Pressure-variable and temperature-variable coupled carbon dioxide adsorption and compression energy storage system and method

Abstract

The invention provides a variable-pressure variable-temperature coupled carbon dioxide adsorption and compression energy storage system and method, and relates to the technical field of energy storage, and the coupled carbon dioxide energy storage system comprises a variable-temperature adsorption tower which is used for realizing adsorption or desorption of carbon dioxide through temperature change; the pressure swing adsorption tower is used for realizing adsorption or desorption of carbon dioxide through pressure change; the compressor is used for compressing carbon dioxide desorbed by the temperature swing adsorption tower and the pressure swing adsorption tower and then conveying the compressed carbon dioxide to the high-pressure gas storage tank; the high-pressure gas storage tank is used for receiving and releasing high-pressure carbon dioxide The expansion machine is used for performing expansion work on the high-pressure carbon dioxide and respectively conveying the expanded low-pressure carbon dioxide to the temperature swing adsorption tower and the pressure swing adsorption tower. According to the invention, the pressure swing / temperature swing adsorption characteristic of the adsorbent is utilized, and the efficient heat and mass circulation of the adsorption subsystem is ensured by adopting the cooperative operation of the double adsorption towers, so that the system has the quick response characteristic of pressure swing adsorption and the high adsorption capacity of temperature swing adsorption, and the stability of the system is improved.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to a variable pressure and variable temperature coupled adsorption and compression carbon dioxide energy storage system and method. Background Art

[0002] With the development of clean energy, the carbon dioxide energy storage system has shown broad application prospects due to its unique advantages. Carbon dioxide has a wide range of sources and can be obtained in large quantities from industrial waste gas and fossil fuel combustion exhaust gas. After compression, low-pressure carbon dioxide is stored in the form of high-pressure carbon dioxide to achieve energy storage; during the energy release process, the high-pressure carbon dioxide drives the turbine to generate power, realizing energy conversion. In the fields of large-scale storage of renewable energy, peak load regulation of power grids, and industrial waste heat recovery, the carbon dioxide energy storage system has shown broad application prospects. Among the related technologies, compressed carbon dioxide energy storage has developed rapidly due to its high energy storage capacity, but the low-pressure carbon dioxide storage method in the system has a significant impact on the system's energy storage capacity and response time, and the system's cyclic stability is difficult to guarantee. Summary of the Invention

[0003] The problem solved by the present invention is how to improve the stability and response time of the carbon dioxide energy storage system.

[0004] To solve the above problems, the present invention provides a pressure-temperature-variable coupled adsorption-compression carbon dioxide energy storage system and method.

[0005] In a first aspect, the present invention provides a pressure-temperature-variable coupled adsorption-compression carbon dioxide energy storage system and method, comprising: Temperature swing adsorption tower, used to fill temperature swing adsorption material and achieve carbon dioxide adsorption or desorption through temperature changes; Pressure swing adsorption tower, used to fill pressure swing adsorption material and achieve carbon dioxide adsorption or desorption through pressure changes; A compressor, configured to compress the carbon dioxide desorbed from the temperature swing adsorption tower and the pressure swing adsorption tower, and deliver the compressed carbon dioxide to a high-pressure gas storage tank; A high-pressure gas storage tank is used to receive and store high-pressure carbon dioxide output by the compressor and to release the high-pressure carbon dioxide stored internally; The expander is used to expand the high-pressure carbon dioxide output from the high-pressure gas storage tank and to deliver the expanded low-pressure carbon dioxide to the temperature swing adsorption tower and the pressure swing adsorption tower respectively; The first heat exchanger is provided between the compressor and the high-pressure gas storage tank, and is used to cool the carbon dioxide compressed by the compressor; The second heat exchanger is arranged between the high-pressure gas storage tank and the expander, and is used to heat the high-pressure carbon dioxide released from the high-pressure storage tank.

[0006] Optionally, the primary side pipeline of the first heat exchanger is respectively connected to the air outlet of the compressor and the air inlet of the high-pressure gas storage tank, and the secondary side pipeline of the first heat exchanger is connected to the temperature swing adsorption tower, which is used to exchange heat between the low-temperature carbon dioxide in the temperature swing adsorption tower and the high-temperature and high-pressure carbon dioxide compressed by the compressor.

[0007] Optionally, the energy storage system further includes a first one-way valve and a first pressure-stabilizing valve, wherein the first one-way valve is arranged at the air outlet of the secondary side pipeline of the first heat exchanger, and the first pressure-stabilizing valve is arranged at the air inlet of the secondary side pipeline of the first heat exchanger.

[0008] Optionally, the primary side pipeline of the second heat exchanger is respectively connected to the gas outlet of the high-pressure gas storage tank and the gas inlet of the expander, and the secondary side pipeline of the second heat exchanger is connected to the temperature swing adsorption tower, and the heat energy released during the adsorption process of the temperature swing adsorption tower is used to heat the high-pressure carbon dioxide released from the high-pressure gas storage tank.

[0009] Optionally, the energy storage system further includes a second one-way valve and a second pressure-stabilizing valve, wherein the second one-way valve is arranged at the air outlet of the secondary side pipeline of the second heat exchanger, and the second pressure-stabilizing valve is arranged at the air inlet of the secondary side pipeline of the second heat exchanger.

[0010] Optionally, the energy storage system further includes a third pressure-stabilizing valve, which is arranged between the expander and the temperature swing adsorption tower.

[0011] Optionally, the adsorbent in the temperature swing adsorption tower is a microporous carbon-based adsorbent, and the adsorbent in the pressure swing adsorption tower is a multi-stage carbon-based adsorbent.

[0012] In a second aspect, a pressure-temperature-variable coupled adsorption-compression carbon dioxide energy storage method is provided, characterized in that it is based on the coupled carbon dioxide energy storage system described in the first aspect; The carbon dioxide energy storage method comprises: Energy storage stage: The desorption of carbon dioxide from the temperature swing adsorption tower is controlled by increasing the temperature in the temperature swing adsorption tower, and the desorption of carbon dioxide from the pressure swing adsorption tower is controlled by decreasing the pressure in the pressure swing adsorption tower; The carbon dioxide desorbed from the pressure swing adsorption tower and the temperature swing adsorption tower is compressed by a compressor, cooled by a heat exchange system, and then input into a high-pressure gas storage tank. The heat generated by the compressor compressing the carbon dioxide is transferred to the adsorbent of the temperature swing adsorption tower through a first heat exchanger for carbon dioxide desorption; Energy release stage: The high-pressure carbon dioxide output from the high-pressure gas tank is heated by the heat exchange system and then expanded by the expander to obtain low-pressure carbon dioxide; The low-pressure carbon dioxide is transported to the pressure swing adsorption tower for pressure swing adsorption storage. After reaching the designed storage pressure, the remaining carbon dioxide is introduced into the temperature swing adsorption tower for adsorption storage. The adsorption heat released by the temperature swing adsorption tower during the adsorption process is transferred to the high-pressure carbon dioxide released from the high-pressure storage tank through the second heat exchanger to achieve heating of the high-pressure carbon dioxide.

