Device for seawater desalination by using ship flue gas waste heat

Abstract

The invention provides a device for seawater desalination by using ship flue gas waste heat, and belongs to the technical field of seawater desalination. The device comprises a flue gas inlet, a first spray pipe, a humidifying device, a salt box, a hygrothermograph, a demister, a fan, a diffuser pipe, a spray cooling cavity, a second spray pipe, a dehumidifying device, a fresh water treatment and storage device, a cooling fresh water injection device and a seawater cooling and injection pipeline, the flue gas inlet is arranged on a ship chimney and is connected with the chimney, and a switch of the flue gas inlet is controlled by a second stop valve; one end of the first spray pipe is connected with the flue gas inlet, and the other end of the first spray pipe is connected with the humidifying device; the humidifying device is a seawater jet flue gas cyclone device, is formed by refitting a cyclone separator, and comprises a cylinder part, a conical part and a middle discharge pipe, and the conical part is positioned below the cylinder part and is combined with the cylinder part into a whole.

Description

Technical Field

[0001] The present invention belongs to the technical field of seawater desalination, and in particular relates to a device for desalinating seawater by utilizing waste heat from ship flue gas. Background Art

[0002] Ocean-going ships need a lot of fresh water to meet the needs of ship equipment and crew. Since the amount of fresh water carried by ships is limited, most ocean-going ships are equipped with seawater desalination equipment. At present, the most mature and widely used technology on merchant ships is vacuum boiling seawater desalination. This method uses the cooling water of the main engine cylinder jacket as a heat source, heats the seawater to boiling in a high vacuum environment, and produces fresh water by condensing water vapor. This method can effectively produce fresh water, but the generation of a high vacuum environment requires a lot of energy consumption, and the equipment sealing requirements are also high, which increases the operating cost and maintenance difficulty. In contrast, if the high-temperature flue gas discharged by the ship can be directly used as the heat source of the seawater desalination device, a high vacuum environment is no longer required, which can greatly reduce the cost of desalination and improve energy utilization. The flue gas discharged by the ship is mainly generated by the ship's main engine, generator or auxiliary boiler, and the temperature is usually around 200℃ or even higher. These high-temperature flue gases contain rich waste heat energy. If they can be effectively used, they can provide the required heat for seawater desalination.

[0003] In the field of seawater desalination technology using flue gas waste heat, there have been some related patent research and development attempts. The patent with application number 202211016000.1 has developed a "ship diesel engine exhaust purification coupled with seawater desalination technology and device". The device heats the seawater spray outside the heat exchange tube through the diesel engine flue gas in the heat exchange tube, generates water vapor and condenses it into fresh water. This indirect heat exchange method has a low heat transfer coefficient, and scaling and clogging are also prone to occur on the seawater side and the flue gas side, increasing the maintenance workload. In addition, the separate design of flue gas purification and seawater desalination makes the overall structure more complicated.

[0004] The patent application number is 201310276412.3, which developed a "seawater desalination system using flue gas waste heat". In the humidification tower, the high-temperature flue gas is in direct contact with seawater, pollutants are removed and a large amount of water vapor is generated to humidify the flue gas. The water vapor is cooled into fresh water in the dehumidification tower through fresh water spray cooling. This direct contact heat exchange method has a higher heat transfer coefficient. However, the design of the traditional scrubbing tower still makes the heat and mass transfer between the flue gas and seawater insufficient, the seawater spraying volume is large, and the concentrated brine discharge increases, making secondary treatment difficult. In addition, the cooling of the high-temperature water vapor in the device is only done by spraying fresh water cooling, which is not thorough enough. In addition, the device also has the disadvantages of poor removal of small particles, large equipment volume, and high construction and maintenance costs.

[0005] In general, the existing technical solutions for desalination of seawater using flue gas waste heat still have some key issues to be further resolved. The most critical technical disadvantage is that the existing solutions cannot achieve efficient heat and mass transfer between flue gas and seawater, resulting in low overall heat exchange efficiency and limited desalination performance. At the same time, scaling and clogging are prone to occur, increasing maintenance costs. Summary of the invention

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

[0007] The present invention is achieved in that:

[0008] The present invention provides a device for desalinating seawater by utilizing waste heat from ship flue gas, which comprises:

[0009] Flue gas inlet, first nozzle, humidification device, salt box, thermometer, demister, fan, diffuser, spray cooling chamber, second nozzle, dehumidification device, fresh water treatment and storage device, cooling fresh water injection device, seawater cooling and injection pipeline;

[0010] The smoke inlet is arranged on the chimney of the ship and connected to the chimney, and its switch is controlled by the second stop valve;

[0011] One end of the first nozzle is connected to the smoke 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 and includes a cylindrical part, a conical part and an intermediate discharge pipe, wherein the conical part is located below the cylindrical part and is integrated with the cylindrical part;

[0013] The upper middle part of the cylindrical part of the humidifying device is provided with seawater spray holes around it for spraying seawater;

[0014] The salt box is arranged below the conical part of the humidifying device and is used to receive the concentrated brine, salt particles and soot particles discharged from the humidifying device;

[0015] The thermo-hygrometer is arranged at the high-temperature humid air outlet on the top of the humidifying device, and is used to measure the temperature and humidity of the high-temperature humid air;

[0016] The demister is arranged after the thermo-hygrometer and is used to remove a small amount of particles or small droplets in the high-temperature humid air;

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

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

[0019] One end of the spray cooling chamber is connected to the diffuser pipe and is used for first-stage cooling of high-temperature humid air;

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

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

[0022] The fresh water treatment and storage device comprises a fresh water tank, a sampling hole, an alkali solution tank, a second filter, a purified fresh water tank and pipelines to the ship's fresh water tanks;

[0023] The cooling fresh water injection device comprises a fresh water pump, a fresh water flow regulating valve and a fresh water nozzle; the fresh water pump in the cooling fresh water injection device is used to provide injection pressure; the fresh water flow regulating valve is used to adjust the injection amount of condensed fresh water; the fresh water nozzles are evenly distributed according to the cross section of the injection cooling cavity;

[0024] The seawater cooling and injection pipeline includes a first filter, a seawater pump, a cooling seawater pipe leading to a purified fresh water tank, a seawater pipeline leading to a dehumidification device, and a seawater flow regulating valve; the first filter can fully filter impurities in the seawater to prevent the seawater spray hole from being blocked; the seawater flow regulating valve is used to adjust the seawater flow rate sprayed into the humidification device.

