Ultrahigh-temperature constant-pressure carbon dioxide adsorption and compression energy storage system and operation method thereof

Abstract

The invention belongs to the technical field of renewable energy utilization and compressed carbon dioxide energy storage, and discloses an ultrahigh-temperature constant-pressure adsorption compressed carbon dioxide energy storage system and an operation method thereof. According to the ultrahigh-temperature constant-pressure carbon dioxide adsorption and compression energy storage system, a compression module comprises a preheater and multiple stages of compression cooling units connected in series, and the preheater is used for inputting carbon dioxide gas desorbed and output by an adsorption module and preheating the carbon dioxide gas; the first-stage compression cooling unit is used for inputting the preheated carbon dioxide gas, compressing and cooling the carbon dioxide gas and then outputting the carbon dioxide gas reaching a preset ultrahigh-temperature state; and the multi-stage series vaporization expansion unit is used for performing vaporization expansion treatment on the input liquid carbon dioxide by utilizing the heat stored by the heat storage module stage by stage. The technical problem that the demanded quantity of adsorbents in an existing adsorption type compressed carbon dioxide energy storage system is large is solved.

Description

Technical Field

[0001] This invention belongs to the field of renewable energy utilization and compressed carbon dioxide energy storage technology, and relates to the field of adsorption gas storage, specifically to an ultra-high temperature constant pressure adsorption compressed carbon dioxide energy storage system and its operation method. Background Technology

[0002] In the energy sector, large-scale energy storage technology is of great significance for balancing energy supply and demand, improving energy efficiency, and reducing dependence on fossil fuels. Compressed carbon dioxide energy storage, as a thermomechanical energy storage technology, demonstrates promising application prospects in the field of large-scale energy storage due to its advantages such as high efficiency and long lifespan.

[0003] Compressed carbon dioxide (CO2) energy storage technology can convert excess electricity generated by renewable energy sources such as wind and solar power into the internal energy or pressure energy of carbon dioxide for storage when there is a surplus. During peak electricity demand periods, the stored energy can be released as electricity, effectively reducing grid pressure and decreasing the use of fossil fuels. However, as carbon dioxide is a greenhouse gas, to avoid the adverse environmental impacts of its leakage, the energy storage system must operate in a closed loop (illustratively, both high-pressure and low-pressure carbon dioxide require sealed storage). This results in problems such as large footprint and low energy density, limiting its large-scale application.

[0004] To address the low density of carbon dioxide storage on the high-pressure side, existing technologies employ carbon dioxide liquefaction, which improves storage density to some extent. However, storing carbon dioxide on the low-pressure side still presents numerous challenges. Currently, some researchers have proposed using adsorption beds for low-pressure carbon dioxide storage, but this approach faces the technical hurdle of requiring large quantities of adsorbent. Further explanation is that the use of large amounts of adsorbent not only increases the complexity and operational difficulty of the energy storage system but also raises the overall construction and operating costs due to the high cost per unit mass of adsorbent, resulting in poor system economics and hindering large-scale market adoption. Summary of the Invention

[0005] The purpose of this invention is to provide an ultra-high temperature constant pressure adsorption-compression carbon dioxide energy storage system and its operation method, so as to solve the technical problems of large adsorbent demand, high cost and poor system economy in existing adsorption-compression carbon dioxide energy storage systems.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, this invention provides an ultra-high temperature constant pressure adsorption-compression carbon dioxide energy storage system, comprising: an adsorption module, a compression module, a constant pressure liquid storage module, an expansion module, and a heat storage module; wherein, The compression module includes a preheater and a multi-stage series compression and cooling unit. The multi-stage series compression and cooling unit is used to compress and cool the input carbon dioxide gas step by step, and store the released heat in the heat storage module step by step. The preheater is used to input the carbon dioxide gas desorbed from the adsorption module, and uses the heat released by the selected stage compression and cooling unit as a heat source to preheat the carbon dioxide gas, so as to ensure that after the first stage compression and cooling unit inputs the preheated carbon dioxide gas and performs compression and cooling treatment, it outputs carbon dioxide gas that reaches the preset ultra-high temperature state. The constant pressure liquid storage module is used to store the liquid carbon dioxide output from the last stage compression cooling unit; The expansion module includes a multi-stage series vaporization expansion unit; the multi-stage series vaporization expansion unit is used to vaporize and expand the input liquid carbon dioxide by utilizing the heat stored in the heat storage module step by step. The adsorption module is used to store the carbon dioxide gas output from the last stage vaporization expansion unit.

