Solar interface evaporation seawater desalination device and seawater desalination method

Abstract

The invention belongs to the technical field of seawater desalination, and particularly relates to a solar interface seawater desalination device and a seawater desalination method. A solar interface evaporation seawater desalination device comprises a water source module and further comprises a water desalination module, the water desalination module comprises an evaporation unit, a gas guide pipe and a condensation unit, the condensation unit is arranged on the lower bottom face of the evaporation unit in an attached mode, and the evaporation unit is communicated with the condensation unit through the gas guide pipe; seawater in the water source module flows out and flows into the evaporation unit to be evaporated into water vapor, the water vapor enters the condensation unit to be condensed into condensed water, and the condensed water is collected to obtain fresh water. The seawater desalination device can desalinate seawater in a clean, environment-friendly and efficient manner with low energy consumption.

Description

Technical Field

[0001] The invention belongs to the technical field of seawater desalination, and in particular relates to a solar interface seawater desalination device and a seawater desalination method. Background Art

[0002] Water resources have an important impact on the sustainable development of human society. Although 71% of the earth's surface is covered by water, the freshwater resources that humans can directly use only account for 0.3% of the total water. And due to population growth, climate change and water pollution, many regions are facing water shortages and water quality decline, which seriously threatens safe drinking water and environmental health.

[0003] Desalinating seawater using multi-stage distillation is an effective way to obtain fresh water.

[0004] However, each stage in multi-stage distillation needs to provide heat energy to realize steam and condensation, which consumes a lot of energy. In addition, multi-stage distillation requires stable heat supply, otherwise the temperature difference between steam and condensation cannot be guaranteed, and the distillation efficiency will be greatly reduced. The instability and periodicity of clean energy such as solar energy determine that clean energy cannot provide stable heat for the multi-stage distillation process. Therefore, a large amount of electricity is required for stable heat supply in multi-stage distillation, and clean energy can only be used as auxiliary power supply, which is very environmentally unfriendly. Therefore, there is an urgent need for a seawater desalination device with low energy consumption, clean and environmental protection, and high desalination efficiency. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art and provide a solar interface evaporation seawater desalination device that can desalinate seawater with low energy consumption, cleanness, environmental protection and high efficiency.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A solar interface seawater desalination device comprises a water source module and a desalinated water module. The desalinated water module comprises an evaporation unit, an air guide pipe and a condensation unit. The condensation unit is arranged on the lower bottom surface of the evaporation unit. The evaporation unit is connected with the condensation unit through the air guide pipe. Seawater in the water source module flows out and flows into the evaporation unit to be evaporated into water vapor. The water vapor enters the condensation unit and condenses into condensed water when it is cold. The condensed water is collected to obtain fresh water.

[0008] Preferably, the evaporation unit includes a double-layer ETFE membrane, an inclined box, a seawater layer and an evaporation space, the box consists of a bottom and side walls, the double-layer ETFE membrane is fixedly arranged on the top of the box, the seawater layer is located at the bottom of the box, and the evaporation space is the space in the box between the seawater layer and the double-layer ETFE membrane; the outside of the side wall of the box is coated with insulation material; the water source module is connected to the seawater layer, and the seawater flows from the water source module into the seawater layer; the lower surface of the seawater layer is the lower surface of the bottom of the box, the upper surface of the condensation unit is fixedly attached to the lower surface of the seawater layer, the air guide pipe connects the evaporation space and the condensation unit, and the outside of the bottom and side walls of the condensation unit is the external environment.

[0009] Preferably, the evaporation unit also includes a capillary layer and a photothermal layer arranged in the box, the lower surface of the capillary layer is immersed in seawater in the seawater layer, the photothermal layer is fixedly arranged on the upper surface of the capillary layer, and the evaporation space is located between the photothermal layer and the double-layer ETFE film.

