A humidification and dehumidification seawater desalination device and method based on thermoacoustic effect

Abstract

This invention discloses a humidification and dehumidification seawater desalination device and method based on thermoacoustic effect, belonging to the field of energy engineering technology. The device includes a heat source, a water pump, a humidification unit, a dehumidification unit, a steam pipe, and a feedback pipe. The humidification unit is equipped with a spray device, a regenerator, and a room temperature heat exchanger, while the dehumidification unit is equipped with a condenser. The humidification unit, steam pipe, dehumidification unit, and feedback pipe are connected end to end to form a loop. The feed seawater is pumped into the condenser by the water pump and preheated therein, while the steam is condensed. The preheated seawater enters the room temperature heat exchanger and is further heated before being sprayed downwards by the spray device. A temperature difference is generated at both ends of the regenerator, thereby generating a standing wave sound field. The regenerator not only plays a role in thermoacoustic conversion but also serves as a heat and mass exchange medium to enhance heat transfer. Under the action of sound waves, a circulating flow is formed in the loop. When the air passes through the humidification and dehumidification units, the heat and mass transfer process with the concentrated seawater and fresh water is more complete, enhancing the water production performance of the device.

Description

Technical Field

[0001] This invention belongs to the field of energy engineering technology, specifically relating to a humidification and dehumidification seawater desalination device and method based on thermoacoustic effect. Background Technology

[0002] Water resources, an indispensable element for human survival and development, are abundant, covering approximately 71% of the Earth's surface. However, seawater and brackish water account for 97.5% of the total, leaving less than 2.5% of freshwater. The global freshwater supply and demand imbalance is becoming increasingly severe. Thermal seawater desalination, adaptable to low-grade energy sources such as solar energy and industrial waste heat, has become a core technology for solving water supply problems in coastal and arid regions, holding irreplaceable strategic significance in ensuring water resources in many water-scarce areas. However, this technology has long been limited by a core bottleneck in heat and mass transfer efficiency: in the seawater evaporation stage, the continuous liquid film formed on the heating surface significantly increases thermal resistance; in the steam condensation stage, the liquid film on the condensing surface forms a concentration boundary layer with non-condensable gases, drastically reducing the mass transfer rate, ultimately resulting in low system water production efficiency and high energy consumption, making it difficult to meet the demands of high-efficiency and energy-saving applications.

[0003] To overcome the aforementioned bottlenecks, various heat and mass transfer enhancement technologies have been explored in the field of solar seawater desalination, but all have significant limitations: structural optimization methods (such as inclined condensing surfaces and multi-effect evaporation structures) can promote gas-liquid separation, but they rely on complex cavity designs, are prone to flow dead zones, and are costly; material modification methods (such as hydrophilic and hydrophobic coatings) can improve interfacial properties, but face problems such as coating aging; among external field auxiliary methods (such as electric fields, magnetic fields, and sound waves), sound wave technology can effectively thin the boundary layer and enhance phase change mass transfer through vibration, cavitation, and acoustic flow effects, showing unique potential, but traditional external sound sources have problems such as large size, low energy efficiency, and the need for additional power supply and control, while electric and magnetic field technologies are prone to electrolytic corrosion, reducing reliability and failing to meet the requirements of low cost, long cycle, and high stability in solar seawater desalination. Faced with these limitations, there is an urgent need to develop a heat and mass transfer enhancement technology that is simple in structure, highly efficient and reliable, and suitable for confined spaces.

[0004] Compared to traditional technologies and external acoustic devices, thermoacoustic-based heat-induced acoustic wave enhancement technology can fine-tune the structure of the heat and mass transfer system, utilizing the system's own temperature difference to generate acoustic waves. These acoustic waves directly act on the heat and mass transfer interface, significantly improving system efficiency while reducing equipment energy consumption and maintenance costs. This technology offers advantages such as simple structure, no moving parts, low cost, long-term operation, and the ability to utilize low-grade heat sources.