[0007] A further improvement of the technical solution of the present invention is that the preset ultra-high temperature state is that carbon dioxide is in a supercritical state and the temperature is between 500℃ and 700℃.

[0008] A further improvement to the technical solution of the present invention lies in that, The adsorption module includes an adsorption bed, a heater, and a final stage cooler. The desorption outlet of the adsorption bed is divided into two branches: one branch is connected to the cold side channel inlet of the preheater, and the other branch is connected to the desorption inlet of the adsorption bed after passing through the heater. The adsorption outlet of the adsorption bed is merged with the outlet pipe of the expansion module after passing through the final stage cooler, and the merged pipe is connected to the adsorption inlet of the adsorption bed.

[0009] A further improvement to the technical solution of the present invention lies in that, In a multi-stage series compression and cooling unit, the last stage compression and cooling unit only includes a cooler, while the remaining stages of the compression and cooling unit all include a compressor and a cooler. In a multi-stage series vaporization expansion unit, the first stage vaporization expansion unit only includes a vaporizer, while the remaining stages of the vaporization expansion unit all include a regenerator and a turbine. In this process, the input carbon dioxide gas is compressed and cooled in stages, and the released heat is stored in the heat storage module in stages. In the process of using the heat stored in the heat storage module to vaporize and expand the input liquid carbon dioxide in stages, the last stage compression and cooling unit corresponds to the first stage vaporization and expansion unit, the first stage compression and cooling unit corresponds to the last stage vaporization and expansion unit, and the intermediate stage compression and cooling units correspond to the intermediate stage vaporization and expansion units in reverse order.

[0010] A further improvement to the technical solution of the present invention lies in that, The constant-pressure liquid storage module includes: a constant-pressure liquid working fluid storage tank, a hydraulic turbine, a first water storage tank, and a water pump; wherein, the carbon dioxide inlet of the constant-pressure liquid working fluid storage tank is connected to the outlet of the compression module, and the carbon dioxide outlet of the constant-pressure liquid working fluid storage tank is connected to the inlet of the expansion module; the water outlet of the constant-pressure liquid working fluid storage tank is connected to the inlet of the first water storage tank via the hydraulic turbine, and the outlet of the first water storage tank is connected to the water inlet of the constant-pressure liquid working fluid storage tank via the water pump.

[0011] A further improvement to the technical solution of the present invention lies in that, The constant-pressure liquid working fluid storage tank includes a tank body and a flexible liquid storage bag disposed inside the tank body. The flexible liquid storage bag is provided with a carbon dioxide inlet and a carbon dioxide outlet, and the tank body is provided with a water outlet and a water inlet. The flexible liquid storage bag is used to store liquid carbon dioxide and separate the stored liquid carbon dioxide from the pressurized water injected into the constant-pressure liquid working fluid storage tank.

[0012] A further improvement to the technical solution of the present invention lies in that, The compression module includes: a preheater, a first compressor, a first cooler, a second compressor, a second cooler, and a third cooler; wherein, the cold-side channel inlet of the preheater is connected to the desorption outlet of the adsorption module, the cold-side channel outlet of the preheater is connected to the inlet of the first compressor, the outlet of the first compressor is connected to the inlet of the second compressor via the hot-side channel of the first cooler, the outlet of the second compressor is connected to the inlet of the hot-side channel of the third cooler via the hot-side channel of the second cooler, and the middle outlet of the hot-side channel of the third cooler, after passing through the hot-side channel of the preheater and merging with the outlet of the hot-side channel of the third cooler, is connected to the inlet of the constant pressure liquid storage module.

[0013] A further improvement to the technical solution of the present invention lies in that, The expansion module includes: a first vaporizer, a second vaporizer, a first regenerator, a first turbine, a second regenerator, and a second turbine; wherein, the carbon dioxide outlet of the constant pressure liquid storage module is divided into two branches, one branch is connected to the cold side channel inlet of the first vaporizer, and the other branch is connected to the middle inlet of the cold side channel of the first vaporizer after passing through the cold side channel of the second vaporizer. The outlet of the cold side channel of the first vaporizer is connected to the inlet of the first turbine after passing through the cold side channel of the first regenerator. The outlet of the first turbine is connected to the inlet of the second turbine after passing through the cold side channel of the second regenerator. The outlet of the second turbine is connected to the adsorption inlet of the adsorption module after passing through the hot side channel of the second vaporizer.

