Pche heat exchanger, gas-liquid separation method, and hydrophobic method

Abstract

The application relates to the technical field of compressed air energy storage, and discloses a PCHE heat exchanger, a gas-liquid separation method and a water draining method. The PCHE heat exchanger provided by the application is provided with multiple turning sections, the density difference of gas-liquid two-phase medium is utilized, a centrifugal force field is constructed in the turning process, when compressed air flows through the turning sections, the condensate water and the gas phase are separated by centrifugal force and attached to the wall surface, an independent steam-water separation device does not need to be additionally arranged or a complex separation component does not need to be additionally arranged in the heat exchanger, compared with the scheme in the prior art in which the heat exchange and the separation function are independent and the synergy is poor, the heat exchange efficiency is guaranteed, the compactness of the structure is effectively improved, and the equipment floor area is significantly reduced.

Description

Technical Field

[0001] This invention relates to the field of compressed air energy storage technology, specifically to PCHE heat exchangers, gas-liquid separation methods, and hydrophobic methods. Background Technology

[0002] Against the backdrop of the rapid development of the new energy industry, the challenge of integrating new energy sources has become a core bottleneck restricting the construction of new power systems. Compressed air energy storage, as a key technology in the field of long-term, large-scale energy storage, plays a vital role in improving grid stability and promoting the integration of renewable energy, while also possessing significant advantages such as large storage capacity, high technological maturity, and outstanding commercial application potential. In compressed air energy storage systems, the interstage cooling process of multi-stage compressors has a significant impact on the overall energy efficiency and operational reliability of the system.

[0003] Currently, interstage cooling in compressed air energy storage systems mostly uses shell-and-tube heat exchangers. These heat exchangers generally suffer from limited heat exchange efficiency and insufficient structural compactness, affecting system operating efficiency and energy economy. Meanwhile, to prevent condensate from being carried into subsequent compressors or energy storage units, causing equipment corrosion, component wear, and seal failure, the system typically requires an additional independent vapor-liquid separation device, or a simple addition of separation components inside the heat exchanger to achieve vapor-liquid separation.

[0004] However, in practical applications, it has been found that shell-and-tube heat exchangers are bulky and have limited heat transfer efficiency under high-pressure conditions. Meanwhile, traditional steam-water separation methods suffer from low separation efficiency, low equipment integration, and large footprint. This makes it difficult for traditional heat exchangers to achieve both efficient heat exchange and compact design with reliable separation, thus hindering the overall performance improvement of compressed air energy storage systems. Summary of the Invention

[0005] This invention provides a PCHE heat exchanger, a gas-liquid separation method, and a hydrophobic method to solve the problem that traditional heat exchangers cannot achieve compact design and reliable separation while ensuring efficient heat exchange.

[0006] In a first aspect, the PCHE heat exchanger provided by the present invention is used for compressed air energy storage and includes a heat exchanger body. The heat exchanger body adopts a printed circuit board type heat exchanger structure, and its interior is provided with a compressed air side flow channel for circulating compressed air and a cooling medium side flow channel for circulating cooling medium. The compressed air side flow channel and the cooling medium side flow channel are arranged in layers and staggered to form a counter-current heat exchange structure. The compressed air side flow channel is provided with multiple turning sections along the air flow direction. The turning sections are used to change the flow direction of the compressed air, so that the condensate entrained in the compressed air is separated and adhered to the flow channel wall under the action of centrifugal force.

[0007] Beneficial effects: By setting up multiple turning sections and utilizing the density difference between the gas and liquid phases, a centrifugal force field is constructed during the turning process. When the compressed air flows through the turning section, the condensate and gas phase are separated by centrifugal force and adhere to the wall surface. There is no need to set up an additional independent steam-water separation device or add complex separation components inside the heat exchanger. Compared with the existing technology where the heat exchange and separation functions are independent and have poor synergy, this invention effectively achieves a compact structure while ensuring heat exchange efficiency and significantly reduces the equipment footprint.

[0008] In one alternative embodiment, the compressed air side channel is arranged vertically so that condensate that pools on the wall surface settles downwards under gravity.

[0009] Beneficial effects: By setting the compressed air side channel vertically, gravity is used as the driving force, causing the condensate that has accumulated on the wall to continuously flow downwards and collect. In other words, compared to traditional methods that use external power or complex components to collect condensate, this invention achieves automatic directional delivery and collection of condensate simply by optimizing the channel layout. This eliminates the need for additional driving components, reduces energy consumption, and features a simple and reliable structure, helping to lower equipment manufacturing costs and simplify operation and maintenance.

