A salt cavern compressed air filtration and dechlorination system

Abstract

This invention discloses a compressed air filtration and dechlorination system for salt caverns, belonging to the field of compressed air energy storage technology. It includes a chloride ion removal device, a glycol storage device, a glycol regeneration device, and a brine purification device arranged sequentially. The chloride ion removal device removes impurities and chloride ions from the air. The glycol storage device receives external glycol, glycol-rich from the chloride ion removal device, and glycol-lean after purification by the glycol regeneration device. The glycol regeneration device removes chloride ions from the glycol-rich and recovers the glycol. The brine purification device treats wastewater from the chloride ion removal device, the glycol storage device, and the glycol regeneration device. This invention can remove impurities, moisture, and chloride ions carried from the compressed air in salt caverns, treating the air exiting the salt cavern into clean air, reducing material corrosion costs, and meeting the intake requirements of expanders.

Description

Technical Field

[0001] This invention relates to the field of compressed air energy storage technology, and in particular to a salt cavern compressed air filtration and dechlorination system. Background Technology

[0002] Compressed air energy storage (CAES), as an important component of new energy storage, plays an increasingly important role in power system regulation due to its advantages such as large capacity, long lifespan, and environmental friendliness. Among these, CAES power plants utilizing underground salt caverns as gas storage facilities have become one of the most economical technological routes due to the large gas storage capacity, low construction cost, and full utilization of abandoned salt cavern resources. However, the complex geological environment of salt caverns means that residual brine and impurities within the cavity can easily enter the gas transmission system under high-pressure airflow, leading to the following prominent problems:

[0003] Corrosion issues: High concentrations of chloride ions (Cl⁻) in the brine cause severe corrosion to critical equipment such as gas pipelines, heat exchangers, and expanders, significantly reducing system reliability and service life. Existing technologies often employ anti-corrosion coatings or upgrade equipment materials (such as titanium alloys or duplex steel) to address this, but these not only significantly increase investment costs but also make it difficult to prevent corrosion failure caused by chloride ion accumulation during long-term operation, thus failing to meet the 30-year design life requirement of power plants.

[0004] Challenges in Impurity Removal: In addition to chloride ions, salt caverns also contain solid impurities such as silt and carbonates, which can easily cause pipe blockage, equipment wear, and affect the stable operation of the system. Existing pretreatment processes (such as simple filtration and chemical neutralization) are insufficient to completely remove these impurities, especially under high pressure and high flow rate conditions, where the problem of impurity carryover is even more prominent.

[0005] Resource waste and environmental risks: Currently, compressed air energy storage power stations mostly use direct discharge or simple evaporation to treat chlorinated brine, which not only wastes salt resources but may also cause environmental problems such as soil salinization, which is inconsistent with the concept of green and low-carbon development.

[0006] Comparative document analysis shows that existing technologies have proposed multiple solutions for brine purification and resource recovery:

[0007] Patent CN114195308A uses processes such as radiation precipitation, carbonic acid neutralization, and evaporation crystallization to separate salt and impurities in waste brine, recover high-purity snow-melting salt, and reduce corrosion risk.

[0008] Patent CN213885035U describes a deep-sea natural gas ethylene glycol regeneration system that effectively removes salt and impurities from brine in salt caverns through pretreatment, desalination, and distillation processes, ensuring long-term stable operation of the system.

[0009] Patent CN218572854U addresses the recovery of triethylene glycol from coal-to-natural gas by employing multi-stage filtration and distillation technology to achieve thorough separation of impurities and resource recycling, thus avoiding environmental pollution.

[0010] In summary, compressed air energy storage power stations urgently need an integrated and efficient brine pretreatment and resource recovery system to solve the problems of chloride ion corrosion, impurity blockage, and resource waste, and promote the large-scale application of brine energy storage technology. Summary of the Invention

[0011] The technical problem to be solved by the present invention is to provide a salt cavern compressed air filtration and dechlorination system, which uses a cyclone separator, a coupling separator and an alcohol injection device for filtration, and can remove impurities, moisture and chloride ions carried in the compressed air in the salt cavern gas storage tank and the chloride ions carried out from the salt cavern. It can treat the air at the salt cavern outlet into clean air, reduce the corrosion protection cost of materials and meet the air intake requirements of the expander.