[0013] Optionally, the heat generated by the compressor compressing the carbon dioxide is transferred to the adsorbent of the temperature swing adsorption tower through a first heat exchanger for desorption of the carbon dioxide, including: Compressing the carbon dioxide desorbed from the pressure swing adsorption tower and the temperature swing adsorption tower by the compressor to obtain high-temperature and high-pressure carbon dioxide; The high-temperature and high-pressure carbon dioxide is subjected to heat absorption and cooling by the second heat exchanger to obtain high-pressure carbon dioxide, and the absorbed heat is transferred to the adsorbent in the temperature swing adsorption tower for desorption of carbon dioxide.

[0014] Optionally, the adsorption heat released by the temperature swing adsorption tower during the adsorption process is transferred to the high-pressure carbon dioxide released by the high-pressure storage tank through a second heat exchanger to heat the high-pressure carbon dioxide, including: Controlling the temperature swing adsorption tower to adsorb low-pressure carbon dioxide and release adsorption heat; The adsorption heat is transferred to the high-pressure carbon dioxide released from the high-pressure gas storage tank through the second heat exchanger to heat the high-pressure carbon dioxide.

[0015] The beneficial effects of the present invention's coupled pressure-and-temperature swing adsorption and compression carbon dioxide energy storage system are as follows: the temperature swing adsorption tower and the pressure swing adsorption tower utilize temperature and pressure changes, respectively, to achieve carbon dioxide adsorption or desorption. The two work together to efficiently store and release carbon dioxide under different operating conditions, ensuring stable carbon dioxide circulation within the system. The compressor compresses the carbon dioxide desorbed by the temperature swing adsorption tower and the pressure swing adsorption tower and delivers it to the high-pressure gas storage tank, ensuring energy storage. The first heat exchanger uses the low-temperature carbon dioxide generated during desorption from the temperature swing adsorption tower to cool the compressed carbon dioxide, preventing its storage stability from being affected by high temperatures. This ensures that the high-pressure gas storage tank safely and stably receives and stores carbon dioxide. The first heat exchanger also utilizes waste heat from compression to provide the heat required for desorption in the temperature swing adsorption tower. The high-pressure gas storage tank, serving as the energy storage core, stably receives and releases high-pressure carbon dioxide. The high-pressure carbon dioxide released from the high-pressure gas storage tank provides a stable gas source for the expander. After the expander expands the high-pressure carbon dioxide and performs work, the low-pressure carbon dioxide is delivered to the pressure swing adsorption tower and the temperature swing adsorption tower, respectively, achieving CO2 recycling. Before the high-pressure carbon dioxide enters the expander, the second heat exchanger utilizes the adsorption heat generated by the adsorbent in the temperature swing adsorption tower to heat it. This optimizes the expander's operating conditions, improves its efficiency, and stabilizes the system's energy conversion process. It also fully utilizes the adsorption heat from the adsorption process, improving the efficiency of the heat generated during the adsorption process. During the different stages of energy storage and release, the coordinated and coordinated operation of the temperature swing adsorption tower, pressure swing adsorption tower, compressor, first heat exchanger, high-pressure gas storage tank, second heat exchanger, and expander effectively improves the stability of the energy storage system at different stages and under different operating conditions, ensuring its reliable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic structural diagram of a coupled carbon dioxide energy storage system according to an embodiment of the present invention; Figure 2 Schematic diagram of the structure of a tubular heat exchanger according to an embodiment of the present invention.

[0017] Description of reference numerals: 1-temperature swing adsorption tower; 2-pressure swing adsorption tower; 3-compressor; 4-first heat exchanger; 41-first pressure-stabilizing valve; 42-first one-way valve; 5-high-pressure gas storage tank; 6-second heat exchanger; 61-second pressure-stabilizing valve; 62-second one-way valve; 7-expander; 8-third pressure-stabilizing valve. DETAILED DESCRIPTION

[0018] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein. Instead, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0019] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0020] The term "including" and its variations used in this document are open inclusions, that is, "including but not limited to"; the term "based on" means "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc. mentioned in the present invention are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0021] It should be noted that the modifications of "one" and "multiple" mentioned in the present invention are illustrative rather than restrictive. Those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0022] The names of the messages or information exchanged between multiple devices in the embodiments of the present invention are only used for illustrative purposes and are not used to limit the scope of these messages or information.

[0023] In related technologies, compressed energy storage systems that use carbon dioxide as a working fluid (the working substance that carries and transfers energy during energy conversion and transfer) have many advantages, such as high carbon dioxide density, low viscosity, high latent heat of phase change, and stable chemical properties. Systems using this as a working fluid have the characteristics of small footprint, multiple application scenarios, and large energy storage capacity, but they also have obvious disadvantages. In compressed energy storage systems using carbon dioxide as a working fluid, carbon dioxide, as a greenhouse gas, must ensure a closed cycle. Therefore, the problem of storing low-pressure carbon dioxide after expansion work becomes a key disadvantage that affects the stability of the energy storage system. If the storage of low-pressure carbon dioxide cannot be properly resolved, it will lead to an imbalance in pressure and temperature within the system, affecting the normal progress of the energy storage and release processes, and thus undermining the stable operation of the system.

[0024] In response to the problems existing in the above-mentioned related technologies, this embodiment provides a pressure-temperature-variable coupled adsorption-compression carbon dioxide energy storage system and method.

[0025] like Figure 1 As shown, an embodiment of the present invention provides a coupled carbon dioxide energy storage system and method, including: The temperature swing adsorption tower 1 is used to fill the temperature swing adsorption material and achieve the adsorption or desorption of carbon dioxide through temperature changes; Specifically, the temperature swing adsorption tower 1 can be a cylindrical stainless steel container, which can include a multi-layer filling structure inside, and each layer is evenly filled with a carbon-based adsorbent. A temperature sensor is configured in the tower to monitor the temperature inside the tower. The temperature swing adsorption tower 1 includes an air inlet and an air outlet. The air inlet is connected to the air outlet of the expander 7, and the air outlet is connected to the air inlet of the compressor 3. Valves are installed on each of the two ports to control the flow of gas. The temperature swing adsorption tower 1 realizes the adsorption or desorption of carbon dioxide by the adsorbent by changing the internal temperature, that is, increasing the temperature causes the adsorbent to desorb carbon dioxide, and decreasing the temperature causes the adsorbent to adsorb carbon dioxide.

[0026] The pressure swing adsorption tower 2 is used to be filled with pressure swing adsorption material to achieve adsorption or desorption of carbon dioxide through pressure changes.

[0027] Specifically, the pressure swing adsorption tower 2 can also be a cylindrical stainless steel container, which can include a multi-layer filling structure inside, and each layer is evenly filled with a pressure swing adsorbent. The pressure swing adsorbent can achieve efficient adsorption or desorption of carbon dioxide by relying on pressure changes. A pressure sensor can be provided in the tower to monitor the internal pressure. The pressure swing adsorption tower 2 includes an air inlet and an air outlet, the air inlet is connected to the air outlet of the expander 7, and the air outlet is connected to the air inlet of the compressor 3, and valves are installed to control the gas flow direction. The pressure swing adsorption tower 2 achieves adsorption or desorption of carbon dioxide by the adsorbent by changing the internal pressure, that is, lowering the pressure causes the adsorbent to desorb carbon dioxide, and increasing the pressure causes the adsorbent to adsorb carbon dioxide.