[0010] In one alternative embodiment, the PCHE heat exchanger further includes a water tank disposed below the heat exchanger body, and the inlet of the water tank is connected to the compressed air side channel for collecting the condensate that has settled after separation.

[0011] Beneficial effects: The compressed air side channel is arranged vertically. Condensate settles along the wall under gravity and flows naturally to the bottom of the channel. By placing the water tank directly below the heat exchanger body, the settled condensate can directly enter the water tank by gravity, eliminating the need for additional pumping devices or diversion mechanisms. This simplifies the system structure, reduces energy consumption and equipment costs, and avoids the risk of condensate failure due to malfunctions of external power components. Furthermore, it fully utilizes the unused space at the bottom of the heat exchanger, without increasing the equipment's footprint, making it suitable for space-constrained applications such as salt caverns and underground chambers in compressed air energy storage systems.

[0012] In one optional embodiment, the water tank integrates a liquid level monitoring module, and the bottom of the water tank is provided with a drain pipe and a drain valve. The drain valve is installed on the drain pipe and is used to open or close the drain pipe according to the signal from the liquid level monitoring module.

[0013] Beneficial effects: The liquid level monitoring module can detect the amount of condensate accumulated in the water tank in real time. When the liquid level reaches the preset threshold, the drain valve will automatically open and will automatically close when the liquid level drops to a safe position. This achieves intelligent control of draining water on demand and draining water when the tank is full, without the need for manual intervention. This significantly reduces the workload of operation and maintenance, and is especially suitable for unattended or minimally staffed energy storage power station scenarios.

[0014] In one alternative embodiment, the cooling medium side channel is a direct current channel structure.

[0015] Beneficial effects: By setting the cooling medium side flow channel to a direct-flow structure, the pressure loss of the cooling medium when flowing through the heat exchanger is minimized, reducing the power consumption of the circulating pump, decreasing system auxiliary energy consumption, and improving the overall energy utilization efficiency of the compressed air energy storage system. Combined with the compressed air side flow channel consisting of multiple deflection sections, a certain flow resistance exists on the compressed air side, while the direct-flow structure on the cooling medium side makes the flow resistance of the cooling medium less than that of the compressed air side. This creates a mechanism of moderate flow obstruction on the high-pressure side and smooth flow on the low-pressure side, ensuring necessary disturbance and separation on the compressed air side while avoiding excessive pressure loss on the cooling medium side, resulting in a more rational overall pressure drop distribution within the heat exchanger.

[0016] In one alternative embodiment, the heat exchanger body is formed by chemically etching heat transfer plates to create microchannels, and then multiple heat transfer plates are fixedly connected by a vacuum diffusion welding process.

[0017] Beneficial effects: Chemical etching allows for flexible design of channel shape, size, and distribution density on heat transfer plates according to heat exchange requirements. Compared to traditional machining methods, chemical etching is burr-free, stress-free, and deformation-free, forming smooth flow channel walls. Furthermore, vacuum diffusion welding enables atomic diffusion at the interfaces of the multi-layer heat transfer plates, forming a seamless, filler-free, integral metallurgical bond structure. This eliminates fusion defects, weakened heat-affected zones, and the risk of dissimilar material connection failure inherent in traditional welding, resulting in a continuous and dense metallic body for the heat exchanger.

[0018] In one alternative implementation, guide arc surfaces are provided at two adjacent turning sections.

[0019] Beneficial effects: By setting guide arc surfaces between adjacent turning sections, the airflow gradually changes direction along the arc surfaces during turning, resulting in smoother flow, significantly reduced vortex intensity, and a substantial decrease in local drag coefficient. This reduces the total pressure drop of compressed air flowing through the heat exchanger and lowers the interstage exhaust pressure loss in the compressor, contributing to improved overall energy conversion efficiency of the compressed air energy storage system. Simultaneously, it makes the airflow velocity distribution more uniform in the turning sections, avoiding localized low-speed and high-speed zones caused by right-angle turns, resulting in a more uniform temperature distribution across the entire flow channel cross-section, thereby improving the temperature field distribution within the flow channel and enhancing heat exchange performance.

[0020] In one optional embodiment, the heat exchanger body is provided with a compressed air inlet and a compressed air outlet, the compressed air inlet and the compressed air outlet are respectively located at the bottom and top of the heat exchanger body, and the axis of the compressed air inlet is parallel to the axis of the compressed air outlet. The compressed air side channel connects the compressed air inlet and the compressed air outlet in the vertical direction.

[0021] Beneficial effects: By setting the compressed air inlet and compressed air outlet at the bottom and top of the heat exchanger body respectively, compressed air enters from the bottom inlet and exits from the top outlet during use, forming an upward flow direction. The condensate adhering to the flow channel wall after centrifugal separation settles naturally downward along the wall under the action of gravity, avoiding condensate from stagnating or accumulating in the middle area inside the flow channel.

