adopted to strengthen the adsorption and desorption processes.

10. A method for comprehensive utilization of heat pump electricity storage and electricity and heat by coupling low-grade heat recovery with medium-low temperature flue gas carbon capture, characterized in that, The carbon capture cycle comprises continuous adsorption and desorption processes and electro-thermal-electric conversion processes, specifically: When the medium and low temperature flue gas enters the first tank body (1) from the flue gas inlet of the first tank body (1), the adsorption medium in the first tank body (1) captures carbon dioxide in the flue gas, and at the same time, the flue gas waste heat and the heat released in the adsorption process are transferred to the first working fluid flowing through the first tank body (1). The first evaporator is driven by electricity, the first working fluid carrying heat passes through the first evaporator (2) to transfer heat to the second working fluid in the heat pump cycle, and at the same time, the first working fluid after releasing heat flows back to the first tank body (1). The second working fluid carrying heat transfers heat to the third working fluid in the heat storage cycle, realizes electric-thermal conversion, and the third working fluid in the heat storage cycle transfers the heat it carries to the heat storage medium in the high-temperature storage tank (8) in the high-temperature storage tank (8). The first working fluid absorbs high-temperature heat from the heat storage medium, then enters the second tank body (6), heats the saturated adsorption medium in the second tank body (6), and makes it desorb and regenerate, and the first working fluid after releasing high-temperature heat flows back to the high-temperature storage tank (8). In this process, the first tank body (1) is an adsorption process, and the second tank body (6) is a desorption process. When the adsorption medium in the first tank body (1) is saturated, the medium and low temperature flue gas enters the second tank body (6) from the flue gas inlet of the second tank body (6), and the adsorption medium in the second tank body (6) captures carbon dioxide in the flue gas. At the same time, the flue gas waste heat and the heat released in the adsorption process are transferred to the first working fluid flowing through the second tank body (6). The first working fluid carrying heat passes through the first evaporator (2) to transfer heat to the second working fluid in the heat pump cycle, and at the same time, the first working fluid after releasing heat flows back to the second tank body (6). The second working fluid carrying heat transfers heat to the third working fluid in the heat storage cycle, realizes electric-thermal conversion, and the third working fluid in the heat storage cycle transfers the heat it carries to the heat storage medium in the high-temperature storage tank (8) in the high-temperature storage tank (8). The first working fluid absorbs high-temperature heat from the heat storage medium, then enters the first tank body (1), heats the saturated adsorption medium in the first tank body (1), and makes it desorb and regenerate, and the first working fluid after releasing high-temperature heat flows back to the high-temperature storage tank (8). In this process, the first tank body (1) is a desorption process, and the second tank body (6) is an adsorption process. The adsorption and desorption functions of the first tank body (1) and the second tank body (6) are switched to realize continuous adsorption and desorption. The low-grade heat source output by the carbon capture cycle is upgraded in grade by the heat pump cycle driven by electricity, and the high-temperature heat is stored in the high-temperature storage tank (8). The third working fluid after releasing high-temperature heat in the high-temperature storage tank (8) is stored in the low-temperature storage tank (7) after releasing heat by the organic Rankine cycle again. The low-temperature working fluid in the low-temperature storage tank (7) absorbs the heat of the second working fluid in the heat pump cycle after the heat pump cycle, and flows back to the high-temperature storage tank (8). The organic Rankine cycle converts the heat energy stored in the high-temperature storage tank (8) into electric energy, realizing heat-electricity conversion.

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