A desalination device combining seawater waste heat utilization with interface evaporation

Abstract

The invention discloses a desalination device combining seawater waste heat utilization with interface evaporation, comprising a base and a transparent top cover arranged on the base, a solar interface evaporation system and a membrane distillation system are arranged on the base, and both the solar interface evaporation system and the membrane distillation system are located in the transparent top cover; the solar interface evaporation system comprises a seawater pool arranged in the middle of the base and a first SSG water collecting tank and a second SSG water collecting tank arranged at both ends of the base, and an interface evaporation device is arranged in the seawater pool; the membrane distillation system comprises an MD water collecting tank and a cold water tank arranged on the base, and the MD water collecting tank is arranged between the seawater pool and the cold water tank, and a through hole is arranged on the pool wall between the seawater pool and the MD water collecting tank, and a PTFE membrane is fixedly installed in the through hole. Based on solar interface evaporation, membrane distillation technology is introduced, and the heat conducted to the seawater by the photothermal film is reasonably utilized to further improve the desalination efficiency of the desalination device and increase the fresh water output.

Description

Technical Field

[0001] The invention relates to the technical field of seawater desalination, and in particular to a desalination device combining seawater waste heat utilization with interface evaporation. Background Art

[0002] Water is the source of life and an indispensable resource for human survival and development. With the rapid growth of the world's population and the freshwater pollution caused by industrial development, there is a serious shortage of water resources worldwide. At present, seawater desalination technology is generally regarded as a practical way to solve the shortage of freshwater. Mainstream seawater desalination technologies include reverse osmosis (RO), multi-effect distillation, multi-stage flash evaporation, etc. However, the above-mentioned seawater desalination technologies usually have high investment costs and high energy consumption, which are not feasible for some remote areas with underdeveloped infrastructure. In addition, existing desalination technologies mainly rely on traditional fossil fuels to provide energy for freshwater production, which aggravates greenhouse gas emissions and air pollution.

[0003] As one of the most promising technologies for obtaining pure water from various non-drinking water resources, solar interfacial evaporation technology uses photothermal conversion materials floating on the liquid surface to further convert the absorbed solar energy into heat to heat the thin layer of liquid at the air-water interface to produce steam. Since the evaporation of water only occurs on the surface of the water, this technology avoids heating a large volume of water that does not participate in evaporation, so it has the advantages of low energy consumption, fast response, no pollution, and high evaporation efficiency. The improvement of evaporation efficiency requires efficient light absorption, good water transport, and small heat loss. Although insulation measures have been taken to further improve the evaporation efficiency, it cannot block the heat transfer from the light absorber to the seawater. Some heat is still transferred to the seawater, and the waste heat of the bottom seawater is still valuable. Therefore, it is very important to further develop and utilize the waste heat of the bottom seawater. Summary of the invention

[0004] The purpose of the present invention is to provide a desalination device combining seawater waste heat utilization with interface evaporation to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above-mentioned object, the present invention provides the following scheme: The present invention provides a desalination device combining waste heat utilization of seawater with interface evaporation, comprising a base and a transparent top cover arranged on the base, wherein a solar interface evaporation system and a membrane distillation system are arranged on the base, and the solar interface evaporation system and the membrane distillation system are both located in the transparent top cover;

[0006] The solar interface evaporation system includes a seawater pool opened in the middle of the base and a first SSG water collecting tank and a second SSG water collecting tank opened at both ends of the base, and an interface evaporation device is arranged in the seawater pool; the membrane distillation system includes an MD water collecting tank and a cold water tank opened on the base, and the MD water collecting tank is arranged between the seawater pool and the cold water tank. A through hole is opened on the pool wall between the seawater pool and the MD water collecting tank, and a PTFE membrane is fixedly installed in the through hole.

[0007] Preferably, the interface evaporation device includes a metal plate fixed on the top of the seawater pool, the metal plate is provided with a mold hole, and a photothermal film is fixedly installed in the mold hole; one end of a fiber paper is fixedly connected to the bottom of the metal plate, the other end of the fiber paper extends into the seawater pool, and the fiber paper is in contact and connected with the bottom of the photothermal film.

[0008] Preferably, a metal straight rib is fixedly connected to the bottom of the metal plate in the circumferential direction, and the fiber paper is located in a cavity formed by the metal straight rib.