[0028] The compressor 3 is used to compress the carbon dioxide desorbed by the temperature swing adsorption tower 1 and the pressure swing adsorption tower 2 , and deliver the compressed carbon dioxide to the high-pressure gas storage tank 5 .

[0029] Specifically, the structure of the compressor 3 mainly includes a body, a transmission assembly, a valve assembly, a lubrication system, and a sealing assembly. The body provides support for the entire compressor 3; the transmission assembly converts the rotational motion of the motor into the reciprocating motion of the piston to achieve the compression of carbon dioxide; the valve assembly mainly includes an inlet valve and an outlet valve, which are used to control the intake and discharge of carbon dioxide; the lubrication system reduces friction between components to ensure the normal operation of the equipment; the sealing assembly prevents carbon dioxide leakage, improving system safety and compression efficiency. The low-pressure carbon dioxide desorbed from the temperature swing adsorption tower 1 and the pressure swing adsorption tower 2 is compressed by the compressor 3, and the compressed high-temperature and high-pressure carbon dioxide is delivered to the high-pressure gas storage tank 5. At the same time, the first heat exchanger 4 can be set between the compressor 3 and the high-pressure gas storage tank 5 to absorb heat and cool the high-temperature and high-pressure carbon dioxide discharged from the compressor 3, thereby obtaining high-pressure carbon dioxide with a relatively low temperature that is finally delivered to the high-pressure gas storage tank 5.

[0030] The high-pressure gas storage tank 5 is used to receive and store the high-pressure carbon dioxide output by the compressor 3 and to release the high-pressure carbon dioxide stored therein.

[0031] Specifically, the high-pressure gas storage tank 5 can be a cylindrical container made of high-strength alloy steel or stainless steel, equipped with an elliptical head to withstand high pressure. The tank body is provided with an air inlet and an air outlet, respectively, for the input and output of carbon dioxide. Safety devices such as a safety valve and a pressure gauge are also installed. The safety valve can automatically release gas when the pressure is too high to prevent the tank from over-pressurizing, and the pressure gauge displays the pressure inside the tank in real time. The carbon dioxide gas is compressed to a high-pressure state by the compressor 3 and then input into the high-pressure gas storage tank 5 for storage. When the carbon dioxide is needed, the air outlet valve is opened, and the carbon dioxide gas flows out of the gas storage tank under the action of pressure.

[0032] The expander 7 is used to expand the high-pressure carbon dioxide output from the high-pressure gas storage tank 5 and to deliver the expanded low-pressure carbon dioxide to the temperature swing adsorption tower 1 and the pressure swing adsorption tower 2 respectively.

[0033] Specifically, high-pressure carbon dioxide enters the expander 7, where it expands and reduces its pressure through components such as the nozzle and impeller. According to the law of conservation of energy, the internal energy of the high-pressure carbon dioxide (fluid) is converted into mechanical energy, thereby generating shaft work. The expander 7 typically consists of a rotor, stator, bearings, and sealing devices. The rotor is the core component, equipped with the impeller and other components. It rotates under the influence of the fluid to generate work. The stator, including the housing and nozzle, guides the fluid and secures components. The bearings support the rotor, ensuring stable rotation. The sealing devices prevent fluid leakage.

[0034] The first heat exchanger 4 is provided between the compressor 3 and the high-pressure gas storage tank 5 and is used to cool the carbon dioxide compressed by the compressor 3 .

[0035] The second heat exchanger 6 is provided between the high-pressure gas storage tank 5 and the expander 7 and is used to heat the high-pressure carbon dioxide released from the high-pressure storage tank.

[0036] Specifically, the first heat exchanger 4 and the second heat exchanger 6 can be tubular heat exchangers, which are mainly composed of a tube side, a shell side and a shell. The shell side refers to the area where the fluid flows outside the heat exchange tube and inside the shell, that is, the primary side pipeline. The tube side refers to the channel and related space where the fluid flows inside the heat exchange tube, that is, the secondary side pipeline.

[0037] For example, during the energy storage phase: Due to the characteristics of the thermal swing adsorbent, the amount of carbon dioxide adsorbed by thermal swing adsorption tower 1 decreases with increasing temperature, i.e., carbon dioxide desorbs as temperature increases. At the beginning of the energy storage phase, the valve at the outlet of thermal swing adsorption tower 1 is opened, while the remaining valves are closed. The carbon dioxide desorbed from thermal swing adsorption tower 1 enters the secondary pipeline of compressor 3 and first heat exchanger 4, respectively. The carbon dioxide entering compressor 3 is compressed and heated to produce high-temperature, high-pressure carbon dioxide. This high-temperature, high-pressure carbon dioxide enters the primary pipeline of the heat exchanger, where it exchanges heat with the low-pressure carbon dioxide in the secondary pipeline. The desorbed low-pressure carbon dioxide in thermal swing adsorption tower 1 absorbs heat from the high-temperature, high-pressure carbon dioxide, cooling it. The cooled, high-pressure carbon dioxide is then transferred to high-pressure gas storage tank 5 for storage. Simultaneously, the low-pressure carbon dioxide in the secondary pipeline of first heat exchanger 4 absorbs heat and heats up, returning to thermal swing adsorption tower 1 to replenish the heat required for the desorption process. This further heats up the adsorbent, accelerating carbon dioxide desorption, thus achieving heat recycling within the energy storage system.

[0038] Pressure swing adsorption tower 2 and temperature swing adsorption tower 1 are coupled together in the energy storage system to jointly adsorb or desorb carbon dioxide from the energy storage system. Pressure swing adsorption tower 2 utilizes the characteristics of the pressure swing adsorbent, whose carbon dioxide adsorption capacity increases with increasing pressure and decreases conversely. This means that carbon dioxide is adsorbed when the pressure is increased and desorbed when the pressure is decreased. During the energy storage phase, the valve at the outlet of pressure swing adsorption tower 2 opens, reducing the internal pressure and the adsorbent's carbon dioxide adsorption capacity. A large amount of carbon dioxide is desorbed and released through the outlet valve. The desorbed carbon dioxide also enters compressor 3 for compression to produce high-temperature, high-pressure carbon dioxide. It is then cooled by first heat exchanger 4 and transported to high-pressure gas storage tank 5 for storage.

[0039] Energy release stage: The high-pressure carbon dioxide in the high-pressure gas storage tank 5 is heated by the second heater and enters the expander 7 to perform work, and then becomes low-pressure carbon dioxide. Part of the low-pressure carbon dioxide enters the temperature swing adsorption tower 1 through the pressure-stabilizing valve. During the adsorption process of the adsorbent, the adsorbent adsorbs carbon dioxide and releases adsorption heat. At the same time, the sensible heat stored in the adsorbent in the energy storage stage is also released. This heat is transferred out through the second heat exchanger 6 and used to heat the unexpanded carbon dioxide output from the outlet of the high-pressure gas storage tank 5, thereby realizing the recycling of adsorption heat and improving the energy utilization rate of the energy storage system. Among them, the primary side pipeline of the second heat exchanger 6 is respectively connected to the air outlet of the high-pressure gas storage tank 5 and the air inlet of the expander 7, and the secondary side pipeline of the second heat exchanger 6 is connected to the temperature swing adsorption tower 1. During the energy release process, the adsorbent in the temperature swing adsorption tower 1 releases heat when adsorbing carbon dioxide. At this time, the temperature in the temperature swing adsorption tower 1 is relatively high. The second heat exchanger 6 introduces the relatively high temperature carbon dioxide in the temperature swing adsorption tower 1 through the secondary side pipeline, and exchanges heat with the relatively low temperature high-pressure carbon dioxide that has not expanded and done work flowing through the primary side pipeline of the second heat exchanger 6. The adsorption heat in the temperature swing adsorption tower 1 is transferred out through the secondary side pipeline of the second heat exchanger 6, and the temperature in the temperature swing gas storage tank is reduced to improve the adsorption effect of the adsorbent on carbon dioxide.

