A thermal edge principle heat pump and flash method coupled seawater desalination system

Abstract

A seawater desalination system coupling a heat pump based on the thermal edge principle and flash evaporation includes a heat pump unit, a seawater pump, a dehumidifier, a humidifier, a Knudsen gas pump, a freshwater storage tank, and a hot concentrated seawater storage tank. It utilizes low-grade heat energy as a driving force with minimal heat loss, resulting in high heat utilization and exchange efficiency. It can be adapted to different application scenarios based on actual desalination volume requirements. The thermal edge principle heat pump system directly utilizes the temperature difference between ambient cold seawater and the hot concentrated seawater (a byproduct) to achieve temperature-driven operation. It can precisely control key parameters such as temperature and pressure in the process, achieving dynamic and precise matching between heat pump energy efficiency and desalination process requirements. The heat pump system components are less susceptible to contamination by seawater impurities, ensuring long-term heat exchange efficiency, extending service life, facilitating maintenance, reducing operating costs, and lowering energy consumption costs. It eliminates the need for traditional auxiliary equipment and reduces the equipment's footprint, avoiding energy waste and environmental thermal pollution caused by direct waste heat discharge.

Description

Technical Field

[0001] This invention belongs to the field of seawater desalination technology, and in particular relates to a seawater desalination system that couples a heat pump based on the thermal edge principle with a flash evaporation method. Background Technology

[0002] Seawater desalination refers to the process of removing salt and minerals from seawater or brackish water and converting it into freshwater that can be used for human drinking, agricultural irrigation, or industrial purposes.

[0003] At present, the mainstream methods of seawater desalination are the membrane exchange method and the distillation method. Both the membrane exchange method and the distillation method actually produce fresh water by creating an unbalanced potential difference and repairing the potential difference in the system.

[0004] However, existing seawater desalination plants generally have the following problems: distillation requires a large amount of high-grade fossil energy, resulting in high energy consumption and low waste heat recovery efficiency; although the exchange membrane method reduces energy consumption, it is heavily dependent on grid power supply, making it difficult to adapt to low-grade heat energy such as solar energy and industrial waste heat, and the system membrane modules are easily contaminated by seawater impurities, have poor adaptability to high-salinity seawater, and require complex pretreatment. Summary of the Invention

[0005] To address the problems of existing technologies, this invention provides a seawater desalination system coupled with a thermal edge principle heat pump and flash evaporation. This system utilizes low-grade heat energy as a driving force, resulting in minimal heat loss, high heat utilization efficiency, and high heat exchange efficiency. It can be adapted to different application scenarios such as islands, coastal industrial parks, and ships based on actual desalination water volume requirements. The thermal edge principle heat pump system directly utilizes the temperature difference between ambient cold seawater and concentrated hot seawater as a byproduct, enabling precise control of key parameters such as temperature and pressure in the process. This allows for dynamic and precise matching of heat pump energy efficiency with desalination process requirements. The heat pump system components are less susceptible to contamination by seawater impurities, ensuring long-term heat exchange efficiency, extending the service life of core equipment, facilitating convenient maintenance, and reducing operating costs, thus significantly lowering energy consumption costs. Waste heat recovery eliminates the need for traditional auxiliary equipment such as boilers and cooling towers, reducing the equipment footprint and avoiding energy waste and environmental thermal pollution caused by direct waste heat emissions.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a seawater desalination system coupled with a heat pump based on the thermal edge principle and flash evaporation, comprising a heat pump unit, a seawater pump, a dehumidifier, a humidifier, a Knudsen gas pump, a freshwater storage tank, and a hot concentrated seawater storage tank; the seawater pump is connected to the dehumidifier; the dehumidifier is connected to the heat pump unit, the humidifier, and the freshwater storage tank respectively; the humidifier is connected to the heat pump unit, the Knudsen gas pump, and the hot concentrated seawater storage tank respectively; the Knudsen gas pump is connected to the heat pump unit; and the freshwater storage tank is connected to the heat pump unit.