[0005] Current research on the engineering applications of thermoacoustic technology mainly focuses on thermoacoustic machinery. Based on the thermoacoustic effect principle it utilizes, thermoacoustic machinery can be divided into thermoacoustic engines or thermoacoustic refrigerators. Based on the sound field distribution inside the equipment, it can be divided into standing wave thermoacoustic devices or traveling wave thermoacoustic devices. Thermoacoustic research primarily focuses on improving thermoacoustic conversion efficiency to achieve thermoacoustic refrigeration or heat pumps, thermoacoustic power generation, and improving the utilization of low-grade heat energy. For this new, advanced, and efficient form of heat engine, the research aims to solve problems related to energy conservation, renewable energy utilization, and environmental protection; very few studies have considered thermoacoustic engines as a stable sound source. In fact, as a sound generator that converts heat energy into sound energy, thermoacoustic engines, in terms of both frequency and intensity, easily meet the needs of enhanced heat and mass transfer technologies. Furthermore, numerous studies have shown that adding a small amount of condensable components (water or organic working fluid) to the original working fluid (air, inert gas, etc.) of a thermoacoustic system can utilize the thermodynamic phase change of the condensable components in the mixed working fluid to lower the system's oscillation temperature. Summary of the Invention

[0006] In view of this, the present invention provides a humidification and dehumidification seawater desalination device and method based on thermoacoustic effect. This device enhances heat and mass transfer through self-excited sound waves without increasing system complexity. The device has a simple structure, no easily damaged functional components, and can ensure long-term stable operation of the system. Furthermore, the device can simultaneously enhance the heat and mass transfer processes in the evaporation and condensation sections, improving water production efficiency while achieving cascaded energy utilization.

[0007] A humidification and dehumidification seawater desalination device based on thermoacoustic effect includes a heat source and N-stage condensation loops (N=1,2,3…i). The condensation loops are inverted U-shapes. The straight pipes on the left and right sides of the condensation loops are humidification and dehumidification units, respectively, and their bottoms are connected by a feedback pipe. Below the humidification and dehumidification units are concentrated seawater tanks and fresh seawater tanks, respectively. The curved pipe at the top is a steam pipe. Inside the humidification unit, from top to bottom, are a spray device, a regenerator, and a room temperature heat exchanger. Inside the dehumidification unit is a condenser, which is connected to the room temperature heat exchanger via a pipe. The N-stage condensation loops are connected in series. The room temperature heat exchanger in the first-stage condensing loop is connected to the condenser in the next-stage condensing loop. In the final-stage condensing loop, the heat source is connected in series outside the condensing loop and located between the room temperature heat exchanger and the spray device. The concentrated seawater, heated by the heat source, is sprayed downwards through the spray device, generating a temperature difference across the regenerator, which in turn generates sound waves. The regenerator serves both as a thermo-acoustic converter and as a heat and mass exchange medium to enhance heat transfer. Under the influence of the sound waves, a circulation is formed in the condensing loop. When the air passes through the humidification and dehumidification units, the heat and mass transfer processes with the concentrated seawater and fresh water are more complete, enhancing the water production performance of the device.

[0008] Furthermore, an auxiliary heat source is provided on the upper part of the regenerator, which is used to heat the air in the humidification unit.

[0009] Furthermore, a fan is installed in the feedback pipe or steam pipe.

[0010] Furthermore, valves are provided at the bottom of the concentrated seawater pool and the fresh seawater pool in the first-stage condensation circuit. By adjusting the opening of the valves, the volume occupied by air in the concentrated seawater pool and the fresh water pool can be adjusted, thereby adjusting the sound field.

[0011] Furthermore, the steam pipe and the load pipe are equal-diameter pipes, variable-diameter pipes, or a combination of both, and are straight pipes, bent pipes, or a combination of both, and are placed horizontally or at an angle.

[0012] Furthermore, the regenerator is a flat plate regenerator with absorbent paper wrapped around its surface, or a honeycomb ceramic regenerator, a wire mesh regenerator, or a regenerator filled with random fibrous material.

