A device for desalination of seawater using exhaust heat of ship smoke

Abstract

The application provides a device for seawater desalination by using ship flue gas waste heat, and belongs to the technical field of seawater desalination. The device for seawater desalination by using ship flue gas waste heat comprises a flue gas inlet, a first nozzle, a humidifying device, a salt tank, a temperature and humidity meter, a demister, a fan, a diffuser, a jet cooling cavity, a second nozzle, a dehumidifying device, a fresh water treatment and storage device, a cooling fresh water jet device and a seawater cooling and jet pipeline. The flue gas inlet is arranged on a ship chimney and connected with the chimney, and the opening and closing thereof is controlled by a second stop valve. One end of the first nozzle is connected with the flue gas inlet, and the other end is connected with the humidifying device. The humidifying device is a seawater jet flue gas cyclone device which is modified from a cyclone separator and comprises a cylindrical part, a conical part and an intermediate discharge pipe. The conical part is located below the cylindrical part and is integrated with the cylindrical part.

Description

Technical Field

[0001] This invention belongs to the field of seawater desalination technology, and more specifically, relates to a device for seawater desalination using waste heat from ship flue gas. Background Technology

[0002] Ocean-going vessels require large quantities of fresh water to meet the needs of their equipment and crew. Since the amount of fresh water carried by the vessels is limited, most ocean-going ships are equipped with seawater desalination systems. Currently, the most mature and widely used technology on merchant ships is vacuum boiling seawater desalination. This method uses the cooling water from the main engine cylinder liner as a heat source to heat seawater to boiling in a high-vacuum environment, and then produces fresh water by condensing the steam. This method can effectively produce fresh water, but generating a high-vacuum environment requires a large amount of energy and places high demands on the equipment's sealing, increasing operating costs and maintenance difficulty. In contrast, if the high-temperature flue gas emitted by the ship can be directly used as the heat source for the seawater desalination unit, a high-vacuum environment is no longer needed, significantly reducing desalination costs and improving energy efficiency. The flue gas emitted by ships is mainly generated by the main engine, generators, or auxiliary boilers, and the temperature is usually around 200℃ or even higher. This high-temperature flue gas contains abundant waste heat energy, which, if effectively utilized, can provide the necessary heat for seawater desalination.

[0003] In the field of seawater desalination using waste heat from flue gas, some related patents have been developed. Patent application number 202211016000.1 describes a "technology and device for coupling seawater desalination with exhaust gas purification from a marine diesel engine." This device heats seawater spray outside the heat exchange tubes with diesel engine exhaust gas, generating water vapor which is then condensed into fresh water. This indirect heat exchange method has a low heat transfer coefficient, and scaling and blockage are prone to occur on both the seawater and exhaust gas sides, increasing maintenance workload. Furthermore, the separate design of exhaust gas purification and seawater desalination makes the overall structure more complex.

[0004] Patent application number 201310276412.3 developed a "seawater desalination system utilizing waste heat from flue gas." In the humidification tower, high-temperature flue gas comes into direct contact with seawater, removing pollutants and generating a large amount of water vapor to humidify the flue gas. The water vapor is then cooled into fresh water in the dehumidification tower through fresh water jet cooling. This direct contact heat exchange method has a higher heat transfer coefficient. However, the design of traditional scrubbing towers results in insufficient heat and mass transfer between flue gas and seawater, a large seawater spray volume, and increased discharge of concentrated brine, causing difficulties in secondary treatment. Furthermore, the cooling of high-temperature water vapor in this device relies solely on fresh water jet cooling, which is not thorough enough. In addition, this device also suffers from drawbacks such as poor removal of small particles, large equipment size, and high construction and maintenance costs.

[0005] In summary, existing technologies for seawater desalination using waste heat from flue gas still have some key issues that need further resolution. The most critical technical drawback is that current solutions cannot achieve efficient heat and mass transfer between flue gas and seawater, resulting in low overall heat exchange efficiency, limited desalination performance, and a tendency to cause scaling and blockage, increasing maintenance costs. Summary of the Invention

[0006] In view of this, the present invention provides a device for seawater desalination using waste heat from ship flue gas, so as to achieve efficient heat and mass transfer between flue gas and seawater.

[0007] This invention is implemented as follows:

[0008] This invention provides a device for seawater desalination using waste heat from ship exhaust gas, comprising:

[0009] Flue gas inlet, first nozzle, humidification device, salt tank, thermometer and hygrometer, demister, fan, diffuser, jet cooling chamber, second nozzle, dehumidification device, freshwater treatment and storage device, cooling freshwater jet device, seawater cooling and jet pipeline;

[0010] The flue gas inlet is located on the ship's chimney and connected to the chimney, and its opening and closing is controlled by a second shut-off valve.

[0011] One end of the first nozzle is connected to the flue gas inlet, and the other end is connected to the humidification device;

[0012] The humidification device is a seawater jet flue gas cyclone device, which is modified from a cyclone separator. It includes a cylindrical part, a conical part and an intermediate discharge pipe. The conical part is located below the cylindrical part and is integrated with the cylindrical part.

[0013] The cylindrical part of the humidification device has seawater spray holes around its upper perimeter for spraying seawater.

[0014] The salt tank is located below the conical part of the humidification device and is used to receive the concentrated brine, salt particles, and carbon soot particles discharged by the humidification device.

[0015] The thermometer and hygrometer are installed at the high-temperature and humid air outlet at the top of the humidification device to measure the temperature and humidity of the high-temperature and humid air.

[0016] The demister is installed after the thermometer and hygrometer to remove small amounts of particulate matter or small droplets from the hot and humid air.

[0017] The inlet of the fan is connected to the demister, and the outlet is connected to the diffuser.

[0018] The diffuser tube is used to increase the pressure of high-temperature humid air and reduce the flow rate of humid air;

[0019] One end of the jet cooling chamber is connected to the diffuser tube and is used for the first stage of cooling of high-temperature and humid air.

[0020] One end of the second nozzle is connected to the spray cooling chamber, and the other end is connected to the dehumidification device;

[0021] The dehumidification device is a modified cyclone separator used for the second stage of cooling of humid air;

[0022] The freshwater treatment and storage device includes a freshwater tank, a sampling port, an alkali tank, a second filter, a purified freshwater tank, and pipelines to the ship's freshwater tank.

[0023] The cooling freshwater injection device includes a freshwater pump, a freshwater flow regulating valve, and freshwater nozzles; the freshwater pump in the cooling freshwater injection device is used to provide injection pressure; the freshwater flow regulating valve is used to regulate the amount of condensed freshwater injected; the freshwater nozzles are uniformly distributed according to the cross-section of the injection cooling chamber.