[0007] The heat pump unit includes a Knudsen compressor, a condenser, an expander, an evaporator, a flash tank, and an ejector. The working medium outlet of the Knudsen compressor is connected to the working medium inlet of the condenser, the working medium outlet of the condenser is connected to the working medium inlet of the expander, the working medium outlet of the expander is connected to the working medium inlet of the evaporator, the working medium outlet of the evaporator is connected to the working medium inlet of the flash tank, and the working medium outlet of the flash tank is connected to the working medium inlet of the Knudsen compressor. The working medium circulates within the loop formed by the Knudsen compressor, condenser, expander, evaporator, and flash tank. The working medium inlet of the ejector is connected to the working medium outlet of the condenser, the working medium outlet of the ejector is connected to the working medium inlet of the Knudsen compressor, and the working medium ejector port is connected to the working medium outlet of the evaporator.

[0008] The condenser is equipped with two sets of heat exchange pipe networks, namely the first heat exchange pipe network and the second heat exchange pipe network, which are independently set up. The evaporator is equipped with two sets of heat exchange pipe networks, namely the third heat exchange pipe network and the fourth heat exchange pipe network, which are independently set up. The third heat exchange pipe network is equipped with a condensate recovery device, which is connected to the inlet of the freshwater storage tank through a pipeline.

[0009] The dehumidifier adopts a box-type structure. A curved heat exchange copper tube is installed inside the box. One end of the curved heat exchange copper tube is connected to the outlet end of the seawater pump, and the inlet end of the seawater pump is connected to the ambient cold seawater through a pipeline. The other end of the curved heat exchange copper tube is connected to the inlet end of the first heat exchange pipe network of the condenser through a pipeline, and the outlet end of the first heat exchange pipe network is connected to the humidifier. A condensate collector is installed at the bottom of the box of the dehumidifier, and the condensate collector is connected to the inlet of the freshwater storage tank through a pipeline.

[0010] The humidifier adopts a box-type structure. A spray distributor is installed in the upper middle part of the inner side of the humidifier box. A porous ceramic filler is installed below the spray distributor. A hot concentrated seawater collector is installed at the bottom of the humidifier box below the porous ceramic filler. The hot concentrated seawater collector is connected to the inlet of the hot concentrated seawater storage tank through a pipeline. The outlet end of the first heat exchange pipeline is connected to the inlet of the spray distributor. A humidified hot air collection port is installed on the top of the humidifier box above the spray distributor. A humidified hot air injection port is installed on the top of the dehumidifier box. The humidified hot air injection port is connected to the humidified hot air collection port through a pipeline.

[0011] A humidified air outlet is provided in the lower part of the dehumidifier housing. The humidified air outlet is connected to the inlet end of the third heat exchange network of the evaporator through a pipeline. The outlet end of the third heat exchange network is connected to the inlet end of the Knudsen air pump. A dry air inlet is provided on the humidifier housing between the porous ceramic filler and the concentrated seawater collector. The outlet end of the Knudsen air pump is connected to the dry air inlet through a pipeline.

[0012] The seawater desalination system coupled with the thermal edge principle heat pump and flash evaporation method also includes a Knudsen air pump; the inlet of the Knudsen air pump is connected to the ambient atmosphere, and the outlet of the Knudsen air pump is connected to the inlet of the second heat exchange network through a pipeline; a dry hot air injection inlet is provided in the middle of the dehumidifier housing, and the outlet of the second heat exchange network is connected to the dry hot air injection inlet through a pipeline.

[0013] A hot air waste heat recovery port is also provided in the middle of the dehumidifier housing. The inlet end of the fourth heat exchange pipe network is connected to the hot air waste heat recovery port through a pipe, and the outlet end of the fourth heat exchange pipe network is connected to the ambient atmosphere.

[0014] The seawater desalination system coupled with the thermal edge principle heat pump and flash evaporation method also includes a Knudsen air pump; a negative pressure suction port is provided on the dehumidifier housing, the inlet end of the Knudsen air pump is connected to the negative pressure suction port through a pipeline, and the outlet end of the Knudsen air pump is connected to the ambient atmosphere.

[0015] The Knudsen gas pump, Knudsen compressor, Knudsen air pump, and Knudsen vacuum pump all adopt the thermal edge principle structure and use temperature difference as the driving force. The ambient cold seawater is used as the cold end cold source, and the hot concentrated seawater, which is a by-product, is used as the hot end heat source.