[0025] The technical effects of the device for desalinating seawater by utilizing the waste heat of ship flue gas provided by the present invention are as follows: Compared with the prior art, the beneficial effects of the device for desalinating seawater by utilizing the waste heat of ship flue gas provided by the present invention are as follows: Based on the seawater jet-flue gas cyclone device, the ship flue gas humidification-dehumidification technology is used to desalinate seawater and remove pollutants. The high-temperature flue gas of the ship and the seawater jet spray are in direct contact, and strong disturbance occurs 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 that the absorption of harmful gases in the flue gas and the evaporation of the seawater jet spray are more complete, and the fresh water output is high. , the discharge of concentrated brine is small; the particulate matter discharged by the diesel engine is moistened and condensed by seawater spray, the particle size increases, it is easier to agglomerate with each other, and can be well removed under the action of centrifugal force; the inner wall of the humidification tower is not easy to scale under the strong flushing of the jet and cyclone. When the inner wall is scaled and polluted, it can be cleaned when the diesel engine is stopped. At this time, the intake air becomes clean air, and the high-pressure hot fresh water or soda solution introduced from the cleaning pipeline is sprayed in, which can easily remove dirt, so the overall maintenance cost of the device is low; the device adopts the form of cyclone separation and cyclone cooling, which has the advantages of compact structure and small system resistance. In summary, the present invention solves the technical problems that the existing scheme cannot achieve efficient heat and mass exchange between flue gas and seawater, resulting in low overall heat exchange efficiency, limited desalination performance, and easy to produce scaling and blockage, which increases maintenance costs.

[0026] On the basis of the above technical solution, the device for desalinating seawater by utilizing waste heat from ship flue gas of the present invention can also be improved as follows:

[0027] The humidifying device is made of one or more of stainless steel, ceramic, geopolymer or high temperature resistant resin and is made by welding, and the material can withstand high temperature above 200°C;

[0028] The smoke inlet of the cyclone separator of the humidification device is rectangular, the air intake mode is tangential, and the gas flow mode in the cyclone separator is countercurrent;

[0029] The outermost side of the humidifying device is provided with a heat-insulating material to reduce the heat transfer of the high-temperature water vapor in the humidifying device to the outside;

[0030] The seawater spray holes of the humidification device are evenly distributed in the entire spraying area, and the total height of the spray hole area is less than the insertion length of the central discharge pipe;

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

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

[0033] The fan adopts 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 that the fresh water spray and the high-temperature humid air are fully mixed;

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

[0037] A cooling water jacket is provided outside the cylindrical and conical parts of the dehumidification device, and a cooling seawater inlet and outlet are provided on the cooling water jacket;

[0038] The cooling seawater in the cooling water jacket enters from the lower seawater inlet, and the seawater with increased temperature after heat exchange with water vapor is discharged from the upper cooling water outlet;

[0039] The middle exhaust pipe of the dehumidification device is the clean flue gas exhaust outlet, and the clean flue gas after low-temperature dehumidification is discharged into the ship chimney through the flue gas exhaust outlet;

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

[0041] Furthermore, the fresh water tank in the fresh water treatment and storage device is used to collect the fresh water condensed by the condenser and precipitate particulate matter;

[0042] The sampling hole is used for sampling to measure the pH value and salinity of the fresh water in the fresh water tank;

[0043] The alkali liquid tank is used to neutralize the residual acid value in the fresh water tank, so that the fresh water in the fresh water tank is neutral;

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

[0045] The fresh water stored in the purified fresh water tank is treated clean fresh water, and is cooled, and the cooling medium is seawater or other cold energy;

[0046] The pipeline to the ship's fresh water tank transports the produced fresh water to the ship's drinking, sanitary or miscellaneous fresh water tanks according to the quality of the fresh water.

[0047] Furthermore, it also includes a flue gas pretreatment unit, which is arranged between the flue gas inlet and the first nozzle and is used 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 is a cylindrical structure, one end of which is connected to the flue gas inlet and the other end is connected to the first nozzle; the material of the pretreatment cylinder is high temperature resistant and corrosion resistant alloy steel; the outside of the pretreatment cylinder is provided with an insulation layer to reduce heat loss.

[0049] Furthermore, the dust removal device is arranged in the upper half of the pretreatment cylinder, including multiple layers of metal grids for filtering large particles in the flue gas; the metal grids are made of high-temperature resistant and corrosion-resistant stainless steel material, and the mesh size gradually decreases from the air inlet end to the air outlet end.

[0050] Furthermore, the condensate collection tray is arranged at the bottom of the pretreatment cylinder and has a shallow dish-shaped structure for collecting moisture condensed in the flue gas; the drain pipe is connected to the condensate collection tray and is used to discharge the collected condensate; a one-way valve is provided on the drain pipe to prevent backflow of external air.

[0051] Furthermore, the temperature sensor and the pressure sensor are respectively installed on the side walls of the pretreatment cylinder, and are used to monitor the temperature and pressure of the flue gas in real time and send them to the host computer through the communication device.

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

[0053] When the device is working, the first stop valve 1 is closed, the second stop valve 2 and the third stop valve 3 are opened, and the high-temperature flue gas in the ship chimney is accelerated through the first nozzle and enters the humidification device tangentially, and the preheated seawater is sprayed into the humidification device from the seawater spray holes around the upper part of the humidification device;

[0054] There is a strong disturbance between the spiral flue gas and the radial seawater jet, which allows sufficient heat and mass transfer. Under the action of centrifugal force and gravity, the evaporated salt particles, unevaporated small droplets, soot particles in the flue gas and other components with higher density fall along the inner wall of the humidification device into the salt box, and 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 wet air enters the dehumidification process, which includes two stages of cooling: first, the cooling fresh water mist sprayed into the steam cooling chamber can quickly cool the high-temperature water vapor, causing part of the water vapor to condense into liquid water; then it enters the condenser, where the 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 hole, and its pH can be adjusted through the alkali solution tank. A small amount of particles inside the water tank settle to the bottom of the tank and are discharged through the slag discharge port at the bottom. The fresh water in the fresh water tank passes through the activated carbon and resin filter and then enters the purified fresh water tank;

[0057] After the fresh water in the purified fresh water tank is cooled by seawater or other low-temperature media, part of it is used in the form of spray to cool the high-temperature water vapor at the outlet of the humidification tower, and the rest is transported to the ship's drinking, sanitary or miscellaneous fresh water tanks according to the quality of the produced fresh water.