[0040] It should be noted that adsorption heat refers to the heat released by the interaction between the adsorbent and the carbon dioxide molecules during the adsorption process. This refers to the interaction forces between the atoms or groups on the adsorbent surface and the carbon dioxide molecules, such as van der Waals forces and electrostatic attraction. When carbon dioxide molecules are adsorbed onto the adsorbent surface, the intermolecular distance decreases. These forces reduce the energy of the system. According to the law of conservation of energy, the excess energy is released as heat, forming adsorption heat.

[0041] Since the pressure swing adsorption tower 2 and the temperature swing adsorption tower 1 are coupled in the energy storage system, during the energy release stage, the low-pressure carbon dioxide after the expander 7 does work is also automatically filled into the pressure swing adsorption tower 2. As the carbon dioxide is filled in, the pressure in the tower increases, and the adsorbent adsorbs the carbon dioxide to achieve the adsorption and storage of carbon dioxide. The adsorption process releases adsorption heat, which increases the system temperature and pressure, and finally reaches a stable adsorption state, completing the storage of the low-pressure carbon dioxide after the expansion work, and ensuring the stable operation of the system.

[0042] In this embodiment, the temperature swing adsorption tower 1 and the pressure swing adsorption tower 2 utilize temperature and pressure changes, respectively, to adsorb or desorb carbon dioxide. The two work together to efficiently store and release carbon dioxide under different operating conditions, ensuring stable carbon dioxide circulation within the system. Compressor 3 compresses the carbon dioxide desorbed from the temperature swing adsorption towers 1 and 2 and delivers it to the high-pressure gas storage tank 5, ensuring energy storage. A first heat exchanger 4 uses the low-temperature carbon dioxide generated during desorption from the temperature swing adsorption tower 1 to cool the compressed carbon dioxide, preventing its storage stability from being affected by high temperatures and ensuring that the high-pressure gas storage tank 5 safely and stably receives and stores the carbon dioxide. As the core of energy storage, the high-pressure gas storage tank 5 stably receives and releases high-pressure carbon dioxide. The high-pressure carbon dioxide released from the high-pressure gas storage tank 5 provides a stable gas source for the expander 7. After the expander 7 expands the high-pressure carbon dioxide and performs work, it delivers the low-pressure carbon dioxide to the temperature swing adsorption tower 1 and the pressure swing adsorption tower 2, respectively, achieving material recycling. Before the high-pressure carbon dioxide enters expander 7, second heat exchanger 6 utilizes the heat of adsorption generated by the adsorbent in temperature swing adsorption tower 1. This optimizes the operating conditions of expander 7, improves its efficiency, and stabilizes the system's energy conversion process. During the various stages of energy storage and release, the coordinated coordination and adjustment of temperature swing adsorption tower 1, pressure swing adsorption tower 2, compressor 3, first heat exchanger 4, high-pressure gas storage tank 5, second heat exchanger 6, and expander 7 effectively improves the stability of the energy storage system at different stages and under different operating conditions, ensuring its reliable operation.

[0043] Alternatively, as Figure 1 As shown, the primary side pipeline of the first heat exchanger 4 is connected to the air outlet of the compressor 3 and the air inlet of the high-pressure gas storage tank 5 respectively, and the secondary side pipeline of the first heat exchanger 4 is connected to the temperature swing adsorption tower 1, which is used to exchange heat between the low-temperature carbon dioxide in the temperature swing adsorption tower 1 and the high-temperature and high-pressure carbon dioxide compressed by the compressor 3.

[0044] Specifically, the first heat exchanger 4 has independent primary and secondary pipelines. One end of the primary pipeline is connected to the outlet of the compressor 3, receiving the high-temperature, high-pressure carbon dioxide output by the compressor 3. The other end is connected to the inlet of the high-pressure gas storage tank 5, transporting the cooled high-pressure carbon dioxide to the high-pressure gas storage tank 5 for storage. The first heat exchanger 4 is connected to the compressor 3 and the other end is connected to the high-pressure gas storage tank 5. The secondary pipeline of the first heat exchanger 4 is connected to the temperature swing adsorption tower 1, thereby introducing the low-temperature carbon dioxide generated during the desorption process of the temperature swing adsorption tower 1 into the secondary pipeline. Inside the first heat exchanger 4, the high-temperature, high-pressure carbon dioxide in the primary pipeline and the low-temperature carbon dioxide in the secondary pipeline do not directly mix. However, heat exchange occurs through the walls of the heat exchanger. The high-temperature, high-pressure carbon dioxide in the primary pipeline transfers heat to the low-temperature carbon dioxide, reducing its own temperature before flowing into the high-pressure gas storage tank 5 for storage.

[0045] For example, Figure 2 As shown, the first heat exchanger 4 can be a tubular heat exchanger, wherein the primary side pipeline is the shell side K of the tubular heat exchanger, and the secondary side pipeline is the tube side G of the tubular heat exchanger. The tube side G is wrapped in the shell side K. The outlet pipe of the tube side G is used to communicate with the temperature swing adsorption tower 1, so that the carbon dioxide in the temperature swing adsorption tower 1 is introduced into the tube side G located inside the shell side K, and heat exchange is carried out through the tube wall, so that the heat of the high-temperature and high-pressure carbon dioxide in the shell side K is transferred to the low-temperature carbon dioxide in the tube side G, realizing accurate and efficient heat transfer.

[0046] In this optional embodiment, the primary side pipeline of the first heat exchanger 4 is respectively connected to the compressor 3 and the high-pressure gas storage tank 5, and the secondary side pipeline is connected to the temperature swing adsorption tower 1. During the heat exchange process, the high-temperature and high-pressure carbon dioxide flows in the primary side pipeline, and the heat is transferred to the low-temperature carbon dioxide on the secondary side, thereby realizing the reasonable distribution of the heat generated by the compressor 3 after compression, improving the energy utilization rate of the system, and delivering the cooled high-pressure carbon dioxide to the high-pressure gas storage tank 5 to ensure the stability of the energy storage system. At the same time, the heat absorbed by the secondary side pipeline of the first heat exchanger 4 provides heating heat for the temperature swing adsorption tower 1, which helps the subsequent desorption of carbon dioxide from the adsorbent. By isolating the primary side pipeline and the secondary side pipeline from each other, it is ensured that carbon dioxide in different states flows in their respective pipelines to avoid mixing, ensure the stable operation of the system, and prevent mutual interference between carbon dioxide at different pressures.

[0047] Optionally, the energy storage system further includes a first one-way valve 42 and a first pressure-stabilizing valve 41 , wherein the first one-way valve 42 is arranged at the air outlet of the secondary side pipeline of the first heat exchanger 4 , and the first pressure-stabilizing valve 41 is arranged at the air inlet of the secondary side pipeline of the first heat exchanger 4 .