[0016] The beneficial effects of this invention are: The seawater desalination system of this invention, which couples a heat pump based on the thermal edge principle with flash evaporation, can utilize low-grade heat energy as a driving force, with minimal heat loss, resulting in high heat utilization and exchange efficiency. It can be adapted to different application scenarios such as islands, coastal industrial parks, and ships according to actual desalination water volume requirements. The thermal edge principle heat pump system directly achieves temperature difference driving by combining ambient cold seawater with hot concentrated seawater as a byproduct. It can precisely control key parameters such as temperature and pressure in the process, achieving dynamic and precise matching between heat pump energy efficiency and desalination process requirements. The heat pump system components are not easily contaminated by seawater impurities, ensuring long-term heat exchange efficiency, extending the service life of core equipment, facilitating convenient maintenance, and reducing operating costs, thus significantly lowering energy consumption costs. Waste heat recovery eliminates the need for traditional auxiliary equipment such as boilers and cooling towers, reducing the equipment footprint and avoiding energy waste and environmental thermal pollution caused by direct waste heat discharge. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structural principle of a seawater desalination system that couples a heat pump based on the thermal edge principle with a flash evaporation method according to the present invention. In the diagram, 1—heat pump unit, 2—seawater pump, 3—dehumidifier, 4—humidifier, 5—Knussen air pump, 6—freshwater storage tank, 7—hot concentrated seawater storage tank, 8—Knussen compressor, 9—condenser, 10—expander, 11—evaporator, 12—flash tank, 13—ejector, 14—recurved heat exchange copper tube, 15—spray distributor, 16—porous ceramic packing, 17—Knussen air pump, 18—Knussen vacuum pump. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0019] like Figure 1 As shown, a seawater desalination system coupled with a heat pump based on the thermal edge principle and flash evaporation includes a heat pump unit 1, a seawater pump 2, a dehumidifier 3, a humidifier 4, a Knudsen gas pump 5, a freshwater storage tank 6, and a hot concentrated seawater storage tank 7. The seawater pump 2 is connected to the dehumidifier 3. The dehumidifier 3 is connected to the heat pump unit 1, the humidifier 4, and the freshwater storage tank 6. The humidifier 4 is connected to the heat pump unit 1, the Knudsen gas pump 5, and the hot concentrated seawater storage tank 7. The Knudsen gas pump 5 is connected to the heat pump unit 1. The freshwater storage tank 6 is connected to the heat pump unit 1.

[0020] The heat pump unit 1 includes a Knudsen compressor 8, a condenser 9, an expander 10, an evaporator 11, a flash tank 12, and an ejector 13. The working medium outlet of the Knudsen compressor 8 is connected to the working medium inlet of the condenser 9, the working medium outlet of the condenser 9 is connected to the working medium inlet of the expander 10, the working medium outlet of the expander 10 is connected to the working medium inlet of the evaporator 11, the working medium outlet of the evaporator 11 is connected to the working medium inlet of the flash tank 12, and the working medium outlet of the flash tank 12 is connected to the working medium inlet of the Knudsen compressor 8. The working medium circulates within the loop formed by the Knudsen compressor 8, condenser 9, expander 10, evaporator 11, and flash tank 12. The working medium inlet of the ejector 13 is connected to the working medium outlet of the condenser 9, the working medium outlet of the ejector 13 is connected to the working medium inlet of the Knudsen compressor 8, and the working medium ejector port of the ejector 13 is connected to the working medium outlet of the evaporator 11.

[0021] The condenser 9 is equipped with two sets of heat exchange pipe networks, namely the first heat exchange pipe network and the second heat exchange pipe network, which are independently set up. The evaporator 11 is equipped with two sets of heat exchange pipe networks, namely the third heat exchange pipe network and the fourth heat exchange pipe network, which are independently set up. The third heat exchange pipe network is equipped with a condensate recovery device, which is connected to the inlet of the freshwater storage tank 6 through a pipeline.