[0012] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0013] A salt cavern compressed air filtration and dechlorination system includes:

[0014] The chloride ion removal device is used to directly contact chlorine-containing high-pressure air from a salt cave with a liquid chlorine absorbent, causing chloride ions to transfer to the liquid phase, and then separating the gas and liquid phases to obtain dechlorinated air and glycol-rich air.

[0015] Glycol storage device for circulating absorption of chlorine agent, including a glycol-rich storage tank connected to a chloride ion removal device and a glycol-lean storage tank connected to a glycol regeneration device;

[0016] A glycol regeneration device, which is in fluid communication with the glycol storage device, is used to recover chlorine adsorbent from glycol-rich glycol to obtain recyclable glycol-poor glycol.

[0017] The brine purification device is used to receive and centrally treat the saline wastewater generated by the system, so that no liquid wastewater is discharged to the outside world during the operation of the system.

[0018] A further improvement to the technical solution of the present invention is that the chloride ion removal device includes:

[0019] Cyclone separators are used to remove solids and free water with a particle size ≥10 μm from high-pressure air;

[0020] The alcohol injection pump, located downstream of the cyclone separator, is used to inject lean glycol into high-pressure air in atomized form to form a gas-liquid mixture.

[0021] A coupling separator, located downstream of the alcohol injection pump, is used to separate the mixed stream into dechlorinated air and glycol-rich fluid.

[0022] A further improvement to the technical solution of the present invention is that the glycol regeneration device includes:

[0023] The regeneration tower strips the glycol-rich gas from the lean solution buffer tank for desulfurization.

[0024] Solution regeneration reactor, used to distill off water from rich glycol and concentrate chloride salts;

[0025] The lean solution buffer tank sends the recovered lean glycol back to the regeneration tower for recycling.

[0026] A further improvement to the technical solution of the present invention is that: medium-temperature hot water from a compressed air energy storage power station is injected into the heat exchanger inlet of the solution regeneration reactor, and low-temperature hot water is discharged from the heat exchanger outlet.

[0027] A further improvement to the technical solution of the present invention is that the glycol storage device includes:

[0028] The lean glycol storage tank has a lean glycol inlet connected to the outlet of the lean solution buffer tank, and the lean glycol outlet is connected to the alcohol injection pump in the chloride ion removal unit.

[0029] The rich glycol storage tank is connected to the coupling separator of the chloride ion removal unit via the rich glycol inlet, and the rich glycol outlet is connected to the lean solution buffer tank.

[0030] A further improvement to the technical solution of the present invention is that the brine purification device includes:

[0031] The brine buffer tank collects saline wastewater from the chloride ion removal unit, glycol storage unit, and glycol regeneration unit.

[0032] The solution evaporation kettle evaporates the brine wastewater collected in the brine buffer tank until solid salt precipitates. The evaporated steam is either directly vented or condensed and recovered, while the solid salt is discharged externally.

[0033] A further improvement to the technical solution of the present invention is that: medium-temperature hot water from a compressed air energy storage power station is injected into the inlet of the heat exchanger of the solution evaporator, and low-temperature hot water is discharged from the outlet of the heat exchanger.

[0034] The technological advancements achieved by this invention due to the adoption of the above technical solutions are as follows:

[0035] 1. This invention, by setting up a chloride ion removal device, a glycol storage device, a glycol regeneration device, and a brine purification device, enables the entire system to discharge no wastewater and meet environmental protection requirements without additional treatment.

[0036] 2. In this invention, the air at the salt cavern outlet can meet the air quality requirements of the expander after being desorbed, thus reducing operation and maintenance costs.

[0037] 3. This invention can reduce the material requirements for heat exchangers, gas pipelines, and expanders, thereby reducing the overall investment cost of a 300MW compressed air energy storage power station.

[0038] 4. The present invention includes a chloride ion removal device, a glycol storage device, a glycol regeneration device, and a brine purification device. The appropriate device can be flexibly selected to achieve the corresponding function according to different needs.