[0009] Preferably, a heat insulation board is provided at the bottom of the metal plate, and the heat insulation board is located in the cavity formed by the metal straight ribs; the fiber paper is laid on the heat insulation board, and the fiber paper is located between the heat insulation board and the photothermal film.

[0010] Preferably, the thermal insulation board is a polystyrene foam board.

[0011] Preferably, the top end of the metal plate is coated with black paint.

[0012] Preferably, the transparent top cover is an inverted V-shaped structure, and the transparent top cover includes an inclined top cover wall and two top cover vertical walls. The inclined top cover wall is an inverted V-shaped structure, and the two top cover vertical walls are respectively fixed on both sides of the inclined top cover wall; the inclined top cover wall and the top cover vertical walls are both fixedly connected to the base, and the two ends of the inclined top cover wall are respectively arranged corresponding to the first SSG water collecting tank and the second SSG water collecting tank.

[0013] Preferably, a guide groove is provided at the bottom of the vertical wall of the top cover, and both ends of the guide groove are respectively connected to the first SSG water collecting groove and the second SSG water collecting groove.

[0014] Preferably, the MD water collecting tank and the cold water tank are both annular tanks, the first SSG water collecting tank, the second SSG water collecting tank and the MD water collecting tank are all connected with a water outlet pipe, and the cold water tank is connected with a cold water tank inlet pipe.

[0015] Preferably, the metal plate is a copper plate.

[0016] The present invention discloses the following technical effects:

[0017] 1. Compared with traditional seawater desalination devices that use fossil energy, this device completely relies on solar energy, a clean energy source, to provide driving force for seawater desalination. In addition, solar interface evaporation technology has the advantages of high efficiency and fast response in the field of solar seawater desalination.

[0018] 2. Introduce membrane distillation technology based on solar interfacial evaporation, and rationally utilize the heat transferred to seawater by the photothermal membrane to further improve the desalination efficiency of the desalination device and increase fresh water production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] Figure 1 is a schematic diagram of the device of the present invention;

[0021] Figure 2 It is a schematic diagram of the base structure of the device of the present invention;

[0022] Figure 3 It is a schematic diagram of the overall structure of the device of the present invention;

[0023] Figure 4 It is a structural schematic diagram of the interface evaporation part of the present invention;

[0024] Among them, the first SSG water collecting trough outlet pipe-1; MD water collecting trough-7 outlet pipe-2; the first SSG water collecting trough-3; the cold water trough-4; the PTFE membrane-5; the seawater pool-6; the MD water collecting trough-7; the second SSG water collecting trough-8; the cold water trough inlet pipe-9; the second SSG water collecting trough outlet pipe-10; the top cover vertical wall-11; the guide trough-12; the photothermal film-13; the metal plate-14; the top cover inclined wall-15; the fiber paper-16; the insulation board-17; the metal straight rib-18. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] The present invention provides a desalination device combining waste heat utilization of seawater with interface evaporation, comprising a base and a transparent top cover arranged on the base, wherein a solar interface evaporation (SSG) system and a membrane distillation (MD) system are arranged on the base, and the solar interface evaporation system and the membrane distillation system are both located in the transparent top cover;

[0028] The solar interface evaporation system includes a seawater pool 6 opened in the middle of the base and a first SSG water collecting tank 3 and a second SSG water collecting tank 8 opened at both ends of the base. The seawater pool 6 is used to hold seawater, and an interface evaporation part is arranged in the seawater pool 6; the membrane distillation system includes an MD water collecting tank 7 and a cold water tank 4 opened on the base, and the MD water collecting tank 7 is arranged between the seawater pool 6 and the cold water tank 4. A through hole is opened on the pool wall between the seawater pool 6 and the MD water collecting tank 7, and a PTFE membrane 5 is fixedly installed in the through hole. The PTFE membrane 5 is a hydrophobic membrane. Seawater cannot pass through the PTFE membrane 5, but steam can pass through the PTFE membrane 5.