[0022] The dehumidifier 3 adopts a box-type structure. A curved heat exchange copper tube 14 is installed inside the box of the dehumidifier 3. One end of the curved heat exchange copper tube 14 is connected to the outlet end of the seawater pump 2, and the inlet end of the seawater pump 2 is connected to the ambient cold seawater through a pipeline. The other end of the curved heat exchange copper tube 14 is connected to the inlet end of the first heat exchange pipe network of the condenser 9 through a pipeline. The outlet end of the first heat exchange pipe network is connected to the humidifier 4. A condensate collector is installed at the bottom of the box of the dehumidifier 3, and the condensate collector is connected to the inlet of the freshwater storage tank 6 through a pipeline.

[0023] The humidifier 4 adopts a box-type structure. A spray distributor 15 is provided in the upper middle part of the inner side of the humidifier 4 box. A porous ceramic filler 16 is provided below the spray distributor 15. A hot concentrated seawater collector is provided at the bottom of the humidifier 4 box below the porous ceramic filler 16. The hot concentrated seawater collector is connected to the inlet of the hot concentrated seawater storage tank 7 through a pipeline. The outlet end of the first heat exchange pipeline is connected to the inlet of the spray distributor 15. A humidified hot air collection port is provided at the top of the humidifier 4 box above the spray distributor 15. A humidified hot air injection port is provided at the top of the dehumidifier 3 box. The humidified hot air injection port is connected to the humidified hot air collection port through a pipeline.

[0024] A humidified air outlet is provided in the lower part of the housing of the dehumidifier 3. The humidified air outlet is connected to the inlet end of the third heat exchange network of the evaporator 11 through a pipeline. The outlet end of the third heat exchange network is connected to the inlet end of the Knudsen air pump 5. A dry air inlet is provided on the housing of the humidifier 4 between the porous ceramic filler 16 and the concentrated seawater collector. The outlet end of the Knudsen air pump 5 is connected to the dry air inlet through a pipeline.

[0025] The seawater desalination system coupled with the hot edge principle heat pump and flash evaporation method also includes a Knudsen air pump 17; the inlet of the Knudsen air pump 17 is connected to the ambient atmosphere, and the outlet of the Knudsen air pump 17 is connected to the inlet of the second heat exchange network through a pipeline; a dry hot air injection inlet is provided in the middle of the housing of the dehumidifier 3, and the outlet of the second heat exchange network is connected to the dry hot air injection inlet through a pipeline.

[0026] A hot air waste heat recovery port is also provided in the middle of the housing of the dehumidifier 3. The inlet end of the fourth heat exchange pipeline is connected to the hot air waste heat recovery port through a pipeline, and the outlet end of the fourth heat exchange pipeline is connected to the ambient atmosphere.

[0027] The seawater desalination system coupled with the heat pump based on the thermal edge principle and the flash evaporation method also includes a Knudsen air pump 18; a negative pressure suction port is provided on the housing of the dehumidifier 3, the inlet end of the Knudsen air pump 18 is connected to the negative pressure suction port through a pipeline, and the outlet end of the Knudsen air pump 18 is connected to the ambient atmosphere.

[0028] The Knudsen air pump 5, Knudsen compressor 8, Knudsen air pump 17 and Knudsen vacuum pump 18 all adopt the thermal edge principle structure and use temperature difference as the driving force. The ambient cold seawater is used as the cold end cold source, and the hot concentrated seawater, which is a by-product, is used as the hot end heat source.

[0029] The following description, in conjunction with the accompanying drawings, illustrates the usage of this invention: First, heat pump unit 1 is started. The working medium flows through Knudsen compressor 8 to form a high-temperature, high-pressure gaseous state. Then, it flows through condenser 9 to release heat, forming a medium-temperature, high-pressure liquid state. Next, it flows through expander 10 to form a low-temperature, low-pressure liquid state. Then, it flows through evaporator 11 to absorb heat, forming a low-temperature, low-pressure gaseous state. Subsequently, it flows through flash tank 12 for gas-liquid separation, ensuring that the working medium is fully converted into a low-temperature, low-pressure gaseous state. Finally, the low-temperature, low-pressure gaseous state returns to Knudsen compressor 8, forming a working medium cycle. During the working medium cycle, the medium-temperature, high-pressure liquid working medium enters ejector 13 through a branch line. Simultaneously, the ejector port of ejector 13 draws a portion of the low-temperature, low-pressure gaseous working medium discharged from evaporator 11 into ejector 13, which, together with the medium-temperature, high-pressure liquid working medium, is injected into Knudsen compressor 8, achieving energy recovery and pressure boosting.

