A carbon sequestration coupled supercritical carbon dioxide energy storage system

Abstract

This application provides a carbon sequestration coupled supercritical carbon dioxide energy storage system, belonging to the field of environmental and energy technology. Specifically, it includes a carbon capture device for processing external carbon-containing gas to obtain carbon dioxide gas; a carbon sequestration module connected to the outlet of the carbon capture device for compressing the carbon dioxide gas; an energy storage module with its inlet connected to the outlet of the carbon sequestration module; a supercritical CO2 storage tank with its inlet connected to the outlet of the energy storage module; an energy release module with its inlet connected to the outlet of the supercritical CO2 storage tank; a heat exchange module located between the energy storage module and the energy release module, forming a heat exchange loop; and a carbon sequestration space with its inlet connected to the outlets of both the carbon sequestration module and the energy release module. Through the processing scheme of this application, carbon sequestration and carbon dioxide energy storage are organically combined, improving energy storage efficiency.

Description

Technical Field

[0001] This application relates to the fields of environmental and energy technology, and in particular to a carbon sequestration coupled supercritical carbon dioxide energy storage system. Background Technology

[0002] With the continuous development of society and the economy, human consumption of energy for production and daily life is constantly increasing. Fossil fuels still account for a large proportion of the current energy utilization system, leading to massive CO2 emissions and a continuous rise in atmospheric CO2 levels. This has triggered numerous environmental and climate problems, directly manifested as the greenhouse effect, and has seriously impacted human life and survival. How to reduce carbon emissions during the utilization of fossil fuels is a technological problem that countries around the world urgently need to develop. Carbon capture and storage (CCS) directly separates CO2 from the fossil fuel utilization process (including before and after combustion) and compresses it to a supercritical high-pressure state, transporting it to geological environments such as underground aquifers. By utilizing the high pressure and sealed geological conditions, CO2 is stored for a long period of time, thereby directly and effectively achieving carbon emission reduction.

[0003] Replacing fossil fuels with renewable energy sources such as solar and wind power is an effective way to solve current energy and environmental problems. However, the volatility and intermittency of renewable energy lead to poor power quality. When power generation is too low or too high, some electricity cannot be connected to the grid, resulting in energy waste such as wind and solar curtailment, reducing the actual utilization efficiency of renewable energy. To solve this problem, large-scale energy storage systems are needed to absorb the electricity that cannot be connected to the grid. These systems can also serve as an effective means of peak shaving and valley filling, improving the safety and stability of the power grid. Compressed air energy storage technology is currently at the forefront of research and application for large-scale physical energy storage, featuring long service life, high power generation efficiency, and good economic benefits.

[0004] Compared with air, carbon dioxide has better physical properties, such as a more easily achievable critical point (critical temperature close to room temperature and moderate critical pressure), low viscosity, high density, and good flow and heat transfer performance. Therefore, using supercritical CO2 to replace compressed air as an energy storage medium can effectively improve energy storage efficiency and has good development prospects.

[0005] Both carbon sequestration and carbon dioxide energy storage use CO2 as the working medium and have matching operating parameters. Combining the two has the potential to improve overall performance. Currently, existing work mainly focuses on studying carbon sequestration and carbon dioxide energy storage separately, and coupled research on the two is still relatively rare. Summary of the Invention

[0006] In view of this, embodiments of this application provide a carbon sequestration coupled supercritical carbon dioxide energy storage system, which organically combines carbon sequestration with carbon dioxide energy storage.

[0007] This application provides a carbon sequestration coupled supercritical carbon dioxide energy storage system, the system comprising:

[0008] A carbon capture device is used to process external carbon-containing gases to obtain carbon dioxide gas;

[0009] A carbon sequestration module, which is connected to the outlet of the carbon capture device, is used to compress carbon dioxide gas.

[0010] An energy storage module, wherein the air inlet of the energy storage module is connected to the air outlet of the carbon sequestration module;

[0011] A supercritical CO2 storage tank, wherein the inlet end of the supercritical CO2 storage tank is connected to the outlet end of the energy storage module;

[0012] An energy release module, wherein the inlet end of the energy release module is connected to the outlet end of the supercritical CO2 storage tank;

[0013] A heat exchange module is provided between the energy storage module and the energy release module to form a heat exchange loop;

[0014] A carbon sequestration space, wherein the air inlet of the carbon sequestration space is connected to the air outlet of the carbon sequestration module and the air outlet of the energy release module, respectively.