[0014] A further improvement to the technical solution of the present invention lies in that, The heat storage module includes: a first molten salt storage tank, a first transfer pump, a second molten salt storage tank, a second transfer pump, a third molten salt storage tank, a third transfer pump, a fourth molten salt storage tank, a fourth transfer pump, a second water storage tank, a fifth transfer pump, a third water storage tank, and a sixth transfer pump; wherein, the outlet of the first molten salt storage tank is connected to the inlet of the second molten salt storage tank via the hot side channel of the first transfer pump and the second regenerator, and the outlet of the second molten salt storage tank is connected to the inlet of the first molten salt storage tank via the cold side channel of the second transfer pump and the first cooler; the third... The outlet of the molten salt storage tank is connected to the inlet of the fourth molten salt storage tank via the hot side channel of the third transfer pump and the first regenerator. The outlet of the fourth molten salt storage tank is connected to the inlet of the third molten salt storage tank via the cold side channel of the fourth transfer pump and the second cooler. The outlet of the second water storage tank is connected to the inlet of the third water storage tank via the hot side channel of the fifth transfer pump and the first vaporizer. The outlet of the third water storage tank is connected to the inlet of the second water storage tank via the cold side channel of the sixth transfer pump and the third cooler.

[0015] In a second aspect, the present invention provides an operation method for an ultra-high temperature constant pressure adsorption-compression carbon dioxide energy storage system, comprising: During the energy storage process, the carbon dioxide desorbed by the adsorption module is input into the preheater. In the preheater, the carbon dioxide gas is preheated by the heat released by the selected level of the compression cooling unit. The first-stage compression cooling unit in the multi-stage series-connected compression cooling unit inputs the preheated carbon dioxide gas and performs compression cooling treatment, outputting carbon dioxide gas that has reached a preset ultra-high temperature state. The multi-stage series-connected compression cooling units perform compression cooling treatment on the input carbon dioxide gas stage by stage, and store the heat of compression stage by stage in the heat storage module, finally outputting liquid carbon dioxide and storing it in the constant pressure liquid storage module. During the energy release process, the liquid carbon dioxide output from the constant pressure liquid storage module is input into the expansion module. The multi-stage series vaporization expansion unit uses the heat stored in the heat storage module to vaporize and expand the input liquid carbon dioxide, and finally outputs carbon dioxide gas, which is adsorbed and stored in the adsorption module.

[0016] Compared with the prior art, the present invention has the following beneficial effects: In compressed carbon dioxide energy storage systems, the low-pressure side faces the challenge of high adsorbent demand. To address the existing problems in current technologies, this invention discloses an ultra-high temperature constant-pressure adsorption-compressed carbon dioxide energy storage system. Through a unique preheating design, the preheater utilizes heat released from a selected compression cooling unit to preheat the carbon dioxide gas desorbed from the adsorption module before it is fed into the first-stage compression cooling unit. After processing by the first-stage compression cooling unit, the carbon dioxide reaches an ultra-high temperature supercritical state. In this state, the ability to generate electricity per unit mass of carbon dioxide is significantly enhanced, resulting in a substantial reduction in the mass flow rate of carbon dioxide for the same power generation needs. Since the amount of adsorbent used is closely related to the amount of carbon dioxide processed, the reduction in mass flow rate directly leads to a reduction in adsorbent usage, thus solving the technical problem of high adsorbent demand. Furthermore, this invention employs a constant-pressure liquid storage module to achieve constant-pressure storage of liquid carbon dioxide. Constant-pressure storage allows for more efficient use of the space in the liquid carbon dioxide storage tank, improving storage efficiency. In summary, the technical solution of this invention reduces the amount of adsorbent used, lowers system costs, and enhances practicality and economy. Simultaneously, by placing carbon dioxide in an ultra-high temperature and supercritical state, it improves energy conversion efficiency, and the constant-pressure liquid storage module optimizes liquid carbon dioxide storage. These improved technical means not only solve the problem of large adsorbent usage in existing technologies but also improve the overall performance and economy of the system, providing strong support for the application of compressed carbon dioxide energy storage technology in large-scale energy storage fields and promoting the further development and widespread application of this technology. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of an ultra-high temperature constant pressure adsorption and compression carbon dioxide energy storage system in an embodiment of the present invention; The explanations of the reference numerals in the figure are as follows: 1. Adsorption bed; 2. Heater; 3. Preheater; 4. First compressor; 5. First cooler; 6. Second compressor; 7. Second cooler; 8. Third cooler; 9. Constant pressure liquid working fluid storage tank; 10. Hydraulic turbine; 11. First water storage tank; 12. Water pump; 13. First vaporizer; 14. Second vaporizer; 15. First regenerator; 16. First turbine; 17. Second regenerator; 18. Second turbine; 19. Final stage cooler; 20. First molten salt storage tank; 21. First transfer pump; 22. Second molten salt storage tank; 23. Second transfer pump; 24. Third molten salt storage tank; 25. Third transfer pump; 26. Fourth molten salt storage tank; 27. Fourth transfer pump; 28. Second water storage tank; 29. ​​Fifth transfer pump; 30. Third water storage tank; 31. Sixth transfer pump. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention; obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] Based on the technical solutions disclosed in the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or devices.