[0024] The seawater cooling and spraying pipeline includes a first filter, a seawater pump, a seawater cooling pipe leading to the purified freshwater tank, a seawater pipe leading to the dehumidification device, and a seawater flow regulating valve; the first filter can fully filter impurities in the seawater and prevent the seawater spray holes from becoming clogged; the seawater flow regulating valve is used to regulate the flow rate of seawater sprayed into the humidification device.

[0025] The technical advantages of the device for seawater desalination using waste heat from ship flue gas provided by this invention are as follows: Compared with the prior art, the beneficial effects of the device for seawater desalination using waste heat from ship flue gas provided by this invention are: Based on the seawater jet-flue gas cyclone device, seawater desalination and pollutant removal are combined using ship flue gas humidification-dehumidification technology. The high-temperature flue gas from the ship and the seawater jet spray are in direct contact, generating strong disturbances between them. The waste heat of the flue gas is fully utilized, and the heat and mass transfer effect is good. The direct result is more complete absorption of harmful gases in the flue gas and evaporation of seawater jet spray, resulting in higher freshwater production. The invention features several advantages: First, it minimizes the discharge of concentrated brine. Second, the particulate matter emitted by the diesel engine, after being wetted and condensed by the seawater spray, increases in size and is more prone to agglomeration, making it easier to remove under centrifugal force. Third, the humidification tower's inner wall is less prone to scaling under the strong scouring of the jet and cyclone. When scaling and contamination do occur, cleaning can be performed while the diesel engine is stopped. In this case, the intake air becomes clean air, and the injected material is high-pressure hot fresh water or soda ash solution from the cleaning pipeline, which easily removes the scale. Therefore, the overall maintenance cost of the device is low. Fourth, the device employs cyclone separation and cyclone cooling, resulting in a compact structure and low system resistance. In summary, this invention solves the technical problems of existing solutions that cannot achieve efficient heat and mass transfer between flue gas and seawater, leading to low overall heat exchange efficiency, limited desalination performance, and easy scaling and blockage, which increases maintenance costs.

[0026] Based on the above technical solution, the device for seawater desalination using waste heat from ship flue gas of the present invention can be further improved as follows:

[0027] The humidification device is made of one or more of stainless steel, ceramic, polymer or high temperature resistant resin, and is manufactured by welding. The material can withstand high temperatures above 200°C.

[0028] The flue gas inlet of the cyclone separator of the humidification device is rectangular, the air intake method is tangential, and the gas flow mode inside the cyclone separator is counter-current.

[0029] The outermost part of the humidification device is provided with heat insulation material to reduce the heat transfer from the high-temperature water vapor inside the humidification device to the outside.

[0030] The seawater nozzles of the humidification device are evenly distributed throughout the spray area, and the total height of the nozzle area is less than the insertion length of the central discharge pipe.

[0031] The inner diameter of the seawater nozzle of the humidification device is selected according to the size parameters of the humidification device and the flue gas parameters.

[0032] The salt tank is equipped with an observation mirror for observing the state and flow of the concentrated brine in the salt tank;

[0033] The fan is a variable frequency, high temperature resistant, and corrosion resistant fan;

[0034] The diffuser tube adopts a circular-to-square structure.

[0035] Furthermore, the length of the spray cooling chamber ensures thorough mixing of the fresh water spray and the high-temperature, humid air;

[0036] The humid air inlet of the dehumidification device is rectangular, including a cylindrical part, a conical part, and a middle discharge pipe part;

[0037] The cylindrical and conical portions of the dehumidification device are provided with a cooling water jacket, which has an inlet and an outlet for cooling seawater.

[0038] The cooling seawater in the cooling water jacket enters from the lower seawater inlet, and the seawater, whose temperature rises after exchanging heat with water vapor, is discharged from the upper cooling water outlet.

[0039] The intermediate discharge pipe of the dehumidification device is a clean flue gas emission outlet. The clean flue gas after low-temperature dehumidification is discharged through the flue gas emission outlet and enters the ship's chimney.

[0040] The lower part of the conical section of the dehumidification device is a fresh water outlet. The condensed fresh water flows out through the fresh water outlet and reaches the fresh water treatment and storage device.

[0041] Furthermore, the freshwater tank in the freshwater treatment and storage device is used to collect the freshwater condensed by the dehumidification device and to settle particulate matter.

[0042] The sampling port is used to sample and measure the pH and salinity of the freshwater in the freshwater tank;

[0043] The alkali tank is used to neutralize the residual acid value in the freshwater tank, so that the freshwater in the tank is neutral.

[0044] The second filter is used to filter oily components and some suspended solids in fresh water, and includes at least two stages of filtration: activated carbon and resin filter.

[0045] The freshwater stored in the purified freshwater tank is treated clean freshwater, and it is cooled by seawater or other cold energy.

[0046] The pipeline to the ship's freshwater tanks delivers freshwater to various sub-tanks for drinking, sanitation, or miscellaneous purposes, depending on the quality of the freshwater produced.

[0047] Furthermore, it also includes a flue gas pretreatment unit, which is disposed between the flue gas inlet and the first nozzle for preliminary treatment of the flue gas entering the system; the flue gas pretreatment unit includes a pretreatment cylinder, a dust removal device, a condensate collection tray, a drain pipe, a temperature sensor, and a pressure sensor.

[0048] Furthermore, the pretreatment cylinder has a cylindrical structure, with one end connected to the flue gas inlet and the other end connected to the first nozzle; the pretreatment cylinder is made of high-temperature resistant and corrosion-resistant alloy steel; the exterior of the pretreatment cylinder is provided with an insulation layer to reduce heat loss.

[0049] Furthermore, the dust removal device is located in the upper part of the pretreatment cylinder and includes multiple layers of metal mesh for filtering large particulate matter in the flue gas; the metal mesh is made of high-temperature resistant and corrosion-resistant stainless steel, and its mesh size gradually decreases from the air inlet end to the air outlet end.

[0050] Furthermore, the condensate collection tray is located at the bottom of the pretreatment cylinder and has a shallow dish-shaped structure for collecting the condensed water in the flue gas; the drain pipe is connected to the condensate collection tray for discharging the collected condensate; the drain pipe is equipped with a one-way valve to prevent backflow of external air.

[0051] Furthermore, the temperature sensor and pressure sensor are respectively installed on the side wall of the pretreatment cylinder to monitor the temperature and pressure of the flue gas in real time and transmit the data to the host computer via a communication device.