[0015] According to a specific implementation of an embodiment of this application, the heat exchange module includes a cold-state thermal storage tank and a hot-state thermal storage tank. Both the energy storage module and the energy release module include a cold fluid channel and a hot fluid channel. The inlet of the cold-state thermal storage tank is connected to the outlet of the hot fluid channel of the energy release module, and the outlet of the cold-state thermal storage tank is connected to the inlet of the cold fluid channel of the energy storage module. The inlet of the hot-state thermal storage tank is connected to the outlet of the cold fluid channel of the energy storage module, and the outlet of the hot-state thermal storage tank is connected to the inlet of the hot fluid channel of the energy release module. The inlet of the hot fluid channel of the energy storage module is connected to the outlet of the carbon sequestration module, and the outlet of the hot fluid channel of the energy storage module is connected to the inlet of the supercritical CO2 tank. The inlet of the cold fluid channel of the energy release module is connected to the outlet of the supercritical CO2 tank, and the outlet of the cold fluid channel of the energy release module is connected to the inlet of the carbon sequestration space.

[0016] According to a specific implementation of an embodiment of this application, the energy storage module has at least one stage. The energy storage module includes a connected energy storage compressor and a heat exchanger. The heat exchanger has a cold fluid channel and a hot fluid channel. The inlet of the hot fluid channel of the heat exchanger of each stage of the energy storage module is connected to the outlet of the energy storage compressor of the same stage. The outlet of the hot fluid channel of the heat exchanger of each stage of the energy storage module is connected to the inlet of the energy storage compressor of the adjacent stage. The inlet of the energy storage compressor of the initial energy storage module is connected to the outlet of the carbon sequestration module. The outlet of the hot fluid channel of the heat exchanger of the final energy storage module is connected to the inlet of the supercritical CO2 storage tank. The inlet of the cold fluid channel of the heat exchanger of each stage of the energy storage module is connected to the outlet of the cold-state heat storage working medium tank. The outlet of the cold fluid channel of the heat exchanger of each stage of the energy storage module is connected to the inlet of the hot-state heat storage working medium tank.

[0017] According to a specific implementation of an embodiment of this application, the energy storage module further includes a thermal storage circulation pump, which is located between the inlet of the cold fluid channel of the thermal storage heat exchanger of each stage of the energy storage module and the outlet of the cold thermal storage working fluid tank.

[0018] According to a specific implementation of an embodiment of this application, the energy release module has at least one stage. The energy release module includes an energy release expander and a heat release heat exchanger connected together. The heat release heat exchanger has a cold fluid channel and a hot fluid channel. The inlet of the energy release expander of each stage of the energy release module is connected to the outlet of the cold fluid channel of the heat release heat exchanger of the same stage. The outlet of the energy release expander of each stage of the energy release module is connected to the inlet of the cold fluid channel of the heat release heat exchanger of the adjacent stage. The inlet of the cold fluid channel of the heat release heat exchanger of the initial stage of the energy release module is connected to the gas outlet of the supercritical CO2 storage tank. The outlet of the energy release expander of the final stage of the energy release module is connected to the gas inlet of the carbon sequestration space. The inlet of the hot fluid channel of the heat release heat exchanger of each stage of the energy release module is connected to the outlet of the hot thermal storage medium tank. The outlet of the hot fluid channel of the heat release heat exchanger of each stage of the energy release module is connected to the inlet of the cold thermal storage medium tank.

[0019] According to a specific implementation of an embodiment of this application, the energy release module further includes a heat release circulation pump, which is located between the inlet of the hot fluid channel of the heat release heat exchanger of each stage of the energy release module and the outlet of the hot thermal storage medium tank.

[0020] According to a specific implementation of an embodiment of this application, a heat storage medium cooler is provided between the inlet of the cold-state heat storage medium tank and the outlet of the hot fluid channel of the energy release module.

[0021] According to a specific implementation of an embodiment of this application, the carbon sequestration module has at least one stage. The carbon sequestration module includes a carbon sequestration compressor and a carbon sequestration compressor cooler connected to each other. The carbon sequestration compressor cooler in each stage of the carbon sequestration module is connected to the carbon sequestration compressor in the adjacent stage of the carbon sequestration module. The carbon sequestration compressor in the initial carbon sequestration module is connected to the outlet end of the carbon capture device. The carbon sequestration compressor cooler in the final carbon sequestration module is connected to the inlet end of the carbon sequestration space and the inlet end of the energy storage module, respectively.

[0022] According to a specific implementation of this application, a carbon storage control valve is provided between the outlet end of the carbon storage module and the inlet end of the carbon storage space, and a first energy storage control valve is provided between the outlet end of the carbon storage module and the inlet end of the energy storage module.

[0023] According to a specific implementation of an embodiment of this application, a second energy storage control valve is provided between the gas inlet end of the supercritical CO2 storage tank and the gas outlet end of the energy storage module, and an energy release control valve is provided between the gas outlet end of the supercritical CO2 storage tank and the gas inlet end of the energy release module.