[0021] Please see Figure 1 The present invention provides an ultra-high temperature constant pressure adsorption and compression carbon dioxide energy storage system, comprising: an adsorption module, a compression module, a constant pressure liquid storage module, an expansion module, and a heat storage module.

[0022] The adsorption module includes an adsorption bed 1, a heater 2, and a final stage cooler 19. The desorption outlet of the adsorption bed 1 is divided into two branches: one connected to the inlet of the compression module, and the other connected to the desorption inlet of the adsorption bed 1 after passing through the heater 2. The adsorption outlet of the adsorption bed 1 merges with the outlet pipe of the expansion module after passing through the final stage cooler 19, and the merged pipe connects to the adsorption inlet of the adsorption bed 1. Explained, the carbon dioxide output from the desorption outlet of the adsorption bed is divided into two streams: one enters the compression module, and the other is heated in the heater before entering the adsorption bed to provide heat for carbon dioxide desorption. The heat generated during the carbon dioxide adsorption process is carried out by the carbon dioxide at the adsorption outlet of the adsorption bed and dissipated in the cooler. The released carbon dioxide merges with the carbon dioxide at the outlet of the expansion module and enters the adsorption inlet of the adsorption bed.

[0023] The compression module includes: a preheater 3, a first compressor 4, a first cooler 5, a second compressor 6, a second cooler 7, and a third cooler 8. The cold-side inlet of the preheater 3 is connected to the desorption outlet of the adsorption module; the cold-side outlet of the preheater 3 is connected to the inlet of the first compressor 4; the outlet of the first compressor 4 is connected to the inlet of the second compressor 6 via the hot-side channel of the first cooler 5; the outlet of the second compressor 6 is connected to the hot-side inlet of the third cooler 8 via the hot-side channel of the second cooler 7; and the middle outlet of the hot-side channel of the third cooler 8, after passing through the hot-side channel of the preheater 3, merges with the hot-side outlet pipe of the third cooler 8 and connects to the inlet of the constant-pressure liquid storage module. Explained, the preheater 3 is used to preheat the carbon dioxide at the inlet of the first compressor 4 to ensure the ultra-high temperature state of the compressed carbon dioxide; wherein, the ultra-high temperature state typically refers to its supercritical state and temperature far exceeding the critical temperature (exemplarily, such as 500℃~700℃).

[0024] The constant pressure liquid storage module includes: a constant pressure liquid working fluid storage tank 9, a hydraulic turbine 10, a first water storage tank 11, and a water pump 12; wherein, the carbon dioxide inlet of the constant pressure liquid working fluid storage tank 9 is connected to the outlet of the compression module, and the carbon dioxide outlet of the constant pressure liquid working fluid storage tank 9 is connected to the inlet of the expansion module; the water outlet of the constant pressure liquid working fluid storage tank 9 is connected to the inlet of the first water storage tank 11 through the hydraulic turbine 10, and the outlet of the first water storage tank 11 is connected to the water inlet of the constant pressure liquid working fluid storage tank 9 through the water pump 12.

