Supercritical carbon dioxide energy storage system based on combined cooling heating and power

Abstract

The invention belongs to the technical field of energy storage, and provides a supercritical carbon dioxide energy storage system based on combined cooling, heating and power, which comprises a carbon dioxide trapping assembly, an absorption tower and a desorption tower which are communicated in sequence, and an alcohol amine solution circulating mechanism; the carbon dioxide energy storage assembly comprises a low-pressure recovery well, an outlet of the low-pressure recovery well is sequentially communicated with a pressurizing part and a high-pressure injection well, and the gas outlet end of the desorption tower is communicated with the high-pressure injection well through a pressurizing part; the carbon dioxide energy release assembly comprises a high-pressure recovery well, an outlet of the high-pressure recovery well is sequentially communicated with a heat exchange part, an expansion part and a low-pressure injection well, and the heat exchange part and the alcohol amine solution circulation mechanism are correspondingly arranged; the combined cooling heating and power assembly comprises a boiler, the smoke end of the boiler communicates with the absorption tower, and a hot end outlet of the boiler communicates with a power generation part, a heat user and a cold user. The requirement for a high-capacity gas storage can be lowered, the heat energy utilization rate of the system is increased, the emission problem of a coal-fired power plant is solved, and waste heat in the production process is fully utilized.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage, and in particular relates to a supercritical carbon dioxide energy storage system based on combined cooling, heating and power generation. Background Art

[0002] Supercritical carbon dioxide energy storage is an important way to solve the problem of renewable energy grid connection. It has the advantages of large energy storage capacity, long service life, and fast response speed. However, supercritical carbon dioxide energy storage currently faces problems such as the need for large-capacity gas storage and low system thermal energy utilization. At the same time, in view of the emission problem of coal-fired thermal power plants, if the carbon dioxide in the flue gas emitted by the boiler can be captured and utilized, combined with supercritical carbon dioxide energy storage technology and boiler waste heat utilization, it will be an efficient method of carbon dioxide capture and utilization to achieve cogeneration of cooling, heat and power. Summary of the invention

[0003] The purpose of the present invention is to provide a supercritical carbon dioxide energy storage system based on cogeneration of cooling, heating and power to solve the above-mentioned problems, thereby reducing the demand for large-capacity gas storage, improving the thermal energy utilization rate of the system, solving emissions from coal-fired power plants and rationally utilizing waste heat from the production process.

[0004] To achieve the above object, the present invention provides the following solution: a supercritical carbon dioxide energy storage system based on combined cooling, heating and power generation, comprising:

[0005] The carbon dioxide capture assembly comprises an absorption tower and a desorption tower which are connected in sequence, and an alcoholamine solution circulation mechanism is arranged between the desorption tower and the absorption tower;

[0006] The carbon dioxide energy storage assembly comprises a low-pressure recovery well, the outlet of the low-pressure recovery well is connected to a pressurizing part, the gas outlet end of the pressurizing part is connected to a high-pressure injection well, and the gas outlet end of the desorption tower is connected to the high-pressure injection well through a pressurizing part;

[0007] A carbon dioxide energy release component, comprising a high-pressure recovery well, wherein the outlet of the high-pressure recovery well is connected to an expansion part through a heat exchange part, the gas outlet end of the expansion part is connected to a low-pressure injection well, the gas outlet end of the desorption tower is connected to the low-pressure injection well, and the heat exchange part is arranged correspondingly to the alcoholamine solution circulation mechanism;

[0008] The trigeneration component of cooling, heating and power includes a boiler, the flue gas end of the boiler is connected to the absorption tower, the hot end outlet of the boiler is connected to a first diverter through a power generation unit, and the outlet end of the first diverter is connected to a hot user or a cold user through a refrigeration unit.

[0009] Preferably, the alcoholamine solution circulation mechanism includes a lean-rich liquid heat exchanger, the cold source side inlet of the lean-rich liquid heat exchanger is connected to the bottom outlet of the absorption tower, the cold source side outlet of the lean-rich liquid heat exchanger is connected to the top inlet of the desorption tower, the bottom outlet of the desorption tower is connected to the outlet of a reboiler, the top outlet of the reboiler is connected to the bottom inlet of the desorption tower, the bottom outlet of the reboiler is connected to the heat source side inlet of the lean-rich liquid heat exchanger, the heat source side outlet of the lean-rich liquid heat exchanger is connected to the inlet of an alcoholamine solution storage tank through the heat exchange part, and the outlet of the alcoholamine solution storage tank is connected to the top of the absorption tower.