[0048] In this optional embodiment, the air inlet and outlet of the secondary side pipeline of the first heat exchanger 4 are respectively connected to the temperature swing adsorption tower 1. The low-temperature carbon dioxide is introduced into the temperature swing adsorption tower 1 through the air inlet of the secondary side pipeline. After heat exchange with the high-temperature and high-pressure carbon dioxide in the primary side pipeline, it re-flows into the temperature swing adsorption tower 1 through the air outlet of the secondary side pipeline. Among them, the first pressure-stabilizing valve 41 is installed at the air inlet of the secondary side pipeline. Its main function is to stabilize the pressure of the low-temperature carbon dioxide entering the heat exchanger. Because the pressure of the carbon dioxide in the temperature swing adsorption tower 1 may fluctuate, the first pressure-stabilizing valve 41 ensures that the pressure of the carbon dioxide entering the heat exchanger is maintained within an appropriate and stable range through its own adjustment mechanism, creating good conditions for an efficient and stable heat exchange process, while preventing the heat exchange efficiency from being affected by excessive pressure fluctuations, thereby ensuring the overall performance of the system. The first one-way valve 42 is installed at the air outlet of the secondary side pipeline of the first heat exchanger 4. Its function is to ensure that the carbon dioxide, after heat exchange and heating, can only flow in one direction, preventing gas backflow. During system operation, if there is no first one-way valve 42, when the operating conditions change, the carbon dioxide at the outlet of the secondary side pipeline may flow back, which will not only interfere with the normal heat exchange process in the heat exchanger, but may also have an adverse effect on the operating state of the temperature swing adsorption tower 1 and even destroy the stability of the entire system. The presence of the first one-way valve 42 effectively prevents this from happening, ensuring that the flow direction of carbon dioxide in the system always meets the design requirements, so that the system can operate continuously and stably.

[0049] Optionally, the primary side pipeline of the second heat exchanger 6 is respectively connected to the gas outlet of the high-pressure gas storage tank 5 and the gas inlet of the expander 7, and the secondary side pipeline of the second heat exchanger 6 is connected to the temperature swing adsorption tower 1, and the heat energy released during the adsorption process of the temperature swing adsorption tower 1 is used to heat the high-pressure carbon dioxide released from the high-pressure gas storage tank 5.

[0050] Optionally, the energy storage system further includes a second one-way valve 62 and a second pressure-stabilizing valve 61 , wherein the second one-way valve 62 is arranged at the air outlet of the secondary side pipeline of the second heat exchanger 6 , and the second pressure-stabilizing valve 61 is arranged at the air inlet of the secondary side pipeline of the second heat exchanger 6 .

[0051] Specifically, the air inlet of the primary side pipeline of the second heat exchanger 6 is connected to the air outlet of the high-pressure gas storage tank 5, and the air outlet is connected to the air inlet of the expander 7, which is responsible for accurately transporting the high-pressure carbon dioxide released from the high-pressure gas storage tank 5 to the expander 7. The air inlet and air outlet of the secondary side pipeline of the second heat exchanger 6 are connected to the temperature swing adsorption tower 1, so that the heat released by the temperature swing adsorption tower 1 during the adsorption process is transferred to the second heat exchanger 6 through the secondary side pipeline. When the temperature swing adsorption tower 1 adsorbs the low-pressure carbon dioxide generated after the expander 7 does work, it releases adsorption heat. This part of heat is transferred to the second heat exchanger 6 through the secondary side pipeline and is used to heat the low-temperature and high-pressure carbon dioxide that is about to enter the expander 7. The heat generated by the adsorption process in the temperature swing adsorption tower 1 is recycled by the second heat exchanger 6, which greatly improves the energy utilization rate of the system and reduces the consumption of additional energy. According to actual use requirements, the second heat exchanger 6 can also adopt a tubular heat exchanger.

[0052] Furthermore, in the secondary side pipeline of the second heat exchanger 6, a second pressure-stabilizing valve 61 is installed at the air inlet position to stabilize the pressure of the low-pressure carbon dioxide from the temperature swing adsorption tower 1 entering the secondary side pipeline. Since the release of adsorption heat and the pressure of the temperature swing adsorption tower 1 may fluctuate in different operating stages, the second pressure-stabilizing valve 61 can automatically adjust according to the real-time pressure conditions to ensure that the pressure of the fluid entering the secondary side pipeline of the second heat exchanger 6 is always maintained at an appropriate and stable level, providing a solid guarantee for an efficient and stable heat exchange process, avoiding a decrease in heat exchange efficiency due to unstable pressure, and thus ensuring the stable operation of the entire system. A second one-way valve 62 is set at the air outlet of the secondary side pipeline of the second heat exchanger 6. Through the second one-way valve 62, only the carbon dioxide after heat exchange is allowed to flow to the temperature swing adsorption tower 1, avoiding backflow. Without the second check valve 62, when system operating conditions change during system operation, backflow may occur at the secondary pipe outlet. This would not only disrupt the orderly heat exchange process within the second heat exchanger 6, but could also negatively impact the normal operation of the temperature swing adsorption tower 1 and the entire system, and even cause system failure. The presence of the second check valve 62 effectively prevents this from occurring, ensuring that the flow direction of the fluid within the system strictly complies with design requirements, effectively maintaining the system's continuous, stable, and efficient operation.

[0053] In this optional embodiment, the second heat exchanger 6 uses the heat released during the adsorption process of the temperature swing adsorption tower 1 to heat the high-pressure carbon dioxide released from the high-pressure gas storage tank 5, thereby achieving heat recycling and greatly improving the energy utilization rate of the system. The second pressure-stabilizing valve 61 is installed at the air inlet of the secondary side pipeline of the second heat exchanger 6 to stabilize the pressure of the incoming fluid and ensure that under different working conditions, especially when the adsorption state of the temperature swing adsorption tower 1 fluctuates, the heat exchange process of the second heat exchanger 6 is always in a stable state. The stable pressure makes the heat transfer more efficient and uniform, avoiding local overheating or overcooling caused by unstable pressure, thereby improving the stability and reliability of the operation of the entire system. The second one-way valve 62 is set at the air outlet of the secondary side pipeline to prevent fluid backflow, avoid interference with the heat exchange process due to backflow, ensure the unidirectionality and orderliness of heat transfer, effectively maintain the normal order of fluid flow within the system, ensure the continuous and stable operation of the system, extend the service life of the equipment, and reduce maintenance costs and potential downtime risks.

[0054] Optionally, the energy storage system further includes a third pressure stabilizing valve 8 , which is disposed between the expander 7 and the temperature swing adsorption tower 1 .