[0025] The expansion module includes: a first vaporizer 13, a second vaporizer 14, a first regenerator 15, a first turbine 16, a second regenerator 17, and a second turbine 18; wherein, the carbon dioxide outlet of the constant pressure liquid working fluid storage tank 9 is divided into two branches, one of which is connected to the cold side inlet of the first vaporizer 13, and the other is connected to the cold side intermediate inlet of the first vaporizer 13 through the cold side channel of the second vaporizer 14. The cold side outlet of the first vaporizer 13 is connected to the inlet of the first turbine 16 through the cold side channel of the first regenerator 15. The outlet of the first turbine 16 is connected to the inlet of the second turbine 18 through the cold side channel of the second regenerator 17. The outlet of the second turbine 18 is connected to the adsorption inlet of the adsorption module through the hot side channel of the second vaporizer 14.

[0026] The heat storage module includes: a first molten salt storage tank 20, a first transfer pump 21, a second molten salt storage tank 22, a second transfer pump 23, a third molten salt storage tank 24, a third transfer pump 25, a fourth molten salt storage tank 26, a fourth transfer pump 27, a second water storage tank 28, a fifth transfer pump 29, a third water storage tank 30, and a sixth transfer pump 31; wherein, the outlet of the first molten salt storage tank 20 is connected to the inlet of the second molten salt storage tank 22 via the hot side channel of the first transfer pump 21 and the second regenerator 17, and the outlet of the second molten salt storage tank 22 is connected to the first molten salt storage tank via the cold side channel of the second transfer pump 23 and the first cooler 5. The inlet of the third molten salt tank 24 is connected to the inlet of the fourth molten salt tank 26 via the hot side channel of the third transfer pump 25 and the first regenerator 15. The outlet of the fourth molten salt tank 26 is connected to the inlet of the third molten salt tank 24 via the cold side channel of the fourth transfer pump 27 and the second cooler 7. The outlet of the second water tank 28 is connected to the inlet of the third water tank 30 via the hot side channel of the fifth transfer pump 29 and the first vaporizer 13. The outlet of the third water tank 30 is connected to the inlet of the second water tank 28 via the cold side channel of the sixth transfer pump 31 and the third cooler 8.

[0027] In a further exemplary optional technical solution of the present invention, the first compressor 4 and the second compressor 6 are coaxially connected to the electric motor; the hydraulic turbine 10, the first turbine 16, and the second turbine 18 are coaxially connected to the generator; a radiator is also provided before the carbon dioxide inlet of the constant pressure liquid working fluid storage tank 9; the above-mentioned electric motor, generator, and radiator are in... Figure 1 Not displayed.

[0028] In a further exemplary optional technical solution of the present invention, the constant pressure liquid working medium storage tank 9 is equipped with a flexible liquid storage bag for separating liquid carbon dioxide from pressurized water, and the liquid carbon dioxide is stored in the flexible liquid storage bag; when carbon dioxide enters the constant pressure liquid working medium storage tank 9, pressurized water is discharged, and when carbon dioxide leaves the constant pressure liquid working medium storage tank 9, pressurized water is injected to maintain the pressure inside the storage tank at a constant level.

[0029] The ultra-high temperature constant pressure adsorption-compression carbon dioxide energy storage system provided in this invention can solve the problem of poor system economics caused by the large amount of adsorbent required and the high cost per unit mass of adsorbent in existing adsorption-compression carbon dioxide energy storage systems. In the technical solution disclosed in this invention, heat recovery is used to increase the temperature at the compressor inlet, ensuring that the carbon dioxide reaches an ultra-high temperature state. This enhances the ability of a unit mass of carbon dioxide to generate electricity, thereby reducing the mass flow rate of carbon dioxide and thus reducing the amount of adsorbent used, improving the system's economics. Exemplarily, the technical solution disclosed in this invention can be applied to renewable energy utilization and grid peak shaving, improving the grid's regulation and anti-interference capabilities, promoting the development of renewable energy power generation technologies, and reducing carbon emissions.