[0010] Preferably, a seawater inlet and a seawater outlet are respectively provided on two opposite sides of the seawater layer; the water source module includes a water tank, a float valve and a water pipe, the water tank is filled with seawater, the float valve is arranged in the water tank, and is used to control the amount of seawater in the water tank, one end of the water pipe is connected to the bottom of the water tank, and the other end of the water pipe is connected to the seawater inlet, and the heights in the vertical direction are arranged in descending order as follows: the bottom of the water tank, the seawater inlet, and the seawater outlet.

[0011] Preferably, a fan is provided in the air guide duct, an air inlet side of the fan faces the evaporation space, and an air outlet side of the fan faces the condensation unit.

[0012] Preferably, a water vapor outlet and a first fresh water drain outlet are respectively provided on two opposite sides of the evaporation space, a second fresh water drain outlet and a water vapor inlet are respectively provided on two opposite sides of the condensing unit, both ends of the air duct are respectively connected to the water vapor outlet and the water vapor inlet, a fan is arranged close to the water vapor outlet, and the heights in the vertical direction are arranged in descending order as follows: the water vapor outlet, the first fresh water drain outlet, the water vapor inlet, and the second fresh water drain outlet.

[0013] Preferably, it also includes an adjusting module, which is arranged at the bottom of the desalinated water module and is used to adjust the inclination angle and height of the desalinated water module.

[0014] Preferably, one end of the double-layer ETFE membrane is an inflation port, and the other end is an air outlet. The inflation pump is arranged in the inflation port, and a solar radiation sensor is arranged in the double-layer ETFE membrane; a salinity sensor is arranged in the seawater layer near the seawater outlet; and an air pressure sensor is also arranged in the evaporation space.

[0015] The present invention also provides a seawater desalination method, which is applied to the above-mentioned solar interface evaporation seawater desalination device, and comprises the following contents:

[0016] During the day:

[0017] S1, move the solar interface evaporation desalination device to a site with sufficient sunlight, and adjust the tilt angle θ of the desalination device according to the geographical location;

[0018] S2, regularly adjusting the inflation volume in the double-layer ETFE membrane, and adjusting the valve openings of the seawater inlet and the seawater outlet at the same time, to ensure that the salinity measured by the salinity sensor is lower than the first salinity threshold; and adjusting the wind speed of the fan at the same time, to ensure that the air pressure measured by the air pressure sensor is lower than the first air pressure threshold; and collecting condensed water flowing out of the first fresh water outlet and the second fresh water outlet;

[0019] At night: fill the double-layer ETFE membrane with air, and adjust the valve opening of the seawater inlet and the seawater outlet at the same time to ensure that the salinity measured by the salinity sensor is lower than the first salinity threshold; at the same time, adjust the wind speed of the fan to ensure that the air pressure measured by the air pressure sensor is lower than the first air pressure threshold; collect condensed water flowing out of the first fresh water outlet and the second fresh water outlet.

[0020] Preferably, the method of timely adjusting the air volume in the double-layer ETFE film further includes sub-steps S21 to S24:

[0021] S21, the current cycle starts, the air outlet is opened, the double-layer ETFE membrane is deflated until the pressure P inside the membrane reaches the first vertical height pressure P1, and the air outlet is closed;

[0022] S22, the air pump is started, and the double-layer ETFE membrane is inflated until the pressure P inside the membrane is the second sagittal pressure P2, and then the air pump is turned off, and the solar radiation sensor records the solar radiation value variation range R corresponding to the pressure P inside the membrane increasing from the first sagittal pressure P1 to the second sagittal pressure P2, and the pressure inside the membrane corresponding to the maximum solar radiation value in the solar radiation value variation range R is recorded as the third sagittal pressure P3, where P1≤P3<1.05P3≤P2;

[0023] S23, in the current cycle, if the pressure inside the membrane P>1.05P3, the air outlet is opened until the pressure inside the membrane P3≤P≤1.05P3, and the air outlet is closed; if the pressure inside the membrane P3≤P≤1.05P3, the air outlet and the air pump are not operated; if the pressure inside the membrane P<P3, the air pump is started until the pressure inside the membrane P3≤P≤1.05P3, and the air pump is closed. The duration of each cycle is t;

[0024] S24, when the current cycle ends, returns to S21 and starts the next cycle to adjust the inflation amount in the double-layer ETFE film.