[0022] In a second aspect, the present invention also provides a gas-liquid separation method based on the PCHE heat exchanger provided in the first aspect, comprising the following steps: introducing high-temperature and high-pressure compressed air into the compressed air side channel; changing the flow direction of the compressed air as it flows through each turning section, using centrifugal force to separate the entrained condensate from the gas phase and attach it to the channel wall; the condensate attached to the wall settles along the channel wall under the action of gravity and collects at the bottom of the heat exchanger body; and discharging the settled condensate from the heat exchanger to complete the gas-liquid separation process.

[0023] Beneficial Effects: By connecting centrifugal separation, gravity settling, and centralized discharge, a complete, closed-loop gas-liquid separation process is formed. During operation, multiple turning sections allow condensate to separate from the gas phase under inertia and adhere to the wall surface. Subsequently, gravity causes the condensate to settle naturally along the vertical flow channel, completing collection and discharge. In other words, the gas-liquid separation function is embedded in the heat exchange flow path of compressed air, allowing gas-liquid separation and heat exchange to be completed simultaneously within the same flow channel. Compared to traditional solutions where heat exchangers and separation devices are arranged in series, requiring either cooling before or after gas separation, this process achieves simultaneous heat exchange and separation, shortening the process flow, reducing equipment footprint, and simplifying piping connections.

[0024] Thirdly, the present invention also provides a hydrophobic method based on the PCHE heat exchanger provided in the first aspect, comprising the following steps: real-time monitoring of the condensate level in the water tank; when the condensate level is detected to reach a preset threshold, opening the drain valve; and after the condensate is discharged to a preset low level, closing the drain valve and resuming the gas-liquid separation process.

[0025] Beneficial effects: By monitoring the condensate accumulation in the water tank in real time through the liquid level monitoring module, the drain valve is only opened when the liquid level reaches a preset threshold, achieving on-demand drainage. That is, the drainage frequency increases when the condensate production rate is high and decreases when the production rate is low, always keeping the liquid level in the water tank within the required range. Compared with the problems of untimely or excessive drainage that may occur with traditional timed drainage, this can achieve intelligent drainage. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a front perspective view of a PCHE heat exchanger provided in an embodiment of the present invention; Figure 2 This is a partial structural schematic diagram of the PCHE heat exchanger provided in an embodiment of the present invention; Figure 3 This is a partial structural schematic diagram of the PCHE heat exchanger provided in an embodiment of the present invention; Figure 4 This is a partial structural diagram of the compressed air side flow channel in the PCHE heat exchanger provided in an embodiment of the present invention; Figure 5 This is a partial structural diagram of the cooling medium side flow channel in the PCHE heat exchanger provided in an embodiment of the present invention; Figure 6 This is a schematic flowchart of the gas-liquid separation method for the PCHE heat exchanger provided in an embodiment of the present invention. Figure 7 This is a schematic flowchart of the hydrophobic method for a PCHE heat exchanger provided in an embodiment of the present invention.

[0028] Explanation of reference numerals in the attached figures: 1. Heat exchanger body; 11. Compressed air side channel; 12. Cooling medium side channel; 13. Compressed air inlet; 14. Compressed air outlet; 15. Cooling medium inlet; 16. Cooling medium outlet; 2. Water bag; 3. Drainage pipes; 4. Drain valve. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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] The following is combined with Figures 1 to 7 The following describes embodiments of the present invention.

[0031] According to an embodiment of the present invention, in one aspect, such as Figures 1 to 5 As shown, the provided PCHE heat exchanger is used for compressed air energy storage and includes a heat exchanger body 1.

[0032] During installation, the heat exchanger body 1 is connected to the pipeline in the compressed air energy storage system via a flange connection, and its interface specifications are adapted to the high-pressure conditions of the system. A metal spiral wound gasket is used to achieve sealing. At the same time, it is necessary to ensure that the heat exchanger body 1 is placed horizontally, that the compressed air side flow channel 11 is parallel to the vertical direction and does not tilt, and that a drain pipe interface is reserved at the bottom of the water tank 2.

[0033] like Figure 1 , Figures 3 to 5 As shown, the heat exchanger body 1 adopts a printed circuit board type heat exchanger structure. It has a compressed air side channel 11 for circulating compressed air and a cooling medium side channel 12 for circulating cooling medium. The compressed air side channel 11 and the cooling medium side channel 12 are arranged in layers and staggered to form a counter-current heat exchange structure. The compressed air side channel 11 has multiple turning sections along the air flow direction. The turning sections are used to change the flow direction of the compressed air, so that the condensate entrained in the compressed air is separated and attached to the channel wall under the action of centrifugal force.