[0024] Beneficial effects

[0025] The carbon sequestration coupled supercritical carbon dioxide energy storage system in this application embodiment organically combines carbon sequestration and carbon dioxide energy storage, effectively improving overall performance. It features long service life, high power generation efficiency, and good economic benefits, and has a promising development prospect. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of a carbon sequestration coupled supercritical carbon dioxide energy storage system according to an embodiment of the present invention;

[0028] Figure 2 This is a diagram showing the CO2 flow path under the carbon sequestration working mode according to an embodiment of the present invention;

[0029] Figure 3 This is a flow path diagram of CO2 and thermal storage medium under the working mode of energy storage (including carbon sequestration) according to an embodiment of the present invention;

[0030] Figure 4This is a flow path diagram of CO2 and thermal storage medium under the energy release (including carbon sequestration) working mode according to an embodiment of the present invention.

[0031] In the diagram: 1. Carbon capture device; 2. Carbon sequestration module; 21-1, Stage 1 carbon sequestration compressor; 21-2, Stage 1 carbon sequestration compressor cooler; 22-1, Stage 2 carbon sequestration compressor; 22-2, Stage 2 carbon sequestration compressor cooler; 2K-1, Stage K carbon sequestration compressor; 2K-2, Stage K carbon sequestration compressor cooler; 3. Energy storage module; 31-1, Stage 1 energy storage compressor; 31-2, Stage 1 thermal energy storage heat exchanger; 31-3, Stage 1 thermal energy storage circulation pump; 32-1, Stage 2 energy storage compressor; 32-2, Stage 2 thermal energy storage heat exchanger; 32-3, Stage 2 thermal energy storage circulation pump; 3M-1, Stage M energy storage compressor; 3M-2, Stage M thermal energy storage heat exchanger; 3M-3, Stage M energy storage compressor; 3M-4, Stage M thermal energy storage compressor; 3M-5, Stage M thermal energy storage compressor; 3M-6, Stage M thermal energy storage compressor; 3M-7, Stage M thermal energy storage compressor; 3M-8, Stage M thermal energy storage compressor; 3M-9, Stage M thermal energy storage compressor; 3M-1, Stage M energy storage compressor; 3M-2, Stage M thermal energy storage heat exchanger; 3M-1, Stage M energy storage compressor; 3M-2, Stage M thermal energy storage heat exchanger; 3M-3, Stage M thermal energy storage compressor; 3M-1, Stage M energy storage compressor; 3M-2 ... 4. Supercritical CO2 storage tank; 5. Energy release module; 51-1, Stage 1 energy release expander; 51-2, Stage 1 heat release heat exchanger; 51-3, Stage 1 heat release circulation pump; 52-1, Stage 2 energy release expander; 52-2, Stage 2 heat release heat exchanger; 52-3, Stage 2 heat release circulation pump; 5N-1, Stage N energy release expander; 5N-2, Stage N heat release heat exchanger; 5N-3, Stage N heat release circulation pump; 6. Carbon sequestration space; 7. Heat exchange module; 71. Cold thermal storage medium tank; 72. Hot thermal storage medium tank; 7C. Thermal storage medium cooler; V0, Carbon sequestration control valve; V1, First energy storage control valve; V2, Second energy storage control valve; V3, Energy release control valve. Detailed Implementation

[0032] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0033] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0035] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0036] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0037] This application provides a carbon sequestration coupled supercritical carbon dioxide energy storage system, which is described below with reference to... Figures 1 to 4 Provide a detailed description.

[0038] Reference Figure 1The carbon sequestration coupled supercritical carbon dioxide energy storage system of this embodiment includes a carbon capture device 1, a carbon sequestration module 2, an energy storage module 3, a supercritical CO2 storage tank 4, an energy release module 5, a heat exchange module 7, and a carbon sequestration space 6. The carbon capture device 1 processes external carbon-containing gas to obtain carbon dioxide gas. It is equipped with an inlet, a first outlet, and a second outlet. The external carbon-containing mixed gas enters the carbon capture device 1 through the inlet. The decarbonized gas, after CO2 removal, is discharged through the second outlet of the carbon capture device 1 or enters a corresponding subsequent processing flow. The carbon dioxide gas is discharged from the first outlet. The carbon sequestration module 2 is connected to the outlet of the carbon capture device 1, specifically to the first outlet, and is used to compress the carbon dioxide gas to obtain high-pressure, room-temperature CO2 that meets the carbon sequestration pressure conditions. The energy storage module 3, with its inlet connected to the outlet of the carbon sequestration module 2, is used to process the high-pressure, room-temperature CO2 through a compression-heat exchange cooling process to obtain supercritical CO2 that meets the energy storage pressure conditions. The inlet of the supercritical CO2 storage tank 4 is connected to the outlet of the energy storage module 3 for storing supercritical CO2; the inlet of the energy release module 5 is connected to the outlet of the supercritical CO2 storage tank 4 for allowing the supercritical CO2 to undergo a heat release, heat exchange, heat replenishment, and energy release expansion process to complete the energy release of the entire energy release process; the heat exchange module 7 is located between the energy storage module 3 and the energy release module 5, forming a heat exchange loop, for providing cold fluid to the energy storage module 3 and hot fluid to the energy release module 5 for heat exchange; the carbon sequestration space 6 has its inlet connected to the outlets of the carbon sequestration module 2 and the energy release module 5 respectively, for storing CO2 that meets the carbon sequestration pressure conditions.