[0010] Preferably, the heat exchange part includes a solar collector, the outlet of the solar collector is connected to the expansion part, the inlet of the solar collector is connected to the cold source side outlet of the high-temperature waste heat exchanger, the cold source side inlet of the high-temperature waste heat exchanger is connected to the high-pressure recovery well, the heat source side outlet of the lean-rich liquid heat exchanger is connected to the heat source side inlet of the high-temperature waste heat exchanger, and the heat source side outlet of the high-temperature waste heat exchanger is connected to the inlet of the alcoholamine solution storage tank.

[0011] Preferably, the pressurizing unit includes a compressor, the inlet of the compressor is connected to the low-pressure recovery well through a low-pressure throttle valve, and the outlet of the compressor is connected to the high-pressure injection well.

[0012] Preferably, the expansion unit includes an expander and a high-pressure throttle valve, the inlet of the expander is connected to the outlet of the solar collector, and the high-pressure throttle valve is connected between the high-pressure recovery well and the cold source side outlet of the high-temperature waste heat exchanger.

[0013] Preferably, the booster comprises an energy replenishment compressor, and the energy replenishment compressor is connected between the gas outlet end of the desorption tower and the high-pressure injection well.

[0014] Preferably, the power generation unit comprises a turbine, an inlet of the turbine is communicated with a hot air outlet of the boiler, and an outlet of the turbine is communicated with an inlet of the first diverter.

[0015] Preferably, an outlet end of the first flow divider is connected to an inlet of an absorption refrigeration machine, and an outlet of the absorption refrigeration machine is connected to a cold user.

[0016] Compared with the prior art, the present invention has the following advantages and technical effects:

[0017] 1. The present invention uses depleted oil and gas reservoirs as gas storage to store high-pressure and low-pressure carbon dioxide, solving the problem of large-capacity gas storage required for carbon dioxide energy storage, and uses geothermal heat in depleted oil and gas reservoirs to heat carbon dioxide to improve the work capacity of carbon dioxide. At the same time, the high-temperature waste heat generated by the carbon dioxide capture system is used to further increase the heat storage temperature, thereby improving the thermal energy utilization rate of the carbon dioxide energy storage system.

[0018] 2. The present invention solves the problem of carbon emissions from coal-fired power plants. It uses a carbon dioxide capture system to capture and utilize the carbon dioxide generated by coal-fired power plants. It is an efficient method for capturing and utilizing carbon dioxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 is a schematic diagram of the energy storage system of the present invention;

[0021] Among them, 1. low-pressure recovery well; 2. low-pressure throttle valve; 3. compressor; 4. high-pressure injection well; 5. high-pressure recovery well; 6. high-pressure throttle valve; 7. solar collector; 8. expander; 9. low-pressure injection well; 10. electric / generator; 11. boiler; 12. turbine; 13. generator; 14. first diverter; 15. absorption refrigerator; 16. absorption tower; 17. lean and rich liquid heat exchanger; 18. desorption tower; 19. reboiler; 20. high-temperature waste heat exchanger; 21. amine solution storage tank; 22. second diverter; 23. energy replenishment compressor. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] Reference Figure 1 The present invention provides a supercritical carbon dioxide energy storage system based on combined cooling, heating and power generation, comprising:

[0025] The carbon dioxide capture assembly includes an absorption tower 16 and a desorption tower 18 which are connected in sequence, and an alcoholamine solution circulation mechanism is provided between the desorption tower 18 and the absorption tower 16;

[0026] The carbon dioxide energy storage assembly includes a low-pressure recovery well 1, the outlet of the low-pressure recovery well 1 is connected to a pressurizing part, the gas outlet of the pressurizing part is connected to a high-pressure injection well 4, and the gas outlet of the desorption tower 18 is connected to the high-pressure injection well 4 through a pressurizing part;

[0027] The carbon dioxide energy release component includes a high-pressure recovery well 5, the outlet of the high-pressure recovery well 5 is connected to an expansion part through a heat exchange part, the gas outlet end of the expansion part is connected to a low-pressure injection well 9, the gas outlet end of the desorption tower 18 is connected to the low-pressure injection well 9, and the heat exchange part is correspondingly arranged with the alcoholamine solution circulation mechanism;

[0028] The trigeneration component of cooling, heating and power includes a boiler 11, the flue gas end of the boiler 11 is connected to the absorption tower 16, the hot end outlet of the boiler 11 is connected to the first diverter 14 through the power generation part, and the outlet end of the first diverter 14 is connected to the heat user or the cold user through the refrigeration part.