[0034] By setting up multiple turning sections and utilizing the density difference between the gas and liquid phases, a centrifugal force field is constructed during the turning process. When compressed air flows through the turning section, the condensate and gas phase are separated by centrifugal force and adhere to the wall surface. There is no need to set up an additional independent steam-water separation device or add complex separation components inside the heat exchanger. Compared with the existing technology where heat exchange and separation functions are independent and have poor coordination, this invention effectively achieves a compact structure while ensuring heat exchange efficiency and significantly reduces the equipment footprint.

[0035] At the same time, constructing a counter-current heat exchange structure can increase the heat transfer temperature difference, thereby improving heat exchange efficiency.

[0036] It can be noted that the inner walls of the compressed air side channel 11 and the cooling medium side channel 12 are treated with anti-corrosion measures.

[0037] For example, a dense chromium oxide passivation film can be formed on the inner wall of stainless steel flow channels through pickling and passivation processes, thereby improving the surface's corrosion resistance.

[0038] For example, an organic or inorganic coating with corrosion-resistant properties, such as an epoxy resin coating, a polytetrafluoroethylene (PTFE) coating, or a ceramic coating, can be applied to the inner wall of the flow channel to isolate condensate from direct contact with the metal substrate.

[0039] Of course, it can also be done by improving the surface finish and corrosion resistance of the inner wall of the flow channel through electrochemical polishing, nickel plating, chromium plating, etc.

[0040] In addition, the heat exchanger body 1 is made of stainless steel that is resistant to high temperature and high pressure.

[0041] It can be noted that this embodiment does not specifically limit the overall structure of the compressed air side channel 11, as long as it can achieve multiple reversals.

[0042] In one embodiment, the compressed air side channel 11 has a Z-shaped structure.

[0043] This configuration allows the fluid to be guided to flow in multiple directions through multiple turns, which can effectively disrupt the heat transfer boundary layer, reduce heat transfer resistance, significantly improve heat transfer efficiency under high flow conditions, ensure the accuracy of interstage cooling temperature control, reduce the heat exchange difference between steam and water, and facilitate the efficient recovery of compression heat.

[0044] Meanwhile, the Z-shaped flow channel constructs a centrifugal force field through multiple turns, and utilizes the inertial difference generated by the density difference between the gas and liquid two-phase media to separate the condensate droplets from the high-pressure airflow under the action of centrifugal force and allow them to adhere to the flow channel wall and coalesce and settle. This effectively realizes the separation function of the baffle plate type gas-water separator, which can effectively prevent condensate from being carried into the next stage compressor and causing failure.

[0045] Of course, in other alternative embodiments, the compressed air side channel 11 may also be S-shaped.

[0046] It can be explained that the compressed air side channel 11 is arranged in a vertical direction so that the condensate that gathers on the wall surface settles downward under the action of gravity.

[0047] By setting the compressed air side channel 11 vertically, gravity is used as the driving force to make the condensate that has accumulated on the wall flow continuously downward along the wall and collect.

[0048] In other words, compared with the traditional method of using external power or complex components to collect condensate, the present invention can achieve automatic directional delivery and collection of condensate simply by optimizing the flow channel arrangement direction. There is no need to add driving components, reducing energy consumption. Moreover, the structure is simple and reliable, which helps to reduce equipment manufacturing costs and operation and maintenance difficulties.

[0049] In one embodiment, such as Figure 1 As shown, the PCHE heat exchanger also includes a water tank 2, which is arranged below the heat exchanger body 1, and the water inlet of the water tank 2 is connected to the compressed air side channel 11 for collecting the condensate that settles after separation.

[0050] The compressed air side channel 11 is arranged vertically. After the condensate settles along the wall under gravity, it flows naturally to the bottom of the channel. By placing the water tank 2 directly below the heat exchanger body 1, the settled condensate can directly enter the water tank 2 by gravity flow, without the need for additional pumping devices or diversion mechanisms. This simplifies the system structure, reduces energy consumption and equipment costs, and avoids the risk of hydrophobic failure due to the failure of external power components.

[0051] At the same time, it makes full use of the unused space at the bottom of the heat exchanger without increasing the equipment's footprint, making it suitable for space-constrained applications such as salt caverns and underground chambers in compressed air energy storage systems.

[0052] It can be noted that the water tank 2 has an integrated liquid level monitoring module. The bottom of the water tank 2 is equipped with a drain pipe 3 and a drain valve 4. The drain valve 4 is installed on the drain pipe 3 and is used to open or close the drain pipe 3 according to the signal of the liquid level monitoring module.