[0030] This invention provides an operating method for an ultra-high temperature constant pressure adsorption-compression carbon dioxide energy storage system, comprising: an energy storage process and an energy release process; wherein, Energy storage process: Under the heat supply of heater 2, carbon dioxide desorbs in adsorption bed 1 and absorbs heat on the hot side of preheater 3. The absorbed carbon dioxide is compressed in first compressor 4 and the heat of compression is transferred to molten salt from second molten salt storage tank 22 in first cooler 5. The heated molten salt is stored in first molten salt storage tank 20. Subsequently, carbon dioxide output from the outlet of first cooler 5 enters second compressor 6, is compressed, and the heat of compression is transferred to molten salt from fourth molten salt storage tank 26 in second cooler 7. The absorbed molten salt is stored in third molten salt storage tank 24. Subsequently, the... The carbon dioxide output from the outlet of the second cooler 7 enters the third cooler 8 to release heat. A stream of carbon dioxide flows out from the middle of the third cooler 8 into the preheater 3 to release heat and liquefy, while another stream continues to release heat in the third cooler 8 to water from the third water storage tank 30. The water that absorbs heat is stored in the second water storage tank 28. Subsequently, the carbon dioxide that has released heat and liquefied in the third cooler 8 and the preheater 3 enters the constant pressure liquid working fluid storage tank 9 for storage. The water in the constant pressure liquid working fluid storage tank 9 enters the hydraulic turbine 10 to expand and is stored in the first water storage tank 11. Thus, the energy storage process is completed.

[0031] Energy release process: The liquid carbon dioxide output from the outlet of the constant pressure liquid working fluid storage tank 9 is divided into two streams. One stream enters the first vaporizer 13 to absorb heat and vaporize, with the heat coming from the water in the second water storage tank 28. The other stream enters the second vaporizer 14 to absorb the heat from the carbon dioxide at the outlet of the second turbine 18 and then enters the first vaporizer 13 from the middle to absorb the heat from the water in the second water storage tank 28. The water that has released heat enters the third water storage tank 30 for storage. In order to maintain the constant pressure of the constant pressure liquid working fluid storage tank 9, during the carbon dioxide discharge process, the water in the first water storage tank 11 is compressed in the water pump 12 and enters the constant pressure liquid working fluid storage tank 9. The carbon dioxide, after absorbing heat and vaporizing, absorbs heat from the molten salt in the third molten salt storage tank 24 in the first regenerator 15 and expands in the first turbine 16 to generate electricity. The released molten salt enters the fourth molten salt storage tank 26 for storage. The carbon dioxide at the outlet of the first turbine 16 absorbs heat from the molten salt in the first molten salt storage tank 20 in the second regenerator 17 and expands in the second turbine 18 to generate electricity. The released molten salt enters the second molten salt storage tank 22 for storage. The carbon dioxide at the outlet of the second turbine 18 enters the second vaporizer 14 to release heat and enters the adsorption bed 1 to be adsorbed and stored. Thus, the energy release process is completed.

[0032] This invention discloses an ultra-high temperature constant pressure adsorption-compression carbon dioxide energy storage system and its operation method. The energy storage system includes an adsorption module, a compression module, a constant pressure liquid storage module, an expansion module, and a heat storage module. The ultra-high temperature constant pressure adsorption-compression carbon dioxide energy storage system utilizes heat recovery to increase the compressor inlet temperature, ensuring that the carbon dioxide reaches an ultra-high temperature state. This enhances the ability of a unit mass of carbon dioxide to generate electricity, reduces the mass flow rate of carbon dioxide, and thus reduces the amount of adsorbent used, improving the system's economic efficiency. This system has the advantages of high cycle efficiency, high energy density, and relatively low adsorbent requirement, solving the problem of existing adsorption-compression carbon dioxide energy storage systems having high adsorbent requirements and high cost per unit mass of adsorbent, leading to poor system economics. In summary, the energy storage system disclosed in this invention has the advantages of high cycle efficiency, high energy density, and relatively low adsorbent requirement, and can achieve the goals of promoting the development of renewable energy power generation technology, improving grid regulation capabilities, and reducing carbon emissions.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A high-temperature constant-pressure adsorption-compression carbon dioxide energy storage system, characterized in that, include: The system comprises an adsorption module, a compression module, a constant-pressure liquid storage module, an expansion module, and a heat storage module; among which, The compression module includes a preheater (3) and a multi-stage series compression and cooling unit; the multi-stage series compression and cooling unit is used to compress and cool the input carbon dioxide gas step by step, and store the released heat in the heat storage module step by step; the preheater (3) is used to input the carbon dioxide gas desorbed and output by the adsorption module, and preheat the carbon dioxide gas with the heat released by the selected stage compression and cooling unit as the heat source, so as to ensure that after the first stage compression and cooling unit inputs the preheated carbon dioxide gas and performs compression and cooling treatment, it outputs carbon dioxide gas that reaches the preset ultra-high temperature state; The constant pressure liquid storage module is used to store the liquid carbon dioxide output from the last stage compression cooling unit; The expansion module includes a multi-stage series vaporization expansion unit; the multi-stage series vaporization expansion unit is used to vaporize and expand the input liquid carbon dioxide by utilizing the heat stored in the heat storage module step by step. The adsorption module is used to store the carbon dioxide gas output from the last stage vaporization expansion unit.