[0052] Furthermore, the working process of the device is as follows:

[0053] When the device is working, the first shut-off valve 1 is closed, the second shut-off valve 2 and the third shut-off valve 3 are open, and the high-temperature flue gas in the ship's chimney is accelerated through the first nozzle and then enters the humidification device tangentially. The preheated seawater is injected from the seawater nozzles around the upper part of the humidification device.

[0054] Strong disturbances occur between the spiral flue gas and the radial seawater jet, resulting in sufficient heat and mass transfer. Under the action of centrifugal force and gravity, the evaporated salt particles, unevaporated small droplets, carbon soot particles in the flue gas, and other denser components spiral down along the inner wall of the humidification device and enter the salt tank. The high-temperature water vapor generated by the evaporation of seawater rises along the inner spiral line and is discharged from the humidification device after passing through the demister.

[0055] After passing through the fan, the humid air enters the dehumidification process, which includes two stages of cooling: First, the cooling fresh water mist sprayed into the spray cooling chamber can quickly cool the high-temperature water vapor, causing some of the water vapor to condense into liquid water; then it enters the dehumidification device, where low-temperature seawater further cools the water vapor into fresh water, which flows into the fresh water tank.

[0056] The pH and salinity of fresh water can be measured through the sampling port. The pH is adjusted through the alkali tank. A small amount of particulate matter inside the tank settles to the bottom of the tank and is released through the slag discharge port at the bottom. The fresh water in the tank enters the purified fresh water tank after passing through activated carbon and resin filters.

[0057] After being cooled by seawater or other low-temperature media, the freshwater in the purified freshwater tank is partially sprayed to cool the high-temperature water vapor at the outlet of the humidification tower, while the remainder is transported to different freshwater tanks on the ship for drinking, sanitary or miscellaneous purposes, depending on the quality of the freshwater produced.

[0058] Compared with existing technologies, the beneficial effects of the device for seawater desalination using waste heat from ship flue gas provided by this invention are as follows: Based on a seawater jet-flue gas cyclone device, the device utilizes ship flue gas humidification-dehumidification technology for seawater desalination combined with pollutant removal. The high-temperature ship flue gas and the seawater jet spray come into direct contact, generating strong disturbances between them. This ensures full utilization of waste heat from the flue gas and excellent heat and mass transfer. The direct result is more complete absorption of harmful gases in the flue gas and more thorough evaporation of the seawater jet spray, leading to more efficient desalination. The invention features high water production and low concentrated brine discharge. Particulate matter emitted from the diesel engine, after being wetted and condensed by the seawater spray, increases in size and is more prone to agglomeration, making it easily removed under centrifugal force. The humidification tower, under the intense scouring of the jet and cyclone, is less prone to scaling on its inner wall. When scaling and contamination do occur, cleaning can be performed while the diesel engine is stopped. At this time, the intake air becomes clean air, and the injected material is high-pressure hot fresh water or soda ash solution from the cleaning pipeline, which easily removes the scale. Therefore, the overall maintenance cost of the device is low. The device employs cyclone separation and cyclone cooling, resulting in a compact structure and low system resistance. In summary, this invention solves the technical problems of existing solutions that cannot achieve efficient heat and mass transfer between flue gas and seawater, leading to low overall heat exchange efficiency, limited desalination performance, and easy scaling and blockage, increasing maintenance costs. Attached Figure Description

[0059] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0060] Figure 1 This is a schematic diagram of the first embodiment of a device for desalination using waste heat from ship exhaust.

[0061] Figure 2 This is a schematic diagram of a second embodiment of a device for seawater desalination using waste heat from ship exhaust.

[0062] Figure 3 This is a schematic diagram of a flue gas pretreatment unit;

[0063] The attached diagram lists the components represented by each number as follows:

[0064] 1. First shut-off valve; 10. Demister; 11. Thermal insulation material; 13. Salt tank; 14. Observation mirror; 15. Freshwater tank; 16. Sampling port; 17. Alkali tank; 18. Second filter; 19. Purified freshwater tank; 2. Second shut-off valve; 20. Freshwater pump; 21. Freshwater flow regulating valve; 22. Freshwater nozzle; 23. Diffuser; 24. Second nozzle; 25. Cooling water jacket; 26. Seawater jet jacket; 27. Cooling pipe; 3. Third shut-off valve; 31. Flue gas pretreatment unit; 311. Pretreatment cylinder; 312. Dust removal device; 313. Temperature sensor; 314. Pressure sensor; 4. First filter; 41. Humidification device; 42. Jet cooling chamber; 43. Dehumidification device; 5. Seawater pump; 6. Seawater flow regulating valve; 7. Seawater nozzle; 8. First nozzle; 9. Thermometer and hygrometer. Detailed Implementation

[0065] 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.

[0066] like Figure 1 The diagram shows the structure of a device for seawater desalination using waste heat from ship exhaust gas, provided by the present invention, comprising:

[0067] Flue gas inlet, first nozzle 8, humidification device 41, salt tank 13, thermometer and hygrometer 9, demister 10, fan, diffuser 23, jet cooling chamber 42, second nozzle 24, dehumidification device 43, freshwater tank 15, sampling port 16, alkali tank 17, second filter 18, purified freshwater tank 19, freshwater pump 20, freshwater flow regulating valve 21, freshwater nozzle 22, first filter 4, seawater pump 5, seawater flow regulating valve 6;

[0068] The flue gas inlet is located on the ship's funnel and connected to the funnel; its opening and closing is controlled by the second shut-off valve 2.

[0069] One end of the first nozzle 8 is connected to the flue gas inlet, and the other end is connected to the humidification device 41;

[0070] The humidification device 41 is a seawater jet flue gas cyclone device, which is modified from a cyclone separator. It includes a cylindrical part, a conical part and an intermediate discharge pipe. The conical part is located below the cylindrical part and is integrated with the cylindrical part.

[0071] The upper part of the cylindrical section of the humidification device 41 is provided with seawater spray holes around its perimeter for spraying seawater.

[0072] The salt tank 13 is located below the conical part of the humidification device 41 and is used to receive the concentrated brine, salt particles, and carbon soot particles discharged from the humidification device 41.

[0073] The temperature and humidity meter 9 is installed at the high temperature and humidity air outlet at the top of the humidification device 41 to measure the temperature and humidity of the high temperature and humidity air;

[0074] The demister 10 is installed after the temperature and humidity meter to remove small amounts of particulate matter or small droplets from the hot and humid air.