[0039] 5. The system of this invention uses glycol as the intermediate medium for dechlorination, and the glycol is recovered and recycled, with an overall glycol recovery rate of over 95%.

[0040] 6. The heat source of this invention is the medium-temperature hot water already available in the energy storage power station, eliminating the need for an additional heat source and making the overall system flexible. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the chloride ion removal device in this invention;

[0042] Figure 2 This is a schematic diagram of the glycol storage device in this invention;

[0043] Figure 3 This is a schematic diagram of the glycol regeneration device in this invention;

[0044] Figure 4 This is a schematic diagram of the brine purification device in this invention;

[0045] The components include: 1. Cyclone separator; 2. First alcohol injection pump; 3. Second alcohol injection pump; 4. Coupled separator; 5. Lean glycol storage tank; 6. Rich glycol storage tank; 7. First lean glycol booster pump; 8. Second lean glycol booster pump; 9. First rich glycol booster pump; 10. Second rich glycol booster pump; 11. Brine buffer tank; 12. Solution evaporator; 13. Tap water tank; 14. Tower top air cooler; 15. Regeneration tower; 16. Solution regeneration kettle; 17. Lean solution buffer tank; 18. Filter. Device, 19. First shut-off valve, 20. Second shut-off valve, 21. First regulating valve, 22. Second regulating valve, 23. Third shut-off valve, 24. Third regulating valve, 25. First check valve, 26. Fourth shut-off valve, 27. Fifth shut-off valve, 28. Fourth regulating valve, 29. Second check valve, 30. Sixth shut-off valve, 31. First alcohol injection valve, 32. Seventh shut-off valve, 33. Rich glycol valve, 34. Eighth shut-off valve, 35. Ninth shut-off valve, 36. Third check valve 37. Tenth shut-off valve; 38. Second alcohol injection valve; 39. Third alcohol injection valve; 40. Eleventh shut-off valve; 41. Twelfth shut-off valve; 42. Fifth regulating valve; 43. Fourth check valve; 44. Feed valve; 45. Fourth alcohol injection valve; 46. Fifth alcohol injection valve; 47. Sixth regulating valve; 48. Seventh regulating valve; 49. Thirteenth shut-off valve; 50. Fourteenth shut-off valve; 51. Drain valve; 52. Solid waste discharge valve; 53. First exhaust valve; 54. Fifteenth shut-off valve. 55. Sixteenth shut-off valve; 56. First regeneration valve; 57. Second regeneration valve; 58. Sixth alcohol injection valve; 59. Seventeenth shut-off valve; 60. Eighteenth shut-off valve; 61. Nineteenth shut-off valve; 62. Twentieth shut-off valve; 63. Twenty-first shut-off valve; 64. Second exhaust valve; 65. Twenty-second shut-off valve; 66. Twenty-third shut-off valve; 67. Twenty-fourth shut-off valve; 68. Twenty-fifth shut-off valve; 69. Twenty-sixth shut-off valve; 70. Rich glycol injection valve. Detailed Implementation

[0046] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0047] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0048] Furthermore, the terms "first," "second," etc., are used only to distinguish similar components and do not indicate order or importance. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include at least one of those features. In the description of this invention, "a number" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0049] A salt cavern compressed air filtration and dechlorination system includes a chloride ion removal device, an glycol storage device, a glycol regeneration device, and a brine purification device arranged in sequence. The chloride ion removal device removes impurities and chloride ions from the air. The glycol storage device receives external glycol, glycol-rich from the chloride ion removal device, and glycol-poor after purification by the glycol regeneration device. The glycol regeneration device removes chloride ions from the glycol-rich and recovers the glycol. The brine purification device treats wastewater from the chloride ion removal device, the glycol storage device, and the glycol regeneration device.

[0050] like Figure 1 As shown, the chloride ion removal device includes:

[0051] Cyclone separator 1, with its tangential inlet connected to the gas coming from the salt cavern, and its purified gas outlet connected to the coupling separator 4, with its dust outlet connected to the brine buffer tank 11;

[0052] The alcohol injection pump includes a first alcohol injection pump 2 and a second alcohol injection pump 3. The pump inlet is connected to the lean glycol booster pump of the glycol storage device. The pump outlet merges with the purified gas outlet branch of the cyclone separator 1 and then flows into the mixed fluid inlet of the coupling separator 4.

