Heat exchanger for compressed air energy storage system

Abstract

The present application belongs to compressed air energy storage system technical field, specifically relates to a heat exchanger for compressed air energy storage system, and the present application includes the closed pressure vessel which is formed by cylinder, upper head and lower head, the inner chamber of pressure vessel includes water collecting and storing area, gas distribution and flow equalization area, heat exchange enhancement area, water distribution and separation area and top exhaust area from bottom to top in turn, the side wall of water collecting and storing area is provided with water outlet, the side wall of gas distribution and flow equalization area is provided with gas inlet, the gas distributor connected with gas inlet is fixedly arranged in gas distribution and flow equalization area, a plurality of filler layers are fixedly arranged in heat exchange enhancement area, the side wall of water distribution and separation area is provided with water inlet, the water distributor is fixedly arranged in water distribution and separation area, the gas-water separation assembly is fixedly arranged on water distributor, and the exhaust port communicating with top exhaust area is arranged at the top end of pressure vessel.The present application can make the overall structure of compressed air energy storage system more compact, and improve heat energy recovery efficiency and system overall circulation efficiency.

Description

Technical Field

[0001] This invention belongs to the technical field of compressed air energy storage systems, specifically relating to a heat exchanger for compressed air energy storage systems. It is particularly suitable for achieving efficient cooling and heat recovery between compressor stages and efficient reheating between expander stages under low-temperature heat storage conditions. It can be widely used in fields such as new energy power consumption, grid peak shaving, and large-scale physical energy storage. Background Technology

[0002] Compressed air energy storage is considered one of the most promising large-scale energy storage technologies. It stores energy through compressed air and releases energy through expanded air, playing a vital role in areas such as grid peak shaving and renewable energy grid integration. The heat exchanger is a core component of a compressed air energy storage system, and its performance directly affects the efficiency and economic benefits of the entire system.

[0003] During energy storage (charging), multi-stage compressors generate a large amount of compression heat. To reduce the compression power consumption of subsequent stages and recover high-quality heat energy, heat exchangers are installed between stages to cool the high-temperature, high-pressure air and store the recovered heat energy. During energy release (discharge), the stored high-pressure air needs to be reheated in a heat exchanger before entering each stage of expander to improve output power and system efficiency. This heat usually comes from the compression heat recovered during the energy storage stage. Since compressed air energy storage uses atmospheric air, which contains varying degrees of moisture, the moisture in the air condenses and is carried away by the air during continuous compression and cooling. To ensure the safety of subsequent equipment, the water in the air needs to be separated after heat exchange. Currently, the compressed air energy storage industry mainly uses independent air-water separators for air-water separation.

[0004] One typical compressed air energy storage system can be found in Chinese patent document CN118008512A, which discloses a compressed air energy storage and power generation system with dehydration, including a gas storage subsystem, an energy release subsystem, a cold and heat storage subsystem, and a controller. The gas storage subsystem is used to absorb and compress air from nature into a high-density, high-pressure effective resource and store it. The cold and heat storage subsystem is used to provide a cold or heat source for the system. The energy release subsystem is used to convert the aforementioned high-density, high-pressure effective resource into electrical energy. The controller is used to control the stable operation of the compressed air energy storage and power generation system with dehydration under certain conditions. The energy release subsystem includes a dehydration device, a reheating device, and an expansion power generation device. The working fluid extracted from the gas storage device is dehydrated by the dehydration device, then heated by the reheating device, and finally enters the expansion power generation device to generate electricity. The dehydration device includes a first expander and a first separator. The working fluid after passing through the first expander contains a liquid working fluid. The gaseous and liquid working fluids are separated in the first separator, and the gaseous working fluid flows out of the outlet of the first separator and into the reheating device for heating. The dehydration device also includes a second separator, the outlet of which is connected to the inlet of the first expander. The inlet of the second separator is connected to the working fluid collected from the gas storage device. The reheating device also includes a second heat exchanger, the cold inlet of which is connected to the outlet gas of the first separator, and the cold outlet of which is connected to the inlet of the second expander. The heat in the hot path of the second heat exchanger is provided by the cold and heat storage subsystem. The gas storage subsystem includes an energy storage compressor unit, a third heat exchanger, and a gas storage device. The hot inlet of the third heat exchanger is connected to the outlet of the energy storage compressor unit, and the hot outlet of the third heat exchanger is connected to the inlet of the gas storage device. The cold inlet of the third heat exchanger is connected to the outlet of the cold storage tank, and the cold outlet of the third heat exchanger is connected to the inlet of the heat storage tank. The third heat exchanger in the above scheme is used to cool the compressed air at the outlet of the energy storage compressor unit and store the heat of the compressed air in a heat storage tank for use by the second heat exchanger of the rewarming system. However, the specific structures of the second and third heat exchangers are not disclosed. In addition, its gas-water separation function is achieved through independently set first and second separators.