[0053] The liquid level monitoring module senses the amount of condensate accumulated in the water tank 2 in real time. When the liquid level reaches the preset threshold, the drain valve 4 is automatically opened and automatically closed when the liquid level drops to a safe position. This achieves intelligent control of draining water as needed and draining water when full, without the need for manual intervention. This significantly reduces the workload of operation and maintenance, and is especially suitable for unattended or minimally staffed energy storage power station scenarios.

[0054] It can be noted that the water tank 2 also integrates a pressure sensor, which measures the water level signal inside the water tank 2 and transmits the measured water level signal to the liquid level monitoring module to convert it into water level data.

[0055] In one embodiment, such as Figure 1 , Figure 3 and Figure 5 As shown, the cooling medium side flow channel 12 is a direct flow channel structure.

[0056] By setting the cooling medium side flow channel 12 as a direct flow channel structure, the pressure loss of the cooling medium when flowing through the heat exchanger is minimized, reducing the power consumption of the circulating pump, reducing the system's auxiliary energy consumption, and improving the overall energy utilization efficiency of the compressed air energy storage system.

[0057] The compressed air side flow channel 11, which consists of multiple turning sections, creates a certain flow resistance on the compressed air side. Meanwhile, the cooling medium side adopts a direct flow channel structure, which makes the flow resistance of the cooling medium less than that of the compressed air side. This forms a mechanism of moderate flow obstruction on the high-pressure side and smooth flow on the low-pressure side. This ensures the necessary disturbance and separation effect on the compressed air side while avoiding excessive pressure loss on the cooling medium side, making the overall pressure drop distribution of the heat exchanger more reasonable.

[0058] It can be explained that the heat exchanger body 1 is formed by chemical etching of heat transfer plates to create microchannels, and then multiple heat transfer plates are fixedly connected by vacuum diffusion welding process.

[0059] Chemical etching allows for flexible design of channel shape, size, and distribution density on heat transfer plates according to heat exchange requirements. Compared to traditional machining methods, chemical etching is burr-free, stress-free, and deformation-free, and can form smooth channel walls.

[0060] Then, through vacuum diffusion welding process, atomic diffusion occurs at the interface of the multi-layer heat transfer plate, forming a seamless and filler-free integral metallurgical bond structure. This eliminates the fusion welding defects, heat-affected zone weakening, and dissimilar material connection failure risks present in traditional welding, making the heat exchanger body 1 a continuous and dense metal whole.

[0061] Among them, each microchannel inside the heat exchanger body 1 needs to meet the structural stability requirements under pressure conditions of 10MPa and higher.

[0062] It can be noted that the diameters of the compressed air side channel 11 and the cooling medium side channel 12 are in the range of 0.5 mm to 2 mm.

[0063] It can be noted that there are guide arc surfaces at the two adjacent turning sections.

[0064] By setting guide arc surfaces between adjacent turning sections, the airflow gradually changes direction along the arc surfaces during turning, resulting in smoother flow, significantly reduced eddy intensity, and a substantial decrease in the local drag coefficient. This reduces the total pressure drop of compressed air flowing through the heat exchanger and lowers the interstage exhaust pressure loss of the compressor, thus helping to improve the overall energy conversion efficiency of the compressed air energy storage system.

[0065] At the same time, it makes the airflow velocity distribution more uniform in the turning section, avoids the local low-speed and high-speed zones caused by right-angle turning, and makes the temperature distribution on the entire flow channel cross section more uniform, thereby improving the temperature field distribution in the flow channel and enhancing the heat exchange effect.

[0066] In one embodiment, such as Figure 1 and Figure 2As shown, the heat exchanger body 1 is provided with a compressed air inlet 13 and a compressed air outlet 14. The compressed air inlet 13 and the compressed air outlet 14 are respectively located at the bottom and top of the heat exchanger body 1, and the axis of the compressed air inlet 13 is parallel to the axis of the compressed air outlet 14. The compressed air side channel 11 connects the compressed air inlet 13 and the compressed air outlet 14 in the vertical direction.

[0067] By setting the compressed air inlet 13 and the compressed air outlet 14 at the bottom and top of the heat exchanger body 1 respectively, when in use, the compressed air enters from the bottom inlet and exits from the top outlet, forming a flow direction from bottom to top. The condensate adhering to the flow channel wall after centrifugal separation naturally settles down along the wall under the action of gravity, avoiding the condensate from stagnating or accumulating in the middle area inside the flow channel.

[0068] That is, the vertically arranged flow channel utilizes the height difference to allow the condensate to settle naturally under gravity and collect at the bottom of the flow channel. With the help of the guide trough and water bag 2, the centralized collection and fixed-point discharge of condensate can be achieved.