[0025] The beneficial effects of the present invention are:

[0026] (1) In the process of desalinating seawater, the seawater desalination device of the present invention mainly performs solar interfacial evaporation in the evaporation unit during the day when there is sunlight, and condensed water is obtained in the condensation unit; at night when there is no sunlight, evaporation can still be performed in the evaporation unit, and condensed water is obtained in the condensation unit. Therefore, the seawater desalination device of the present invention can desalinate seawater around the clock.

[0027] (2) In the process of desalinating seawater, if all power-consuming components such as fans, air pumps and sensors are turned off, the seawater can still be desalinated without consuming any electricity. If all power-consuming components such as fans, air pumps and sensors are turned on, only a small amount of electricity is consumed, which can greatly improve the desalination efficiency. Compared with multi-stage distillation for desalination of seawater, the present invention has low energy consumption and is very energy-saving and environmentally friendly.

[0028] (3) In the seawater desalination device of the present invention, the upper surface of the condensation unit is arranged in close contact with the lower surface of the seawater layer, and the lower surface and the outside of the side wall of the condensation unit are the external environment. By utilizing the huge difference in specific heat capacity between air and seawater, no matter under what circumstances, a place with a low temperature relative to water vapor can be created in the condensation unit, so that water vapor can be smoothly condensed into condensed water as soon as it enters the condensation unit.

[0029] (4) The top of the evaporation unit in the seawater desalination device of the present invention adopts a double-layer ETFE film with good thermal insulation performance and flexibly adjustable light transmittance. When there is sunlight during the day, the inflation volume of the double-layer ETFE film is adjusted to ensure that the double-layer ETFE film maintains a high light transmittance under the current lighting conditions. In this way, the seawater desalination device of the present invention can desalinate seawater efficiently for a long time during the day.

[0030] (5) Compared with large-scale multi-stage distillation equipment, the seawater desalination device of the present invention can be flexibly moved, occupies a small area, and has a high site utilization rate. Not only can the amount of fresh water obtained be increased by increasing the number of seawater desalination devices of the present invention; but also as many seawater desalination devices as possible can be set according to the use area of ​​the site to obtain as much fresh water as possible.

[0031] (6) In the seawater desalination method of the present invention, by regularly adjusting the amount of air in the double-layer ETFE film, the average light transmittance of the double-layer ETFE film can be maintained at a relatively high value in each cycle, thereby greatly improving the seawater desalination efficiency in each cycle. In addition, the seawater desalination method of the present invention can desalinate seawater with low energy consumption, cleanness, environmental protection and high efficiency, and has high flexibility in the seawater desalination process.

[0032] (7) The seawater desalination method of the present invention can further increase the rate at which the seawater desalination device of the present invention produces fresh water, thereby increasing the desalination efficiency of the seawater desalination device. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic structural diagram of a solar interface evaporation seawater desalination device of the present invention;

[0034] Figure 2 for Figure 1 A is an enlarged schematic diagram;

[0035] Figure 3 for Figure 1 The enlarged schematic diagram of point B in FIG.

[0036] The actual correspondence between the reference numerals and component names of the present invention is as follows:

[0037] 1. Water source module; 11. Water tank; 12. Float valve; 13. Water pipe;

[0038] 2. Desalination water module;

[0039] 21. Evaporation unit; 211. Double-layer ETFE film; 211a. Air filling port; 211b. Air pump; 211c. Air outlet; 211d. Solar radiation sensor; 212. Box; 213. Seawater layer; 213a. Seawater inlet; 213b. Seawater outlet; 213c. Salinity sensor; 214. Capillary layer; 215. Photothermal layer; 216. Evaporation space; 216a. First freshwater drainage port; 216b. Water vapor outlet; 216c. Air pressure sensor;

[0040] 22. air duct; 22a. fan;

[0041] 23. Condensation unit; 23a. Second fresh water outlet; 23b. Water vapor inlet;

[0042] 3. Adjustment module; 31. Telescopic bracket; 32. Universal wheel. DETAILED DESCRIPTION

[0043] In order to make the technical solution of the present invention clearer and more specific, the present invention is clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. The solutions derived from equivalent replacements of the technical features of the technical solution of the present invention and conventional reasoning by ordinary technicians in this field without making any creative work all fall within the protection scope of the present invention.