[0053] The coupling separator 4 has its gas phase outlet connected to the expander generator system and its liquid phase outlet connected to the glycol storage device, the glycol-rich storage tank 6.

[0054] The cyclone separator 1 is connected to the brine buffer tank 11 through the first and second drain pipes. The first drain pipe is equipped with a first shut-off valve 19 and a first regulating valve 21, and the second drain pipe is equipped with a second shut-off valve 20 and a second regulating valve 22. After passing through the cyclone separator 1, the air at the salt cavern outlet is freed of impurities larger than 10μm and free water.

[0055] Lean glycol from the glycol booster pump enters the first glycol injection valve 31 through the first and second lean glycol pipelines, atomizing the glycol and injecting it into the air after the cyclone separator 1. This dilutes the chloride ions in the air and condenses free water droplets smaller than 10μm into droplets larger than 10μm. The air injected with atomized glycol is separated in the coupling separator, where chloride ions in the air are absorbed by the glycol and become rich glycol, which is then removed from the air. The purified air is then sent to the rich glycol storage tank 6 via the seventh shut-off valve 32 and the rich glycol valve 33, and then sent to the expansion power generation system. The first lean glycol pipeline is sequentially equipped with the third shut-off valve 23, the third regulating valve 24, the first glycol injection pump 2, the first check valve 25, and the fourth shut-off valve 26. The second lean glycol pipeline is sequentially equipped with the fifth shut-off valve 27, the fourth regulating valve 28, the second glycol injection pump 3, the second check valve 29, and the sixth shut-off valve 30.

[0056] like Figure 2 As shown, the glycol storage device includes:

[0057] The lean glycol storage tank 5 has two lean glycol inlets connected to the lean glycol buffer tank of the glycol regeneration unit and the glycol unloading port, respectively. The gas inlet is connected to the nitrogen cylinder, the lean glycol outlet is connected to the lean glycol booster pump, and the lean glycol drain outlet is connected to the brine buffer tank 11.

[0058] The lean glycol booster pump includes a first lean glycol booster pump 7 and a second lean glycol booster pump 8, with the pump outlets connected to the alcohol injection pump in the chloride ion removal device, respectively.

[0059] Rich glycol storage tank 6, rich glycol inlet is connected to the coupling separator of chloride ion removal device, gas inlet is connected to nitrogen cylinder, rich glycol outlet is connected to rich glycol booster pump, rich glycol drain outlet is connected to brine buffer tank 11.

[0060] The glycol-rich booster pump includes a first glycol-rich booster pump 9 and a second glycol-rich booster pump 10, and the pump outlet is connected to the lean solution buffer tank 17 of the glycol regeneration unit.

[0061] Among them, an eighth shut-off valve 34 is installed between the glycol unloading port and the first lean glycol inlet, and the incoming glycol is replenished to the lean glycol storage tank 5 through the eighth shut-off valve 34; a tenth shut-off valve 37 is installed between the lean glycol buffer tank and the second lean glycol inlet, and the regenerated glycol is sent into the lean glycol storage tank 5 through the tenth shut-off valve 37; a ninth shut-off valve 35 and a third check valve 36 are installed between the nitrogen cylinder and the gas inlet of the lean glycol storage tank 5, and the nitrogen enters the lean glycol storage tank 5 for inert protection through the ninth shut-off valve 35 and the third check valve 36.

[0062] The lean glycol outlet splits into two paths after passing through the first and second pressurization pipelines. One path connects to the glycol regeneration device via the eleventh shut-off valve 40, and the other path connects to the chloride ion removal device via the twelfth shut-off valve 41. During regeneration, the lean glycol is sent to the glycol regeneration device via the eleventh shut-off valve 40. During filtration, the lean glycol is sent to the chloride ion removal device via the twelfth shut-off valve 41. The first pressurization pipeline is equipped with a second alcohol injection valve 38 and a first lean glycol booster pump 7 in sequence, and the second pressurization pipeline is equipped with a third alcohol injection valve 39 and a second lean glycol booster pump 8 in sequence. The drain outlet of the lean glycol storage tank 5 is connected to the brine buffer tank 11 via the fourteenth shut-off valve 50.