[0039] Specifically, the heat exchange module 7 includes a cold-state thermal storage tank 71 and a hot-state thermal storage tank 72. Both the energy storage module 3 and the energy release module 5 include a cold fluid channel and a hot fluid channel. The inlet of the cold-state thermal storage tank 71 is connected to the outlet of the hot fluid channel of the energy release module 5. The outlet of the cold-state thermal storage tank 71 is connected to the inlet of the cold fluid channel of the energy storage module 3. The inlet of the hot-state thermal storage tank 72 is connected to the outlet of the cold fluid channel of the energy storage module 3, and the outlet of the hot-state thermal storage tank 72 is connected to the inlet of the hot fluid channel of the energy release module 5. The inlet of the hot fluid channel of the energy storage module 3 is connected to the outlet of the carbon sequestration module 2, and the outlet of the hot fluid channel of the energy storage module 3 is connected to the inlet of the supercritical CO2 storage tank 4. The inlet of the cold fluid channel of the energy release module 5 is connected to the outlet of the supercritical CO2 storage tank 4, and the outlet of the cold fluid channel of the energy release module 5 is connected to the inlet of the carbon sequestration space 6.

[0040] In one embodiment, the carbon sequestration module 2 has at least one stage. The carbon sequestration module 2 includes a connected carbon sequestration compressor and a carbon sequestration compressor cooler. The carbon sequestration compressor cooler in each stage of the carbon sequestration module 2 is connected to the carbon sequestration compressor in the adjacent stage of the carbon sequestration module 2. The carbon sequestration compressor at the beginning of the carbon sequestration module 2 is connected to the outlet end of the carbon capture device 1, and the carbon sequestration compressor coolers at the end of the carbon sequestration module 2 are respectively connected to the inlet end of the carbon sequestration space 6 and the inlet end of the energy storage module 3.

[0041] As Figure 1 , the carbon sequestration module 2 has K stages. The k (1 ≤ k ≤ K) stage carbon sequestration compressor and the k stage carbon sequestration compressor cooler are both provided with inlets and outlets. The inlet of the first stage carbon sequestration compressor 21-1 is connected to the first outlet of the carbon capture device 1. The outlet of the k stage carbon sequestration compressor is connected to the inlet of the k stage carbon sequestration compressor cooler. The outlet of the k (k < K) stage carbon sequestration cooler is connected to the inlet of the (k + 1) stage carbon sequestration compressor.

[0042] Furthermore, a carbon sequestration control valve V0 is provided between the outlet end of the carbon sequestration module 2 and the inlet end of the carbon sequestration space 6, and a first energy storage control valve V1 is provided between the outlet end of the carbon sequestration module 2 and the inlet end of the energy storage module 3.

[0043] A second energy storage control valve V2 is provided between the inlet end of the supercritical CO2 storage tank 4 and the outlet end of the energy storage module 3, and an energy release control valve V3 is provided between the outlet end of the supercritical CO2 storage tank 4 and the inlet end of the energy release module 5.

[0044] Specifically, a carbon sequestration control valve V0 is provided between the outlet of the carbon sequestration compressor cooler at the end of the carbon sequestration module 2 (the outlet of the K stage carbon sequestration compressor cooler 2K-2) and the inlet end of the carbon sequestration space 6, and a first energy storage control valve V1 is provided between the outlet of the carbon sequestration compressor cooler at the end of the carbon sequestration module 2 (the outlet of the K stage carbon sequestration compressor cooler 2K-2) and the energy storage module 3.

[0045] In one embodiment, the energy storage module 3 has at least one stage. The energy storage module 3 includes an energy storage compressor and a heat storage heat exchanger connected to each other. The heat storage heat exchanger has a cold fluid passage and a hot fluid passage. The inlet of the hot fluid passage of the heat storage heat exchanger of each stage of the energy storage module 3 is connected to the outlet of the energy storage compressor of the same stage, and the outlet of the hot fluid passage of the heat storage heat exchanger of each stage of the energy storage module 3 is connected to the inlet of the energy storage compressor of the adjacent stage. The inlet of the energy storage compressor of the initial-stage energy storage module 3 is connected to the gas outlet end of the carbon sequestration module 2, and the outlet of the hot fluid passage of the heat storage heat exchanger of the terminal-stage energy storage module 3 is connected to the gas inlet end of the supercritical CO2 storage tank 4; the inlet of the cold fluid passage of the heat storage heat exchanger of each stage of the energy storage module 3 is connected to the outlet of the cold-state heat storage working medium storage tank 71, and the outlet of the cold fluid passage of the heat storage heat exchanger of each stage of the energy storage module 3 is connected to the inlet of the hot-state heat storage working medium storage tank 72.