[0044] Example 1

[0045] like Figure 1 to Figure 3As shown, a solar interface evaporation seawater desalination device of the present invention comprises a water source module 1, a desalinated water module 2 and a regulating module 3. The regulating module 3 is arranged at the bottom of the desalinated water module 2, and is used to move the desalinated water module 2 or adjust the inclination angle and height of the desalinated water module 2; the desalinated water module 2 comprises an evaporation unit 21 and a condensation unit 23, and the evaporation unit 21 and the condensation unit 23 are connected. Seawater flows out of the water source module 1 and flows into the evaporation unit 21 to be evaporated into water vapor. The water vapor enters the condensation unit 23 and condenses into condensed water when it is cold. The condensed water is collected to obtain fresh water.

[0046] The water source module 2 includes a water tank 11, a float valve 12 and a water pipe 13. The float valve 12 is arranged in the water tank 11. The water tank 11 contains seawater. One end of the water pipe 13 is connected to the bottom of the water tank 11, and the other end of the water pipe 13 is connected to the evaporation unit 21. The float valve 12 is used to control the amount of seawater contained in the water tank 11. When the water tank 11 contains too little seawater, the ball of the float valve 12 sinks to increase the opening of the water inlet valve of the water tank 11, and the amount of water entering the water tank 11 increases; when the water tank 11 contains more seawater, the ball of the float valve 12 rises to reduce or close the opening of the water inlet valve of the water tank 11, and the amount of water entering the water tank 11 decreases or stops. The water inlet valve of the water tank 11 is not drawn in the figure.

[0047] The evaporation unit 21 includes a double-layer ETFE film 211, a box 212, a seawater layer 213, a capillary layer 214, a photothermal layer 215, and an evaporation space 216. The double-layer ETFE film 211 is fixedly arranged on the top of the box 212, and the inside of the box 212 is the evaporation space 216, the photothermal layer 215, the capillary layer 214, and the seawater layer 213 from top to bottom.

[0048] The box body 212 has only a bottom and side walls, but no top, and the double-layer ETFE film 211 is fixedly arranged on the top of the box body 212. The side walls of the box body 212 are made of heat-insulating material, or the side walls of the box body 212 are coated with heat-insulating material.

[0049] The double-layer ETFE film 211 is a double-layer air pillow structure, with air, nitrogen or inert gas filled in the middle. One end of the double-layer ETFE film 211 is an air filling port 211a, and the other end is an air outlet 211c, and an air pump 211b is arranged in the air filling port 211a. Compared with the unadjustable light transmittance and heat preservation effect of glass, the light transmittance of the double-layer ETFE film 211 can be adjusted by changing the air filling amount in the double-layer ETFE film 211, and the maximum light transmittance of the double-layer ETFE film 211 is also greater than the light transmittance of glass, and as long as the double-layer ETFE film 211 has a certain amount of air filling, its heat preservation effect is far greater than that of glass. Generally, there will be a certain amount of air filling in the double-layer ETFE film 211, and it will not be completely airless.

[0050] Optionally, the solar radiation sensor 211d is arranged on the side of the double-layer ETFE film 211, so that not only the solar radiation value passing through the double-layer ETFE film 211 can be measured, but also the double-layer ETFE film 211 and the top of the box body 212 will not be blocked.

[0051] Inside the box 212, the evaporation space 216 refers to the internal space of the box 212 between the double-layer ETFE film 211 and the photothermal layer 215. The upper surface of the evaporation space 216 is the lower surface of the double-layer ETFE film 211, the lower surface of the evaporation space 216 is the upper surface of the photothermal layer 215, and the side of the evaporation space 216 is the inner side wall of the box 212. The two opposite sides of the evaporation space 216 are respectively recorded as the first side and the second side. The first side of the evaporation space 216 is provided with a water vapor outlet 216b.