2. The ultra-high temperature constant pressure adsorption-compression carbon dioxide energy storage system according to claim 1, characterized in that, The preset ultra-high temperature state is when carbon dioxide is in a supercritical state and the temperature is between 500℃ and 700℃.

3. The ultra-high temperature constant pressure adsorption and compression carbon dioxide energy storage system according to claim 1, characterized in that, The adsorption module includes an adsorption bed (1), a heater (2), and a final stage cooler (19). The desorption outlet of the adsorption bed (1) is divided into two branches. One branch is connected to the cold side channel inlet of the preheater (3), and the other branch is connected to the desorption inlet of the adsorption bed (1) after passing through the heater (2). The adsorption outlet of the adsorption bed (1) is connected to the outlet pipe of the expansion module after passing through the final stage cooler (19), and the combined pipe is connected to the adsorption inlet of the adsorption bed (1).

4. The ultra-high temperature constant pressure adsorption and compression carbon dioxide energy storage system according to claim 1, characterized in that, In a multi-stage series compression and cooling unit, the last stage compression and cooling unit only includes a cooler, while the remaining stages of the compression and cooling unit all include a compressor and a cooler. In a multi-stage series vaporization expansion unit, the first stage vaporization expansion unit only includes a vaporizer, while the remaining stages of the vaporization expansion unit all include a regenerator and a turbine. In this process, the input carbon dioxide gas is compressed and cooled in stages, and the released heat is stored in the heat storage module in stages. In the process of using the heat stored in the heat storage module to vaporize and expand the input liquid carbon dioxide in stages, the last stage compression and cooling unit corresponds to the first stage vaporization and expansion unit, the first stage compression and cooling unit corresponds to the last stage vaporization and expansion unit, and the intermediate stage compression and cooling units correspond to the intermediate stage vaporization and expansion units in reverse order.

5. The ultra-high temperature constant pressure adsorption-compression carbon dioxide energy storage system according to claim 1, characterized in that, The constant pressure liquid storage module includes: a constant pressure liquid working fluid storage tank (9), a hydraulic turbine (10), a first water storage tank (11), and a water pump (12); wherein, the carbon dioxide inlet of the constant pressure liquid working fluid storage tank (9) is connected to the outlet of the compression module, and the carbon dioxide outlet of the constant pressure liquid working fluid storage tank (9) is connected to the inlet of the expansion module; the water outlet of the constant pressure liquid working fluid storage tank (9) is connected to the inlet of the first water storage tank (11) through the hydraulic turbine (10), and the outlet of the first water storage tank (11) is connected to the water inlet of the constant pressure liquid working fluid storage tank (9) through the water pump (12).

6. The ultra-high temperature constant pressure adsorption-compression carbon dioxide energy storage system according to claim 5, characterized in that, The constant pressure liquid working medium storage tank (9) includes a tank body and a flexible liquid storage bag disposed inside the tank body. The flexible liquid storage bag is provided with the carbon dioxide inlet and the carbon dioxide outlet, and the tank body is provided with the water outlet and the water inlet. The flexible liquid storage bag is used to store liquid carbon dioxide and separate the stored liquid carbon dioxide from the pressurized water injected into the constant pressure liquid working medium storage tank (9).