[0013] Furthermore, the humidification unit and the dehumidification unit are cylindrical or rectangular cavities.

[0014] Furthermore, the spraying device is one or more combinations of a fixed nozzle, an oscillating nozzle, a rotating nozzle, a fan-shaped nozzle, a cone-shaped nozzle, and a full-circle nozzle.

[0015] Furthermore, the heat source is solar energy, electric heating rod, industrial waste heat, or exhaust gas waste heat.

[0016] Furthermore, the room temperature heat exchanger and the condenser are shell-and-tube heat exchangers, coaxial heat exchangers, plate-fin heat exchangers, spiral plate heat exchangers, plate-and-shell heat exchangers, finned tube heat exchangers, or heat pipe heat exchangers.

[0017] This invention also provides a humidification and dehumidification seawater desalination method based on thermoacoustic effect. This method is implemented based on the aforementioned device and includes two stages: seawater circulation and air circulation.

[0018] The seawater circulation process includes: feed seawater is pumped into the condenser in the first-stage condensation loop and preheated therein, while steam is condensed; the preheated concentrated seawater leaves the first-stage condenser and enters the first-stage room-temperature heat exchanger for further preheating; the concentrated seawater sequentially passes through the second-stage condenser, the second-stage room-temperature heat exchanger... and the i-th stage condenser and the i-th stage room-temperature heat exchanger before entering the heat source for further heating; the heated concentrated seawater first enters the i-th stage humidification unit, where it is humidified by the i-th stage... The spray device sprays downwards, creating a temperature difference across the regenerator, which in turn generates sound waves. The regenerator serves both as a thermo-acoustic converter and as a heat-mass exchange medium to enhance heat transfer. The concentrated seawater exchanges heat and moisture with the dry air in the i-th stage humidification unit, simultaneously wetting the i-th stage regenerator. Subsequently, the concentrated seawater is collected in the i-th stage concentrated seawater pool and sequentially pumped by the water pump into the (i-1)th stage...the first stage device; the above steps are repeated; finally, the remaining concentrated seawater is collected in the concentrated seawater pool of the first stage condensation circuit.

[0019] The air circulation process includes: dry and cold air in each stage of the condensation circuit undergoes heat and mass exchange with sprayed hot seawater in the humidification unit to generate humid and hot air. The humid and hot air is cooled by entering the dehumidification unit through the steam pipe under the action of sound waves and fans, and then generates fresh water, which flows into the fresh water pool for collection.

[0020] Beneficial effects:

[0021] 1. This invention sets up a heat source outside the condensation circuit. The heat source heats the concentrated seawater coming out of the room temperature end heat exchanger in the last stage condensation circuit. The sound waves are generated by the temperature difference of the seawater desalination device itself. There is no need to rely on external sound generation equipment, which significantly reduces equipment energy consumption and maintenance costs, greatly reduces space occupation, and improves the adaptability of the system under different operating conditions.

[0022] 2. The present invention provides an auxiliary heat source at the top of the regenerator. The auxiliary heat source helps to build a temperature gradient at both ends of the regenerator, generating a temperature difference, thereby stimulating sound waves. This temperature difference is more stable and controllable than that generated by spraying seawater after heating it with a heat source alone. At the same time, the auxiliary heat source can also heat the air in the humidification unit to form hot steam, which helps to improve the efficiency of seawater desalination.

[0023] 3. This invention incorporates a spray device, a regenerator, and a room temperature heat exchanger within the humidification unit of the condensation circuit. Seawater sprayed by the spray device flows onto the regenerator, replenishing it with condensable components. The phase change of these condensable components can be used to lower the oscillation temperature and generate sound waves. Furthermore, dry, cold air enters the humidification unit from the dehumidification unit via a feedback pipe, creating a temperature difference between the upper and lower ends of the regenerator, thereby generating sound waves. The sound waves are directly generated within the heat and mass transfer system. The periodic pressure fluctuations and flow field disturbances formed by the sound wave vibrations can directly act on the heat and mass transfer interface, significantly reducing the sound wave attenuation and effectively ensuring the enhanced effect.