[0005] Most heat exchangers currently used for compressed air energy storage are traditional shell-and-tube heat exchangers (such as shell-and-tube and plate-and-fin heat exchangers). These heat exchangers transfer heat through metal walls and have the following drawbacks when applied to compressed air energy storage systems: (1) Limited heat transfer performance: The metal walls have thermal resistance, and in order to adapt to high-pressure conditions, the metal walls are thickened to avoid further reducing the efficiency of heat recovery and utilization; (2) Large pressure loss, affecting system efficiency: When the gas flows through complex tube bundles or finned channels, the flow resistance is large, resulting in a loss of power generation efficiency; (3) Poor high-pressure adaptability and bulky equipment: In order to withstand high-pressure conditions, the wall thickness of the equipment is greatly increased, resulting in a large size and high cost.

[0006] In contrast, direct contact heat exchange, through direct contact between the gas and liquid phases, allows for more complete heat exchange. Applying it to interstage coolers and reheaters in compressed air energy storage systems holds promise for efficient recovery and utilization of compression heat, further improving system cycle efficiency. However, most existing direct contact heat exchangers are designed for atmospheric pressure, and there is a lack of adaptable modification schemes for compressed air energy storage systems.

[0007] In addition, in the existing technology, heat exchangers and gas-water separators are usually arranged separately. In compressed air energy storage power stations, a gas-water separator is generally required after each heat exchanger. The purpose is to separate the water that is released after the air is cooled, so as to reduce the water content of the air, ensure the safe and stable operation of the compressor, expander and gas storage equipment, and improve the service life of the equipment. However, this separate arrangement has the following problems: (1) Large footprint: The heat exchanger and gas-water separator are arranged separately, which occupies a lot of plant space; (2) Long connecting pipelines: The equipment is connected by riser pipes and downpipes, which consumes a lot of pipes and plates; (3) High flow resistance: The pipeline system increases the air side pressure drop, which has an adverse effect on the conversion efficiency of the energy storage power station; (4) Heat loss: There is heat loss during pipeline transportation, which affects the overall efficiency of the system. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a heat exchanger for a compressed air energy storage system, which can make the overall structure of the compressed air energy storage system more compact, while improving the heat recovery efficiency and the overall system circulation efficiency.

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a heat exchanger for a compressed air energy storage system, comprising a closed pressure vessel consisting of a cylindrical body, an upper head, and a lower head. Both the upper and lower heads are spherical arc-shaped shells. The axis of the pressure vessel is vertically oriented. The inner cavity of the pressure vessel, from bottom to top, includes a water collection and storage area, an air distribution and equalization area, an enhanced heat exchange area, a water separation area, and a top exhaust area. An outlet is provided on the side wall of the water collection and storage area of ​​the pressure vessel, and the outlet is positioned below the designed minimum liquid level. The pressure vessel is equipped with a drain outlet at its bottom, connecting to the water collection and storage area; an air inlet is located on the side wall of the air distribution and equalization zone, and a gas distributor is fixedly installed within the air distribution and equalization zone, with its inlet end connected to the air inlet; several packing layers are fixedly installed within the enhanced heat exchange zone, with the outer periphery of the packing layers relatively sealed to the inner wall of the pressure vessel; a water inlet is located on the side wall of the water distribution and separation zone, and a water distributor is fixedly installed within the water distribution and separation zone, comprising a main water distribution pipe and multi-stage concentric annular water distribution pipes. The multi-stage concentric annular water distribution pipe includes multiple annular water distribution pipes arranged coaxially with respect to the cylindrical body. The inlet ends of each annular water distribution pipe are connected to the inlet via a main water distribution pipe. Multiple atomizing nozzles are evenly spaced along the annular direction at the bottom of each annular water distribution pipe, with the inlet ends of the atomizing nozzles connected to the outlet ends of the annular water distribution pipes. The height of the multiple annular water distribution pipes decreases progressively from the axis of the cylindrical body to the outer wall of the cylindrical body. An air-water separation assembly is fixedly installed on the water distributor. The components include a horizontal gas-water separator and a conical annular gas-water separator. The horizontal gas-water separator is located in the inner circumferential region of the innermost annular water distribution pipe. The conical annular gas-water separator is located between two adjacent annular water distribution pipes. If the outermost annular water distribution pipe has a gap relative to the inner circumferential wall of the pressure vessel, a conical annular gas-water separator is also provided between the outermost annular water distribution pipe and the inner circumferential wall of the pressure vessel. The top of the pressure vessel is provided with an exhaust port that connects to the top exhaust area.