[0030] Once the heat pump unit 1 is running stably, the Knudsen air pump 5 is started first. Under the pumping action, the air in the dehumidifier 3 chamber flows through the third heat exchange pipe network of the evaporator 11 and the Knudsen air pump 5 in sequence before entering the humidifier 4 chamber. Then it flows upward through the porous ceramic filler 16, then over the spray distributor 15, and then flows through the humid air collection port and the humid air spray port in sequence before returning to the dehumidifier 3 chamber, forming an air flow circulation.

[0031] Once the airflow circulation stabilizes, the seawater pump 2 is started to pump the ambient cold seawater into the dehumidifier 3 and through the convoluted heat exchange copper tube 14. The ambient cold seawater flowing out of the convoluted heat exchange copper tube 14 then directly enters the first heat exchange pipe network of the condenser 9. During the process of flowing through the first heat exchange pipe network, it absorbs the heat released by the condenser 9 and heats up to become hot seawater after flowing out of the first heat exchange pipe network. The hot seawater then flows into the humidifier 4 and enters the spray distributor 15.

[0032] When hot seawater enters the spray distribution device 15, it is discharged and falls in the form of spray, and seeps into the porous ceramic filler 16. At this time, the downward seeping hot seawater will come into full contact with the upward airflow in the pores inside the porous ceramic filler 16. A large amount of water vapor in the hot seawater will evaporate into the upward airflow. When the airflow overflows the upper surface of the porous ceramic filler 16, it forms humid and hot air with high humidity. After the hot seawater flows downward out of the lower surface of the porous ceramic filler 16, it forms hot concentrated seawater due to water loss. Finally, it flows into the hot concentrated seawater storage tank 7 through the hot concentrated seawater collector at the bottom of the humidifier 4, thus realizing the collection of hot concentrated seawater.

[0033] When humid and hot air is formed, it first passes over the spray distribution device 15, and then flows sequentially through the humid and hot air collection port and the humid and hot air spray port into the dehumidifier 3. Since the ambient cold seawater continuously flows through the curved heat exchange copper tube 14, the curved heat exchange copper tube 14 is stably maintained at a low temperature. When the humid and hot air flows over the surface of the curved heat exchange copper tube 14, the water vapor in the humid and hot air will quickly condense into liquid water on the surface of the curved heat exchange copper tube 14. This liquid water will continuously form and drip downwards. The dripping liquid water will eventually flow into the fresh water storage tank 6 through the condensate collector at the bottom of the dehumidifier 3, realizing the collection of fresh water.

[0034] When the hot and humid air flows out of the area of ​​the curved heat exchange copper tube 14, the humidity is reduced in the first stage, and the temperature also decreases. Then, the dehumidified and deheated air enters the third heat exchange network of the evaporator 11 through the hot and humid air outlet. During the process of flowing through the third heat exchange network, the heat in the air is further absorbed by the evaporator 11, and the water vapor in the air is further condensed in the third heat exchange network. This condensed liquid water will flow into the condensate recovery device set up in the third heat exchange network, and finally flow into the fresh water storage tank 6 through the condensate recovery device to achieve the secondary collection of fresh water.

[0035] After the air flows out from the third heat exchange network, the humidity decreases in the second stage, and the temperature also decreases again, eventually forming room temperature dry air. At this time, the room temperature dry air first flows through the Knudsen air pump 5, then enters the humidifier 4 chamber and flows upward through the porous ceramic filler 16, and participates in the dehumidification of the hot seawater again. At this time, the seawater desalination system enters the stable operation stage.

[0036] During the stable operation of the seawater desalination system, the Knudsen air pump 17 can be started, and the second heat exchange network and the dry hot air inlet can be activated simultaneously. Under the action of the Knudsen air pump 17, ambient temperature air flows through the Knudsen air pump 17 and enters the second heat exchange network. During the process of flowing through the second heat exchange network, the ambient temperature air absorbs the heat released by the condenser 9. After flowing out of the second heat exchange network, it forms dry hot air, which then flows through the dry hot air inlet into the dehumidifier 3 and mixes with the humid hot air flowing in from the humid hot air inlet. This process replenishes the heat of the humid hot air, ensuring the condensation efficiency of the humid hot air when it flows through the surface of the curved heat exchange copper tube 14, thereby improving the freshwater production efficiency.