[0046] Referring to Figure 1 , the energy storage module 3 has M stages. The m (1≤m≤M) stage energy storage compressors and the m stage heat storage circulation pumps are both provided with inlets and outlets. The m stage heat storage heat exchangers are provided with hot fluid passages and cold fluid passages, and both the hot fluid passages and the cold fluid passages are provided with inlets and outlets. The inlet of the 1-stage energy storage compressor 31-1 is connected to the outlet of the first energy storage control valve V1; the outlet of the m-stage energy storage compressor is connected to the inlet of the hot fluid passage of the m-stage heat storage heat exchanger, and the outlet of the hot fluid passage of the m (m<M) stage heat storage heat exchanger is connected to the inlet of the (m + 1) stage energy storage compressor; the outlet of the hot fluid passage of the M-stage heat storage heat exchanger 3M-2 is connected to the inlet of the second energy storage control valve V2, and the outlet of the second energy storage control valve V2 is connected to the inlet of the supercritical CO2 storage tank 4; the outlet of the m-stage heat storage water pump is connected to the inlet of the cold fluid passage of the m-stage heat storage heat exchanger.

[0047] Furthermore, the energy storage module 3 further includes a heat storage circulation pump, and the heat storage circulation pump is arranged between the inlet of the cold fluid passage of the heat storage heat exchanger of each stage of the energy storage module 3 and the outlet of the cold-state heat storage working medium storage tank 71. Specifically, the 1-stage energy storage module is provided with a 1-stage heat storage circulation pump 31-3, the 2-stage energy storage module is provided with a 2-stage heat storage circulation pump 32-3, and the M-stage energy storage module is provided with an M-stage heat storage circulation pump 3M-3, which are respectively located between the inlet of the cold fluid passage of the 1-stage heat storage heat exchanger 31-2, the inlet of the cold fluid passage of the 2-stage heat storage heat exchanger 32-2, and the inlet of the cold fluid passage of the M-stage heat storage heat exchanger 3M-2 and the outlet of the cold-state heat storage working medium storage tank 71.

[0048] In one embodiment, the energy release module 5 has at least one stage. The energy release module 5 includes an energy release expander and a heat release heat exchanger connected to each other. The heat release heat exchanger has a cold fluid channel and a heat fluid channel. The inlet of the energy release expander of each stage of the energy release module 5 is connected to the outlet of the cold fluid channel of the heat release heat exchanger of the same stage. The outlet of the energy release expander of each stage of the energy release module 5 is connected to the inlet of the cold fluid channel of the heat release heat exchanger of the adjacent stage. The inlet of the cold fluid channel of the heat release heat exchanger of the initial energy release module 5 is connected to the gas outlet end of the supercritical CO2 storage tank 4. The outlet of the energy release expander of the terminal energy release module 5 is connected to the gas inlet end of the carbon sequestration space 6; the inlet of the heat fluid channel of the heat release heat exchanger of each stage of the energy release module 5 is connected to the outlet of the hot thermal energy storage working medium storage tank 72. The outlet of the heat fluid channel of the heat release heat exchanger of each stage of the energy release module 5 is connected to the inlet of the cold thermal energy storage working medium storage tank 71.

[0049] Furthermore, the energy release module 5 further includes a heat release circulation pump, and the heat release circulation pump is provided between the inlet of the heat fluid channel of the heat release heat exchanger of each stage of the energy release module 5 and the outlet of the hot thermal energy storage working medium storage tank 72.

[0050] Furthermore, a heat storage working medium cooler 7C is provided between the inlet of the cold thermal energy storage working medium storage tank 71 and the outlet of the heat fluid channel of the energy release module 5.

[0051] Refer to Figure 1 , the energy release module 5 has N stages. The n (1≤n≤N) stage energy release expanders and the n stage heat release circulation pumps are both provided with inlets and outlets. The n stage heat release heat exchangers are provided with heat fluid channels and cold fluid channels, and both the heat fluid channels and the cold fluid channels are provided with inlets and outlets. The inlet of the cold fluid channel of the first stage heat release heat exchanger 51-2 is connected to the outlet of the energy release control valve V3; the outlet of the cold fluid channel of the n stage heat release heat exchanger is connected to the inlet of the n stage energy release expander. The outlet of the n (n<N) stage energy release expander is connected to the inlet of the cold fluid channel of the (n + 1) stage heat release heat exchanger; the outlet of the N stage energy release expander 5N-1 is connected to the inlet of the carbon sequestration space 6; the outlet of the n stage heat release circulation pump is connected to the inlet of the heat fluid channel of the n stage heat release heat exchanger. The inlets of the heat release circulation pumps (51-3 to 5N-3) of each stage are connected to the outlet of the hot thermal energy storage working medium storage tank 72, and the outlets of the heat fluid channels of the heat release heat exchangers (51-2 to 5N-2) of each stage are connected to the inlet of the heat storage working medium cooler 7C.