[0010] A further preferred embodiment is that the packing layer is supported by a grid-type packing support plate, which is fixedly connected to the inner peripheral wall of the pressure vessel.

[0011] A further preferred embodiment is that the packing layer includes a regular corrugated packing layer and a graphite sheet composite heat exchange layer arranged sequentially from bottom to top, wherein the graphite sheet composite heat exchange layer is composed of multiple graphite sheets stacked or combined in parallel along the vertical direction.

[0012] A further preferred option is that the gas-water separation component uses a wire mesh demister.

[0013] A further preferred option is to have three circular water distribution pipes.

[0014] A further preferred embodiment is that the inner circumferential conical surfaces of all conical annular air-water separators are located on the same conical surface; and the circumferential central axes of all annular water distribution pipes are located on the same conical surface.

[0015] A further preferred embodiment is: the angle formed by the generatrix corresponding to the inner conical surface of the conical annular gas-water separator relative to the horizontal plane is set as 'a', and the value of 'a' ranges from 15° to 45°.

[0016] A further preferred embodiment is: the gas distributor includes a main gas distribution pipe extending horizontally along the radial direction of the cylindrical body, one end of the main gas distribution pipe being connected to the air inlet, and the other end being closedly connected to the inner wall of the cylindrical body or sealed by a first sealing plate; multiple gas distribution branch pipes are fixedly provided on the side wall of the main gas distribution pipe, the gas distribution branch pipes are arranged at intervals along the axial direction of the main gas distribution pipe, and are symmetrically arranged on both sides of the main gas distribution pipe; the axis of each gas distribution branch pipe is arranged horizontally along the radial direction of the main gas distribution pipe, one end of the gas distribution branch pipe is connected to the main gas distribution pipe, and the other end is closedly connected to the inner wall of the cylindrical body or sealed by a second sealing plate; the bottom of the gas distribution branch pipe is provided with several evenly distributed air outlets, and the air outlet direction of a single air outlet is vertically downward or inclined downward.

[0017] A further preferred embodiment is as follows: the air outlet with a vertical downward air outlet direction is designated as the first air outlet, and the air outlet with an inclined downward air outlet direction is designated as the second air outlet. Each air distribution branch pipe has one set of first air outlets and two sets of second air outlets at its bottom. The axis of the first air outlet is located in the vertical plane where the axis of the air distribution branch pipe is located. The two sets of second air outlets are mirror-symmetrical with respect to the vertical plane where the axis of the air distribution branch pipe is located. The angle formed by the axis of the second air outlet with respect to the horizontal plane is b, and the value of b is in the range of 45° to 75°.

[0018] The heat exchanger can be used for interstage cooling of the compressor or interstage reheat of the expander. In the energy storage (compression) stage, high-temperature and high-pressure air and cooling water come into direct contact from bottom to top, achieving interstage cooling and heat recovery. The humid air after heat exchange enters the gas-water separation component, where the entrained water mist is removed. The separated condensate falls directly into the water distribution area below, where it participates in heat exchange downwards together with the cooling water sprayed from the atomizing nozzle, achieving in-situ reuse of water resources. In the energy release (expansion) stage, high-pressure air and high-temperature water come into direct contact from bottom to top, achieving interstage reheat.

[0019] The heat exchanger of the present invention has no intermediate heat-conducting wall. It achieves integrated water distribution and separation through the composite structure of water distributor and gas-water separation component. It achieves efficient heat exchange through the packing layer (a composite heat exchange layer of regular corrugated packing and graphite sheet). The conical arrangement structure of the gas-water separation component guides the gas to converge towards the center, thereby achieving precise control of air-side pressure drop.

[0020] In summary, compared with the prior art, the beneficial effects of the present invention are as follows: (1) Applicable to compression heat recovery and reuse processes. This heat exchanger can be used for interstage cooling of the compressor or interstage reheat of the expander, which can meet the functional requirements of the heat exchange equipment in the compression heat recovery and reuse process; realize high recovery and utilization of compression heat, and improve the cycle efficiency of the system.

[0021] (2) Improve heat exchange efficiency under high pressure conditions and reduce equipment volume. This heat exchanger adopts a direct gas-liquid contact method, eliminating the thermal resistance of the metal wall surface of the indirect heat exchanger. High-pressure atomized spray increases the initial gas-liquid contact area, and the regular corrugated packing layer extends the contact time and regularizes the flow channel. At the same time, a graphite sheet composite heat exchange layer is set above the regular corrugated packing layer to further increase the gas-liquid contact interface. The combined effect of the regular corrugated packing layer and the graphite sheet composite heat exchange layer can make the overall heat transfer coefficient significantly higher than that of the indirect heat exchanger. Under the same heat exchange conditions, the equipment volume and weight can be reduced accordingly, which helps to reduce equipment investment and floor space.