[0058] Compared with the prior art, the beneficial effects of the device for desalinating seawater by utilizing the waste heat of ship flue gas provided by the present invention are as follows: Based on the seawater jet-flue gas cyclone device, the ship flue gas humidification-dehumidification technology is used to desalinate seawater and remove pollutants. The high-temperature flue gas of the ship and the seawater jet spray are in direct contact, and strong disturbance occurs between them. The waste heat of the flue gas is fully utilized, and the heat and mass transfer effect is good. As a direct result, the absorption of harmful gases in the flue gas and the evaporation of the seawater jet spray are more complete, and the desalination is more effective. The water production is high and the discharge of concentrated brine is small; the particulate matter discharged by the diesel engine is moistened and condensed by seawater spray, and the particle size increases, and it is easier to agglomerate with each other, and can be well removed under the action of centrifugal force; the inner wall of the humidification tower is not easy to scale under the strong flushing of the jet and cyclone. When the inner wall is scaled and polluted, it can be cleaned when the diesel engine is stopped. At this time, the intake air becomes clean air, and the high-pressure hot fresh water or soda solution introduced from the cleaning pipeline is sprayed in, which can easily remove dirt, so the overall maintenance cost of the device is low; the device adopts the form of cyclone separation and cyclone cooling, and has the advantages of compact structure and small system resistance. In summary, the present invention solves the technical problems that the existing scheme cannot achieve efficient heat and mass exchange between flue gas and seawater, resulting in low overall heat exchange efficiency, limited desalination performance, and easy to produce scaling and blockage, which increases maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0060] Figure 1 It is a structural schematic diagram of a first embodiment of a device for desalinating seawater using waste heat from ship flue gas;

[0061] Figure 2 It is a structural schematic diagram of a second embodiment of a device for desalinating seawater using waste heat from ship flue gas;

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

[0063] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0064] 1. First stop valve; 10. demister; 11. insulation material; 13. salt box; 14. observation mirror; 15. fresh water tank; 16. sampling hole; 17. alkali liquid tank; 18. second filter; 19. purified fresh water tank; 2. second stop valve; 20. fresh water pump; 21. fresh water flow regulating valve; 22. fresh water nozzle; 23. diffuser; 24. second nozzle; 25. cooling water jacket; 26. seawater jet jacket; 27. cooling pipe; 3. third stop 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. spray cooling chamber; 43. dehumidification device; 5. seawater pump; 6. seawater flow regulating valve; 7. seawater spray hole; 8. first nozzle; 9. thermometer and hygrometer. DETAILED DESCRIPTION

[0065] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0066] like Figure 1 As shown, the structure of a device for desalinating seawater using waste heat from ship flue gas provided by the present invention comprises:

[0067] Flue gas inlet, first nozzle 8, humidification device 41, salt box 13, thermometer 9, demister 10, fan, diffuser 23, spray cooling chamber 42, second nozzle 24, dehumidification device 43, fresh water tank 15, sampling hole 16, alkali liquid tank 17, second filter 18, purified fresh water tank 19, fresh water pump 20, fresh water flow regulating valve 21, fresh water nozzle 22, first filter 4, sea water pump 5, sea water flow regulating valve 6;

[0068] The smoke inlet is arranged on the ship chimney and connected to the chimney, and its switch is controlled by the second stop 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 and includes a cylindrical part, a conical part and an intermediate discharge pipe, wherein the conical part is located below the cylindrical part and is integrated with the cylindrical part;

[0071] Seawater spray holes are provided around the upper middle portion of the cylindrical portion of the humidifying device 41 for spraying seawater;

[0072] The salt box 13 is disposed below the conical portion of the humidifying device 41 and is used to receive concentrated brine, salt particles, and soot particles discharged from the humidifying device 41;

[0073] The thermo-hygrometer 9 is arranged at the high-temperature humid air outlet at the top of the humidifying device 41, and is used to measure the temperature and humidity of the high-temperature humid air;

[0074] The demister 10 is arranged after the thermohygrometer and is used to remove a small amount of particles or small droplets in the high-temperature 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 23 is used to increase the pressure of the high-temperature humid air and reduce the flow rate of the humid air;

[0077] One end of the spray cooling chamber 42 is connected to the diffuser pipe 23, which is used for the first stage cooling of the high temperature humid air;

[0078] One end of the second spray pipe 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 modified from a cyclone separator and is used for the second stage cooling of the wet air;

[0080] The fresh water treatment and storage device includes a fresh water tank 15, a sampling hole 16, an alkali liquid tank 17, a second filter 18, a purified fresh water tank 19 and pipelines to the ship's fresh water tanks;

[0081] The cooling fresh water injection device comprises a fresh water pump 5, a fresh water flow regulating valve 21, and a fresh water nozzle 22; the fresh water pump 5 in the cooling fresh water injection device is used to provide injection pressure; the fresh water flow regulating valve 21 is used to adjust the injection amount of condensed fresh water; the fresh water nozzle 22 is evenly distributed according to the cross section of the injection cooling cavity;

[0082] The seawater cooling and injection pipeline includes a first seawater filter 4, a seawater pump 5, a cooling seawater pipe leading to the purified fresh water tank, a seawater pipeline leading to the dehumidification device, and a seawater flow regulating valve 6; the first seawater filter 4 can fully filter impurities in the seawater to prevent the seawater spray hole from being blocked; the seawater flow regulating valve 6 is used to adjust the seawater flow rate sprayed into the humidification device.