[0052] Optionally, a first fresh water drain port 216a is provided on the second side surface of the evaporation space 216, and the first side surface is higher in the vertical direction than the second side surface.

[0053] Optionally, an air pressure sensor 216c is further provided in the evaporation space 216. In this embodiment, the air pressure sensor 216c is provided below the water vapor outlet 216b on the first side.

[0054] The photothermal layer 215 is fixedly disposed on the upper surface of the capillary layer 214, the side wall of the capillary layer 214 is fixedly disposed on the inner side wall of the box body 212, and the capillary layer 214 covers the upper surface of the seawater layer 213. Part or all of the capillary layer 214 is immersed in seawater.

[0055] The seawater layer 213 contains flowing seawater, and the upper surface of the seawater layer 213 is the lower surface of the capillary layer 214, so the seawater in the capillary layer 214 does not belong to the seawater layer 213, that is, the seawater layer 213 cannot directly contact the photothermal layer 215. The lower surface of the seawater layer 213 is the bottom of the box 212. The side of the seawater layer 213 is also the inner side wall of the box 212. The two opposite sides of the seawater layer 213 are respectively recorded as the third side and the fourth side. The third side of the seawater layer 213 is provided with a seawater inlet 213a, and the fourth side of the seawater layer 213 is provided with a seawater outlet 213b. The height of the seawater inlet 213a in the vertical direction is always higher than the seawater outlet 213b. Valves for controlling the size of the water flow are provided in the seawater inlet 213a and the seawater outlet 213b.

[0056] One end of the water pipe 13 is connected to the bottom of the water tank 11 , and the other end of the water pipe 13 is connected to the seawater inlet 213 a . The height of the seawater inlet 213 a in the vertical direction is lower than the bottom of the water tank 11 .

[0057] Optionally, the seawater layer 213 further includes a salinity sensor 213c disposed near the seawater outlet 213b.

[0058] The photothermal layer 215 is one of metal nanomaterials, semiconductor-based materials or carbon-based materials, and its function is to convert the light energy of sunlight into heat energy.

[0059] The capillary layer 214 is one of a water-absorbing sponge, carbonized wood or carbonized natural biological material. Its function is to absorb the seawater in the seawater layer 213 into the photothermal layer 215 for evaporation. The photothermal layer 215 uses thermal energy to accelerate the evaporation of the seawater in the photothermal layer 215 to obtain water vapor. The water vapor enters the evaporation space 216, and the water vapor is gaseous fresh water.

[0060] The upper surface of the condensing unit 23 is arranged close to the lower surface of the seawater layer 213, and the outside of the bottom and side walls of the condensing unit 23 is the external environment, that is, the outside of the bottom and side walls of the condensing unit 23 is directly in contact with the external air. The two opposite side surfaces of the condensing unit 23 are respectively recorded as the fifth side surface and the sixth side surface, and the second fresh water drain port 23a is arranged on the sixth side surface of the condensing unit 23, and the water vapor inlet 23b is arranged on the fifth side surface of the condensing unit 23, and the height of the water vapor inlet 23b in the vertical direction is higher than the second fresh water drain port 23a.

[0061] Both ends of the air guide pipe 22 are connected to the water vapor inlet 23b and the water vapor outlet 216b respectively.

[0062] Optionally, a fan 22a is provided in the air guide duct 22, the air inlet side of the fan 22a faces the water vapor outlet 216b, and the air outlet side of the fan 22a faces the water vapor inlet 23b.

[0063] Optionally, the fan 22a is close to the water vapor outlet 216b.

[0064] The adjustment module 3 includes a telescopic bracket 31 disposed on the lower surface of the condensing unit 23, and the telescopic bracket 31 includes two adjustment rods, one adjustment rod is close to the fifth side surface of the condensing unit 23, and the other adjustment rod is close to the sixth side surface of the condensing unit 23. The two adjustment rods can be adjusted to different heights respectively to tilt the condensing unit 23 relative to the horizontal plane.