[0022] (3) Reduce gas-side pressure drop. The heat exchanger adopts a uniform low-speed gas distribution design, combined with the regular flow channels of the regular corrugated packing layer, and the airflow guidance effect of the conical arrangement structure of the gas-water separation component, to control the air-side flow pressure drop at an extremely low level, which can reduce gas flow resistance, improve system efficiency and reduce power generation costs.

[0023] (4) Eliminate the inherent defects of the separate arrangement of the gas-water separator. By saving the gas-water separator equipment, the number of pipes in the heat exchange system is reduced, the complexity is reduced, and thus the resistance loss caused by the air inlet and outlet of the separator and the connecting pipes is reduced. By embedding the gas-water separation component inside the heat exchanger, gas-water separation is carried out directly after the air is separated into water. On the one hand, this reduces the number of energy storage system equipment, reduces the energy storage system piping configuration and pressure loss, and on the other hand, it saves energy storage system costs.

[0024] (5) The composite structure of water distributor and gas-water separation component achieves high integration and functional coupling. In this invention, the independent gas-water separator in the traditional solution is integrated into the heat exchanger and combined with the water distributor into an integral composite structure; through the layered arrangement of multi-level concentric ring water distribution pipes, and the overall layout of the conical structure, the gas-water separation component is set in the gap area between the ring water distribution pipes to achieve space reuse; the separated condensate falls directly into the water distribution area without the need for additional pipelines, realizing in-situ water resource reuse.

[0025] (6) The conical arrangement of the gas-water separation component optimizes gas flow and significantly reduces pressure drop. The multi-stage concentric ring water distribution pipe is arranged in a conical shape (high in the center and low around the edges), forming a natural gas convergence channel in cross-section; the rising gas converges towards the center under the guidance of the conical structure, reducing flow resistance; compared with the traditional planar water distribution structure, it can reduce gas pressure drop.

[0026] (7) Condensate is reused in situ, simplifying the system process. The condensate captured by the gas-liquid separation component drips directly downwards under gravity and merges with the spray water to participate in heat exchange; there is no need to set up independent condensate collection pipelines and drainage devices, reducing system components and reducing the risk of leakage; achieving efficient recycling of water resources and reducing system water consumption. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the planar layout structure of the present invention; Figure 2 for Figure 1 The bottom view corresponding to the AA section; Figure 3 for Figure 1 The bottom view corresponding to the BB section.

[0028] Component markings in the diagram: 1-Cylindrical body; 2-Upper end cap; 3-Lower end cap; 4-Air inlet; 5-Exhaust outlet; 6-Water inlet; 7-Water outlet; 8-Sewage outlet; 9-Gas distributor; 10-Regulated corrugated packing layer; 11-Graphite sheet composite heat exchange layer; 12-Grid-type packing support plate; 13-Main water distribution pipe; 14-First-stage annular water distribution pipe; 15-Second-stage annular water distribution pipe; 16-Third-stage annular water distribution pipe; 17-Atomizing nozzle; 18-Gas-water separation component; 91-Main gas distribution pipe; 92-Branch gas distribution pipe; 93-Air outlet. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Please see Figures 1 to 3This invention comprises a closed pressure vessel consisting of a cylindrical body 1, an upper end cap 2, and a lower end cap 3. Both the upper end cap 2 and the lower end cap 3 are spherical arc-shaped shells, and the axis of the pressure vessel is vertically oriented. The pressure vessel uses a vertical cylindrical body 1 as its main structure, with both ends sealed to the spherical arc-shaped end caps, which can better adapt to high-pressure operating conditions. In the specific manufacturing process, the pressure vessel can be made from a conventional pressure vessel material of appropriate thickness according to the specific operating conditions of the compressed air energy storage system.

[0031] The inner cavity of the pressure vessel, from bottom to top, includes a water collection and storage area, a gas distribution and equalization area, an enhanced heat exchange area, a water separation area, and a top venting area. The side wall of the water collection and storage area is equipped with an outlet 7, positioned below the design minimum liquid level. A drain outlet 8, connected to the water collection and storage area, is located at the bottom of the pressure vessel. The water collection and storage area, located at the bottom of the pressure vessel, is formed by the inner wall of the lower head 3 and the lower inner wall of the cylindrical body 1. Its main function is to collect and discharge the heat-exchanged liquid. The outer port of the outlet 7 is used to connect to the outlet pipe; the outer port of the drain outlet 8 is used to connect to the drainage pipe (with a vent valve). During shutdown and maintenance, the internal water is drained using the drain outlet 8. The outlet 7 is positioned below the design minimum liquid level to ensure a stable water seal at the bottom, preventing high-pressure gas from entering the outlet pipe.