[0069] It can be noted that compressed air inlet 13 is connected to a compressor.

[0070] In one embodiment, it remains as follows Figure 1 and Figure 2 As shown, the heat exchanger body 1 is also provided with a cooling medium inlet 15 and a cooling medium outlet 16, which are respectively arranged at two opposite ends of the heat exchanger body.

[0071] Furthermore, the cooling medium side channel 12 is made of the same material and is etched on a flat plate. The width and depth of the channel are designed to be adapted to the cooling water volume requirements.

[0072] In the above embodiments, the compressed air energy storage system can be integrated into the heat exchanger body 1 for interstage cooling, waste heat recovery and efficient steam-water separation, thereby improving energy efficiency and compactness, which is conducive to large-capacity, high-parameter commercial applications.

[0073] In the above embodiment, the compressed air side channel 11 is arranged in a vertical direction, so that the compressed air can change direction multiple times, and the water droplets it carries will collide with the plate wall and converge into large droplets. The condensed water that settles under gravity will be collected in the water bag 2 through the guide groove at the bottom of the channel along the wall surface. Meanwhile, the compressed air continues to flow forward along the channel wall surface without direct contact with the guide groove and will not carry droplets again.

[0074] Meanwhile, by promptly draining the accumulated water in water tank 2, the water level is prevented from being excessively high and being re-entrained by compressed air. After drainage is completed, the valve automatically closes, achieving unattended automatic drainage.

[0075] According to embodiments of the present invention, in a second aspect, the present invention also provides a gas-liquid separation method based on the PCHE heat exchanger provided in the first aspect, such as... Figure 6 As shown, the process includes the following steps: introducing high-temperature and high-pressure compressed air into the compressed air side channel 11; changing the flow direction of the compressed air as it flows through each turning section, using centrifugal force to separate the entrained condensate from the gas phase and attach it to the channel wall; the condensate attached to the wall settles along the channel wall under the action of gravity and collects at the bottom of the heat exchanger body 1; and discharging the settled condensate from the heat exchanger to complete the gas-liquid separation process.

[0076] By connecting the three stages of centrifugal separation, gravity settling, and centralized discharge, a complete and closed-loop gas-liquid separation process is formed. In operation, multiple turning sections are used to allow the condensate to separate from the gas phase under inertia and adhere to the wall surface. Then, using its own gravity, the condensate that has accumulated on the wall surface settles naturally along the vertical straight channel, and is then collected and discharged.

[0077] That is, the gas-liquid separation function is embedded in the heat exchange flow path of compressed air, so that the two processes of gas-liquid separation and heat exchange are completed simultaneously in the same flow channel.

[0078] Compared to traditional solutions where heat exchangers and separation devices are arranged in series and the gas needs to be cooled before or separated before cooling, this process of simultaneous heat exchange and separation shortens the process flow, reduces the equipment footprint, and lowers the complexity of pipeline connections.

[0079] It can be explained that the process of introducing high-temperature and high-pressure compressed air into the compressed air side channel 11 specifically includes: high-temperature and high-pressure compressed air (pressure meets 10MPa, temperature depends on the compression stage) discharged from the multi-stage compressor of the compressed air energy storage system is introduced into the compressed air side channel 11 inside the heat exchanger body 1 through the compressed air inlet 13. The compressed air inlet 13 is located at the top of the heat exchanger body 1, and the compressed air enters the channel from top to bottom, with the flow direction consistent with the direction of gravity.

[0080] It can be explained that the process by which compressed air changes its flow direction as it flows through each turning section, using centrifugal force to separate the entrained condensate from the gas phase and adhere it to the channel wall, specifically includes: After entering the compressed air side channel 11, the compressed air flows along a Z-shaped path. As it flows through each turning section, the airflow direction changes, generating a turning centrifugal force field. Due to the density difference between the gas and liquid phases, the condensate droplets gain significant inertial force under centrifugal force, detaching from the mainstream gas phase and impacting and adhering to the channel wall. The guide arc surfaces set at adjacent turning sections make the airflow turning smoother, reducing flow resistance and enhancing the stability of the centrifugal force field, thus ensuring the separation effect.

[0081] It can be explained that the process by which condensate adhering to the wall surface settles along the channel wall under gravity and collects at the bottom of the heat exchanger body 1 specifically includes: after centrifugal separation, the condensate adhering to the channel wall surface settles naturally downwards along the vertically arranged channel wall under gravity. The inner wall of the channel is treated with anti-corrosion measures (such as passivation or coating with an anti-corrosion coating) to reduce the risk of corrosion from the condensate. During the settling process, the condensate continuously coalesces and eventually collects at the lowest point at the bottom of the compressed air side channel 11.