[0083] Among them, in the above technical solution, the material of the humidification device is one or more of stainless steel, ceramic, geopolymer or high temperature resistant resin, and is made by welding, and the material can withstand high temperature above 200°C;

[0084] The flue gas inlet of the cyclone separator of the humidifying device 41 is rectangular, the air intake mode is tangential, and the gas flow mode in the cyclone separator is countercurrent;

[0085] The outermost side of the humidifying device 41 is provided with a heat insulating material to reduce the heat transfer from the high temperature water vapor in the humidifying device to the outside;

[0086] The seawater spray holes of the humidifying device 41 are evenly distributed in the entire spraying area, and the total height of the spray hole area is less than the insertion length of the central discharge pipe;

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

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

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

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

[0091] Further, 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 wet air inlet of the dehumidification device 43 is rectangular, including a cylindrical portion, a conical portion and a middle discharge pipe portion;

[0093] A cooling water jacket 25 is provided outside the cylindrical and conical parts of the dehumidification device 43, and a cooling seawater inlet and outlet are provided on the cooling water jacket 25;

[0094] The cooling seawater in the cooling water jacket 25 enters from the lower seawater inlet, and the seawater with increased temperature after heat exchange with the water vapor is discharged from the upper cooling water outlet;

[0095] The middle exhaust pipe of the dehumidification device 43 is the clean flue gas exhaust outlet, and the clean flue gas after low-temperature dehumidification is discharged through the flue gas exhaust outlet and enters the chimney of the ship;

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

[0097] Furthermore, in the above technical solution, the fresh water tank in the fresh water treatment and storage device is used to collect the fresh water condensed by the condenser and precipitate particulate matter;

[0098] The sampling hole 16 is used for sampling to measure the pH value and salinity of the fresh water in the fresh water tank;

[0099] The alkali liquid 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 the oily components and some suspended matter in the fresh water, and includes at least two-stage filtration of activated carbon and resin filter;

[0101] The fresh water stored in the purified fresh water tank 19 is treated clean fresh water and is cooled, and the cooling medium is seawater or other cold energy;

[0102] The pipeline to the ship's fresh water tank transports the fresh water to the ship's drinking, sanitary or miscellaneous fresh water tanks according to the quality of the produced fresh water.

[0103] like Figure 3 As shown, in the above technical solution, a flue gas pretreatment unit 31 is also included. The flue gas pretreatment unit 31 is arranged between the flue gas inlet and the first nozzle 8, and is used for preliminary treatment of 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 is a cylindrical structure, one end of which is connected to the flue gas inlet, and the other end is connected to the first nozzle 8; the material of the pretreatment cylinder 311 is high temperature resistant and corrosion resistant alloy steel; the outside of the pretreatment cylinder 311 is provided with an insulation layer to reduce heat loss.

[0105] Furthermore, in the above technical solution, the dust removal device 312 is arranged in the upper half of the pretreatment cylinder 311, and includes multiple layers of metal grids for filtering large particles in the flue gas; the metal grids are made of high-temperature resistant and corrosion-resistant stainless steel material, and the mesh size gradually decreases from the air inlet end to the air outlet end.

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

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

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

[0109] When the device is working, the first stop valve 1 is closed, the second stop valve 2 and the third stop valve 3 are opened, and the high-temperature flue gas in the ship chimney is accelerated through the first nozzle 8 and then tangentially enters the humidification device 41, and the preheated seawater is sprayed into the humidification device 41 from the seawater spray holes around the upper part of the humidification device 41;

[0110] There is a strong disturbance between the spiral flue gas and the radial seawater jet, and sufficient heat and mass transfer is carried out. Under the action of centrifugal force and gravity, the evaporated salt particles, unevaporated small droplets, soot particles in the flue gas and other components with higher density fall along the inner wall of the humidification device 41 into the salt box in a spiral, and 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 wet air enters the dehumidification process, which includes two stages of cooling: first, the cooling fresh water mist sprayed into the steam cooling chamber can quickly cool the high-temperature water vapor, causing part of the water vapor to condense into liquid water; then it enters the condenser, where the 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 the sampling hole 16, and its pH is adjusted through the alkali liquid tank 17. A small amount of particulate matter inside the water tank settles to the bottom of the tank and is released through the lower slag discharge port. The fresh water in the fresh water tank 15 passes through the activated carbon and resin filter and then enters the purified fresh water tank 15;

[0113] After the fresh water in the purified fresh water tank 15 is cooled by seawater or other low-temperature media, part of it is used in the form of spray to cool the high-temperature water vapor at the outlet of the humidification tower, and the rest is transported to the ship's drinking, sanitary or miscellaneous fresh water tanks according to the quality of the produced fresh water.

[0114] Embodiment 1:

[0115] A method and device for desalination of seawater by utilizing waste heat of ship flue gas and removal of pollutants, comprising a flue gas inlet, a first nozzle 8, a humidification device 41, a salt box 13, a thermometer 9, a demister 10, a fan, a diffuser 23, a spray cooling 42, a second nozzle 24, a dehumidification device 43, a fresh water treatment and storage device, a cooling fresh water injection device, a sea water cooling and injection pipeline, etc. connected in sequence; the flue gas inlet is opened on the ship chimney and connected to the chimney, and its switch is controlled by the second stop valve 2; the material of the flue gas inlet is selected from high temperature resistant and corrosion resistant 310S stainless steel, with a wall thickness of not less than 5mm. The inlet diameter is determined according to the power of the ship's main engine, usually between 500-1000mm. The front of the first nozzle 8 is connected to the flue gas inlet, and the rear is connected to the humidification device 41; the first nozzle adopts a square structure, the material is 310S stainless steel, and the wall thickness is 6mm. The cross-sectional area of ​​the first nozzle gradually decreases, and the ratio of the inlet to the outlet area is about 3:1, so as to accelerate the flue gas. Preferably, the smoke inlet and the first nozzle joint are both square structures; the humidification device 41 is a "seawater jet-smoke cyclone device", which is modified based on a cyclone separator. The cyclone separator includes a cylindrical part, a conical part and an intermediate discharge pipe. The conical part is located below the cylindrical part and is combined into one; the humidification device 41 is made of 2205 duplex stainless steel and is made by welding. The material can withstand a temperature of up to 350°C. The diameter of the cylindrical part is 1500mm and the height is 2000mm; the bottom diameter of the conical part is 500mm and the height is 1500mm. The diameter of the intermediate discharge pipe is 600mm, and the insertion depth is 2 / 3 of the height of the cylinder. Furthermore, the humidifying device 41 can be made of corrosion-resistant and high-temperature-resistant materials such as stainless steel, ceramics, geopolymers, and high-temperature-resistant resins, and can be made by welding, 3D printing, etc. The material is required to withstand high temperatures above 200°C; further, the flue gas inlet of the cyclone separator of the humidifying device is rectangular, the air intake mode is tangential, and the gas flow mode in the cyclone separator is countercurrent; further, the outermost side of the humidifying device is provided with a heat-insulating material 11 to minimize the heat transfer of high-temperature water vapor in the humidifying device to the outside; the heat-insulating material is made of high-temperature resistant ceramic fiber with a thickness of 50mm. The outer side of the heat-insulating layer is coated with 0.5mm thick aluminum foil to improve the reflectivity. Seawater spray holes 7 are opened around the middle and upper part of the cylindrical part, and the seawater in the seawater spray jacket 26 is sprayed into the inner cavity of the humidifying device under the pressure of the seawater pump 5; a total of 120 spray holes are set, with an inner diameter of 5mm, evenly distributed in the spray area with a height of 500mm. The spray holes are made of corrosion-resistant Hastelloy C-276 material.The seawater in the seawater jet jacket is preheated seawater, which comes from the cooling water jacket in the dehumidification device; further, the seawater spray holes of the humidification device are evenly distributed in the entire spray area, and the total height of the spray hole area is less than the insertion length of the central discharge pipe; further, the inner diameter of the seawater spray hole is selected according to the size parameters of the humidification device and the flue gas parameters; the salt box 13 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 salt box material is glass fiber reinforced plastic, lined with polytetrafluoroethylene (PTFE) to enhance corrosion resistance. The volume of the salt box is 1m. 3 , a drain valve is provided at the bottom. Furthermore, an observation mirror is provided on the salt box to observe the state and flow of concentrated brine in the salt box; the observation mirror is a tempered glass with a diameter of 150mm. There is a high-temperature humid air outlet in the middle of the top of the humidification device. The high-temperature humid air passes through the thermometer 9, the demister 10, the fan and the diffuser 23, and then enters the steam cooling 42; the thermometer 9 is used to measure the temperature and humidity of the high-temperature humid air discharged from the top of the humidification device 41; a high-temperature resistant temperature and humidity sensor is used, and the measurement range is: temperature 0-200℃, humidity 0-100%RH. The sensor signal is transmitted to the control system via a 4-20mA analog signal. The demister 10 is used to remove a small amount of particulate matter or small droplets in the high-temperature humid air; a stainless steel wire mesh demister is used, the mesh diameter is 0.28mm, and the mesh size is 0.13mm. The thickness of the demister 10 is 100mm, and the pressure drop does not exceed 200Pa. The fan inlet is connected to the demister and the outlet is connected to the diffuser. The main purpose of the fan is to increase the air velocity of the humidification device and the dehumidification device, and to improve the heat transfer, mass transfer and separation effect. Furthermore, the fan should be variable frequency, high temperature resistant and corrosion resistant. A centrifugal fan is used, and the fan impeller material is titanium alloy. The fan has a rated power of 30kW and a maximum air volume of 10,000m 3 / h, maximum wind pressure 6000Pa.