[0024] 4. The present invention sets up a fan in the feedback pipe or steam pipe. The DC power generated by the fan can be superimposed with the alternating flow generated by the self-excited sound wave of the system, thereby promoting the steam in the humidifier to enter the condenser and improving the water production rate.

[0025] 5. In the seawater desalination process, after the cooled seawater passes through the dehumidification unit, it needs to exchange heat with the air in the humidification unit at the lower end of the regenerator before entering the heat source to be heated. Before being sprayed, the heated seawater needs to pass through the auxiliary heat source at the upper end of the regenerator, thereby forming a temperature difference between the upper and lower ends of the regenerator. The temperature difference between the low-grade heat source (temperature 70℃~90℃) and the seawater intake is used to directly stimulate sound waves to enhance heat and mass transfer.

[0026] 6. The device of the present invention consists of a heat source and multiple condensation circuits. The condensation circuits are equipped with a spray device, a regenerator, a room temperature heat exchanger and a condenser. The system has a simple structure and features high reliability, wide applicability to a wide range of media, easy operation and no secondary pollution. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0028] Figure 2 This is a schematic diagram of the structure of Embodiment 2 of the present invention.

[0029] Among them: 1-heat source, 2-water pump, 3-dehumidification unit, 4-condenser, 5-steam pipe, 6-humidification unit, 7-spray device, 8-regenerator, 9-room temperature end heat exchanger, 10-concentrated seawater pool, 11-fan, 12-feedback pipe, 13-fresh water pool, 14-valve, 15-auxiliary heat source. Detailed Implementation

[0030] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0031] Example 1:

[0032] Figure 1 This is a schematic diagram of an embodiment of a three-stage solar-powered humidification and dehumidification seawater desalination device based on the thermoacoustic effect. Figure 1 As shown, the seawater desalination device in this embodiment is divided into three stages, and its specific components include: heat source 1, water pump 2, first-stage dehumidification unit 3a, second-stage dehumidification unit 3b, third-stage dehumidification unit 3c, first-stage condenser 4a, second-stage condenser 4b, third-stage condenser 4c, first-stage steam pipe 5a, second-stage steam pipe 5b, third-stage steam pipe 5c, first-stage humidification unit 6a, second-stage humidification unit 6b, third-stage humidification unit 6c, first-stage spray device 7a, second-stage spray device 7b, third-stage spray device 7c, first-stage regenerator 8a, second-stage regenerator 8b, and the third-stage regenerator 8c. The system includes a three-stage regenerator, a first-stage room-temperature heat exchanger 9a, a second-stage room-temperature heat exchanger 9b, a third-stage room-temperature heat exchanger 9c, a first-stage concentrated seawater tank 10a, a second-stage concentrated seawater tank 10b, a third-stage concentrated seawater tank 10c, a first-stage fan 11a, a second-stage fan 11b, a third-stage fan 11c, a first-stage feedback pipe 12a, a second-stage feedback pipe 12b, a third-stage feedback pipe 12c, a first-stage freshwater tank 13a, a second-stage freshwater tank 13b, a third-stage freshwater tank 13c, a valve 14, a first-stage auxiliary heat source 15a, a second-stage auxiliary heat source 15b, and a third-stage auxiliary heat source 15c.

[0033] In this embodiment, the heat source 1 is solar energy, and the first-stage auxiliary heat source 15a, the second-stage auxiliary heat source 15b, and the third-stage auxiliary heat source 15c are heating rods.

[0034] In this embodiment, the heat source 1 heats the concentrated seawater exiting from the third-stage room temperature end heat exchanger 9c.

[0035] In this embodiment, the dehumidification unit 3 and the humidification unit 6 are cylindrical cavities.

[0036] In this embodiment, the condenser 4 and the room temperature heat exchanger 9 are plate-fin heat exchangers.

[0037] In this embodiment, the steam pipe 5 is a bend of equal diameter, and the feedback pipe 12 is a straight pipe of equal diameter placed horizontally.