[0075] The inlet of the fan is connected to the demister 10, and the outlet is connected to the diffuser 23;

[0076] The diffuser tube 23 is used to increase the pressure of high-temperature humid air and reduce the flow velocity of humid air;

[0077] One end of the jet cooling chamber 42 is connected to the diffuser tube 23 for the first stage of cooling of high-temperature and humid air;

[0078] One end of the second nozzle 24 is connected to the spray cooling chamber 42, and the other end is connected to the dehumidification device 43;

[0079] The dehumidification device 43 is a modified cyclone separator used for the second stage of cooling of humid air;

[0080] The freshwater treatment and storage device includes a freshwater tank 15, a sampling port 16, an alkali tank 17, a second filter 18, a purified freshwater tank 19, and pipelines to the ship's freshwater tank.

[0081] The cooling freshwater injection device includes a freshwater pump 5, a freshwater flow regulating valve 21, and freshwater nozzles 22. The freshwater pump 5 in the cooling freshwater injection device is used to provide injection pressure; the freshwater flow regulating valve 21 is used to regulate the amount of condensed freshwater injected; and the freshwater nozzles 22 are evenly distributed according to the cross-section of the spray cooling chamber.

[0082] The seawater cooling and jetting pipeline includes a first seawater filter 4, a seawater pump 5, a cooling seawater pipe leading to the purified freshwater tank, a seawater pipe leading to the dehumidification device, and a seawater flow regulating valve 6. The first seawater filter 4 can fully filter impurities in the seawater and prevent the seawater jets from becoming clogged. The seawater flow regulating valve 6 is used to regulate the flow rate of seawater injected into the humidification device.

[0083] In the above technical solution, the humidification device is made of one or more of stainless steel, ceramic, polymer or high temperature resistant resin, and is manufactured by welding. The material can withstand high temperatures above 200°C.

[0084] The flue gas inlet of the cyclone separator of the humidification device 41 is rectangular, the air intake method is tangential, and the gas flow mode inside the cyclone separator is counter-current.

[0085] The outermost part of the humidification device 41 is provided with heat insulation material to reduce the heat transfer from the high-temperature water vapor inside the humidification device to the outside.

[0086] The seawater nozzles of the humidification device 41 are evenly distributed throughout the entire spray area, and the total height of the nozzle area is less than the insertion length of the central discharge pipe.

[0087] The inner diameter of the seawater nozzle of the humidification device 41 is selected according to the size parameters of the humidification device and the flue gas parameters;

[0088] The salt tank 13 is equipped with an observation mirror 14 for observing the state and flow of the concentrated brine in the salt tank 13;

[0089] The fan is a variable frequency, high temperature resistant, and corrosion resistant fan;

[0090] The diffuser tube 23 adopts a circular-to-square structure.

[0091] Furthermore, in the above technical solution, the length of the spray cooling chamber ensures that the fresh water spray and the high-temperature humid air are fully mixed;

[0092] The humid air inlet of the dehumidification device 43 is rectangular, including a cylindrical part, a conical part and an intermediate discharge pipe part;

[0093] The cylindrical and conical parts of the dehumidification device 43 are provided with a cooling water jacket 25, which has an inlet and an outlet for cooling seawater.

[0094] In the cooling water jacket 25, the cooling seawater enters from the lower seawater inlet, and the seawater, whose temperature rises after exchanging heat with the water vapor, is discharged from the upper cooling water outlet.

[0095] The intermediate discharge pipe of the dehumidification device 43 is the clean flue gas emission outlet. The clean flue gas after low-temperature dehumidification is discharged through the flue gas emission outlet and enters the ship's chimney.

[0096] The lower part of the conical section of the dehumidification device 43 is a fresh water outlet. The condensed fresh water flows out through the fresh water outlet and reaches the fresh water treatment and storage device.

[0097] Furthermore, in the above technical solution, the freshwater tank in the freshwater treatment and storage device is used to collect the freshwater condensed by the dehumidification device and to settle particulate matter.

[0098] Sampling port 16 is used to sample and measure the pH and salinity of the freshwater in the freshwater tank;

[0099] The alkali tank 17 is used to neutralize the residual acid value in the fresh water tank 15, so that the fresh water in the fresh water tank is neutral;

[0100] The second filter 18 is used to filter oily components and some suspended solids in fresh water, and includes at least two stages of filtration: activated carbon and resin filter.

[0101] The freshwater stored in the purified freshwater tank 19 is treated clean freshwater and is cooled by seawater or other cold energy.

[0102] The pipelines to the ship's freshwater tanks deliver freshwater to various sub-tanks for drinking, sanitation, or miscellaneous purposes, depending on the quality of the freshwater produced.

[0103] like Figure 3 As shown, the above technical solution also includes a flue gas pretreatment unit 31, which is located between the flue gas inlet and the first nozzle 8 and is used to pre-treat the flue gas entering the system. The flue gas pretreatment unit 31 includes a pretreatment cylinder 311, a dust removal device 312, a condensate collection tray, a drain pipe, a temperature sensor 313, and a pressure sensor 314.

[0104] Furthermore, in the above technical solution, the pretreatment cylinder 311 has a cylindrical structure, with one end connected to the flue gas inlet and the other end connected to the first nozzle 8; the pretreatment cylinder 311 is made of high-temperature resistant and corrosion-resistant alloy steel; the pretreatment cylinder 311 is provided with an insulation layer on the outside to reduce heat loss.

[0105] Furthermore, in the above technical solution, the dust removal device 312 is installed in the upper part of the pretreatment cylinder 311, including multiple layers of metal mesh for filtering large particulate matter in the flue gas; the metal mesh is made of high temperature and corrosion resistant stainless steel, and its mesh size gradually decreases from the air inlet end to the air outlet end.

[0106] Furthermore, in the above technical solution, the condensate collection tray is set at the bottom of the pretreatment cylinder 311 and has a shallow dish-shaped structure, which is used to collect the condensed water in the flue gas; the drain pipe is connected to the condensate collection tray and is used to discharge the collected condensate; the drain pipe is equipped with a one-way valve to prevent external air from flowing back in.

[0107] Furthermore, in the above technical solution, temperature sensor 313 and pressure sensor 314 are respectively installed on the side wall of pretreatment cylinder 311 to monitor the temperature and pressure of flue gas in real time and transmit them to the host computer through a communication device.

[0108] Furthermore, in the above technical solution, the working process of the device is as follows:

[0109] When the device is working, the first shut-off valve 1 is closed, the second shut-off valve 2 and the third shut-off valve 3 are open, and the high-temperature flue gas in the ship's chimney is accelerated by the first nozzle 8 and then enters the humidification device 41 tangentially. The preheated seawater is sprayed in from the seawater nozzles around the upper part of the humidification device 41.