[0116] The diffuser 23 is used to increase the pressure of the high-temperature humid air, reduce the flow rate of the humid air, and allow the high-temperature water vapor to have sufficient cooling time; preferably, the diffuser adopts a circular to square structure; the inlet diameter is 600mm, and the outlet is a square of 800mm×800mm. The material is 304 stainless steel with a wall thickness of 4mm. The front of the spray cooling 42 is connected to the diffuser, which is the first stage of cooling of the high-temperature humid air; further, the high-temperature humid air is cooled by fresh water spray in the spray cooling chamber, and the length of the spray cooling chamber should ensure that the fresh water spray and the high-temperature humid air are fully mixed; the length of the cooling chamber is 3000mm and the cross-sectional area is 800mm×800mm. There are 3 rows of 15 atomizing nozzles inside, and the nozzles are made of corrosion-resistant titanium alloy. The front end of the second nozzle 24 is connected to the steam cooling chamber, and the rear end is connected to the dehumidification device 43. The main purpose is to increase the inlet flow rate of the dehumidification device and improve the cooling effect; the second nozzle adopts a square structure, and the cross-sectional area gradually decreases from 800mm×800mm to 600mm×400mm. The material is 304 stainless steel with a wall thickness of 3mm. The dehumidifier 43 is also a modified cyclone separator, which is the second-stage cooling of the wet air; further, the wet air inlet of the dehumidifier is rectangular, mainly including a cylindrical part, a conical part and an intermediate discharge pipe part; the cylinder has a diameter of 1200mm and a height of 1500mm; the bottom diameter of the cone is 400mm and the height is 1200mm. The material is 316L stainless steel with a wall thickness of 6mm. Furthermore, a cooling water jacket 25 is provided on the outside of the cylinder and conical parts of the dehumidifier, and a cooling seawater inlet and outlet are provided on the cooling water jacket; the thickness of the cooling water jacket is 50mm and is designed in a spiral winding manner. The cooling water inlet is located at the bottom and the outlet is located at the top, and the pipe diameter is DN80. Furthermore, cooling seawater enters the cooling water jacket from the lower seawater inlet, and the seawater with increased temperature after heat exchange with water vapor is discharged from the upper cooling water outlet; the middle discharge pipe of the dehumidification device is the clean flue gas discharge outlet, and the clean flue gas after low-temperature dehumidification is discharged into the ship chimney through the flue gas discharge port; the lower part of the conical part of the dehumidification device 43 is the fresh water output port, and the condensed fresh water flows out through the fresh water output port and reaches the fresh water treatment and storage device; the fresh water treatment and storage device includes a fresh water tank, a sampling hole, an alkali liquid tank, a second filter, a purified fresh water tank (including cooling pipelines) and pipelines to the ship's fresh water tanks; the fresh water tank is used to collect the fresh water condensed by the condenser and precipitate particulate matter; the volume is 5m 3, made of fiberglass. There are partitions inside to form the primary sedimentation area and the clear water area. There is a drain valve at the bottom for regular discharge of sediment. The sampling hole is used to take samples to measure the pH value and salinity of the fresh water in the fresh water tank; the diameter is DN25 and it is made of 316L stainless steel. It is equipped with a quick-connect connector for easy sampling. The alkali liquid tank is used to neutralize the residual acid value in the fresh water tank to make the fresh water in the fresh water tank neutral; the volume is 200L and it is made of polyethylene. It is equipped with a liquid level meter and a pH meter to monitor the amount of alkali liquid and the pH value of fresh water. The second filter is to filter the oily components and some suspended matter in the fresh water, at least two-stage filtration of activated carbon and resin filter; the activated carbon filter uses granular activated carbon with a filling height of 1000mm. The resin filter uses strong acid cation exchange resin with a filling height of 800mm. The fresh water stored in the purified fresh water tank (including cooling pipeline) is treated clean fresh water and cooled. The cooling medium is seawater (in winter) or other cold energy (in summer, such as mechanical refrigeration or LNG ship cold energy). The volume is 10m 3 , made of 316L stainless steel. There are cooling coils inside, with a total area of ​​20m 2 . Equipped with temperature sensors and liquid level gauges. The pipeline to the ship's fresh water tank is transported to the ship's drinking, sanitary or miscellaneous fresh water tanks according to the quality of the produced fresh water; the cooling fresh water injection device includes a fresh water pump 20, a fresh water flow regulating valve 21, and a fresh water nozzle 22. The cooled fresh water is sprayed into the steam cooling 42 through the fresh water nozzle under the pressure of the water pump; the fresh water pump 20: a vertical multi-stage centrifugal pump with a rated flow of 10m 3 / h, head 60m. The pump body is made of 316L stainless steel, and the impeller is made of chromium-nickel-molybdenum alloy. The fresh water flow control valve 21 is used to adjust the injection amount of condensed fresh water; an electric control valve is used, and the valve body is made of 316L stainless steel. Control accuracy ±2%, response time <10s. The fresh water nozzle 22 should be evenly distributed according to the cross section of the spray cooling cavity; a hollow cone nozzle is used, and the material is titanium alloy. The nozzle aperture is 0.8mm, and a total of 15 are set, evenly distributed on the spray cooling 42 cross section.

[0117] The seawater cooling and injection pipeline includes the first seawater filter 4, the seawater pump 5, the cooling seawater pipe to the purified fresh water tank, the seawater pipe to the dehumidification device 43, and the seawater flow regulating valve 6; the first filter 4 should be able to fully filter the impurities in the seawater to prevent the seawater spray hole from being blocked; a self-cleaning filter with a filtration accuracy of 50μm is used. The filter material is nickel-copper alloy, which has good seawater corrosion resistance. Seawater pump 5: A horizontal centrifugal pump with a rated flow of 50m 3 / h, head 40m. The pump body and impeller are made of super duplex stainless steel SAF 2507. The seawater flow regulating valve 6 is used to adjust the seawater flow injected into the humidification device. The adjustment is mainly based on the load of the ship's diesel engine (including the ship's main engine and generator) and the operation of the auxiliary boiler, and refers to the value of the thermometer and hygrometer 9 at the outlet of the humidification device and the concentrated seawater flow seen through the salt box observation mirror 14; a pneumatic regulating valve is used, and the valve body is made of duplex stainless steel. The control accuracy is ±3%, and the response time is <5s.

[0118] The working process is as follows: when the device is working, the first stop valve 1 is closed. The second stop valve 2 and the third stop valve 3 are opened, and the high-temperature flue gas in the ship chimney is accelerated through the first nozzle 8 and then enters the humidification device tangentially, and the preheated seawater is sprayed into the humidification device from the seawater spray holes around the upper part of the humidification device ( Figure 1 ), there is a strong disturbance between the spiral flue gas and the radial seawater jet, and sufficient heat and mass transfer is carried out. Under the action of centrifugal force and gravity, the evaporated salt particles, unevaporated small droplets, soot particles in the flue gas and other components with higher density fall along the inner wall of the humidification device into the salt box 13, and 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 passes through the fan and enters the dehumidification process, including two-stage cooling. First, the cooling fresh water mist sprayed into the steam cooling chamber can quickly cool the high-temperature water vapor, so that part of the water vapor condenses into liquid water; enters the condenser, and the low-temperature seawater further cools the water vapor into fresh water, which flows into the fresh water tank 15; the pH and salinity of the fresh water can be measured through the sampling hole 16, and its pH is adjusted through the alkali liquid tank 17. A small amount of particulate matter inside the water tank is precipitated to the bottom of the tank and discharged through the lower slag discharge port. The fresh water in the fresh water tank 15 passes through the activated carbon and resin filter and enters the purified fresh water tank 19; after the fresh water in the purified fresh water tank is cooled by seawater (or other low-temperature media), part of it is used in the form of spray to cool the high-temperature water vapor at the outlet of the humidification tower, and the rest is transported to the fresh water tanks for drinking, sanitation or miscellaneous use on the ship according to the quality of the produced fresh water. The dehumidification device 43 in the first embodiment is a cyclone condenser.