[0037] During the stable operation of the seawater desalination system, the Knudsen air pump 18 can be started to adjust the pressure environment inside the dehumidifier 3 box. By adjusting the pressure environment inside the dehumidifier 3 box, the amount of condensate produced on the surface of the curved heat exchange copper tube 14 can be dynamically adjusted. The lower the pressure, the lower the amount of condensate produced, thereby adjusting the freshwater production per unit time. When the Knudsen air pump 18 is not used, the amount of condensate produced is in a normal state.

[0038] During the stable operation of the seawater desalination system, the hot air waste heat recovery port and the fourth heat exchange pipe network can also be activated. The air after dehumidification in the dehumidifier 3 box still carries a certain amount of latent heat. This air carrying latent heat can flow through the hot air waste heat recovery port into the fourth heat exchange pipe network. During the flow through the second heat exchange pipe network, the latent heat in the air will be absorbed by the evaporator 11, thereby realizing the recovery of air waste heat. This provides external heat supplementation for the working medium of the evaporator 11 to form a low temperature and low pressure gaseous state. The air after heat exchange can be directly discharged into the ambient air.

[0039] In addition, the cold end cold source and the hot end heat source of Knudsen air pump 5, Knudsen compressor 8, Knudsen air pump 17 and Knudsen vacuum pump 18 can be equipped with temperature control devices. The temperature difference between the two can be precisely adjusted by precisely controlling the cold end temperature and the hot end temperature, thereby meeting the adjustment of drive power and energy efficiency ratio.

[0040] In addition, the entire seawater desalination system can be controlled by a PLC controller. Temperature sensors, pressure sensors, mass flow meters, and electrically controlled on / off valves can be installed on the working medium circulation pipeline of heat pump unit 1, the circulation pipeline of hot and humid air, and the circulation pipeline of seawater. All temperature sensors, pressure sensors, mass flow meters, and electrically controlled on / off valves are electrically connected to the PLC controller, thereby meeting the requirements of intelligent and automated freshwater production.

[0041] The solutions in the embodiments are not intended to limit the scope of protection of the present invention. All equivalent implementations or modifications that do not depart from the present invention are included in the scope of protection of the present invention.

Claims

1. A seawater desalination system coupling a heat pump based on the thermal edge principle with flash evaporation, characterized in that: It includes a heat pump unit, a seawater pump, a dehumidifier, a humidifier, a Knudsen gas pump, a freshwater storage tank, and a hot concentrated seawater storage tank; the seawater pump is connected to the dehumidifier; the dehumidifier is connected to the heat pump unit, the humidifier, and the freshwater storage tank respectively; the humidifier is connected to the heat pump unit, the Knudsen gas pump, and the hot concentrated seawater storage tank respectively; the Knudsen gas pump is connected to the heat pump unit; and the freshwater storage tank is connected to the heat pump unit.

2. The seawater desalination system coupled with a heat pump based on the thermal edge principle and flash evaporation method according to claim 1, characterized in that: The heat pump unit includes a Knudsen compressor, a condenser, an expander, an evaporator, a flash tank, and an ejector. The working medium outlet of the Knudsen compressor is connected to the working medium inlet of the condenser, the working medium outlet of the condenser is connected to the working medium inlet of the expander, the working medium outlet of the expander is connected to the working medium inlet of the evaporator, the working medium outlet of the evaporator is connected to the working medium inlet of the flash tank, and the working medium outlet of the flash tank is connected to the working medium inlet of the Knudsen compressor. The working medium circulates within the loop formed by the Knudsen compressor, condenser, expander, evaporator, and flash tank. The working medium inlet of the ejector is connected to the working medium outlet of the condenser, the working medium outlet of the ejector is connected to the working medium inlet of the Knudsen compressor, and the working medium ejector port is connected to the working medium outlet of the evaporator.