[0110] Strong disturbance occurs between the spiral flue gas and the radial seawater jet, resulting in sufficient heat and mass transfer. Under the action of centrifugal force and gravity, the evaporated salt particles, unevaporated small droplets, carbon soot particles and other denser components in the flue gas spiral down along the inner wall of the humidification device 41 and enter the salt tank. The high-temperature water vapor generated by the evaporation of seawater rises along the inner spiral line and is discharged from the humidification device after passing through the demister 10.

[0111] After passing through the fan, the humid air enters the dehumidification process, which includes two stages of cooling: First, the cooling fresh water mist sprayed into the spray cooling chamber can quickly cool the high-temperature water vapor, causing some of the water vapor to condense into liquid water; then it enters the dehumidification device, where low-temperature seawater further cools the water vapor into fresh water, which flows into the fresh water tank.

[0112] The pH and salinity of fresh water can be measured through sampling port 16. The pH is adjusted through alkali tank 17. A small amount of particulate matter inside the water tank settles to the bottom of the tank and is released through the slag discharge port at the bottom. The fresh water in fresh water tank 15 enters the purified fresh water tank 15 after passing through activated carbon and resin filters.

[0113] After being cooled by seawater or other low-temperature media, the freshwater in the purified freshwater tank 15 is partially sprayed to cool the high-temperature water vapor at the outlet of the humidification tower, and the remainder is transported to different freshwater tanks on the ship for drinking, sanitary or miscellaneous purposes, depending on the quality of the freshwater produced.

[0114] Example 1:

[0115] A method and apparatus for utilizing waste heat from ship flue gas for seawater desalination and combined pollutant removal includes, in sequence, a flue gas inlet, a first nozzle 8, a humidification device 41, a salt tank 13, a thermometer and hygrometer 9, a demister 10, a fan, a diffuser 23, a spray cooling system 42, a second nozzle 24, a dehumidification device 43, a freshwater treatment and storage system, a cooling freshwater spraying system, and seawater cooling and spraying pipelines. The flue gas inlet is located on and connected to the ship's funnel, and its operation is controlled by a second shut-off valve 2. The flue gas inlet is made of high-temperature and corrosion-resistant 310S stainless steel with a wall thickness of not less than 5mm. The inlet diameter is determined based on the ship's main engine power, typically between 500-1000mm. The first nozzle 8 is connected to the flue gas inlet at the front and to the humidification device 41 at the rear. The first nozzle has a square structure, is made of 310S stainless steel, and has a wall thickness of 6mm. The cross-sectional area of ​​the first nozzle gradually decreases, with an inlet-to-outlet area ratio of approximately 3:1 to accelerate the flue gas flow. Preferably, both the flue gas inlet and the first nozzle connector are square structures. The humidification device 41 is a "seawater jet-flue gas cyclone device," which is modified from a cyclone separator. The cyclone separator includes a cylindrical section, a conical section, and an intermediate discharge pipe. The conical section is located below the cylindrical section and is integrated into one unit. The humidification device 41 is made of 2205 duplex stainless steel, manufactured by welding, and the material can withstand temperatures up to 350℃. The cylindrical section has a diameter of 1500mm and a height of 2000mm; the conical section has a bottom diameter of 500mm and a height of 1500mm. The intermediate discharge pipe has a diameter of 600mm and an insertion depth of 2 / 3 of the cylindrical height. Furthermore, the humidification device 41 can be made of corrosion-resistant and high-temperature-resistant materials such as stainless steel, ceramics, polymers, and high-temperature resistant resins, and can be manufactured through welding, 3D printing, etc. The materials are required to withstand temperatures above 200℃. Furthermore, the flue gas inlet of the cyclone separator in the humidification device is rectangular, with a tangential air intake, and the gas flow within the cyclone separator is counter-current. Furthermore, the outermost part of the humidification device is equipped with heat insulation material 11 to minimize heat transfer from the high-temperature water vapor inside the humidification device to the outside. The heat insulation material is made of high-temperature resistant ceramic fiber with a thickness of 50mm. The heat insulation layer is covered with 0.5mm thick aluminum foil to improve reflectivity. Seawater nozzles 7 are opened around the upper part of the cylindrical section. Seawater in the seawater jet jacket 26 is injected into the inner cavity of the humidification device under the pressure of the seawater pump 5. A total of 120 nozzles are provided, with an inner diameter of 5mm, evenly distributed within a 500mm high spray area. The nozzles are made of corrosion-resistant Hastelloy C-276 material.The seawater in the seawater jet jacket is preheated and comes from the cooling water jacket of the dehumidification device. Furthermore, the seawater nozzles of the humidification device are evenly distributed throughout the entire spray area, and the total height of the nozzle area is less than the insertion length of the central discharge pipe. Furthermore, the inner diameter of the seawater nozzles is selected based on the size parameters of the humidification device and the flue gas parameters. The salt tank 13 is located below the conical part of the humidification device and is used to receive the concentrated brine, salt particles, and carbon particulate matter discharged from the humidification device. The salt tank is made of fiberglass and lined with polytetrafluoroethylene (PTFE) to enhance corrosion resistance. The salt tank has a volume of 1 m³ and a drain valve at the bottom. Furthermore, an observation mirror is installed on the salt tank to observe the state and flow of the concentrated brine; the observation mirror is made of tempered glass with a diameter of 150 mm. The humidification device has a high-temperature, humid air exhaust port at the top center. The high-temperature, humid air passes through a thermometer / hygrometer 9, a demister 10, a fan, and a diffuser 23 before entering the steam cooling unit 42. The thermometer / hygrometer 9 measures the temperature and humidity of the high-temperature, humid air exhausted from above the humidification device 41. It uses a high-temperature resistant temperature and humidity sensor with a measurement range of 0-200℃ and 0-100%RH. The sensor signal is transmitted to the control system via a 4-20mA analog signal. The demister 10 removes small amounts of particulate matter or droplets from the high-temperature, humid air. It uses a stainless steel wire mesh demister with a wire diameter of 0.28mm and a mesh size of 0.13mm. The demister 10 is 100mm thick and has a pressure drop not exceeding 200Pa. The fan inlet connects to a demister, and the outlet connects to a diffuser. The main purpose of the fan is to increase the airflow velocity into the humidification and dehumidification devices, thereby improving heat and mass transfer and separation efficiency. Furthermore, the fan should ideally be a variable frequency, high-temperature resistant, and corrosion-resistant type; a centrifugal fan with a titanium alloy impeller is preferred. The fan has a rated power of 30kW, a maximum air volume of 10000m³ / h, and a maximum air pressure of 6000Pa.