[0032] An air inlet 4 is provided on the side wall of the air distribution and equalization zone of the pressure vessel. A gas distributor 9 is fixedly installed in the air distribution and equalization zone, and the inlet end of the gas distributor 9 is connected to the air inlet 4. The outer port of the air inlet 4 is used to connect to the air inlet pipeline. The gas distributor 9 is used to ensure that compressed air can enter the enhanced heat exchange zone evenly and stably. Several packing layers are fixedly installed in the enhanced heat exchange zone. The outer periphery of the packing layer is relatively sealed with the inner wall of the pressure vessel. That is, the compressed air introduced from the air inlet 4 must pass through the packing layer to enter the top exhaust zone, and the heat exchange liquid medium (usually water) introduced from the water inlet 6 must pass through the packing layer to enter the bottom water collection and storage zone. The packing layer is the core component for heat exchange between the gas and liquid phases.

[0033] The side wall of the water distribution separation zone of the pressure vessel is provided with an inlet 6. A water distributor 9 is fixedly installed in the water distribution separation zone. The water distributor 9 includes a main water distribution pipe 13 and a multi-stage concentric annular water distribution pipe. The multi-stage concentric annular water distribution pipe includes multiple annular water distribution pipes arranged coaxially with respect to the cylindrical body 1. The inlet end of each annular water distribution pipe is connected to the inlet 6 through the main water distribution pipe 13. Multiple atomizing nozzles 17 are evenly spaced along the annular direction at the bottom of the annular water distribution pipe. The inlet end of the atomizing nozzle 17 is connected to the outlet end of the annular water distribution pipe. The main water distribution pipe 13 is used to distribute the heat exchange liquid medium (usually water) to each annular water distribution pipe. The atomizing nozzles 17 are used to disperse the liquid introduced from the inlet 6 into fine droplets and spray them evenly to the enhanced heat exchange zone below.

[0034] In the direction from the axis of cylindrical body 4 towards the outer wall of cylindrical body 4, the height of the multiple annular water distribution pipes decreases progressively. Specifically, the innermost annular water distribution pipe with the smallest diameter is positioned highest, with the height of the other annular water distribution pipes decreasing sequentially, and the outermost annular water distribution pipe with the largest diameter being positioned lowest. The multi-stage concentric annular water distribution pipes have a conical structure (high in the center and low around the edges). This arrangement has the following advantages: it reduces the flow resistance of rising gas, guides gas towards the center, and facilitates smooth gas entry into the exhaust port 5; it also enables multi-layered and uniform distribution of the heat exchange liquid medium across the heat exchanger cross-section.

[0035] A gas-water separation component 18 is fixedly installed on the water distributor 9. The gas-water separation component 18 includes a horizontal gas-water separator and a conical annular gas-water separator. The conical annular gas-water separator refers to a component whose inner and outer circumferential surfaces are both conical (without a cone tip). The horizontal gas-water separator is located in the inner circumferential area of ​​the innermost annular water distribution pipe. The conical annular gas-water separator is located between two adjacent annular water distribution pipes. If the outermost annular water distribution pipe has a gap area relative to the inner circumferential wall of the pressure vessel, a conical annular gas-water separator is also provided between the outermost annular water distribution pipe and the inner circumferential wall of the pressure vessel. That is, in some embodiments, the outermost annular water distribution pipe can be directly fixed to the inner circumferential wall of the pressure vessel. In this case, the conical annular gas-water separator is only provided between two adjacent annular water distribution pipes. The top of the pressure vessel is provided with an exhaust port 5 that connects to the top exhaust zone. The top of the pressure vessel is the top of the upper head 2. The top exhaust zone is mainly the inner cavity of the upper head 2. The outer port of the exhaust port 5 is used to connect to the exhaust pipeline. The gas after heat exchange is collected in the top exhaust zone and discharged from the heat exchanger through the exhaust port 5. Depending on the arrangement of the main water distribution pipe 13, if the main water distribution pipe 13 needs to pass through the air-water separation component 18, the air-water separation component 18 has a corresponding clearance notch. For example, in the preferred embodiment shown in the figure, the main water distribution pipe 13 is a straight pipe arranged at an inclination relative to the horizontal plane. The central axis of the main water distribution pipe 13 and the circumferential central axis of the annular water distribution pipe are located on the same conical surface. Except for the innermost annular water distribution pipe (i.e., the third-level annular water distribution pipe 16 shown in the figure), the other annular water distribution pipes (i.e., the first-level annular water distribution pipe 14 and the second-level annular water distribution pipe 15 shown in the figure) all have a break notch. That is, the first-level annular water distribution pipe 14 and the second-level annular water distribution pipe 15 are not complete annular structures, but two branch pipe inlets are formed at the break notch, and are connected to the two sides of the main water distribution pipe 13 through the branch pipe inlets. The conical annular air-water separator has a clearance notch corresponding to the main water distribution pipe 13. When the rising humid air passes through the gas-water separation component 18, the droplets in the airflow are captured and condensed. The separated condensate drips directly downwards and, together with the water sprayed from the atomizing nozzle 17, enters the enhanced heat exchange zone to participate in the heat exchange cycle. The gas-water separation component 18 also adopts a conical structure layout, which can reduce the flow resistance when the gas rises, guide the gas to converge towards the center, and facilitate the smooth entry of the gas into the exhaust port 5.