[0052] The carbon sequestration coupled supercritical carbon dioxide energy storage system of this application has three operating modes: carbon sequestration mode, energy storage mode, and energy release mode. The operation of the carbon sequestration mode depends on the carbon-containing feed gas. As long as the carbon-containing gas is continuously supplied, the carbon sequestration mode will continue to operate regardless of whether it is in energy storage or energy release mode. When there is excess electrical energy to be stored, the entire system enters the energy storage mode. In this mode, the low-pressure CO2 obtained through the carbon capture device reaches the carbon sequestration pressure through a multi-stage carbon sequestration compression-cooling process. A portion of the CO2 is directly sequestered, while the other portion continues to pass through the energy storage compression-cooling process to form high-pressure, room-temperature CO2, which is then stored in the supercritical CO2 storage tank. When it is necessary to output electrical energy, the system enters the energy release mode. In this mode, the stored supercritical CO2 performs work and generates electricity through a multi-stage reheating-expansion process. The expanded CO2 reaches the carbon sequestration pressure and is then sequestered. The above processes are described in detail below:

[0053] (1) Carbon sequestration working mode

[0054] In the carbon sequestration working mode, the system only starts the carbon sequestration compressors at each stage and the carbon sequestration compressor cooler. The carbon sequestration control valve V0 is in the open state, while the first energy storage control valve V1, the second energy storage control valve V2, and the energy release control valve V3 are in the closed state.

[0055] CO2 flow path under carbon sequestration operating mode is as follows Figure 2 As shown, carbon-containing gas (which may be CO2-containing tail gas discharged from industrial systems, CO2-containing mixed gas produced by coal gasification, etc.) enters carbon capture device 1. The decarbonized tail gas after CO2 removal is discharged into the air or enters the corresponding subsequent treatment stage. After CO2 is captured, it enters the carbon storage and compression stage. In the carbon sequestration compression stage, CO2 first enters the first-stage carbon sequestration compressor 21-1 to increase pressure and temperature. After being pressurized and heated, the CO2 is cooled to room temperature by the first-stage carbon sequestration compressor cooler 21-2. The cooled CO2 then undergoes a series of carbon sequestration compression and cooling processes from stage 2 to stage K. Taking stage k (2≤k≤K) as an example, the CO2 cooled by the stage k-1 carbon sequestration compressor cooler enters the stage k carbon sequestration compressor for pressurization and temperature increase. The pressurized and heated CO2 then enters the stage k carbon sequestration compressor cooler for cooling to room temperature. After the above multi-stage carbon sequestration compression-cooling process, high-pressure room-temperature CO2 that meets the carbon sequestration pressure conditions is obtained, and then enters the carbon sequestration space 6 for sequestration through the carbon sequestration control valve V0.

[0056] (2) Energy storage working mode

[0057] In this mode, carbon sequestration and energy storage processes can be carried out simultaneously according to actual carbon sequestration needs. Carbon sequestration control valve V0, first energy storage control valve V1, and second energy storage control valve V2 are in the open state, while energy release control valve V3 is in the closed state.

[0058] The flow paths of CO2 and thermal storage medium in energy storage (including carbon sequestration) working mode are as follows: Figure 3 As shown, at this time, the carbon capture device 1, the carbon storage compressors at each stage, and the carbon storage compressor cooler operate in the same manner as in the carbon storage mode. The high-pressure ambient temperature CO2 discharged from the K-stage carbon storage compressor cooler (2K-2) enters the carbon storage space 6 and the energy storage compression stage through the carbon storage control valve V0 and the first energy storage control valve V1, respectively. In the energy storage compression stage, high-pressure, ambient-temperature CO2 enters the first-stage energy storage compressor 31-1 via the first energy storage control valve V1 to increase its pressure and temperature. The pressurized and heated CO2 enters the hot fluid channel of the first-stage heat exchanger 31-2, where it exchanges heat with the cold-state heat storage medium from the cold-state heat storage tank 71, which is driven into the cold fluid channel of the first-stage heat storage circulation pump 31-3. The CO2 temperature drops to ambient temperature, the cold-state heat storage medium heats up to a hot-state heat storage medium, and flows to the hot-state heat storage tank 72. The cooled CO2 then undergoes a series of energy storage compression and heat exchange cooling processes from stage 2 to stage M. Taking the m-th stage (2≤m≤M) as an example, the CO2 passes through m-1... After being cooled by the first-stage heat exchanger, CO2 enters the m-stage carbon storage compressor for pressurization and temperature increase. The pressurized and heated CO2 then enters the hot fluid channel of the m-stage heat exchanger, where it exchanges heat with the cold heat storage medium from the cold heat storage medium tank 71, which is driven into the cold fluid channel of the m-stage heat storage compressor by the m-stage heat storage circulation pump. The CO2 temperature drops to room temperature, the cold heat storage medium heats up to become a hot heat storage medium, and flows to the hot heat storage medium tank 72. After the above multi-stage compression-heat storage and cooling process, supercritical CO2 with the energy storage pressure conditions is obtained, and then enters the supercritical CO2 storage tank 4 through the second energy storage control valve V2, completing the supercritical CO2 energy storage process.