[0038] In this embodiment, the spraying device 7 is a fan-shaped nozzle.

[0039] In this embodiment, the regenerator 8 is a flat plate regenerator with absorbent paper wrapped around its surface.

[0040] In this embodiment, the fan 11 is placed in the feedback pipe 12.

[0041] The dehumidification unit 3, steam pipe 5, humidification unit 6, and feedback pipe 12, which form the condensation circuit, are connected end to end in an inverted U-shaped ring. The spray device 7, regenerator 8, and room temperature heat exchanger 9 are located in the humidification unit 6, and the condenser 4 is located in the dehumidification unit 3.

[0042] The seawater desalination device in this embodiment 1 specifically includes the following steps:

[0043] Seawater circulation: Feed seawater is pumped by water pump 2 to the first-stage condenser 4a for preheating, while simultaneously condensing the humid and hot air in the first-stage dehumidification unit 3a; the preheated concentrated seawater leaves the first-stage condenser 4a and enters the first-stage room temperature heat exchanger 9a for further heating; subsequently, the concentrated seawater is heated sequentially through the second-stage condenser 4b, the second-stage room temperature heat exchanger 9b, the third-stage condenser 4c, and the third-stage room temperature heat exchanger 9c, and is finally further heated by heat source 1; the heated hot seawater first enters the third-stage spray device 7c, where it is sprayed and exchanges heat and moisture with the dry and cold air in the third-stage humidification unit 6c, while simultaneously wetting the third-stage regenerator 8c, and preheating the cold seawater in the third-stage room temperature heat exchanger 9c, after which the hot seawater is collected and sequentially enters the second-stage and first-stage condensation loops, repeating the above steps; finally, the remaining concentrated seawater is collected in the concentrated seawater pool 10a of the first-stage condensation loop.

[0044] Air circulation: The dry and cold air in each stage of the condensation loop undergoes heat and mass exchange with the sprayed hot seawater in the humidification unit 6 to generate humid and hot air. The auxiliary heat source 15 heats the air in the humidification unit 6 to form humid and hot steam. The humid and hot air and steam are cooled in the dehumidification unit 3 through the steam pipe 5 under the action of sound waves and fan 11, and then generate fresh water, which flows into the fresh water pool 14 for collection.

[0045] Under the influence of sound waves and fan 11, dry, cold air enters the humidification unit 6 from the dehumidification unit 3 via feedback pipe 12. A temperature difference is generated above and below the regenerator 8, thereby generating sound waves. The sound waves have two effects: First, during the droplet spraying and evaporation process, the sound waves act on the gas-liquid interface of the droplets, causing violent disturbances, reducing heat and mass transfer resistance, and significantly increasing the evaporation rate. Second, during the condensation of humid air, the sound waves act on the condenser surface, promoting the breakup or detachment of the liquid film, reducing condensation thermal resistance, and significantly increasing the condensation rate. Therefore, under the influence of sound waves, the heat and mass transfer process between the air and seawater / fresh water is more complete when the air passes through the humidification unit 6 and dehumidification unit 3, enhancing the water production performance of the device.

[0046] Example 2:

[0047] Figure 2 This is a schematic diagram of an embodiment of a seawater desalination device based on the waste heat from primary exhaust gas using the thermoacoustic effect, as shown below. Figure 2As shown, the seawater desalination device in this embodiment includes: a heat source 1, a water pump 2, a dehumidification unit 3, a condenser 4, a steam pipe 5, a humidification unit 6, a spray device 7, a regenerator 8, a room temperature end heat exchanger 9, a concentrated seawater tank 10, a feedback pipe 12, a freshwater tank 13, a valve 14, and an auxiliary heat source 15.

[0048] In this embodiment, the heat source 1 is the waste heat of exhaust gas, and the auxiliary heat source 15 is hot seawater heated by the heat source.

[0049] In this embodiment, the heat source 1 is located outside the humidification unit 6 and heats the seawater flowing out of the room temperature heat exchanger 9.