[0029] The main function of the absorption tower 16 is to use the alcohol amine solution of the alcohol amine solution circulation mechanism to absorb the carbon dioxide in the flue gas of the boiler 11 and discharge the clean gas; the main function of the desorption tower 18 is to desorb and regenerate the flue gas that absorbs the carbon dioxide, so that the carbon dioxide enters the depleted oil and gas reservoir; the main function of the alcohol amine solution circulation mechanism is to make the alcohol amine solution complete the cycle of absorption and regeneration between the absorption tower 16 and the desorption tower 18; the main function of the pressurizing part is to pressurize the low-pressure carbon dioxide to a high-pressure state; the main function of the expansion part is to make the high-pressure carbon dioxide work and convert the energy of the high-pressure carbon dioxide into mechanical energy; the main function of the heat exchange part is to use the waste heat generated in the alcohol amine solution circulation mechanism to further heat the carbon dioxide, improve its workability, and further improve the thermal efficiency of the system; the main function of the power generation part is to use the hot air generated by the boiler 11 to generate electricity; the main function of the first diverter 14 is to transport the high-temperature waste heat generated by the boiler 11 to the heat users and to the cold users through the refrigeration parts to achieve cogeneration of heat, cold and power.

[0030] To further optimize the solution, the amine solution circulation mechanism includes a lean-rich liquid heat exchanger 17, the cold source side inlet of the lean-rich liquid heat exchanger 17 is connected to the bottom outlet of the absorption tower 16, the cold source side outlet of the lean-rich liquid heat exchanger 17 is connected to the top inlet of the desorption tower 18, the bottom outlet of the desorption tower 18 is connected to the outlet of a reboiler 19, the top outlet of the reboiler 19 is connected to the bottom inlet of the desorption tower 18, the bottom outlet of the reboiler 19 is connected to the heat source side inlet of the lean-rich liquid heat exchanger 17, the heat source side outlet of the lean-rich liquid heat exchanger 17 is connected to the inlet of an amine solution storage tank 21 through a heat exchange portion, and the outlet of the amine solution storage tank 21 is connected to the top of the absorption tower 16.

[0031] The flue gas discharged from the boiler 11 is transported to the bottom of the absorption tower 16 after denitration and desulfurization. The flue gas at the bottom of the absorption tower 16 is countercurrently contacted with the lean alcoholamine solution (the alcoholamine solution that does not absorb carbon dioxide is called lean liquid) flowing down from the top of the absorption tower 16 to absorb carbon dioxide. After that, the flue gas with carbon dioxide removed is discharged from the top of the carbon dioxide absorption tower 16, and the alcoholamine rich liquid is sent to the desorption tower 18 for desorption and regeneration after heat exchange treatment in the lean and rich liquid heat exchanger 17 (the operating temperature of the absorption tower 16 is lower than that of the desorption tower 18, so it needs to be heated by the lean and rich liquid heat exchanger 17). In the desorption process, the rich liquid is decomposed by steam heating in the desorption tower 18, and the alcoholamine and carbon dioxide are regenerated. At this time, part of the alcoholamine solution that does not absorb carbon dioxide is discharged through the bottom of the desorption tower 18, enters the reboiler 19 for heating again, so as to completely desorb carbon dioxide. The desorbed carbon dioxide enters the desorption tower 18 and is discharged from the top of the tower for sealing or utilization. The desorbed amine solution is again passed into the lean-rich liquid heat exchanger 17 and the high-temperature waste heat exchanger 20 to be cooled to a temperature equivalent to that of the flue gas, and then stored in the amine solution storage tank 21 for recovery, to be reused when the capture system is operated next time.

[0032] To further optimize the solution, the heat exchange part includes a solar collector 7, the outlet of the solar collector 7 is connected to the expansion part, the inlet of the solar collector 7 is connected to the cold source side outlet of the high-temperature waste heat exchanger 20, the cold source side inlet of the high-temperature waste heat exchanger 20 is connected to the high-pressure recovery well 5, the heat source side outlet of the lean-rich liquid heat exchanger 17 is connected to the heat source side inlet of the high-temperature waste heat exchanger 20, and the heat source side outlet of the high-temperature waste heat exchanger 20 is connected to the inlet of the alcoholamine solution storage tank 21.

[0033] like Figure 1 As shown, the desorbed amine solution still has a relatively high temperature after heat exchange in the lean-rich liquid heat exchanger 17, and is heat exchanged using the high-temperature waste heat exchanger 20. The high-temperature waste heat of the desorbed amine solution is used to further increase the temperature of the carbon dioxide discharged from the high-pressure recovery well 5, thereby improving its working capacity.