[0082] To illustrate, the process of discharging the settled condensate from the heat exchanger to complete the gas-liquid separation involves the following steps: the condensate collected at the bottom of the flow channel flows through a guide channel into the water tank 2 below the heat exchanger body 1. The water tank 2 serves as a temporary storage container for the condensate and integrates a liquid level monitoring module. When the condensate level in the water tank 2 reaches a preset threshold (e.g., 1 / 3 of the water tank 2's volume), the liquid level monitoring module sends a signal, automatically opening the drain valve 4 to discharge the condensate from the system. Once the liquid level drops to the preset low level, the drain valve 4 automatically closes, resuming the gas-liquid separation process. During the drainage process, an anti-vortex baffle prevents the airflow from carrying condensate a second time.

[0083] The above steps are performed continuously and cyclically during the operation of the compressed air energy storage system. As long as compressed air continues to flow through the heat exchanger, the gas-liquid separation process proceeds automatically without manual intervention. When the system is shut down, the heat exchanger can be purged during maintenance to remove residual moisture from the flow channels, further ensuring the long-term reliability of the equipment.

[0084] The gas-liquid separation method for PCHE heat exchangers provided by this invention forms an efficient, reliable, and energy-saving separation process through the organic integration of centrifugal separation, gravity settling, and centralized discharge. It has significant technical advantages in ensuring separation effect, reducing energy consumption, simplifying control, and adapting to changing operating conditions. It is suitable for high-pressure, high-flow-rate interstage cooling conditions in compressed air energy storage systems.

[0085] According to embodiments of the present invention, in a third aspect, the present invention also provides a hydrophobic method based on the PCHE heat exchanger provided in the first aspect, such as... Figure 7 As shown, the process includes the following steps: real-time monitoring of the condensate level in water tank 2; when the condensate level reaches a preset threshold, opening drain valve 4; and closing drain valve 4 after the condensate is discharged to a preset low level, thus resuming the gas-liquid separation process.

[0086] The liquid level monitoring module senses the amount of condensate accumulated in water tank 2 in real time, and the drain valve 4 is only opened when the liquid level reaches a preset threshold, thus achieving on-demand drainage. That is, the drainage frequency increases when the condensate production rate is high and decreases when the production rate is low, always keeping the liquid level in water tank 2 within the required range. Compared with the problems of untimely or excessive drainage that may occur with traditional timed drainage, this can achieve intelligent drainage.

[0087] Specifically, the process of real-time monitoring of the condensate level in water tank 2 includes the following: During the operation of the compressed air energy storage system, the condensate collected after centrifugal separation and gravity settling continuously flows into water tank 2 through a guide channel. The level monitoring module monitors the condensate level in water tank 2 in real time and transmits the level signal to the control system. The control system can be a standalone controller or integrated into the centralized control system (DCS or PLC) of the compressed air energy storage system.

[0088] It can be explained that the process of opening drain valve 4 when the condensate level reaches the preset threshold includes: when the level monitoring module detects that the condensate level in water tank 2 has reached the preset opening threshold, the control system issues an opening command to automatically open drain valve 4. The opening threshold can be set according to the heat exchanger design parameters and actual operating conditions, and is preferably set to 1 / 3 of the volume of water tank 2.

[0089] When selecting the threshold, it is necessary to ensure that there is enough buffer space in the water tank 2 to avoid the liquid level being too high and causing the condensate to be carried away by the airflow again; and to ensure that the drain valve 4 is not opened too frequently, which would affect the service life of the valve.

[0090] It can be explained that after the condensate is drained to the preset low liquid level, the drain valve 4 is closed, and the gas-liquid separation process resumes. Specifically, after the drain valve 4 is opened, the condensate in the water tank 2 is discharged from the system through the drain pipe 3 under gravity. The liquid level monitoring module continuously monitors the liquid level change. When the condensate level drops to the preset low liquid level, the control system issues a shutdown command and automatically closes the drain valve 4. The low liquid level is preferably set to 1 / 10 of the volume of the water tank 2. The difference between the opening threshold and the closing threshold forms a hysteresis control range, effectively avoiding the problem of frequent opening and closing of the drain valve 4 when the liquid level fluctuates near the critical value.

[0091] After drain valve 4 is closed, the gas-liquid separation process resumes normal operation, and condensate continues to flow into water tank 2, causing the liquid level to rise again. The above steps are repeated when the opening threshold is reached again. This cycle continues, achieving automatic and continuous discharge of condensate.