[0055] In this optional embodiment, when the expander 7 is operating, it expands the high-pressure carbon dioxide from the high-pressure gas storage tank 5 to produce work. This process causes the carbon dioxide pressure to drop sharply. Due to the dynamic changes in the operating state of the expander 7 and the system operating conditions, the low-pressure carbon dioxide pressure output by the expander 7 may fluctuate significantly. A third pressure-stabilizing valve 8, located at the outlet of the expander 7 and the inlet of the temperature swing adsorption tower 1, monitors and controls the low-pressure carbon dioxide pressure output by the expander 7 in real time. When the pressure is too high, the valve automatically adjusts its opening, increasing the flow resistance and reducing the pressure to a set stable value. When the pressure is too low, the valve opening is adjusted to reduce the flow resistance and increase the pressure. This sophisticated regulation mechanism ensures that the carbon dioxide pressure entering the temperature swing adsorption tower 1 is always maintained within an appropriate and stable range. Stable pressure is crucial to the efficient operation of the temperature swing adsorption tower 1. On the one hand, the appropriate pressure ensures sufficient contact between the adsorbent and the carbon dioxide, making the adsorption process more stable and efficient, improving the amount and efficiency of carbon dioxide adsorbed, and thus ensuring the energy storage capacity of the system. On the other hand, stable pressure helps to maintain the stability of the temperature field and concentration field in the temperature swing adsorption tower 1, reduce the risk of adsorption performance degradation or equipment damage caused by pressure fluctuations, extend the service life of the temperature swing adsorption tower 1, and improve the reliability and stability of the entire energy storage system.

[0056] Optionally, the adsorbent in the temperature swing adsorption tower 1 is a microporous carbon-based adsorbent, and the adsorbent in the pressure swing adsorption tower 2 is a multi-stage carbon-based adsorbent.

[0057] In this optional embodiment, the adsorbent filled in the temperature-swing adsorption tower 1 can be a microporous carbon-based adsorbent, which has a rich and narrow micropore structure. The size of these micropores is similar to that of carbon dioxide molecules, and the carbon dioxide molecules can be captured inside the micropores through physical adsorption. When the temperature is low, the adsorbent has a strong adsorption capacity for carbon dioxide and can adsorb a large amount of carbon dioxide; when the temperature rises, the molecular thermal motion intensifies, and the carbon dioxide molecules obtain enough energy to break free from the adsorption force and achieve desorption. This characteristic of achieving efficient adsorption and desorption based on temperature changes is consistent with the working principle of the temperature-swing adsorption tower 1 to store and release carbon dioxide through temperature regulation, which helps to make full use of the heat resources in the system and improve energy storage efficiency.

[0058] The adsorbent in the pressure swing adsorption tower 2 can be a multi-stage carbon-based adsorbent, which has a unique multi-stage pore structure, including macropores, mesopores and micropores. The macropores and mesopores provide a fast transmission channel for carbon dioxide molecules, allowing them to quickly diffuse into the interior of the adsorbent, while the micropores are responsible for the adsorption and storage of carbon dioxide. When the pressure is high, the carbon dioxide molecules pass through the macropores and mesopores quickly under the pressure drive, and are adsorbed at the micropores, achieving high-capacity adsorption and storage; when the pressure drops, the carbon dioxide molecules can quickly desorb along the original route. The multi-stage carbon-based adsorbent, an efficient adsorption and desorption mechanism based on pressure changes, fully utilizes the advantages of the pressure swing adsorption tower 2 in storing and releasing carbon dioxide through pressure regulation, effectively improves the energy storage capacity and response speed of the system, and works in conjunction with the temperature swing adsorption tower 1 to jointly ensure the stable and efficient operation of the entire energy storage system.

[0059] A coupled carbon dioxide energy storage method, based on the coupled carbon dioxide energy storage system described above; The carbon dioxide energy storage method comprises: Energy storage stage: The desorption of carbon dioxide from the temperature swing adsorption tower 1 is controlled by increasing the temperature in the temperature swing adsorption tower 1, and the desorption of carbon dioxide from the pressure swing adsorption tower 2 is controlled by decreasing the pressure in the pressure swing adsorption tower 2; The carbon dioxide desorbed from the pressure swing adsorption tower 2 and the temperature swing adsorption tower 1 is compressed by the compressor 3, cooled by the heat exchange system 4, and then input into the high-pressure gas storage tank 5. The heat generated by the compressor 3 when compressing the carbon dioxide is transferred to the adsorbent of the temperature swing adsorption tower 1 through the first heat exchanger 4 for carbon dioxide desorption.

[0060] Specifically, the microporous carbon-based adsorbent filled in the temperature swing adsorption tower 1 has a carbon dioxide adsorption capacity that is closely related to temperature. When the system needs to store energy, the temperature of the temperature swing adsorption tower 1 is increased so that the carbon dioxide molecules on the adsorbent obtain sufficient energy to overcome the constraints of the adsorption force, thereby achieving carbon dioxide desorption. The adsorption performance of the multi-stage carbon-based adsorbent in the pressure swing adsorption tower 2 is significantly affected by pressure. By reducing the pressure in the pressure swing adsorption tower 2, the adsorption capacity of the adsorbent for carbon dioxide decreases, and carbon dioxide detaches from the adsorbent to achieve desorption.

[0061] Furthermore, the carbon dioxide desorbed from the temperature swing adsorption tower 1 and the pressure swing adsorption tower 2 is collected and compressed by compressor 3. During the compression process, the distance between carbon dioxide molecules decreases, intensifying molecular motion and generating a large amount of heat. To achieve efficient energy utilization, a first heat exchanger 4 is installed between compressor 3 and high-pressure gas storage tank 5. First heat exchanger 4 acts as an energy bridge, transferring the heat generated by compressor 3 when compressing carbon dioxide to the adsorbent in temperature swing adsorption tower 1. The low-pressure carbon dioxide desorbed from temperature swing adsorption tower 1 serves as the heat transfer medium. This heat provides the sensible heat required to raise the adsorbent's temperature; it also acts as desorption heat, facilitating smoother desorption of carbon dioxide molecules from the adsorbent. This not only achieves carbon dioxide desorption but also fully utilizes the heat generated by compressor 3, avoiding energy waste and improving the energy efficiency of the entire system. After heat exchange in the first heat exchanger 4, the high-pressure carbon dioxide is transferred to high-pressure gas storage tank 5 for storage. High-pressure gas storage tank 5 provides a stable storage environment for the carbon dioxide, allowing it to be stored at high pressure, ready for the subsequent energy release stage. The temperature swing adsorption tower 1 and the pressure swing adsorption tower 2 respectively realize carbon dioxide desorption through temperature and pressure control. The two cooperate with each other and work in coordination. The compressor 3 compresses the desorbed carbon dioxide and stores it in the high-pressure gas storage tank 5, forming a complete closed-loop system. In this process, the energy transfer and material flow between various links are closely related and balanced with each other. The heat generated by the compressor 3 is used for desorption in the temperature swing adsorption tower 1 through the first heat exchanger 4, which not only avoids heat waste but also reduces additional energy input, making the system more balanced and stable in energy utilization, ensuring the stable flow of materials and energy in the entire energy storage process, improving the system's ability to cope with various changes in working conditions, and enhancing the overall stability of the system.

[0062] Energy release stage: The high-pressure carbon dioxide output from the high-pressure gas storage tank 5 is heated by the heat exchange system 6 and then expanded by the expander 7 to obtain low-pressure carbon dioxide; The low-pressure carbon dioxide is transported to the pressure swing adsorption tower 2 for pressure swing adsorption storage. After reaching the designed storage pressure, the remaining carbon dioxide is introduced into the temperature swing adsorption tower 1 for adsorption storage. The adsorption heat released by the temperature swing adsorption tower 1 during the adsorption process is transferred to the high-pressure carbon dioxide released by the high-pressure storage tank 5 through the second heat exchanger 6, thereby heating the high-pressure carbon dioxide.