[0065] Optionally, the first side of the evaporation space 216 and the third side of the seawater layer 213 are located above the fifth side of the condensation unit 23, and the second side of the evaporation space 216 and the fourth side of the seawater layer 213 are located above the sixth side of the condensation unit 23. At this time, the height of the top of the adjustment rod close to the fifth side of the condensation unit 23 is higher than the height of the top of the adjustment rod close to the sixth side of the condensation unit 23, so that the fifth side of the condensation unit 23 is naturally higher in the vertical direction than the sixth side of the condensation unit 23, and the first side of the evaporation space 216 is higher in the vertical direction than the second side of the evaporation space 216, and the third side of the seawater layer 213 is higher in the vertical direction than the fourth side of the seawater layer 213.

[0066] For the convenience of description, the height of the fifth side of the condensation unit 23 in the vertical direction is higher than the sixth side of the condensation unit 23, which is recorded as the inclination of the condensation unit 23; the height of the first side of the evaporation space 216 in the vertical direction is higher than the second side of the evaporation space 216, which is recorded as the inclination of the evaporation space 216; the height of the third side of the seawater layer 213 in the vertical direction is higher than the fourth side of the seawater layer 213, which is recorded as the inclination of the seawater layer 213.

[0067] Optionally, the regulating module 3 further includes a universal wheel 32 disposed under the telescopic bracket 31 to facilitate movement of the seawater desalination device of the present invention.

[0068] The principle of the seawater desalination device of the present invention is described below:

[0069] The float valve 12 can ensure that there is always seawater in the water source module 2, and the existence of the float valve 12 can automatically adjust the water intake of the water source module 2 according to the real-time water level of the seawater in the water source module 2, so the water level of the seawater contained in the water source module 2 will not be too low. The technician does not need to monitor whether there is seawater in the water source module 2.

[0070] The valves of the seawater inlet 213a and the seawater outlet 213b are both open. Because the height of the seawater inlet 213a in the vertical direction is lower than the bottom of the water tank 11, under the action of gravity, the seawater in the water source module 2 continuously enters the seawater layer 213 from the seawater inlet 213a. And because the height of the seawater inlet 213a in the vertical direction is always higher than the seawater outlet 213b, whether the seawater layer 213 is horizontal or inclined, the seawater will automatically flow out from the seawater outlet 213b, ensuring that the seawater in the seawater layer 213 is always flowing; the process of seawater flowing through the seawater layer 213 makes the capillary layer 214 always soaked with seawater. The capillary layer 214 absorbs seawater from the seawater layer 214 into the photothermal layer 215.

[0071] Regardless of whether the seawater layer 213 is horizontal or inclined, the technicians can adjust the valve openings of the seawater inlet 213a and the seawater outlet 213b to ensure that the seawater flowing in the seawater layer 213 only wets the lower surface of the capillary layer 214 instead of accumulating too much inside the box 212, so that a seawater horizontal surface formed by seawater accumulation will not be formed in the evaporation space 216.

[0072] Solar radiation penetrates the double-layer ETFE film 211 to reach the photothermal layer 215 and is converted into thermal energy by the photothermal layer 215, so the temperature of the photothermal layer 215 is relatively high; at the same time, because the double-layer ETFE film 211 has a good thermal insulation effect, the temperature in the entire evaporation space 216 is also relatively high, which will accelerate the evaporation of seawater in the photothermal layer 215. After the seawater in the photothermal layer 215 evaporates, it becomes water vapor in the evaporation space 216, and the water vapor is gaseous fresh water.

[0073] The solar radiation sensor 211 d collects the solar radiation value to adjust the light transmittance of the double-layer ETFE film 211 , that is, to adjust the inflation volume of the double-layer ETFE film 211 .