[0036] This invention is applicable to compression heat recovery and reuse processes. It can operate in both compressor interstage cooling and expander interstage reheat, meeting the functional requirements of heat exchange equipment in compression heat recovery and reuse processes, achieving high recovery and utilization of compression heat, and improving the system's cycle efficiency. In the energy storage (compression) stage, high-temperature, high-pressure air and cooling water directly contact each other from bottom to top, achieving interstage cooling and heat recovery. The humid air after heat exchange enters the gas-water separation component 18, where entrained water mist is removed. The separated condensate falls directly into the lower water distribution area, where it participates in heat exchange downwards together with the cooling water sprayed from the atomizing nozzle 17, achieving in-situ water reuse. In the energy release (expansion) stage, high-pressure air and high-temperature water directly contact each other from bottom to top, achieving interstage reheat.

[0037] To facilitate the installation and fixing of the packing layer, in a preferred embodiment, the packing layer is supported by a grid-type packing support plate 12, which is fixedly connected to the inner peripheral wall of the pressure vessel. The grid-type packing support plate 12 and the inner peripheral wall of the pressure vessel are generally fixed by welding.

[0038] To enhance heat exchange and reduce gas pressure drop, the packing layer comprises a regularly corrugated packing layer 10 and a graphite sheet composite heat exchange layer 11 arranged sequentially from bottom to top. The graphite sheet composite heat exchange layer 11 is composed of multiple graphite sheets stacked or composited and arranged side-by-side along the vertical direction. The regularly corrugated packing layer 10 utilizes its regular flow channels to simultaneously increase the heat transfer area, extend the contact time, and reduce gas flow resistance. The graphite sheet composite heat exchange layer 11 is composed of stacked or composited graphite sheets with high thermal conductivity. Utilizing the high thermal conductivity and porous structure of graphite material, it constructs efficient microscopic heat conduction channels between the gas and liquid phases, further increasing the gas-liquid contact area and allowing the liquid to form a more uniform liquid film on the graphite surface. The combined effect of the regularly corrugated packing layer 10 and the graphite sheet composite heat exchange layer 11 results in an overall heat transfer coefficient significantly higher than that of a partitioned heat exchanger; under the same heat exchange conditions, the equipment volume and weight can be correspondingly reduced, helping to reduce equipment investment and floor space.

[0039] In specific implementation, the gas-water separation component 18 can adopt a wire mesh demister, baffle plate, swirl blade or a combination of the above structures. In the preferred embodiment, the gas-water separation component 18 adopts a wire mesh demister, which has the characteristics of simple structure, low pressure drop and high separation efficiency.

[0040] Depending on the equipment diameter and flow requirements, the multi-stage concentric annular water distribution pipe can be configured as a two-stage, three-stage, or four-stage concentric annular water distribution pipe. The more stages, the better the water distribution uniformity, but the structural complexity increases. In a preferred embodiment, a three-stage concentric annular water distribution pipe is used, which is equivalent to having three annular water distribution pipes, corresponding to the first-stage annular water distribution pipe 14, the second-stage annular water distribution pipe 15, and the third-stage annular water distribution pipe 16.

[0041] To further facilitate gas accumulation and reduce pressure drop, in a preferred embodiment, the inner circumferential conical surfaces of all the conical annular gas-water separators are located on the same conical surface. Correspondingly, the circumferential central axes of all the annular water distribution pipes are also located on the same conical surface. In a further preferred embodiment, the vertical spacing between the circumferential central axes of the multiple annular water distribution pipes in the up-down direction is the same.