[0063] In this optional embodiment, during the energy release phase, the coupled carbon dioxide energy storage system begins releasing stored energy to meet actual needs, resulting in a tight and efficient workflow. First, the high-pressure gas storage tank 5, serving as the core energy storage medium, outputs high-pressure carbon dioxide to the expander 7. Expander 7 is a key device in the energy release phase, utilizing the expansion properties of gas to achieve energy conversion. Inside expander 7, the high-pressure carbon dioxide rapidly expands, driving mechanical components such as the impeller to rotate, thereby performing external work and converting the potential energy stored in the high-pressure carbon dioxide into mechanical energy, achieving efficient energy release. During this process, as the potential energy is consumed, the pressure of the carbon dioxide decreases dramatically, transforming it into low-pressure carbon dioxide. The low-pressure carbon dioxide is then transported to temperature swing adsorption tower 1 and pressure swing adsorption tower 2, respectively. The microporous carbon-based adsorbent filling temperature swing adsorption tower 1 has a strong adsorption capacity for carbon dioxide under low-temperature and low-pressure conditions. Once the low-pressure carbon dioxide enters temperature swing adsorption tower 1, the adsorbent rapidly captures the carbon dioxide molecules and adsorbs them within its microporous structure, thereby achieving adsorption and storage of the carbon dioxide. During this adsorption process, the adsorbent releases adsorption heat when adsorbing carbon dioxide. This adsorption heat is transferred through the second heat exchanger 6 to the high-pressure carbon dioxide newly released from the high-pressure storage tank and about to enter the expander 7 for heating. The second heat exchanger 6 transfers the adsorption heat generated during the adsorption process of the temperature swing adsorption tower 1 to the high-pressure carbon dioxide, so that the high-pressure carbon dioxide can be heated before entering the expander 7. The heated high-pressure carbon dioxide can expand and work more fully in the expander 7, thereby improving the work efficiency of the expander 7 and thus improving the energy release efficiency of the entire system. At the same time, the multi-stage carbon-based adsorbent in the pressure swing adsorption tower 2 also uses its multi-stage pore structure to adsorb and store low-pressure carbon dioxide under low-pressure conditions. The macropores and mesopores provide a fast transmission channel for carbon dioxide molecules, allowing them to quickly reach the micropores to be adsorbed, completing the storage process. During the energy release stage, the various links such as the work of the expander 7, carbon dioxide adsorption and storage, and heat transfer are interrelated and influence each other, forming an organic whole. The stable operation of each link enables the entire system to release energy and circulate materials in a relatively stable state. The stable transfer of adsorption heat ensures the stability of the carbon dioxide temperature at the inlet of the expander 7, and thus ensures the stability of the work of the expander 7. The stable operation of the expander 7 provides a stable low-pressure carbon dioxide gas source for the adsorption tower, so that the adsorption process can proceed stably, thereby being able to better cope with external interference and internal parameter fluctuations, and improving the overall stability and reliability of the energy storage system.

[0064] Optionally, the heat generated by the compressor 3 compressing the carbon dioxide is transferred to the adsorbent in the temperature swing adsorption tower 1 through the first heat exchanger 4 for desorption of carbon dioxide, including: The carbon dioxide desorbed from the pressure swing adsorption tower 2 and the temperature swing adsorption tower 1 is compressed by the compressor 3 to obtain high-temperature and high-pressure carbon dioxide; The second heat exchanger 6 absorbs heat from the high-temperature and high-pressure carbon dioxide to obtain high-pressure carbon dioxide, and transfers the absorbed heat to the adsorbent in the temperature swing adsorption tower 1 for desorption of carbon dioxide.

[0065] In this optional embodiment, after the pressure swing adsorption tower 2 and the temperature swing adsorption tower 1 complete the desorption of carbon dioxide during the energy storage phase, the desorbed low-pressure carbon dioxide enters the compressor 3. Compressor 3 compresses this low-pressure carbon dioxide. During this process, the distance between carbon dioxide molecules decreases, intermolecular collisions intensify, and mechanical energy is converted into internal energy of the carbon dioxide, causing its temperature and pressure to rise sharply, resulting in high-temperature, high-pressure carbon dioxide. The high-temperature, high-pressure carbon dioxide then enters the first heat exchanger 4. The first heat exchanger 4 exchanges heat with the low-temperature, low-pressure carbon dioxide desorbed from the temperature swing adsorption tower 1. During this process, the high-temperature, high-pressure carbon dioxide releases heat, lowering its temperature and transforming into high-pressure carbon dioxide. The heat absorbed by the first heat exchanger 4 is precisely transferred to the adsorbent in the temperature swing adsorption tower 1 via the low-pressure carbon dioxide in the secondary pipeline. This transferred heat is crucial for the microporous carbon-based adsorbent in the temperature swing adsorption tower 1. After absorbing heat, the adsorbent's temperature rises, disrupting its adsorption equilibrium for carbon dioxide. The carbon dioxide molecules obtain enough energy to overcome the adsorption force and desorb from the adsorbent surface and microporous structure, which promotes a new round of carbon dioxide desorption process in the temperature swing adsorption tower 1, providing conditions for continuous energy storage of the system. It also cleverly utilizes the heat generated by the compressor 3 when compressing carbon dioxide, avoids energy waste, greatly improves the energy utilization efficiency of the system, and makes the entire energy storage system operate more stably and efficiently in energy circulation and material conversion.

[0066] Optionally, the adsorption heat released by the temperature swing adsorption tower 1 during the adsorption process is transferred to the high-pressure carbon dioxide released by the high-pressure storage tank through the second heat exchanger 6 for heating, including: Controlling the temperature swing adsorption tower 1 to adsorb low-pressure carbon dioxide and release adsorption heat; The adsorption heat is transferred to the high-pressure carbon dioxide released from the high-pressure gas storage tank 5 through the second heat exchanger 6 to heat the high-pressure carbon dioxide.

[0067] In this optional embodiment, after the expander 7 completes the expansion work on the high-pressure carbon dioxide output from the high-pressure gas storage tank 5, the generated low-pressure carbon dioxide is transported to the temperature swing adsorption tower 1. The temperature swing adsorption tower 1 is filled with a microporous carbon-based adsorbent. The adsorbent captures the low-pressure carbon dioxide molecules in the microporous structure by virtue of the physical adsorption effect between the adsorbent and the carbon dioxide molecules, and releases adsorption heat when the adsorbent adsorbs the carbon dioxide molecules. At this time, the second heat exchanger 6 begins to play a role as a bridge connecting the energy transfer between the temperature swing adsorption tower 1 and the high-pressure gas storage tank 5. The design and structure of the second heat exchanger 6 enables it to efficiently transfer the adsorption heat released by the temperature swing adsorption tower 1 to the high-pressure carbon dioxide newly released from the high-pressure gas storage tank 5. The temperature of the high-pressure carbon dioxide rises after absorbing the heat. After the high-pressure carbon dioxide with increased temperature enters the expander 7, it can more fully convert the internal energy into mechanical energy during the expansion process, thereby improving the work efficiency of the expander 7 and further improving the energy release efficiency of the entire system. The whole process not only realizes the adsorption and storage of carbon dioxide, but also cleverly utilizes the adsorption heat and converts it into key energy to improve the system performance, ensuring that the system can operate stably and efficiently during the energy release stage, reflecting the high degree of synergy of the system in energy utilization and material circulation.