[0116] The diffuser 23 is used to increase the pressure of the high-temperature humid air and reduce its flow rate, allowing sufficient cooling time for the high-temperature water vapor. Preferably, the diffuser has a circular-to-square structure with an inlet diameter of 600mm and an outlet of 800mm×800mm square. It is made of 304 stainless steel with a wall thickness of 4mm. The spray cooling 42 is connected to the diffuser and serves as the first stage of cooling for the high-temperature humid air. Further, the spray cooling chamber uses fresh water spray to cool the high-temperature humid air. The length of the spray cooling chamber should ensure thorough mixing of the fresh water spray and the high-temperature humid air. The cooling chamber is 3000mm long with a cross-sectional area of ​​800mm×800mm. It contains 15 atomizing nozzles arranged in 3 rows, made of corrosion-resistant titanium alloy. The second spray pipe 24 is connected to the spray cooling chamber at the front and to the dehumidification device 43 at the rear. Its main purpose is to increase the airflow velocity of the dehumidification device and improve the cooling effect. The second spray pipe has a square structure with a cross-sectional area gradually decreasing from 800mm×800mm to 600mm×400mm. The material is 304 stainless steel with a wall thickness of 3mm. The dehumidification device 43 is also a modified cyclone separator, serving as the second-stage cooling for humid air. Furthermore, the humid air inlet of the dehumidification device is rectangular, mainly consisting of a cylindrical section, a conical section, and an intermediate discharge pipe. The cylinder has a diameter of 1200mm and a height of 1500mm; the cone has a bottom diameter of 400mm and a height of 1200mm. The material is 316L stainless steel with a wall thickness of 6mm. Further, the cylindrical and conical sections of the dehumidification device are externally equipped with a cooling water jacket 25, which has a cooling seawater inlet and outlet. The cooling water jacket is 50mm thick and uses a spiral winding design. The cooling water inlet is located at the bottom, and the outlet is located at the top, both with a pipe diameter of DN80. Furthermore, the cooling seawater in the cooling water jacket enters from the lower seawater inlet, and the seawater, after exchanging heat with water vapor, is discharged from the upper cooling water outlet. The middle discharge pipe of the dehumidification device is the clean flue gas emission outlet, through which the clean flue gas after low-temperature dehumidification is discharged into the ship's funnel. The lower part of the conical section 43 of the dehumidification device is the freshwater outlet, through which the condensed freshwater flows out and reaches the freshwater treatment and storage device. The freshwater treatment and storage device includes a freshwater tank, sampling port, alkali tank, second filter, purified freshwater tank (including cooling pipes), and pipes to the ship's freshwater tanks. The freshwater tank is used to collect the freshwater condensed by the dehumidification device and to settle particulate matter; it has a volume of 5m³ and is made of fiberglass. Internal partitions form a primary sedimentation zone and a clear water zone. A drain valve is located at the bottom for periodically discharging sediment. The sampling port is used to sample and measure the pH and salinity of the freshwater in the tank; it has a diameter of DN25 and is made of 316L stainless steel. Equipped with quick-connect fittings for easy sampling. The alkali tank neutralizes residual acid in the freshwater tank, ensuring the freshwater is neutral; it has a volume of 200L and is made of polyethylene. It is equipped with a level gauge and a pH meter to monitor alkali usage and freshwater pH.The second filter removes oily components and some suspended solids from the freshwater, employing at least two stages of filtration: activated carbon and resin filters. The activated carbon filter uses granular activated carbon with a filling height of 1000mm. The resin filter uses strongly acidic cation exchange resin with a filling height of 800mm. The purified freshwater tank (including cooling piping) stores treated, clean freshwater and cools it using seawater (in winter) or other cooling energy (in summer, such as mechanical refrigeration or LNG ship cooling energy). It has a volume of 10m³ and is constructed of 316L stainless steel. It is equipped with internal cooling coils with a total coil area of ​​20m². Temperature sensors and level gauges are also included. The freshwater pipeline delivers freshwater to various sub-tanks (drinking, sanitary, or miscellaneous) based on the quality of the produced freshwater. The cooling freshwater spray system includes a freshwater pump 20, a freshwater flow regulating valve 21, and freshwater nozzles 22. Cooled freshwater is sprayed into the steam cooling 42 through the freshwater nozzles under pump pressure. The freshwater pump 20 is a vertical multistage centrifugal pump with a rated flow rate of 10 m³ / h and a head of 60 m. The pump body is made of 316L stainless steel, and the impeller is made of chromium-nickel-molybdenum alloy. The freshwater flow regulating valve 21 adjusts the amount of condensed freshwater sprayed; it is an electrically operated valve with a 316L stainless steel body. The control accuracy is ±2%, and the response time is <10 s. The freshwater nozzles 22 should be evenly distributed across the cross-section of the spray cooling chamber; they are hollow conical nozzles made of titanium alloy. Each nozzle has a 0.8 mm orifice diameter and consists of 15 nozzles evenly distributed across the spray cooling 42 cross-section.

[0117] The seawater cooling and injection piping system includes a first seawater filter 4, a seawater pump 5, a cooling seawater pipe leading to the purified freshwater tank, a seawater pipe leading to the dehumidification device 43, and a seawater flow regulating valve 6. The first filter 4 should effectively filter impurities in the seawater to prevent clogging of the seawater nozzles; it is a self-cleaning filter with a filtration accuracy of 50μm. The filter screen is made of nickel-copper alloy, which has good resistance to seawater corrosion. The seawater pump 5 is a horizontal centrifugal pump with a rated flow rate of 50m³ / h and a head of 40m. The pump body and impeller are made of super duplex stainless steel SAF 2507. The seawater flow regulating valve 6 is used to regulate the seawater flow rate injected into the humidification device. The regulation is mainly based on the load of the ship's diesel engine (including the main engine and generator) and the operating status of the auxiliary boiler, referring to the value of the thermo-hygrometer 9 at the outlet of the humidification device and the concentrated seawater flow rate seen through the salt tank observation mirror 14; it is a pneumatic regulating valve with a valve body made of duplex stainless steel. The control accuracy is ±3%, and the response time is <5s.