[0063] The coupling separator is connected to the inlet of the rich glycol via the feed valve 44. The rich glycol in the coupling separator is then fed into the rich glycol storage tank 6 via the feed valve 44. The nitrogen cylinder is connected to the gas inlet of the rich glycol storage tank 6 via the fifth regulating valve 42 and the fourth check valve 43. The nitrogen enters the rich glycol storage tank 6 for inert protection via the fifth regulating valve 42 and the fourth check valve 43.

[0064] The rich glycol outlet is connected to the glycol regeneration unit after passing through the third and fourth pressurization pipelines. The third pressurization pipeline is equipped with the fourth glycol injection valve 45, the first rich glycol pressurization pump 9, and the sixth regulating valve 47 in sequence. The fourth pressurization pipeline is equipped with the fifth glycol injection valve 46, the second rich glycol pressurization pump 10, and the seventh regulating valve 48 in sequence. After passing through the fourth and fifth glycol injection valves 45 and 46, the rich glycol is sent to the rich glycol pressurization pump for pressurization, and then sent to the glycol regeneration unit after passing through the sixth and seventh regulating valves 47 and 48. The sewage outlet of the rich glycol storage tank 6 is connected to the brine buffer tank 11 through the thirteenth shut-off valve 49.

[0065] like Figure 3 As shown, the glycol regeneration device includes:

[0066] The tap water tank 13 has its tap water outlet connected to the cooling water inlet of the regeneration tower 15 via the tower top air cooler 14.

[0067] The rich liquid inlet of the regeneration tower 15 is connected to the rich glycol outlet of the lean solution buffer tank 17. The first glycol outlet and the second glycol outlet are connected to the rich liquid inlet and the rich liquid inlet of the solution regeneration kettle 16, respectively. The stripping gas inlet is connected to the non-condensable gas outlet of the solution regeneration kettle 16.

[0068] The solution regeneration reactor 16 has its alcohol outlet connected to the first inlet of the lean solution buffer tank 17, and its drain outlet connected to the brine buffer tank 11. Medium-temperature hot water is injected into the heat exchanger inlet of the solution regeneration reactor 16, and low-temperature hot water is discharged from the heat exchanger outlet.

[0069] The lean solution buffer tank 17 has a second inlet connected to the rich glycol booster pump of the glycol storage device and connected to the rich glycol outlet through an internal pipeline. The third inlet is connected to the lean glycol booster pump of the glycol storage device. The lean solution outlet of the lean solution buffer tank 17 is connected to the lean glycol storage tank 5 of the glycol storage device through a filter 18. The drain outlet of the lean solution buffer tank 17 is connected to the brine buffer tank 11. The drain outlet of the filter 18 is connected to the brine buffer tank 11.

[0070] Specifically, the third and fourth pressurization lines of the glycol storage device are combined and connected to the second inlet of the lean solution buffer tank 17 via the twenty-fifth shut-off valve 68. The rich glycol outlet is connected to the rich liquid inlet of the regeneration tower 15 via the twenty-sixth shut-off valve 69 and the rich glycol injection valve 70. The outlet of the tap water tank 13 is connected to the cooling water inlet of the regeneration tower 15 via the seventeenth tap water shut-off valve 59 and the tower top air cooler 14. The first glycol outlet of the regeneration tower 15 is connected to the first rich liquid inlet of the solution regeneration vessel 16 via the first regeneration valve 56. The second glycol outlet of the regeneration tower 15 is connected to the second rich liquid inlet of the solution regeneration vessel 16 via the second regeneration valve 57. The alcohol outlet of the solution regeneration reactor 16 is connected to the first inlet of the lean solution buffer tank 17 via the sixth alcohol injection valve 58. The rich glycol is sent to the lean solution buffer tank via the twenty-fifth shut-off valve 68 to cool the lean glycol solution, and then sent to the regeneration tower 15 via the twenty-sixth shut-off valve 69 and the rich glycol injection valve 70. At the same time, tap water from the tap water tank 13 is sent to the top air cooler 14 via the seventeenth shut-off valve 59 and then into the regeneration tower 15. The glycol in the regeneration tower 15 is sent to the solution regeneration reactor 16 via the first regeneration valve 56 and the second regeneration valve 57. After regeneration, the glycol is sent to the lean solution buffer tank 17 via the sixth alcohol injection valve 58, and after mixing with the reflux lean glycol, the process of converting rich glycol into lean glycol is completed.