[0050] In this embodiment, the auxiliary heat source 15 is located above the regenerator 8. The auxiliary heat source 15 heats the air in the humidification unit 6 and the seawater sprayed down by the spray device 7.

[0051] In this embodiment, the dehumidification unit 3 and the humidification unit 6 are rectangular cavities.

[0052] In this embodiment, the condenser 4 is a plate-fin heat exchanger, and the room temperature end heat exchanger 9 is a shell-and-tube heat exchanger.

[0053] In this embodiment, the steam pipe 5 is a straight pipe of equal diameter placed at an angle, and the feedback pipe 12 is a straight pipe of equal diameter placed horizontally.

[0054] In this embodiment, the spraying device 7 is a fixed nozzle, and the regenerator 8 is a honeycomb ceramic regenerator.

[0055] The dehumidification unit 3, steam pipe 5, humidification unit 6, and feedback pipe 12 are connected end to end in a ring. The auxiliary heat source 15, spray device 7, regenerator 8, and room temperature heat exchanger 9 are located in the humidification unit 6, and the condenser 4 is located in the dehumidification unit 3.

[0056] The seawater desalination device in this embodiment 2 specifically includes the following steps:

[0057] Seawater circulation: The feed seawater is pumped by water pump 2 to condenser 4 for preheating, while condensing the air in dehumidification unit 3; then, the preheated seawater leaves condenser 4 and enters room temperature heat exchanger 9, heat source 1 and auxiliary heat source 15 for further heating; then it enters spray device 7 and sprays downward, where the seawater exchanges heat and moisture with the dry hot air in humidification unit 6, while wetting regenerator 8, and finally the remaining concentrated seawater enters concentrated seawater pool 10.

[0058] Air circulation: The auxiliary heat source 15 heats the dry and cold air in the humidification unit 6. The heated dry and cold air exchanges heat and mass with the sprayed seawater to generate humid and hot air. Under the action of sound waves, the humid and hot air enters the dehumidification unit 3 through the steam pipe 5 and is cooled, and then generates fresh water, which flows into the fresh water pool 14 and is collected.

[0059] Under the action of sound waves, the dry and cold air from the dehumidification unit 3 enters the humidification unit 6 through the feedback pipe 12, generating a temperature difference above and below the regenerator 8, thereby generating sound waves. Under the action of sound waves, when the air passes through the humidification unit 6 and the dehumidification unit 3, the heat and mass transfer process with seawater and fresh water is more complete, enhancing the water production performance of the device.

[0060] In this embodiment, the auxiliary heat source is hot seawater heated by heat source 1. It can generate sound waves without consuming additional energy, changing the structural complexity, or introducing mechanical moving parts. The temperature difference is built up at both ends of the regenerator by cold seawater and hot seawater.

[0061] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A humidification and dehumidification seawater desalination device based on thermoacoustic effect, characterized in that, It includes a heat source and N-stage condensing loops (N=1,2,3…i). The condensing loops are inverted U-shapes. The straight pipes on the left and right sides of the condensing loops are the humidification unit and the dehumidification unit, respectively, and their bottoms are connected by a feedback pipe. Below the humidification unit and the dehumidification unit, respectively, are a concentrated seawater tank and a fresh seawater tank. The curved pipe at the top is a steam pipe. Inside the humidification unit, from top to bottom, are a spray device, a regenerator, and a room temperature heat exchanger. Inside the dehumidification unit is a condenser, which is connected to the room temperature heat exchanger through a pipe. The N-stage condensing loops are connected in series. The room temperature heat exchanger in the first-stage condensing loop… The end heat exchanger is connected to the condenser in the next stage of the condensation loop. In the last stage of the condensation loop, the heat source is connected in series outside the condensation loop and located between the room temperature end heat exchanger and the spray device. The concentrated seawater heated by the heat source is sprayed downwards through the spray device, generating a temperature difference at both ends of the regenerator, thereby generating sound waves. The regenerator can play the role of thermo-acoustic conversion and also serve as a heat and mass exchange medium to enhance heat exchange. Under the action of the sound waves, a circulation is formed in the condensation loop. When the air passes through the humidification unit and the dehumidification unit, the heat and mass transfer process with the concentrated seawater and fresh water is more complete, enhancing the water production performance of the device.