3. The seawater desalination system coupled with a heat pump based on the thermal edge principle and flash evaporation method according to claim 2, characterized in that: The condenser is equipped with two sets of heat exchange pipe networks, namely the first heat exchange pipe network and the second heat exchange pipe network, which are independently set up. The evaporator is equipped with two sets of heat exchange pipe networks, namely the third heat exchange pipe network and the fourth heat exchange pipe network, which are independently set up. The third heat exchange pipe network is equipped with a condensate recovery device, which is connected to the inlet of the freshwater storage tank through a pipeline.

4. The seawater desalination system coupled with a heat pump based on the thermal edge principle and flash evaporation method according to claim 3, characterized in that: The dehumidifier adopts a box-type structure. A curved heat exchange copper tube is installed inside the box. One end of the curved heat exchange copper tube is connected to the outlet end of the seawater pump, and the inlet end of the seawater pump is connected to the ambient cold seawater through a pipeline. The other end of the curved heat exchange copper tube is connected to the inlet end of the first heat exchange pipe network of the condenser through a pipeline, and the outlet end of the first heat exchange pipe network is connected to the humidifier. A condensate collector is installed at the bottom of the box of the dehumidifier, and the condensate collector is connected to the inlet of the freshwater storage tank through a pipeline.

5. A seawater desalination system coupled with a heat pump based on the thermal edge principle and flash evaporation as described in claim 4, characterized in that: The humidifier adopts a box-type structure. A spray distributor is installed in the upper middle part of the inner side of the humidifier box. A porous ceramic filler is installed below the spray distributor. A hot concentrated seawater collector is installed at the bottom of the humidifier box below the porous ceramic filler. The hot concentrated seawater collector is connected to the inlet of the hot concentrated seawater storage tank through a pipeline. The outlet end of the first heat exchange pipeline is connected to the inlet of the spray distributor. A humidified hot air collection port is installed on the top of the humidifier box above the spray distributor. A humidified hot air injection port is installed on the top of the dehumidifier box. The humidified hot air injection port is connected to the humidified hot air collection port through a pipeline.

6. The seawater desalination system coupled with a heat pump based on the thermal edge principle and flash evaporation as described in claim 5, characterized in that: A humidified air outlet is provided in the lower part of the dehumidifier housing. The humidified air outlet is connected to the inlet end of the third heat exchange network of the evaporator through a pipeline. The outlet end of the third heat exchange network is connected to the inlet end of the Knudsen air pump. A dry air inlet is provided on the humidifier housing between the porous ceramic filler and the concentrated seawater collector. The outlet end of the Knudsen air pump is connected to the dry air inlet through a pipeline.

7. A seawater desalination system coupled with a heat pump based on the thermal edge principle and flash evaporation as described in claim 6, characterized in that: It also includes a Knudsen air pump; the inlet of the Knudsen air pump is connected to the ambient atmosphere, and the outlet of the Knudsen air pump is connected to the inlet of the second heat exchange network through a pipeline; a dry hot air injection inlet is provided in the middle of the dehumidifier housing, and the outlet of the second heat exchange network is connected to the dry hot air injection inlet through a pipeline.

8. A seawater desalination system coupled with a heat pump based on the thermal edge principle and flash evaporation as described in claim 7, characterized in that: A hot air waste heat recovery port is also provided in the middle of the dehumidifier housing. The inlet end of the fourth heat exchange pipe network is connected to the hot air waste heat recovery port through a pipe, and the outlet end of the fourth heat exchange pipe network is connected to the ambient atmosphere.

9. A seawater desalination system coupled with a heat pump based on the thermal edge principle and flash evaporation as described in claim 8, characterized in that: It also includes a Knudsen air pump; a negative pressure suction port is provided on the housing of the dehumidifier, the inlet end of the Knudsen air pump is connected to the negative pressure suction port through a pipeline, and the outlet end of the Knudsen air pump is connected to the ambient atmosphere.

10. A seawater desalination system coupled with a heat pump based on the thermal edge principle and flash evaporation method according to claim 9, characterized in that: The Knudsen gas pump, Knudsen compressor, Knudsen air pump, and Knudsen vacuum pump all adopt the thermal edge principle structure and use temperature difference as the driving force. The ambient cold seawater is used as the cold end cold source, and the hot concentrated seawater, which is a by-product, is used as the hot end heat source.

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