[0092] It can be explained that before the compressed air energy storage system is started, the control system checks whether there is any residual condensate in water tank 2. If there is residual condensate, the drainage operation is performed first to ensure that water tank 2 is in a low liquid level state before starting the system.

[0093] After the system is shut down, the control system performs a complete drainage operation to empty the water tank 2 and the compressed air side channel 11 of any residual condensate. Subsequently, the compressed air side channel 11 can be purged by introducing dry gas to remove any residual moisture and further reduce the risk of corrosion.

[0094] It should be noted that when the liquid level monitoring module detects the following abnormalities, the control system will issue an alarm signal and take corresponding protective measures: (1) The liquid level continues to rise abnormally: If the liquid level continues to rise or does not drop to a low level for a long time after the drain valve 4 is opened, it may indicate that the drain valve 4 is faulty, the drain pipe 3 is blocked, or the condensate production rate is abnormally increased. The control system will issue an alarm and prompt maintenance. (2) No change in liquid level for a long time: If the liquid level of water tank 2 does not change for a long time during system operation, it may indicate that the liquid level monitoring module is faulty or that the condensate cannot flow into water tank 2 normally. The control system will issue an alarm and prompt for inspection. (3) Abnormal operation of drain valve 4: The control system monitors the opening and closing status of drain valve 4 through feedback signals. If the valve status is not correctly fed back after the command is executed, the control system issues an alarm and prompts for maintenance.

[0095] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A PCHE heat exchanger for compressed air energy storage, characterized in that, include: The heat exchanger body (1) adopts a printed circuit board type heat exchanger structure. It is provided with a compressed air side channel (11) for circulating compressed air and a cooling medium side channel (12) for circulating cooling medium. The compressed air side channel (11) and the cooling medium side channel (12) are arranged in layers and staggered to form a counter-current heat exchange structure. The compressed air side channel (11) is provided with multiple turning sections along the air flow direction. The turning sections are used to change the flow direction of the compressed air, so that the condensate entrained in the compressed air is separated and attached to the channel wall under the action of centrifugal force.

2. The PCHE heat exchanger according to claim 1, characterized in that, The compressed air side channel (11) is arranged in a vertical direction so that the condensate that accumulates on the wall surface settles downward under the action of gravity.

3. The PCHE heat exchanger according to claim 1, characterized in that, It also includes a water tank (2), which is arranged below the heat exchanger body (1), and the water inlet of the water tank (2) is connected to the compressed air side channel (11) for collecting the condensate that has settled after separation.

4. The PCHE heat exchanger according to claim 3, characterized in that, The water tank (2) has an integrated liquid level monitoring module inside. The bottom of the water tank (2) is provided with a drainage pipe (3) and a drainage valve (4). The drainage valve (4) is installed on the drainage pipe (3) and is used to open or close the drainage pipe (3) according to the signal of the liquid level monitoring module.

5. The PCHE heat exchanger according to claim 1, characterized in that, The cooling medium side channel (12) is a direct flow channel structure.

6. The PCHE heat exchanger according to any one of claims 1 to 5, characterized in that, The heat exchanger body (1) is formed by chemical etching of heat transfer plates to create microchannels, and then multiple heat transfer plates are fixedly connected by vacuum diffusion welding process.

7. The PCHE heat exchanger according to claim 1, characterized in that, A guide arc surface is provided at two adjacent turning sections.

8. The PCHE heat exchanger according to claim 1, characterized in that, The heat exchanger body (1) is provided with a compressed air inlet (13) and a compressed air outlet (14). The compressed air inlet (13) and the compressed air outlet (14) are respectively located at the bottom and top of the heat exchanger body (1), and the axis of the compressed air inlet (13) is parallel to the axis of the compressed air outlet (14). The compressed air side channel (11) connects the compressed air inlet (13) and the compressed air outlet (14) in the vertical direction.

9. A gas-liquid separation method based on the PCHE heat exchanger according to any one of claims 1 to 8, characterized in that, Includes the following steps: High-temperature and high-pressure compressed air is introduced into the compressed air side channel (11). As compressed air flows through each turning section, it changes its flow direction and uses centrifugal force to separate the entrained condensate from the gas phase and attach it to the flow channel wall. The condensate adhering to the wall settles along the flow channel wall under the action of gravity and collects at the bottom of the heat exchanger body (1); The settled condensate is discharged from the heat exchanger, completing the gas-liquid separation process.

10. A hydrophobic method for a PCHE heat exchanger based on any one of claims 1 to 8, characterized in that, Includes the following steps: Real-time monitoring of the condensate level in the water tank (2); When the condensate level is detected to reach the preset threshold, the drain valve (4) is opened. After the condensate is drained to the preset low liquid level, close the drain valve (4) and resume the gas-liquid separation process.

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