[0071] The lean solution buffer tank 17 is connected to the lean glycol storage tank 5 of the alcohol storage device via the eighteenth shut-off valve 60, filter 18, and nineteenth shut-off valve 61. The lean glycol is sent to the lean glycol storage tank 5 after passing through the eighteenth shut-off valve 60, filter 18, and nineteenth shut-off valve 61 to complete the regeneration process.

[0072] The heat exchanger inlet of the solution regeneration reactor 16 is equipped with a 20th shut-off valve 62, the heat exchanger outlet is equipped with a 21st shut-off valve 63, and the steam outlet of the solution regeneration reactor 16 is equipped with a second exhaust valve 64. The heat source of the solution regeneration reactor 16 is hot water stored in a compressed air energy storage power station. The medium-temperature hot water enters through the 20th shut-off valve 62, and after heat exchange, it becomes low-temperature hot water and is discharged through the 21st shut-off valve 63. The exhaust gas of the solution regeneration reactor 16 is discharged into the atmosphere through the second exhaust valve 64.

[0073] The drain ports of the solution regeneration vessel 16, the lean solution buffer tank 17, and the filter 18 are respectively equipped with a 22nd shut-off valve 65, a 23rd shut-off valve 66, and a 24th shut-off valve 67.

[0074] like Figure 4 As shown, the brine purification device includes:

[0075] The brine buffer tank 11 has its brine inlet connected to the cyclone separator 1 of the chloride ion removal device, the lean glycol storage tank 5 of the glycol storage device, the rich glycol storage tank 6 of the glycol storage device, and the filter 18 of the glycol regeneration device. The brine outlet is connected to the dilute solution inlet of the solution evaporator 12.

[0076] The solution evaporator 12 discharges solid particles from the solid particle outlet, injects medium-temperature hot water into the heat exchanger inlet, and discharges low-temperature hot water from the heat exchanger outlet of the solution evaporator 12.

[0077] The brine outlet of the brine buffer tank 11 is connected to the solution evaporator 12 via a drain valve 51. The solid particle outlet of the solution evaporator 12 is equipped with a solid discharge valve 52, and the steam outlet of the solution evaporator 12 is equipped with a first steam exhaust valve 53. The brine in the brine buffer tank 11 is injected into the solution evaporator 12 via the drain valve 51. The brine evaporates and crystallizes in the evaporator. The steam is discharged into the atmosphere via the first steam exhaust valve 53. After crystallization, the solid particles are discharged and stored via the solid discharge valve 52.

[0078] The heat exchanger inlet of the solution evaporator 12 is equipped with a fifteenth shut-off valve 54, and the heat exchanger outlet of the solution evaporator 12 is equipped with a sixteenth shut-off valve 55. The heat source of the solution evaporator 12 is a compressed air energy storage power station storing hot water. The medium-temperature hot water enters through the fifteenth shut-off valve 54, and after heat exchange, it becomes low-temperature hot water and is discharged through the sixteenth shut-off valve 55.

[0079] A method for operating a salt cavern compressed air filtration and dechlorination system includes the following steps:

[0080] S1. Pre-separation of air intake: High-pressure air from the salt cavern first enters the cyclone separator 1, where centrifugal force removes solid particles with a diameter greater than 10μm and free water, and the bottom sewage is discharged to the brine buffer tank 11.

[0081] S2, Atomized alcohol mixing: Lean glycol is pressurized by a lean glycol booster pump and then atomized and injected into the air pipeline through a nozzle. Glycol absorbs chloride ions and causes water droplets with a diameter of less than 10μm to coalesce into large droplets.