[0059] During this process, the cold thermal storage medium in the cold thermal storage medium tank 71 enters the thermal storage heat exchangers of each stage through the thermal storage circulation pumps of each stage, absorbing the compression heat generated during the compression process of each stage of energy storage. The temperature of the cold thermal storage medium rises to form a hot thermal storage medium, which then enters the hot thermal storage medium tank 72, completing the thermal storage process of the energy storage process.

[0060] (3) Energy release working mode

[0061] In this mode, carbon sequestration and energy release processes can be carried out simultaneously according to actual carbon sequestration needs. Carbon sequestration control valve V0 and energy release control valve V3 are in the open state, while the first energy storage control valve V1 and the second energy storage control valve V2 are in the closed state.

[0062] The flow paths of CO2 and thermal storage medium under the energy release (including carbon sequestration) working mode are as follows: Figure 4As shown, at this time, the carbon capture device 1, the various stages of carbon sequestration compressors, and the carbon sequestration compressor cooler operate in the same state as in the carbon sequestration mode. The supercritical CO2 in the supercritical CO2 storage tank 4 enters the cold fluid channel of the first-stage heat exchanger 51-2 via the energy release control valve V3, and exchanges heat with the hot thermal storage medium from the hot thermal storage medium tank 72, which is driven into the hot fluid channel of the first-stage heat exchanger 51-2 by the first-stage heat release circulation pump 51-3. The CO2 is heated and its temperature rises, while the temperature of the hot thermal storage medium drops. After being further cooled by the thermal storage medium cooler 7C, it flows to the cold thermal storage medium tank 71. After being reheated and heated, the high-pressure CO2 enters the first-stage energy release expander 51-1 to expand and do work, resulting in a decrease in CO2 pressure and temperature. The CO2 after the first-stage expansion then undergoes a 2-N stage heat release and heat exchange reheating-energy release expansion process. Taking the nth stage (2≤n≤N) as an example, the CO2 after being expanded and depressurized and cooled in the n-1 stage enters the cold fluid channel of the nth-stage heat release heat exchanger, where it exchanges heat with the hot thermal storage medium from the hot thermal storage medium tank 72, which is driven into the hot fluid channel of the nth-stage heat release heat exchanger by the nth-stage heat release circulation pump. The CO2 is reheated and heated, while the temperature of the hot thermal storage medium decreases. After being further cooled by the thermal storage medium cooler 7C, it flows to the cold thermal storage medium tank 71. The high-pressure CO2 after being reheated and heated enters the nth-stage energy release expander to expand and do work, resulting in a decrease in CO2 pressure and temperature. After the above-mentioned multi-stage heat release, heat exchange, heat replenishment, and energy release expansion process, the energy release of the entire energy release process is completed. At the same time, the CO2 pressure drops to the carbon sequestration pressure and enters the carbon sequestration space 6 for sequestration.

[0063] During this process, the hot thermal storage medium in the hot thermal storage medium tank 72 enters the heat release heat exchangers (1-N stages) through the heat release circulation pumps of each stage. The stored heat is released to the CO2 before the energy release expansion of each stage. The temperature of the hot thermal storage medium drops to form a cold thermal storage medium, which is then stored in the cold thermal storage medium tank 71, completing the heat release process of the energy release process.

[0064] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A carbon sequestration coupled supercritical carbon dioxide energy storage system, characterized in that, The system includes: A carbon capture device is used to process external carbon-containing gases to obtain carbon dioxide gas; A carbon sequestration module, which is connected to the outlet of the carbon capture device, is used to compress carbon dioxide gas. An energy storage module, wherein the air inlet of the energy storage module is connected to the air outlet of the carbon sequestration module; A supercritical CO2 storage tank, wherein the inlet end of the supercritical CO2 storage tank is connected to the outlet end of the energy storage module; An energy release module, wherein the inlet end of the energy release module is connected to the outlet end of the supercritical CO2 storage tank; A heat exchange module is provided between the energy storage module and the energy release module to form a heat exchange loop; A carbon sequestration space, wherein the air inlet of the carbon sequestration space is connected to the air outlet of the carbon sequestration module and the air outlet of the energy release module, respectively. The carbon sequestration module has at least one stage. The carbon sequestration module includes a carbon sequestration compressor and a carbon sequestration compressor cooler connected to each other. The carbon sequestration compressor cooler in each stage of the carbon sequestration module is connected to the carbon sequestration compressor in the adjacent stage of the carbon sequestration module. The carbon sequestration compressor in the initial carbon sequestration module is connected to the outlet end of the carbon capture device. The carbon sequestration compressor cooler in the final carbon sequestration module is connected to the inlet end of the carbon sequestration space and the inlet end of the energy storage module, respectively. A carbon storage control valve is provided between the outlet end of the carbon storage module and the inlet end of the carbon storage space, and a first energy storage control valve is provided between the outlet end of the carbon storage module and the inlet end of the energy storage module. A second energy storage control valve is provided between the gas inlet end of the supercritical CO2 storage tank and the gas outlet end of the energy storage module, and an energy release control valve is provided between the gas outlet end of the supercritical CO2 storage tank and the gas inlet end of the energy release module.