[0119] The detailed working process and operation steps are as follows: 1. Startup preparation: Check the status of each device to ensure that there is no abnormality. Start the seawater pump 5 and open the seawater flow regulating valve 6. Start the freshwater pump 20 and adjust the freshwater flow regulating valve 21 to the appropriate position. 2. System startup: Close the first stop valve 1 and open the second stop valves 2 and 3. Start the fan and adjust it to the appropriate speed. Gradually increase the seawater flow until it reaches the set value. 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 box observation mirror 14 and adjust the seawater flow regulating valve 6. Regularly check the pH value and salinity of the fresh water in the freshwater tank 15, and adjust the amount of alkali solution added if necessary. 4. System stop: Gradually reduce the seawater flow until it is completely closed. Close the second stop valves 2 and 3 and open the first stop valve 1. Stop the fan and freshwater pump 20. Continue to run the seawater pump 5 for a period of time and flush the system. 5. Maintenance: Clean the first filter 4 every week. Check and clean the inside of the humidification device 41 and the dehumidification device 43 every month. Replace the activated carbon and resin in the filter 18 every quarter. Check the wear of the fan impeller every six months and replace it if necessary.

[0120] Through the above detailed implementation methods, the ship flue gas waste heat seawater desalination combined with pollutant removal device of the present invention can effectively utilize the waste heat of ship flue gas, and simultaneously realize seawater desalination and pollutant removal, thereby improving energy utilization efficiency and reducing ship pollutant emissions. The main advantages of the device include: 1. Efficient utilization of waste heat: Through ingenious design, the waste heat in the ship flue gas is fully utilized to improve energy utilization efficiency. 2. Multifunctional integration: The two functions of seawater desalination and pollutant removal are realized in one system, saving ship space and equipment investment. 3. Significant environmental benefits: Through the pollutant removal function, the environmental pollution of the ship is effectively reduced, which complies with increasingly stringent international maritime environmental regulations. 4. Flexible operation: The system can be adjusted according to the actual operation of the ship to adapt to different working conditions. 5. Easy maintenance: Through reasonable design and material selection, the difficulty and frequency of system maintenance are reduced.

[0121] Embodiment 2:

[0122] like Figure 2 Another specific embodiment of the present invention is shown. This embodiment differs from the above embodiment in that a cooling pipe 27 is used instead of a cooling water jacket 25. This is the second embodiment of the device, wherein the dehumidification device 43 is a conventional condenser. The steps of use are as follows:

[0123] The stop valve 1 is closed. The stop valves 2 and 3 are opened, and the high-temperature flue gas in the ship's chimney is accelerated by the nozzle 8 and enters the humidification device tangentially. The preheated seawater is sprayed into the humidification device from the seawater spray holes around the upper part of the humidification device ( Figure 1), there is a strong disturbance between the spiral flue gas and the radial seawater jet, and sufficient heat and mass transfer is carried out. Under the action of centrifugal force and gravity, the evaporated salt particles, unevaporated small droplets, soot particles in the flue gas and other components with higher density fall along the inner wall of the humidification device into the salt box 13, and 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 passes through the fan and enters the dehumidification process, including two-stage cooling. First, the cooling fresh water mist sprayed into the steam cooling chamber can quickly cool the high-temperature water vapor and condense part of the water vapor into liquid water; entering the dehumidification device (conventional condenser), the low-temperature seawater further cools the water vapor into fresh water and flows into the fresh water tank 15; the pH and salinity of the fresh water can be measured through the sampling hole 16, and its pH is adjusted through the alkali liquid tank 17. A small amount of particulate matter inside the water tank is precipitated to the bottom of the tank and discharged through the slag discharge port at the bottom. The fresh water in the fresh water tank 15 passes through the activated carbon and resin filter and enters the purified fresh water tank 19; after the fresh water in the purified fresh water tank is cooled by seawater (or other low-temperature media), part of it is used in the form of spray to cool the high-temperature water vapor at the outlet of the humidification tower, and the rest is transported to the ship's drinking, sanitary or miscellaneous fresh water tanks according to the quality of the produced fresh water.

[0124] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A device for desalinating seawater using waste heat from ship flue gas, characterized in that: include: Flue gas inlet, first nozzle, humidification device, salt box, thermometer, demister, fan, diffuser, spray cooling chamber, second nozzle, dehumidification device, fresh water treatment and storage device, cooling fresh water injection device, seawater cooling and injection pipeline; The smoke inlet is arranged on the chimney of the ship and connected to the chimney, and its switch is controlled by the second stop valve; One end of the first nozzle is connected to the smoke 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 and includes a cylindrical part, a conical part and an intermediate discharge pipe, wherein the conical part is located below the cylindrical part and is integrated with the cylindrical part; The upper middle part of the cylindrical part of the humidifying device is provided with seawater spray holes around it for spraying seawater; The salt box is arranged below the conical part of the humidifying device and is used to receive the concentrated brine, salt particles and soot particles discharged from the humidifying device; The thermo-hygrometer is arranged at the high-temperature humid air outlet on the top of the humidifying device, and is used to measure the temperature and humidity of the high-temperature humid air; The demister is arranged after the thermo-hygrometer and is used to remove a small amount of particles or small droplets in the high-temperature humid air; The inlet of the fan is connected to the demister, and the outlet is connected to the diffuser; The diffuser is used to increase the pressure of high-temperature humid air and reduce the flow rate of humid air; One end of the spray cooling chamber is connected to the diffuser pipe and is used for first-stage cooling of high-temperature humid air; One end of the second spray pipe is connected to the spray cooling chamber, and the other end is connected to the dehumidification device; The dehumidification device is modified from a cyclone separator and is used for the second stage cooling of wet air; The fresh water treatment and storage device comprises a fresh water tank, a sampling hole, an alkali solution tank, a second filter, a purified fresh water tank and pipelines to the ship's fresh water tanks; The cooling fresh water injection device comprises a fresh water pump, a fresh water flow regulating valve and a fresh water nozzle; the fresh water pump in the cooling fresh water injection device is used to provide injection pressure; the fresh water flow regulating valve is used to adjust the injection amount of condensed fresh water; the fresh water nozzles are evenly distributed according to the cross section of the injection cooling cavity; The seawater cooling and injection pipeline includes a first filter, a seawater pump, a cooling seawater pipe leading to a purified fresh water tank, a seawater pipeline leading to a dehumidification device, and a seawater flow regulating valve; the first filter can fully filter impurities in the seawater to prevent the seawater spray hole from being blocked; the seawater flow regulating valve is used to adjust the seawater flow rate sprayed into the humidification device.