[0082] S3, Coupling Separation for Chlorine Removal: The gas-liquid mixture enters the coupling separator 4, where the packing layer completes efficient separation; the top clean air (Cl⁻≤5 mg / m³) is sent to the expansion power generation, and the bottom rich glycol flows into the rich glycol storage tank 6;

[0083] S4. Glycol Recovery and Regeneration: Rich glycol enters the regeneration tower 15 for stripping and dechlorination, then enters the solution regeneration kettle 16 (heated with hot water at 80-90 ℃) to evaporate residual water. Lean glycol is returned to the lean glycol storage tank 5 through filter 18 for recycling (recovery rate ≥95%).

[0084] S5. Zero wastewater discharge treatment: All wastewater is collected in brine buffer tank 11 and pumped into solution evaporation kettle 12 at regular intervals. Hot water evaporates and crystallizes, steam is discharged into the air, and crystallized salt is transported out. The system achieves zero wastewater discharge.

[0085] In summary, this invention can remove impurities, moisture, and chloride ions carried from the compressed air in the salt cavern gas storage tank, and can treat the air outlet of the salt cavern into clean air, reducing the corrosion protection cost of materials and meeting the air intake requirements of the expander.

Claims

1. A salt cavern compressed air filtration dechlorination system characterized by: The system comprises: a chlorine ion removal device for directly contacting high-pressure air containing chlorine from a salt cavern with liquid chlorine-adsorbing agent to transfer chlorine ions to the liquid phase, and then separating the gas-liquid two phases to obtain dechlorinated air and rich glycol; a glycol storage device for circulating the chlorine-adsorbing agent, comprising a rich glycol storage tank connected to the chlorine ion removal device and a poor glycol storage tank connected to the glycol regeneration device; a glycol regeneration device in fluid communication with the glycol storage device for recovering the chlorine-adsorbing agent from the rich glycol to obtain poor glycol for recycling; a brine purification device for receiving and centrally processing salt-containing wastewater generated by the system so that no liquid wastewater is discharged to the outside during system operation; the chlorine ion removal device comprises: a cyclone separator (1) for removing solid particles with a particle size of ≥10 μm and free water in the high-pressure air; an alcohol injection pump downstream of the cyclone separator (1) for injecting poor glycol into the high-pressure air in the form of mist to form a gas-liquid mixed flow; a coupling separator (4) downstream of the alcohol injection pump for separating the mixed flow into dechlorinated air and rich glycol; the glycol regeneration device comprises: a regeneration tower (15) for stripping the rich glycol in the poor solution buffer tank (17) to remove sulfur; a solution regeneration kettle (16) for evaporating water from the rich glycol and concentrating chlorine salt; a poor solution buffer tank (17) for sending the recovered poor glycol back to the regeneration tower (15) for recycling; the glycol storage device comprises: a poor glycol storage tank (5) with a poor glycol inlet connected to the outlet of the poor solution buffer tank (17) and a poor glycol outlet connected to the alcohol injection pump in the chlorine ion removal device; a rich glycol storage tank (6) with a rich glycol inlet connected to the coupling separator (4) of the chlorine ion removal device and a rich glycol outlet connected to the poor solution buffer tank (17); the brine purification device comprises: a brine buffer tank (11) for collecting salt-containing wastewater from the chlorine ion removal device, the glycol storage device and the glycol regeneration device; a solution evaporation kettle (12) for evaporating the salt-containing wastewater collected by the brine buffer tank (11) to precipitate solid salt, and directly venting or condensing the evaporation steam, and discharging the solid salt.

2. The salt cavern compressed air filtration dechlorination system of claim 1, wherein: The heat exchanger inlet of the solution regeneration kettle (16) is injected with medium-temperature hot water from the compressed air energy storage power station, and the heat exchanger outlet is discharged with low-temperature hot water.

3. The salt cavern compressed air filtration dechlorination system of claim 1, wherein: The heat exchanger inlet of the solution evaporation kettle (12) is injected with medium-temperature hot water from the compressed air energy storage power station, and the heat exchanger outlet is discharged with low-temperature hot water.

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