2. The carbon sequestration coupled supercritical carbon dioxide energy storage system according to claim 1, characterized in that, The heat exchange module includes a cold-state thermal storage medium tank and a hot-state thermal storage medium tank. Both the energy storage module and the energy release module include a cold fluid channel and a hot fluid channel. The inlet of the cold-state thermal storage medium tank is connected to the outlet of the hot fluid channel of the energy release module, the outlet of the cold-state thermal storage medium tank is connected to the inlet of the cold fluid channel of the energy storage module, the inlet of the hot-state thermal storage medium tank is connected to the outlet of the cold fluid channel of the energy storage module, and the outlet of the hot-state thermal storage medium tank is connected to the inlet of the hot fluid channel of the energy release module. The inlet of the hot fluid channel of the energy storage module is connected to the outlet of the carbon sequestration module, and the outlet of the hot fluid channel of the energy storage module is connected to the inlet of the supercritical CO2 storage tank; the inlet of the cold fluid channel of the energy release module is connected to the outlet of the supercritical CO2 storage tank, and the outlet of the cold fluid channel of the energy release module is connected to the inlet of the carbon sequestration space.

3. The carbon sequestration coupled supercritical carbon dioxide energy storage system according to claim 2, characterized in that, The energy storage module has at least one stage. The energy storage module includes a connected energy storage compressor and a heat exchanger. The heat exchanger has a cold fluid channel and a hot fluid channel. The inlet of the hot fluid channel of the heat exchanger of each stage of the energy storage module is connected to the outlet of the energy storage compressor of the same stage. The outlet of the hot fluid channel of the heat exchanger of each stage of the energy storage module is connected to the inlet of the energy storage compressor of the adjacent stage. The inlet of the energy storage compressor of the initial energy storage module is connected to the gas outlet of the carbon sequestration module. The outlet of the hot fluid channel of the heat exchanger of the final energy storage module is connected to the gas inlet of the supercritical CO2 storage tank. The inlet of the cold fluid channel of the heat exchanger of each stage of the energy storage module is connected to the outlet of the cold-state heat storage medium tank, and the outlet of the cold fluid channel of the heat exchanger of each stage of the energy storage module is connected to the inlet of the hot-state heat storage medium tank.

4. The carbon sequestration coupled supercritical carbon dioxide energy storage system according to claim 3, characterized in that, The energy storage module also includes a thermal storage circulation pump, which is located between the inlet of the cold fluid channel of the thermal storage heat exchanger of each stage of the energy storage module and the outlet of the cold thermal storage working medium tank.

5. The carbon sequestration coupled supercritical carbon dioxide energy storage system according to claim 2, characterized in that, The energy release module has at least one stage. The energy release module includes an energy release expander and a heat release heat exchanger connected to each other. The heat release heat exchanger has a cold fluid channel and a hot fluid channel. The inlet of the energy release expander of each stage of the energy release module is connected to the outlet of the cold fluid channel of the heat release heat exchanger of the same stage. The outlet of the energy release expander of each stage of the energy release module is connected to the inlet of the cold fluid channel of the heat release heat exchanger of the adjacent stage. The inlet of the cold fluid channel of the heat release heat exchanger of the initial stage of the energy release module is connected to the gas outlet of the supercritical CO2 storage tank. The outlet of the energy release expander of the final stage of the energy release module is connected to the gas inlet of the carbon sequestration space. The inlet of the hot fluid channel of the heat release heat exchanger of each stage of the energy release module is connected to the outlet of the hot thermal storage medium tank, and the outlet of the hot fluid channel of the heat release heat exchanger of each stage of the energy release module is connected to the inlet of the cold thermal storage medium tank.

6. The carbon sequestration coupled supercritical carbon dioxide energy storage system according to claim 5, characterized in that, The energy release module also includes a heat release circulation pump, which is located between the inlet of the hot fluid channel of the heat release heat exchanger in each stage of the energy release module and the outlet of the hot storage medium tank.

7. The carbon sequestration coupled supercritical carbon dioxide energy storage system according to claim 2, characterized in that, A heat storage medium cooler is provided between the inlet of the cold-state heat storage medium tank and the outlet of the hot fluid channel of the energy release module.

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