[0029] Furthermore, the interface evaporation part includes a metal plate 14 fixed to the top of the seawater pool 6, the metal plate 14 is a copper plate, the top of the seawater pool 6 is closed by the metal plate 14, a mold hole is opened on the metal plate 14, a photothermal film 13 is fixedly installed in the mold hole, the photothermal film 13 is prepared by applying a graphene oxide solution on dust-free paper and then vacuum drying, and the photothermal film 13 has high light absorption rate and good hydrophilicity; one end of a fiber paper 16 is fixedly connected to the bottom of the metal plate 14, and the other end of the fiber paper 16 extends into the seawater in the seawater pool 6, and the fiber paper 16 is in contact with and connected to the bottom of the photothermal film 13. The fiber paper 16 pumps seawater to the bottom of the photothermal film 13 through capillary action and wets the entire photothermal film 13. The seawater pumped up by the fiber paper 16 will flow through the metal plate 14 when it flows to the bottom of the photothermal film 13. The metal plate 14 can preheat the seawater on the fiber paper 16, thereby reducing the evaporation time of the photothermal film 13. The bottom of the metal plate 14 is circumferentially fixed with metal straight ribs 18, preferably copper straight ribs. The metal plate 14 can absorb sunlight and convert it into heat. The heat can be transferred to the seawater pool 6 through the metal straight ribs 18 connected to the metal plate 14 to heat the seawater, thereby providing a thermal energy driving force for the membrane distillation system. The fiber paper 16 is located in the cavity formed by the metal straight ribs 18. In order to reduce the heat conduction loss of the photothermal film 13 to the seawater and maximize the efficiency of interface evaporation, an insulation board 17 is fixed to the bottom of the metal plate 14. The insulation board 17 is a polystyrene foam board. The insulation board 17 is located in the cavity formed by the metal straight ribs 18. The fiber paper 16 is located between the insulation board 17 and the photothermal film 13. The fiber paper 16 is laid on the insulation board 17. The insulation board 17 is used to reduce the heat conduction loss of the photothermal film 13 to the seawater, thereby maximizing the efficiency of interface evaporation.

[0030] Furthermore, in order to enhance the light absorption efficiency, the top of the metal plate 14 is coated with black paint.

[0031] Furthermore, the transparent top cover is an inverted V-shaped structure, and the transparent top cover includes a top cover inclined wall 15 and two top cover vertical walls 11. The top cover inclined wall 15 is an inverted V-shaped structure, and the two top cover vertical walls 11 are respectively fixed on both sides of the top cover inclined wall 15; the top cover inclined wall 15 and the top cover vertical walls 11 are both fixedly connected to the base, and the two ends of the top cover inclined wall 15 are respectively arranged corresponding to the first SSG water collecting tank 3 and the second SSG water collecting tank 8; a guide groove 12 is arranged at the bottom of the top cover vertical wall 11, and the guide groove 12 is an inverted V-shaped structure, and the two ends of the guide groove 12 are respectively connected to the first SSG water collecting tank 3 and the second SSG water collecting tank 8. The steam generated by the photothermal film 13 condenses on the transparent top cover. Part of it forms condensed water on the inclined wall 15 of the top cover and flows into the first SSG water collecting tank 3 and the second SSG water collecting tank 8. The other part forms condensed water on the vertical wall 11 of the top cover and flows into the guide groove 12, and then flows into the first SSG water collecting tank 3 and the second SSG water collecting tank 8.

[0032] Furthermore, in order to facilitate the discharge of desalinated water and the provision of cooling water to the cold water tank 4, the MD water collecting tank 7 and the cold water tank 4 are both annular tanks, and the first SSG water collecting tank 3, the second SSG water collecting tank 8 and the MD water collecting tank 7 are all connected with an outlet pipe, and the cold water tank 4 is connected with a cold water tank inlet pipe 9.

[0033] The present invention provides a desalination device combining seawater waste heat utilization with interface evaporation. The fiber paper 16 pumps seawater to the bottom of the photothermal film 13 through capillary action. The seawater moistens the entire photothermal film 13. The photothermal film 13 converts the absorbed sunlight into heat and localizes it on the film surface. Only the water in the film layer of the photothermal film 13 is heated to evaporate it, thereby improving the evaporation efficiency of the water in the film layer of the photothermal film 13. Moreover, the fiber paper 16 can compensate for the seawater required for the evaporation of the photothermal film 13, ensuring that the photothermal film 13 can evaporate stably. The steam escaping from the surface of the photothermal film 13 condenses on the transparent top cover, and the condensed water flows downstream into the first SSG water collecting tank 3 and the second SSG water collecting tank 8, flows out from the first SSG water collecting tank outlet pipe 1 and the second SSG water collecting tank outlet pipe 10, and is collected. In addition, four through holes are opened on the side walls around the seawater pool 6, so that the PTFE membrane 5 can be fixed in the through holes, the MD water collecting tank 7 and the seawater pool 6 are separated by the hydrophobic PTFE membrane 5, and cold water is contained in the cold water tank 4, so that a temperature difference is formed on both sides of the PTFE membrane 5. Under the vapor pressure difference caused by the temperature difference on both sides of the PTFE membrane 5, the seawater in the seawater pool 6 evaporates, and a large amount of water vapor enters the MD water collecting tank 7 through the micropores of the PTFE membrane 5. The top of the MD water collecting tank 7 is sealed to prevent the steam from the seawater side through the PTFE membrane 5 from escaping from the top of the MD water collecting tank 7. In the MD water collecting tank 7, the water vapor encounters the cold wall of the cold water tank 4 and condenses into condensed water, and flows out from the outlet pipe 2 of the MD water collecting tank 7 and is collected.