[0034] The main function of the solar collector 7 is to utilize solar energy to further increase the temperature of the carbon dioxide before it enters the expansion unit.

[0035] According to a further optimized solution, the pressurizing part includes a compressor 3 , the inlet of the compressor 3 is connected to the low-pressure recovery well 1 through a low-pressure throttle valve 2 , and the outlet of the compressor 3 is connected to the high-pressure injection well 4 .

[0036] According to a further optimization scheme, the expansion part includes an expander 8 and a high-pressure throttle valve 6. The inlet of the expander 8 is connected to the outlet of the solar collector 7. The high-pressure throttle valve 6 is connected between the high-pressure recovery well 5 and the cold source side outlet of the high-temperature waste heat exchanger 20.

[0037] According to a further optimized solution, the compressor 3 and the expander 8 are transmission-connected with an electric motor / generator 10.

[0038] According to a further optimized solution, the booster includes an energy replenishment compressor 23 , which is connected between the gas outlet of the desorption tower 18 and the high-pressure injection well 4 .

[0039] Energy storage process: During the low electricity consumption period, the electric / generator 10 drives the compressor 3 to operate, and the supercritical carbon dioxide in the low-pressure recovery well 1 is released, and the pressure is maintained stable through the low-pressure throttle valve 2. After that, the carbon dioxide enters the compressor 3 and is compressed to a high-temperature and high-pressure state and injected into the depleted oil and gas reservoir by the high-pressure injection well 4 for storage. This is the energy storage process of the supercritical carbon dioxide energy storage system. While the energy storage process is in progress, the carbon dioxide discharged from the desorption tower 18 is directly injected into the low-pressure injection well 9 or injected into the depleted oil and gas reservoir by the high-pressure injection well 4 after being compressed by the energy replenishment compressor 23, so as to ensure the constant pressure of the depleted oil and gas reservoir, maintain the stability of the system, and improve the system performance.

[0040] Energy release process: During the peak period of electricity consumption, the high-pressure recovery well 5 releases high-temperature and high-pressure carbon dioxide. After the pressure is stabilized by the high-pressure throttle valve 6, the high-temperature waste heat is utilized by the high-temperature waste heat exchanger 20, and the temperature of the high-pressure carbon dioxide is further increased by the solar collector 7. After that, the high-temperature and high-pressure carbon dioxide enters the expander 8 to do work, so that the expander 8 drives the electric motor / generator 10 to operate and generate electricity, and drives the electric motor / generator 10 to generate electricity. The carbon dioxide after doing work is injected into the depleted oil and gas reservoir through the low-pressure injection well 9, completing the energy release process.

[0041] To further optimize the solution, the top gas outlet of the desorption tower 18 is connected to the outlet of the second diverter 22, and the two outlets of the second diverter 22 are respectively connected to the low-pressure injection well 9 and the inlet of the energy replenishment compressor.

[0042] According to a further optimized solution, the power generation unit includes a turbine 12 , the inlet of the turbine 12 is connected to the hot air outlet of the boiler 11 , and the outlet of the turbine 12 is connected to the inlet of the first diverter 14 .

[0043] According to a further optimized solution, an outlet end of the first flow divider 14 is connected to an inlet of an absorption refrigerator 15, and an outlet of the absorption refrigerator 15 is connected to a cold user.

[0044] Operation process of the trigeneration system: air is heated by the boiler 11 and then introduced into the turbine 12. The turbine 12 performs work and drives the generator 13 to generate electricity, thereby outputting electric energy. At the same time, the air discharged from the turbine 12 after the work still has a high heat content. The air is split by the first splitter 14. One stream is directly supplied to the heat user, and the other stream is cooled by the absorption refrigeration machine 15 and supplied to the cold user.

[0045] The trigeneration system can utilize the high-temperature waste heat generated by the coal-fired power plant to supply heat users or to cool through an absorption refrigeration machine and supply it to cold users, thus achieving efficient utilization of thermal energy and the trigeneration function of heat, cooling and power. At the same time, the carbon dioxide in the flue gas generated by the boiler 11 can be absorbed and used as a raw material supplement for the carbon dioxide energy storage system.