[0042] The angle between the generatrix of the inner conical surface of the conical annular gas-water separator and the horizontal plane is set as 'a'. The larger the value of 'a', the better the gas gathering effect, but it may increase the height of the equipment. In a preferred embodiment, the value of 'a' ranges from 15° to 45°.

[0043] In a preferred embodiment, the gas distributor 9 includes a main gas distribution pipe 91 extending horizontally along the radial direction of the cylindrical body 1. One end of the main gas distribution pipe 91 is connected to the air inlet 4, and the other end is either closedly connected to the inner wall of the cylindrical body 1 or sealed by a first sealing plate. A plurality of gas distribution branch pipes 92 are fixedly provided on the side wall of the main gas distribution pipe 91. The gas distribution branch pipes 92 are arranged at intervals along the axial direction of the main gas distribution pipe 91 and are symmetrically arranged on both sides of the main gas distribution pipe 91. The axis of each gas distribution branch pipe 92 is arranged horizontally along the radial direction of the main gas distribution pipe 91. One end of the gas distribution branch pipe 92 is connected to the main gas distribution pipe 91, and the other end is closedly connected to the inner wall of the cylindrical body 1 or sealed by a second sealing plate. In a preferred embodiment, the end of the gas distribution branch pipe 92 is spaced at a certain distance from the inner wall of the cylindrical body 1 and sealed by a second sealing plate. A plurality of evenly distributed air outlets 93 are provided at the bottom of the gas distribution branch pipe 92. The air outlet direction of a single air outlet 93 is vertically downward or inclined downward. The number of gas distribution branch pipes 92 can be reasonably determined according to the inner diameter of the cylindrical body 1. The diameter and spacing of the outlet holes 93 are determined according to the requirements of gas flow rate and distribution uniformity. It is preferred to adopt an equal spacing and equal diameter design. The outlet direction of the outlet holes 93 in the above scheme is vertically downward or inclined downward. It can be interpreted in a broad sense, that is, it is equivalent to having the following three schemes: (1) The outlet direction of all outlet holes 93 is vertically downward, that is, the airflow direction is vertically downward and turns back upward through the bottom; (2) The outlet direction of all outlet holes 93 is inclined downward (preferably at an angle of 45° to 75° with the horizontal direction), that is, the airflow direction is towards the side and downward; (3) The outlet holes with vertically downward and inclined downward are arranged alternately to realize multi-directional airflow distribution. It can be that all gas distribution branch pipes 92 are arranged with vertically downward and inclined downward outlet holes at the same time, or it can be that some gas distribution branch pipes 92 are used to arrange outlet holes with vertically downward and other gas distribution branch pipes 92 are used to arrange outlet holes with inclined downward.

[0044] In a further preferred embodiment, an outlet 93 with a vertically downward airflow direction is designated as the first outlet, and an outlet 93 with an inclined downward airflow direction is designated as the second outlet. Each air distribution branch pipe 92 has one set of first outlets and two sets of second outlets at its bottom. The axis of the first outlet is located in the vertical plane containing the axis of the air distribution branch pipe 92. The two sets of second outlets are mirror-symmetrical with respect to the vertical plane containing the axis of the air distribution branch pipe 92. The angle formed by the axis of the second outlet with respect to the horizontal plane is 'b', where 'b' ranges from 45° to 75°. The airflow first flows laterally and downwards from the outlet 93, then upwards, and finally enters the enhanced heat exchange zone uniformly, stably, and without deviation.