[0118] Its working process is as follows: When this device is working, the first shut-off valve 1 is closed. The second shut-off valve 2 and the third shut-off valve 3 are opened. The high-temperature flue gas in the ship's chimney is accelerated by the first nozzle 8 and then enters the humidification device tangentially. The preheated seawater is injected from the seawater nozzles around the upper part of the humidification device. Figure 1The spiral flue gas and the radial seawater jet are strongly disturbed, and sufficient heat and mass transfer occurs. Under the action of centrifugal force and gravity, the evaporated salt particles, unevaporated small droplets, carbon soot particles and other denser components in the flue gas spiral down along the inner wall of the humidification device and enter the salt tank 13. The high-temperature water vapor generated by the evaporation of seawater rises along the inner spiral line and is discharged from the humidification device after passing through the demister 10. The humid air enters the dehumidification process after passing through the fan, which includes two-stage cooling. First, the cooling freshwater mist sprayed into the jet cooling chamber rapidly cools the high-temperature water vapor, causing some of the water vapor to condense into liquid water. This water then enters the dehumidification device, where low-temperature seawater further cools the water vapor into freshwater, which flows into the freshwater tank 15. The pH and salinity of the freshwater can be measured through sampling port 16. The pH is adjusted through the alkali tank 17. A small amount of particulate matter inside the tank settles to the bottom and is discharged through the lower slag outlet. The freshwater in the tank 15 passes through activated carbon and resin filters before entering the purified freshwater tank 19. After being cooled by seawater (or other low-temperature media), part of the freshwater in the purified tank is sprayed to cool the high-temperature water vapor at the humidification tower outlet, while the remainder is transported to different freshwater tanks on the ship, designated for drinking, sanitary, or miscellaneous uses, depending on the quality of the produced freshwater. The dehumidification device 43 in Example 1 is a cyclone dehumidification device.

[0119] The detailed working process and operating steps are as follows: 1. Start-up preparation: Check the status of each piece of equipment to ensure there are no abnormalities. Start seawater pump 5 and open seawater flow regulating valve 6. Start freshwater pump 20 and adjust freshwater flow regulating valve 21 to the appropriate position. 2. System start-up: Close the first shut-off valve 1 and open the second shut-off valves 2 and 3. Start the blower and adjust it to the appropriate speed. Gradually increase the seawater flow until the set value is reached. 3. Normal operation: Monitor the reading of the thermometer and hygrometer 9 and keep the outlet temperature of the humidification device within the range of 90-100℃. Observe the concentrated seawater flow through the salt tank observation mirror 14 and adjust the seawater flow regulating valve 6. Regularly check the pH value and salinity of the freshwater in the freshwater tank 15 and adjust the amount of alkali solution added if necessary. 4. System shutdown: Gradually reduce the seawater flow until it is completely shut off. Close the second shut-off valves 2 and 3 and open the first shut-off valve 1. Stop the blower and freshwater pump 20. Continue to run seawater pump 5 for a period of time to flush the system. 5. Maintenance: Clean the first filter 4 weekly. Inspect and clean the inside of humidification unit 41 and dehumidification unit 43 monthly. Replace the activated carbon and resin in filter 18 quarterly. Inspect the wear of the fan impeller every six months and replace it if necessary.

[0120] Through the detailed implementation methods described above, the ship flue gas waste heat desalination and pollutant removal device of the present invention can effectively utilize the waste heat of ship flue gas, simultaneously achieving seawater desalination and pollutant removal, thereby improving energy efficiency and reducing ship pollutant emissions. The main advantages of this device include: 1. High-efficiency waste heat utilization: Through ingenious design, it fully utilizes the waste heat in ship flue gas, improving energy efficiency. 2. Multifunctional integration: It integrates seawater desalination and pollutant removal functions into one system, saving ship space and equipment investment. 3. Significant environmental benefits: Through the pollutant removal function, it effectively reduces ship environmental pollution, complying with increasingly stringent international maritime environmental regulations. 4. Flexible operation: The system can be adjusted according to the actual operating conditions of the ship, adapting to different working conditions. 5. Simple maintenance: Through reasonable design and material selection, the system's maintenance difficulty and frequency are reduced.

[0121] Example 2:

[0122] like Figure 2 The diagram shows another specific embodiment of the present invention. This embodiment differs from the one described above in that a cooling pipe 27 is used instead of a cooling water jacket 25. This is the second embodiment of the device, and the dehumidification device 43 is a conventional dehumidification device. The usage steps are as follows:

[0123] Shut-off valve 1 is closed. Shut-off valves 2 and 3 are open. The high-temperature flue gas in the ship's chimney is accelerated by nozzle 8 and then enters the humidification device tangentially. Preheated seawater is injected from the seawater nozzles around the upper part of the humidification device. Figure 1 The spiral flue gas and the radial seawater jet are strongly disturbed, and sufficient heat and mass transfer occurs. Under the action of centrifugal force and gravity, the evaporated salt particles, unevaporated small droplets, carbon soot particles and other denser components in the flue gas spiral down along the inner wall of the humidification device and enter the salt tank 13. The high-temperature water vapor generated by the evaporation of seawater rises along the inner spiral line and is discharged from the humidification device after passing through the demister 10. The humid air enters the dehumidification process after passing through the fan, which includes two-stage cooling. First, the cooling freshwater mist sprayed into the jet cooling chamber can quickly cool the high-temperature water vapor, causing some of the water vapor to condense into liquid water. It then enters the dehumidification device (conventional condenser), where low-temperature seawater further cools the water vapor into freshwater, which flows into the freshwater tank 15. The pH and salinity of the freshwater can be measured through the sampling port 16, and the pH is adjusted through the alkali tank 17. A small amount of particulate matter inside the tank settles to the bottom of the tank and is released through the slag discharge port at the bottom. The freshwater in the freshwater tank 15 enters the purified freshwater tank 19 after passing through activated carbon and resin filters. After being cooled by seawater (or other low-temperature media), part of the freshwater in the purified freshwater tank is sprayed to cool the high-temperature water vapor at the outlet of the humidification tower, while the remainder is transported to the ship's drinking, sanitary, or miscellaneous freshwater tanks according to the quality of the produced freshwater.