[0046] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0047] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A supercritical carbon dioxide energy storage system based on combined cooling, heating and power generation, characterized in that: include: A carbon dioxide capture assembly comprises an absorption tower (16) and a desorption tower (18) which are connected in sequence, wherein an alcoholamine solution circulation mechanism is arranged between the desorption tower (18) and the absorption tower (18); A carbon dioxide energy storage assembly comprises a low-pressure recovery well (1), the outlet of the low-pressure recovery well (1) is connected to a pressurizing part, the gas outlet end of the pressurizing part is connected to a high-pressure injection well (4), and the gas outlet end of the desorption tower (18) is connected to the high-pressure injection well (4) via a pressurizing component; A carbon dioxide energy release component comprises a high-pressure recovery well (5), the outlet of the high-pressure recovery well (5) is connected to an expansion part through a heat exchange part, the gas outlet end of the expansion part is connected to a low-pressure injection well (9), the gas outlet end of the desorption tower (18) is connected to the low-pressure injection well (9), and the heat exchange part is arranged corresponding to the alcohol amine solution circulation mechanism; A cooling, heating and power trigeneration component comprises a boiler (11), wherein the flue gas end of the boiler (11) is connected to the absorption tower (18), the hot end outlet of the boiler (11) is connected to a first diverter (14) via a power generation unit, and the outlet end of the first diverter (14) is respectively connected to a hot user or to a cold user via a refrigeration unit.

2. A supercritical carbon dioxide energy storage system based on combined cooling, heating and power according to claim 1, characterized in that: The alcoholamine solution circulation mechanism comprises a lean-rich liquid heat exchanger (17), the cold source side inlet of the lean-rich liquid heat exchanger (17) is connected to the bottom outlet of the absorption tower (16), the cold source side outlet of the lean-rich liquid heat exchanger (17) is connected to the top inlet of the desorption tower (18), the bottom outlet of the desorption tower (18) is connected to the outlet of a reboiler (19), the top outlet of the reboiler (19) is connected to the bottom inlet of the desorption tower (18), the bottom outlet of the reboiler (19) is connected to the heat source side inlet of the lean-rich liquid heat exchanger (17), the heat source side outlet of the lean-rich liquid heat exchanger (17) is connected to the inlet of an alcoholamine solution storage tank (21) through the heat exchange part, and the outlet of the alcoholamine solution storage tank (21) is connected to the top of the absorption tower (16).

3. A supercritical carbon dioxide energy storage system based on combined cooling, heating and power according to claim 2, characterized in that: The heat exchange part comprises a solar collector (7), the outlet of the solar collector (7) is connected to the expansion part, the inlet of the solar collector (7) is connected to the cold source side outlet of the high-temperature waste heat exchanger (20), the cold source side inlet of the high-temperature waste heat exchanger (20) is connected to the high-pressure recovery well (5), the heat source side outlet of the lean-rich liquid heat exchanger (17) is connected to the heat source side inlet of the high-temperature waste heat exchanger (20), and the heat source side outlet of the high-temperature waste heat exchanger (20) is connected to the inlet of the alcohol amine solution storage tank (21).

4. A supercritical carbon dioxide energy storage system based on combined cooling, heating and power generation according to claim 1, characterized in that: The pressurizing unit comprises a compressor (3), the inlet of the compressor (3) is connected to the low-pressure recovery well (1) through a low-pressure throttle valve (2), and the outlet of the compressor (3) is connected to the high-pressure injection well (4).

5. A supercritical carbon dioxide energy storage system based on combined cooling, heating and power generation according to claim 3, characterized in that: The expansion unit comprises an expander (8) and a high-pressure throttle valve (6), the inlet of the expander (8) is connected to the outlet of the solar collector (7), and the high-pressure throttle valve (6) is connected between the high-pressure recovery well (5) and the cold source side outlet of the high-temperature waste heat exchanger (20).

6. A supercritical carbon dioxide energy storage system based on combined cooling, heating and power generation according to claim 1, characterized in that: The booster comprises an energy replenishment compressor (23), and the energy replenishment compressor (23) is connected between the gas outlet end of the desorption tower (18) and the high-pressure injection well (4).

7. A supercritical carbon dioxide energy storage system based on combined cooling, heating and power according to claim 1, characterized in that: The power generation unit comprises a turbine (12), the inlet of the turbine (12) being connected to the hot air outlet of the boiler (11), and the outlet of the turbine (12) being connected to the inlet of the first diverter (14).

8. The supercritical carbon dioxide energy storage system based on combined cooling, heating and power generation according to claim 1, characterized in that: An outlet end of the first flow divider (14) is connected to the inlet of an absorption refrigeration machine (15), and an outlet of the absorption refrigeration machine (15) is connected to a cold user.

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