2. The device for desalinating seawater using waste heat from ship flue gas according to claim 1, characterized in that: The humidification device is made of one or more of stainless steel, ceramic, geopolymer or high temperature resistant resin and is made by welding. The material can withstand high temperature above 200°C. The smoke inlet of the cyclone separator of the humidification device is rectangular, the air intake mode is tangential, and the gas flow mode in the cyclone separator is countercurrent; The outermost side of the humidifying device is provided with a heat-insulating material to reduce the heat transfer of the high-temperature water vapor in the humidifying device to the outside; The seawater spray holes of the humidification device are evenly distributed in the entire spraying area, and the total height of the spray hole area is less than the insertion length of the central discharge pipe; The inner diameter of the seawater spray hole of the humidification device is selected according to the size parameters of the humidification device and the flue gas parameters; The salt box is provided with an observation mirror for observing the state and flow of concentrated brine in the salt box; The fan adopts a variable frequency, high temperature resistant and corrosion resistant fan; The diffuser tube adopts a circular-to-square structure.

3. The device for desalinating seawater using waste heat from ship flue gas according to claim 2, characterized in that: The length of the spray cooling chamber ensures that the fresh water spray and the high-temperature humid air are fully mixed; The wet air inlet of the dehumidification device is rectangular, including a cylindrical portion, a conical portion and a middle discharge pipe portion; A cooling water jacket is provided outside the cylindrical and conical parts of the dehumidification device, and a cooling seawater inlet and outlet are provided on the cooling water jacket; The cooling seawater in the cooling water jacket enters from the lower seawater inlet, and the seawater with increased temperature after heat exchange with water vapor is discharged from the upper cooling water outlet; The middle exhaust pipe of the dehumidification device is the clean flue gas exhaust outlet, and the clean flue gas after low-temperature dehumidification is discharged into the ship chimney through the flue gas exhaust outlet; The lower part of the conical part of the dehumidification device is a fresh water outlet, through which the condensed fresh water flows out and reaches the fresh water processing and storage device.

4. The device for desalinating seawater using waste heat from ship flue gas according to claim 3 is characterized in that: The fresh water tank in the fresh water treatment and storage device is used to collect the fresh water condensed by the condenser and precipitate particulate matter; The sampling hole is used for sampling to measure the pH value and salinity of the fresh water in the fresh water tank; The alkali liquid tank is used to neutralize the residual acid value in the fresh water tank, so that the fresh water in the fresh water tank is neutral; The second filter is used to filter the oily components and some suspended matter in the fresh water, and includes at least two stages of filtration, namely activated carbon and resin filter; The fresh water stored in the purified fresh water tank is treated clean fresh water, and is cooled, and the cooling medium is seawater or other cold energy; The pipeline to the ship's fresh water tank transports the produced fresh water to the ship's drinking, sanitary or miscellaneous fresh water tanks according to the quality of the fresh water.

5. The device for desalinating seawater using waste heat from ship flue gas according to claim 4, characterized in that: It also includes a flue gas pretreatment unit, which is arranged between the flue gas inlet and the first nozzle and is used 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 desalinating seawater using waste heat from ship flue gas according to claim 5, characterized in that: The pretreatment cylinder is a cylindrical structure, one end of which is connected to the flue gas inlet and the other end is connected to the first nozzle; the material of the pretreatment cylinder is high temperature resistant and corrosion resistant alloy steel; the outside of the pretreatment cylinder is provided with an insulation layer to reduce heat loss.

7. The device for desalinating seawater by utilizing waste heat from ship flue gas according to claim 6, characterized in that: The dust removal device is arranged in the upper half of the pretreatment cylinder, and includes multiple layers of metal grids for filtering large particles in the flue gas; the metal grids are made of high-temperature resistant and corrosion-resistant stainless steel materials, and the mesh size gradually decreases from the air inlet end to the air outlet end.

8. The device for desalinating seawater using waste heat from ship flue gas according to claim 7, characterized in that: The condensate collection tray is arranged at the bottom of the pretreatment cylinder and has a shallow dish-shaped structure for collecting moisture condensed in the flue gas; the drain pipe is connected to the condensate collection tray and is used to discharge the collected condensate; a one-way valve is provided on the drain pipe to prevent backflow of external air.

9. The device for desalinating seawater using waste heat from ship flue gas according to claim 8, characterized in that: The temperature sensor and the pressure sensor are respectively installed on the side walls of the pretreatment cylinder, and are used to monitor the temperature and pressure of the flue gas in real time and send them to the host computer through the communication device.

10. A device for desalinating seawater using waste heat from ship flue gas according to any one of claims 1 to 9, characterized in that: The working process of the device is: When the device is working, the first stop valve 1 is closed, the second stop valve 2 and the third stop valve 3 are opened, and the high-temperature flue gas in the ship chimney is accelerated through the first nozzle and enters the humidification device tangentially, and the preheated seawater is sprayed into the humidification device from the seawater spray holes around the upper part of the humidification device; There is a strong disturbance between the spiral flue gas and the radial seawater jet, which allows sufficient heat and mass transfer. Under the action of centrifugal force and gravity, the evaporated salt particles, unevaporated small droplets, soot particles in the flue gas and other components with higher density fall along the inner wall of the humidification device into the salt box, and 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. After passing through the fan, the wet air enters the dehumidification process, which includes two stages of cooling: first, the cooling fresh water mist sprayed into the steam cooling chamber can quickly cool the high-temperature water vapor, causing part of the water vapor to condense into liquid water; then it enters the condenser, where the low-temperature seawater further cools the water vapor into fresh water, which flows into the fresh water tank; The pH and salinity of fresh water can be measured through the sampling hole, and its pH can be adjusted through the alkali solution tank. A small amount of particles inside the water tank settle to the bottom of the tank and are discharged through the slag discharge port at the bottom. The fresh water in the fresh water tank passes through the activated carbon and resin filter and then enters the purified fresh water tank; After the fresh water in the purified fresh water tank is cooled by seawater or other low-temperature media, part of it is used in the form of spray to cool the high-temperature water vapor at the outlet of the humidification tower, and the rest is transported to the ship's drinking, sanitary or miscellaneous fresh water tanks according to the quality of the produced fresh water.

Images