[0034] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0035] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A desalination device combining seawater waste heat utilization with interface evaporation, characterized in that: It comprises a base and a transparent top cover arranged on the base, wherein a solar interface evaporation system and a membrane distillation system are arranged on the base, and the solar interface evaporation system and the membrane distillation system are both located in the transparent top cover; The solar interface evaporation system comprises a seawater pool (6) disposed in the middle of the base, and a first SSG water collecting tank (3) and a second SSG water collecting tank (8) disposed at two ends of the base, wherein an interface evaporation section is disposed in the seawater pool (6); the membrane distillation system comprises an MD water collecting tank (7) and a cold water tank (4) disposed on the base, wherein the MD water collecting tank (7) is disposed between the seawater pool (6) and the cold water tank (4), and a through hole is disposed on the pool wall between the seawater pool (6) and the MD water collecting tank (7), wherein a PTFE membrane (5) is fixedly installed in the through hole; The interface evaporation portion comprises a metal plate (14) fixed to the top of the seawater pool (6), the metal plate (14) being provided with a mold hole, and a photothermal film (13) being fixedly installed in the mold hole; one end of a fiber paper (16) is fixedly connected to the bottom of the metal plate (14), the other end of the fiber paper (16) extending into the seawater pool (6), and the fiber paper (16) is in contact and connection with the bottom of the photothermal film (13); The transparent top cover is an inverted V-shaped structure, comprising a top cover inclined wall (15) and two top cover vertical walls (11); the top cover inclined wall (15) is an inverted V-shaped structure, and the two top cover vertical walls (11) are respectively fixed on both sides of the top cover inclined wall (15); the top cover inclined wall (15) and the top cover vertical walls (11) are both fixedly connected to the base, and the two ends of the top cover inclined wall (15) are respectively arranged corresponding to the first SSG water collecting tank (3) and the second SSG water collecting tank (8).

2. The desalination device combining seawater waste heat utilization and interface evaporation according to claim 1 is characterized in that: A metal straight rib (18) is fixedly connected to the bottom of the metal plate (14) in a circumferential direction, and the fiber paper (16) is located in a cavity formed by the metal straight rib (18).

3. The desalination device combining seawater waste heat utilization and interface evaporation according to claim 2 is characterized in that: A heat insulation board (17) is arranged at the bottom of the metal plate (14), and the heat insulation board (17) is located in the cavity formed by the metal straight ribs (18); the fiber paper (16) is laid on the heat insulation board (17), and the fiber paper (16) is located between the heat insulation board (17) and the photothermal film (13).

4. The desalination device combining seawater waste heat utilization and interface evaporation according to claim 3 is characterized in that: The heat insulation board (17) is a polystyrene foam board.

5. The desalination device combining seawater waste heat utilization and interface evaporation according to claim 1 is characterized in that: The top end of the metal plate (14) is coated with black paint.

6. The desalination device combining seawater waste heat utilization and interface evaporation according to claim 1 is characterized in that: A guide groove (12) is provided at the bottom of the vertical wall (11) of the top cover, and two ends of the guide groove (12) are respectively connected to the first SSG water collecting groove (3) and the second SSG water collecting groove (8).

7. The desalination device combining seawater waste heat utilization and interface evaporation according to claim 1 is characterized in that: The MD water collecting trough (7) and the cold water trough (4) are both annular troughs; the first SSG water collecting trough (3), the second SSG water collecting trough (8) and the MD water collecting trough (7) are all connected to a water outlet pipe; and the cold water trough (4) is connected to a cold water trough water inlet pipe (9).

8. The desalination device combining seawater waste heat utilization and interface evaporation according to any one of claims 1 to 7, characterized in that: The metal plate (14) is a copper plate.

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