[0068] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A variable pressure and variable temperature coupled adsorption and compression carbon dioxide energy storage system, characterized in that: include: A temperature swing adsorption tower (1) is used to be filled with a temperature swing adsorption material and to achieve adsorption or desorption of carbon dioxide through temperature changes; A pressure swing adsorption tower (2) is used to fill a pressure swing adsorption material and achieve adsorption or desorption of carbon dioxide through pressure changes; A compressor (3) is used to compress the carbon dioxide desorbed by the temperature swing adsorption tower (1) and the pressure swing adsorption tower (2), and to deliver the compressed carbon dioxide to a high-pressure gas storage tank (5); A high-pressure gas storage tank (5) is used to receive and store high-pressure carbon dioxide output by the compressor (3) and to release the high-pressure carbon dioxide stored therein; An expander (7) is used to expand the high-pressure carbon dioxide output from the high-pressure gas storage tank (5) to perform work, and to deliver the expanded low-pressure carbon dioxide to the temperature swing adsorption tower (1) and the pressure swing adsorption tower (2) respectively; A first heat exchanger (4) is provided between the compressor (3) and the high-pressure gas storage tank (5) and is used to cool the carbon dioxide compressed by the compressor (3); The second heat exchanger (6) is arranged between the high-pressure gas storage tank (5) and the expander (7) and is used to heat the high-pressure carbon dioxide released from the high-pressure storage tank.

2. The pressure-temperature-variable coupled adsorption-compression carbon dioxide energy storage system according to claim 1 is characterized in that: The primary side pipeline of the first heat exchanger (4) is respectively connected to the air outlet of the compressor (3) and the air inlet of the high-pressure gas storage tank (5), and the secondary side pipeline of the first heat exchanger (4) is connected to the temperature swing adsorption tower (1) for performing heat exchange between the low-temperature carbon dioxide in the temperature swing adsorption tower (1) and the high-temperature and high-pressure carbon dioxide compressed by the compressor (3).

3. The pressure and temperature variable coupled adsorption and compression carbon dioxide energy storage system according to claim 2 is characterized in that: It also includes a first one-way valve (42) and a first pressure-stabilizing valve (41), wherein the first one-way valve (42) is arranged at the air outlet of the secondary side pipeline of the first heat exchanger (4), and the first pressure-stabilizing valve (41) is arranged at the air inlet of the secondary side pipeline of the first heat exchanger (4).

4. The pressure and temperature variable coupled adsorption and compression carbon dioxide energy storage system according to claim 1 is characterized in that: The primary side pipeline of the second heat exchanger (6) is respectively connected to the gas outlet of the high-pressure gas storage tank (5) and the gas inlet of the expander (7), and the secondary side pipeline of the second heat exchanger (6) is connected to the temperature swing adsorption tower (1), and the heat energy released during the adsorption process of the temperature swing adsorption tower (1) is used to heat the high-pressure carbon dioxide released from the high-pressure gas storage tank (5).

5. The pressure and temperature variable coupled adsorption and compression carbon dioxide energy storage system according to claim 4 is characterized in that: It also includes a second one-way valve (62) and a second pressure-stabilizing valve (61), wherein the second one-way valve (62) is arranged at the air outlet of the secondary side pipeline of the second heat exchanger (6), and the second pressure-stabilizing valve (61) is arranged at the air inlet of the secondary side pipeline of the second heat exchanger (6).

6. The pressure and temperature variable coupled adsorption and compression carbon dioxide energy storage system according to claim 1 is characterized in that: It also includes a third pressure stabilizing valve (8), which is arranged between the expander (7) and the temperature swing adsorption tower (1).

7. The pressure and temperature variable coupled adsorption and compression carbon dioxide energy storage system according to claim 1, characterized in that: The adsorbent in the temperature swing adsorption tower (1) is a microporous carbon-based adsorbent, and the adsorbent in the pressure swing adsorption tower (2) is a hierarchical pore carbon-based adsorbent.

8. A method for adsorption and compression of carbon dioxide energy storage coupled with variable pressure and temperature, characterized in that: The adsorption compression carbon dioxide energy storage system based on the voltage and temperature variable coupling according to any one of claims 1 to 7; The carbon dioxide energy storage method comprises: Energy storage stage: Controlling the desorption of carbon dioxide from the temperature swing adsorption tower (1) by increasing the temperature in the temperature swing adsorption tower (1), and controlling the desorption of carbon dioxide from the pressure swing adsorption tower (2) by decreasing the pressure in the pressure swing adsorption tower (2); The carbon dioxide desorbed from the pressure swing adsorption tower (2) and the temperature swing adsorption tower (1) is compressed by a compressor (3), cooled by a heat exchange system (4), and then input into a high-pressure gas storage tank (5), wherein the heat generated by the compressor (3) when compressing the carbon dioxide is transferred to the adsorbent of the temperature swing adsorption tower (1) through a first heat exchanger (4) for desorption of the carbon dioxide; Energy release stage: The high-pressure carbon dioxide outputted from the high-pressure gas storage tank (5) is heated by the heat exchange system (6) and then expanded by the expander (7) to obtain low-pressure carbon dioxide; The low-pressure carbon dioxide is transported to a pressure swing adsorption tower (2) for pressure swing adsorption storage. After reaching the designed storage pressure, the remaining carbon dioxide is introduced into a temperature swing adsorption tower (1) for adsorption storage. The adsorption heat released by the temperature swing adsorption tower (1) during the adsorption process is transferred to the high-pressure carbon dioxide released from the high-pressure storage tank (5) through a second heat exchanger (6), thereby heating the high-pressure carbon dioxide.

9. The coupled carbon dioxide energy storage method according to claim 8, characterized in that: The heat generated by the compressor (3) compressing the carbon dioxide is transferred to the adsorbent in the temperature swing adsorption tower (1) through the first heat exchanger (4) for desorption of the carbon dioxide, comprising: The carbon dioxide desorbed from the pressure swing adsorption tower (2) and the temperature swing adsorption tower (1) is compressed by the compressor (3) to obtain high-temperature and high-pressure carbon dioxide; The high-temperature and high-pressure carbon dioxide is subjected to heat absorption by the second heat exchanger (6) to obtain high-pressure carbon dioxide, and the absorbed heat is transferred to the adsorbent in the temperature swing adsorption tower (1) for desorption of carbon dioxide.

10. The pressure-temperature-variable coupled adsorption-compression carbon dioxide energy storage method according to claim 8, characterized in that: The adsorption heat released by the temperature swing adsorption tower (1) during the adsorption process is transferred to the high-pressure carbon dioxide released by the high-pressure storage tank through the second heat exchanger (6) for heating, comprising: Controlling the temperature swing adsorption tower (1) to adsorb low-pressure carbon dioxide and release adsorption heat; The adsorption heat is transferred to the high-pressure carbon dioxide released from the high-pressure gas storage tank (5) through the second heat exchanger (6), thereby heating the high-pressure carbon dioxide.

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