2. The seawater desalination device based on thermoacoustic effect as described in claim 1, characterized in that, An auxiliary heat source is provided at the top of the regenerator, which is used to heat the air in the humidification unit.

3. The seawater desalination device based on thermoacoustic effect as described in claim 2, characterized in that, A fan is installed in the feedback pipe or steam pipe.

4. The seawater desalination device based on thermoacoustic effect as described in claim 3, characterized in that, In the first-stage condensation circuit, valves are installed at the bottom of the concentrated seawater pool and the fresh seawater pool. By adjusting the opening of the valves, the volume occupied by air in the concentrated seawater pool and the fresh water pool is adjusted, thereby adjusting the sound field.

5. A humidification and dehumidification seawater desalination device based on thermoacoustic effect as described in claim 4, characterized in that, The steam pipe and the load pipe are equal-diameter pipes, variable-diameter pipes, or a combination of both; they are straight pipes, bent pipes, or a combination of both; and the steam pipe and the load pipe are placed horizontally or at an angle.

6. A seawater desalination device based on thermoacoustic effect as described in claim 6, characterized in that, The humidification unit and the dehumidification unit are cylindrical or rectangular cavities.

7. A seawater desalination device based on thermoacoustic effect as described in claim 7, characterized in that, The spraying device is one or more combinations of fixed nozzles, oscillating nozzles, rotating nozzles, fan-shaped nozzles, conical nozzles, and full-circle nozzles.

8. A humidification and dehumidification seawater desalination device based on thermoacoustic effect as described in claim 8, characterized in that, The heat source is solar energy, electric heating rods, industrial waste heat, or exhaust gas waste heat.

9. A humidification and dehumidification seawater desalination device based on thermoacoustic effect as described in claim 9, characterized in that, The room temperature heat exchanger and the condenser are shell-and-tube heat exchangers, coaxial heat exchangers, plate-fin heat exchangers, spiral plate heat exchangers, plate-and-shell heat exchangers, finned tube heat exchangers, or heat pipe heat exchangers.

10. A seawater desalination method based on the thermoacoustic effect-based humidification and dehumidification seawater desalination device according to any one of claims 1-9, characterized in that, It includes two stages: seawater circulation and air circulation. The seawater circulation process includes: feed seawater is pumped into the condenser in the first-stage condensation loop and preheated therein, while steam is condensed; the preheated concentrated seawater leaves the first-stage condenser and enters the first-stage room-temperature heat exchanger for further preheating; the concentrated seawater sequentially passes through the second-stage condenser, the second-stage room-temperature heat exchanger... and the i-th stage condenser and the i-th stage room-temperature heat exchanger before entering the heat source for further heating; the heated concentrated seawater first enters the i-th stage humidification unit, where it is humidified by the i-th stage... The spray device sprays downwards, creating a temperature difference across the regenerator, which in turn generates sound waves. The regenerator serves both as a thermo-acoustic converter and as a heat-mass exchange medium to enhance heat transfer. The concentrated seawater exchanges heat and moisture with the dry air in the i-th stage humidification unit, simultaneously wetting the i-th stage regenerator. Subsequently, the concentrated seawater is collected in the i-th stage concentrated seawater pool and sequentially pumped by the water pump into the (i-1)th stage...the first stage device; the above steps are repeated; finally, the remaining concentrated seawater is collected in the concentrated seawater pool of the first stage condensation circuit. The air circulation process includes: dry and cold air in each stage of the condensation circuit undergoes heat and mass exchange with sprayed hot seawater in the humidification unit to generate humid and hot air. The humid and hot air is cooled by entering the dehumidification unit through the steam pipe under the action of sound waves and fans, and then generates fresh water, which flows into the fresh water pool for collection.

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