[0124] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for seawater desalination using waste heat from ship exhaust gas, characterized in that, include: Flue gas inlet, first nozzle, humidification device, salt tank, thermometer and hygrometer, demister, fan, diffuser, jet cooling chamber, second nozzle, dehumidification device, freshwater treatment and storage device, cooling freshwater jet device, seawater cooling and jet pipeline; The flue gas inlet is located on the ship's chimney and connected to the chimney, and its opening and closing is controlled by a second shut-off valve. One end of the first nozzle is connected to the flue gas inlet, and the other end is connected to the humidification device; The humidification device is a seawater jet flue gas cyclone device, which is modified from a cyclone separator. It includes a cylindrical part, a conical part and an intermediate discharge pipe. The conical part is located below the cylindrical part and is integrated with the cylindrical part. The cylindrical part of the humidification device has seawater spray holes around its upper perimeter for spraying seawater. The salt tank is located below the conical part of the humidification device and is used to receive the concentrated brine, salt particles, and carbon soot particles discharged by the humidification device. The thermometer and hygrometer are installed at the high-temperature and humid air outlet at the top of the humidification device to measure the temperature and humidity of the high-temperature and humid air. The demister is installed after the thermometer and hygrometer to remove small amounts of particulate matter or small droplets from the hot and humid air. The inlet of the fan is connected to the demister, and the outlet is connected to the diffuser. The diffuser tube is used to increase the pressure of high-temperature humid air and reduce the flow rate of humid air; One end of the jet cooling chamber is connected to the diffuser tube and is used for the first stage of cooling of high-temperature and humid air. One end of the second nozzle is connected to the spray cooling chamber, and the other end is connected to the dehumidification device; The dehumidification device is a modified cyclone separator used for the second stage of cooling of humid air; The freshwater treatment and storage device includes a freshwater tank, sampling port, alkali tank, second filter, purified freshwater tank, and pipelines to the ship's freshwater tank. The cooling freshwater injection device includes a freshwater pump, a freshwater flow regulating valve, and freshwater nozzles; the freshwater pump in the cooling freshwater injection device is used to provide injection pressure; the freshwater flow regulating valve is used to regulate the amount of condensed freshwater injected; the freshwater nozzles are evenly distributed according to the cross-section of the spray cooling chamber. The seawater cooling and spraying pipeline includes a first filter, a seawater pump, a seawater cooling pipe leading to the purified freshwater tank, a seawater pipe leading to the dehumidification device, and a seawater flow regulating valve; the first filter can effectively filter impurities in the seawater and prevent the seawater spray holes from clogging; the seawater flow regulating valve is used to regulate the flow rate of seawater sprayed into the humidification device. The humidification device has a rectangular flue gas inlet for the cyclone separator, a tangential air intake, and a counter-current gas flow pattern within the cyclone separator.

2. The device for seawater desalination using waste heat from ship exhaust gas according to claim 1, characterized in that, The humidification device is made of one or more of stainless steel, ceramic, polymer or high-temperature resistant resin, and is manufactured by welding. The material can withstand high temperatures above 200°C. The outermost part of the humidification device is provided with heat insulation material to reduce the heat transfer from the high-temperature water vapor inside the humidification device to the outside. The seawater nozzles of the humidification device are evenly distributed throughout the spray area, and the total height of the nozzle area is less than the insertion length of the central discharge pipe. The inner diameter of the seawater nozzle of the humidification device is selected according to the size parameters of the humidification device and the flue gas parameters. The salt tank is equipped with an observation mirror for observing the state and flow of the concentrated brine in the salt tank; The fan is a variable frequency, high temperature resistant, and corrosion resistant fan; The diffuser tube adopts a circular-to-square structure.

3. The device for seawater desalination using waste heat from ship exhaust gas according to claim 2, characterized in that, The length of the jet cooling chamber ensures thorough mixing of the fresh water spray and the high-temperature, humid air. The humid air inlet of the dehumidification device is rectangular, including a cylindrical part, a conical part, and a middle discharge pipe part; The cylindrical and conical portions of the dehumidification device are provided with a cooling water jacket, which has an inlet and an outlet for cooling seawater. The cooling seawater in the cooling water jacket enters from the lower seawater inlet, and the seawater, whose temperature rises after exchanging heat with water vapor, is discharged from the upper cooling water outlet. The intermediate discharge pipe of the dehumidification device is a clean flue gas emission outlet. The clean flue gas after low-temperature dehumidification is discharged through the flue gas emission outlet and enters the ship's chimney. The lower part of the conical section of the dehumidification device is a fresh water outlet. The condensed fresh water flows out through the fresh water outlet and reaches the fresh water treatment and storage device.

4. The device for seawater desalination using waste heat from ship exhaust gas according to claim 3, characterized in that, The freshwater tank in the freshwater treatment and storage device is used to collect the freshwater condensed by the dehumidification device and to settle particulate matter. The sampling port is used to sample and measure the pH and salinity of the freshwater in the freshwater tank; The alkali tank is used to neutralize the residual acid value in the freshwater tank, so that the freshwater in the tank is neutral. The second filter is used to filter oily components and some suspended solids in fresh water, and includes at least two stages of filtration: activated carbon and resin filter. The freshwater stored in the purified freshwater tank is treated clean freshwater, and it is cooled by seawater or other cold energy. The pipeline to the ship's freshwater tanks delivers freshwater to various sub-tanks for drinking, sanitation, or miscellaneous purposes, depending on the quality of the freshwater produced.

5. The device for seawater desalination using waste heat from ship exhaust gas according to claim 4, characterized in that, It also includes a flue gas pretreatment unit, which is located between the flue gas inlet and the first nozzle, for preliminary treatment of the flue gas entering the system; the flue gas pretreatment unit includes a pretreatment cylinder, a dust removal device, a condensate collection tray, a drain pipe, a temperature sensor and a pressure sensor.

6. The device for seawater desalination using waste heat from ship exhaust gas according to claim 5, characterized in that, The pretreatment cylinder is a cylindrical structure, with one end connected to the flue gas inlet and the other end connected to the first nozzle; the pretreatment cylinder is made of high-temperature resistant and corrosion-resistant alloy steel; the exterior of the pretreatment cylinder is provided with an insulation layer to reduce heat loss.

7. The device for seawater desalination using waste heat from ship exhaust gas according to claim 6, characterized in that, The dust removal device is located in the upper part of the pretreatment cylinder and includes multiple layers of metal mesh for filtering large particulate matter in the flue gas. The metal mesh is made of high-temperature resistant and corrosion-resistant stainless steel, and the mesh size gradually decreases from the air inlet end to the air outlet end.

8. The device for seawater desalination using waste heat from ship exhaust gas according to claim 7, characterized in that, The condensate collection tray is located at the bottom of the pretreatment cylinder and has a shallow dish-shaped structure, used to collect the condensed water in the flue gas; the drain pipe is connected to the condensate collection tray and used to discharge the collected condensate; the drain pipe is equipped with a one-way valve to prevent backflow of external air.

9. The device for seawater desalination using waste heat from ship exhaust gas according to claim 8, characterized in that, The temperature sensor and pressure sensor are respectively installed on the side wall of the pretreatment cylinder to monitor the temperature and pressure of the flue gas in real time and transmit the data to the host computer via a communication device.

Images