7. The ultra-high temperature constant pressure adsorption and compression carbon dioxide energy storage system according to claim 1, characterized in that, The compression module includes: a preheater (3), a first compressor (4), a first cooler (5), a second compressor (6), a second cooler (7), and a third cooler (8); wherein, the cold side channel inlet of the preheater (3) is connected to the desorption outlet of the adsorption module, the cold side channel outlet of the preheater (3) is connected to the inlet of the first compressor (4), the outlet of the first compressor (4) is connected to the inlet of the second compressor (6) through the hot side channel of the first cooler (5), the outlet of the second compressor (6) is connected to the inlet of the hot side channel of the third cooler (8) through the hot side channel of the second cooler (7), and the middle outlet of the hot side channel of the third cooler (8) is connected to the inlet of the constant pressure liquid storage module after passing through the hot side channel of the preheater (3) and merging with the outlet of the hot side channel of the third cooler (8).

8. The ultra-high temperature constant pressure adsorption-compression carbon dioxide energy storage system according to claim 7, characterized in that, The expansion module includes: a first vaporizer (13), a second vaporizer (14), a first regenerator (15), a first turbine (16), a second regenerator (17), and a second turbine (18); wherein, the carbon dioxide outlet of the constant pressure liquid storage module is divided into two branches, one branch is connected to the cold side channel inlet of the first vaporizer (13), and the other branch is connected to the middle inlet of the cold side channel of the first vaporizer (13) after passing through the cold side channel of the second vaporizer (14). The outlet of the cold side channel of the first vaporizer (13) is connected to the inlet of the first turbine (16) through the cold side channel of the first regenerator (15). The outlet of the first turbine (16) is connected to the inlet of the second turbine (18) after passing through the cold side channel of the second regenerator (17). The outlet of the second turbine (18) is connected to the adsorption inlet of the adsorption module after passing through the hot side channel of the second vaporizer (14).

9. The ultra-high temperature constant pressure adsorption-compression carbon dioxide energy storage system according to claim 8, characterized in that, The heat storage module includes: a first molten salt tank (20), a first transfer pump (21), a second molten salt tank (22), a second transfer pump (23), a third molten salt tank (24), a third transfer pump (25), a fourth molten salt tank (26), a fourth transfer pump (27), a second water tank (28), a fifth transfer pump (29), a third water tank (30), and a sixth transfer pump (31); wherein, the outlet of the first molten salt tank (20) is connected to the inlet of the second molten salt tank (22) through the hot side channel of the first transfer pump (21) and the second regenerator (17), and the outlet of the second molten salt tank (22) is connected to the inlet of the first molten salt tank (20) through the cold side channel of the second transfer pump (23) and the first cooler (5). The outlet of the third molten salt tank (24) is connected to the inlet of the fourth molten salt tank (26) through the hot side channel of the third transfer pump (25) and the first regenerator (15), and the outlet of the fourth molten salt tank (26) is connected to the inlet of the third molten salt tank (24) through the cold side channel of the fourth transfer pump (27) and the second cooler (7); the outlet of the second water tank (28) is connected to the inlet of the third water tank (30) through the hot side channel of the fifth transfer pump (29) and the first vaporizer (13), and the outlet of the third water tank (30) is connected to the inlet of the second water tank (28) through the cold side channel of the sixth transfer pump (31) and the third cooler (8).

10. A method for operating the ultra-high temperature constant pressure adsorption-compression carbon dioxide energy storage system according to claim 1, characterized in that, include: During the energy storage process, the carbon dioxide desorbed by the adsorption module is input into the preheater (3). In the preheater (3), the carbon dioxide gas is preheated by the heat released by the selected level of the compression cooling unit. The first-level compression cooling unit in the multi-stage series compression cooling unit inputs the preheated carbon dioxide gas and performs compression cooling treatment, and then outputs carbon dioxide gas that reaches the preset ultra-high temperature state. The multi-stage series compression cooling unit performs compression cooling treatment on the input carbon dioxide gas step by step, and stores the compression heat in the heat storage module step by step, and finally outputs liquid carbon dioxide and stores it in the constant pressure liquid storage module. During the energy release process, the liquid carbon dioxide output from the constant pressure liquid storage module is input into the expansion module. The multi-stage series vaporization expansion unit uses the heat stored in the heat storage module to vaporize and expand the input liquid carbon dioxide, and finally outputs carbon dioxide gas, which is adsorbed and stored in the adsorption module.

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