Claims

1. A heat exchanger for a compressed air energy storage system, characterized in that: The pressure vessel is a closed pressure vessel consisting of a cylindrical body (1), an upper head (2), and a lower head (3). Both the upper head (2) and the lower head (3) are spherical arc shells. The axis of the pressure vessel is vertically oriented. The inner cavity of the pressure vessel includes, from bottom to top, a water collection and storage area, a gas distribution and equalization area, an enhanced heat exchange area, a water distribution and separation area, and a top exhaust area. The side wall of the water collection and storage area of ​​the pressure vessel is provided with an outlet (7). The position of the outlet (7) is lower than the design minimum liquid level. The bottom end of the pressure vessel is provided with a drain outlet (8) that connects to the water collection and storage area. An air inlet (4) is provided on the side wall of the gas distribution and equalization zone of the pressure vessel. A gas distributor (9) is fixedly installed in the gas distribution and equalization zone, and the air inlet end of the gas distributor (9) is connected to the air inlet (4). Several packing layers are fixedly installed in the enhanced heat exchange zone, and the outer periphery of the packing layer is relatively closed to the inner wall of the pressure vessel. A water inlet (6) is provided on the side wall of the water distribution and separation zone of the pressure vessel. A water distributor (9) is fixedly installed in the water distribution and separation zone. The water distributor (9) includes a main water distribution pipe (13) and a multi-stage concentric ring water distribution pipe. The multi-stage concentric ring water distribution pipe includes a phase For the multiple annular water distribution pipes arranged coaxially on the cylindrical body (1), the water inlet end of the annular water distribution pipe is connected to the water inlet (6) through the main water distribution pipe (13). Multiple atomizing nozzles (17) are evenly spaced at the bottom of the annular water distribution pipe along its annular direction. The inlet end of the atomizing nozzle (17) is connected to the water outlet end of the annular water distribution pipe. In the direction from the axis of the cylindrical body (4) to the outer wall of the cylindrical body (4), the height of the multiple annular water distribution pipes decreases. An air-water separation component (18) is fixedly installed on the water distributor (9). The gas-water separation assembly (18) includes a horizontal gas-water separator and a conical annular gas-water separator. The horizontal gas-water separator is located in the inner circumferential area of ​​the innermost annular water distribution pipe. The conical annular gas-water separator is located between two adjacent annular water distribution pipes. If the outermost annular water distribution pipe has a gap relative to the inner circumferential wall of the pressure vessel, a conical annular gas-water separator is also provided between the outermost annular water distribution pipe and the inner circumferential wall of the pressure vessel. The top of the pressure vessel is provided with an exhaust port (5) that connects to the top exhaust area.

2. The heat exchanger for a compressed air energy storage system as described in claim 1, characterized in that: The packing layer is supported by a grid-type packing support plate (12), which is fixedly connected to the inner circumferential wall of the pressure vessel.

3. The heat exchanger for a compressed air energy storage system as described in claim 1, characterized in that: The packing layer includes a regular corrugated packing layer (10) arranged from bottom to top and a graphite sheet composite heat exchange layer (11). The graphite sheet composite heat exchange layer (11) is composed of multiple graphite sheets stacked or combined in parallel along the vertical direction.

4. The heat exchanger for a compressed air energy storage system as described in claim 1, characterized in that: The gas-water separation component (18) uses a wire mesh demister.

5. The heat exchanger for a compressed air energy storage system as described in claim 1, characterized in that: There are three circular water distribution pipes.

6. The heat exchanger for a compressed air energy storage system as described in claim 1, characterized in that: The inner circumferential conical surfaces of all conical annular air-water separators are located on the same conical surface; the circumferential central axes of all annular water distribution pipes are located on the same conical surface.

7. The heat exchanger for a compressed air energy storage system as described in claim 1, characterized in that: The angle formed by the generatrix corresponding to the inner conical surface of the conical annular gas-water separator with respect to the horizontal plane is set as 'a', and the value of 'a' ranges from 15° to 45°.

8. The heat exchanger for a compressed air energy storage system as described in any one of claims 1 to 7, characterized in that: The gas distributor (9) includes a gas distribution main pipe (91) extending horizontally along the radial direction of the cylindrical body (1). One end of the gas distribution main pipe (91) is connected to the air inlet (4), and the other end is closedly connected to the inner wall of the cylindrical body (1) or sealed by a first sealing plate. Multiple gas distribution branch pipes (92) are fixedly provided on the side wall of the gas distribution main pipe (91). The gas distribution branch pipes (92) are arranged at intervals along the axial direction of the gas distribution main pipe (91) and symmetrically arranged on both sides of the gas distribution main pipe (91). The axis of each gas distribution branch pipe (92) is arranged horizontally along the radial direction of the gas distribution main pipe (91). One end of the gas distribution branch pipe (92) is connected to the gas distribution main pipe (91), and the other end is closedly connected to the inner wall of the cylindrical body (1) or sealed by a second sealing plate. Several evenly distributed air outlets (93) are provided at the bottom of the gas distribution branch pipe (92). The air outlet direction of a single air outlet (93) is vertically downward or inclined downward.

9. The heat exchanger for a compressed air energy storage system as described in claim 8, characterized in that: The air outlet (93) with the air outlet direction vertically downward is set as the first air outlet, and the air outlet (93) with the air outlet direction inclined downward is set as the second air outlet. Each air distribution branch pipe (92) has a set of first air outlets and two sets of second air outlets at its bottom. The axis of the first air outlet is located in the vertical plane where the axis of the air distribution branch pipe (92) is located. The two sets of second air outlets are mirror symmetrical with respect to the vertical plane where the axis of the air distribution branch pipe (92) is located. The angle formed by the axis of the second air outlet with respect to the horizontal plane is b, and the value of b is in the range of 45° to 75°.

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