[0074] The fan 22a is turned on to accelerate the discharge of water vapor from the evaporation space 216 and enter the condensation unit 23. At the same time, the turning on of the fan 22a will reduce the air pressure and water vapor content in the evaporation space 216, further promoting the evaporation of seawater in the photothermal layer 215; on the other hand, reducing the water vapor content can also reduce the loss of light reflection and light scattering caused by the presence of water vapor in the evaporation space 216, further maintaining the high evaporation rate of seawater in the photothermal layer 215.

[0075] As seawater evaporates, the salinity of the seawater in the seawater layer 213 will increase, which is not conducive to the evaporation of seawater. Therefore, the seawater desalination device of the present invention is provided with a salinity sensor 213c in the seawater layer 213. When the seawater in the seawater layer 213 is too high, the salinity sensor 213c will sound an alarm to notify the technicians to increase the valve opening of the seawater outlet 213b and the seawater inlet 213a to speed up the flow rate of seawater in the seawater layer 213, so as to reduce the salinity of the seawater flowing in the seawater layer 213 to a suitable concentration range, so as not to slow down the evaporation rate of seawater; at the same time, it also avoids the precipitation of crystallized salt in the seawater layer 213.

[0076] When the seawater layer 213 is inclined, the salt concentration at a relatively low point in the vertical direction is the highest, and the position where the salinity sensor 213c of the present invention is set, that is, the seawater layer 213 close to the seawater outlet 213b, is the relatively low point of the seawater layer 213 in the vertical direction. It is very scientific to use the highest salt concentration in the seawater layer 213 as the basis for adjusting the seawater flow rate in the seawater layer 213.

[0077] The seawater discharged from the seawater outlet 213b is directly discharged into the ocean.

[0078] Water vapor enters the condensation unit 23 from the water vapor inlet 23b through the air guide 22, and condenses into condensed water when it encounters cold in the condensation unit. Because the water vapor inlet 23b is higher in the vertical direction than the second fresh water drain 23a, the condensed water will gather at the second fresh water drain 23a and be discharged from the second fresh water drain 23a. The condensed water discharged from the second fresh water drain 23a can be collected to obtain fresh water. The opening of the fan 22a increases the air pressure in the condensation unit 23, and the water vapor is more likely to condense into condensed water when it encounters cold in the condensation unit 23.

[0079] The air pressure sensor 216c is used to detect the water vapor content in the evaporation space 216 in real time. The technician adjusts the speed of the fan 22a according to the water vapor content in the evaporation space 216 to keep the water vapor content in the evaporation space 216 at a lower value.

[0080] When the outside environment temperature is low at night, the good heat preservation performance of the double-layer ETFE film 211 and the side wall of the box 212 makes the temperature in the evaporation space 216 higher than the outside environment. The upper surface of the condensation unit 23 is arranged close to the lower surface of the seawater layer 213. Because the specific heat capacity of seawater is much greater than that of air, the temperature of the seawater layer 213 is also high. However, the outside of the bottom and side wall of the condensation unit 23 is the outside environment with a lower temperature. Therefore, in this case, the water vapor in the condensation unit 23 is mainly condensed into condensed water when it encounters cold on the bottom and side wall of the condensation unit 23.

[0081] When the external environment temperature is low during the day, the double-layer ETFE film 211 and the side wall of the box 212 have good thermal insulation performance, and because the photothermal layer 215 converts sunlight into heat energy, further increasing the temperature in the evaporation space 216, the temperature in the evaporation space 216 is much higher than the external environment. The upper surface of the condensation unit 23 is arranged close to the lower surface of the seawater layer 213. Because the specific heat capacity of seawater is much greater than that of air, the temperature of the seawater layer 213 is also high. However, the outside of the bottom and side walls of the condensation unit 23 is the external environment with a lower temperature. Therefore, in this case, the water vapor in the condensation unit 23 is mainly condensed into condensed water when it encounters cold on the bottom and side walls of the condensation unit 23.

[0082] When the external environment temperature is high during the day, the double-layer ETFE film 211 and the side wall of the box 212 have good thermal insulation performance, and because the photothermal layer 215 converts sunlight into heat energy, further increasing the temperature in the evaporation space 216, the temperature in the evaporation space 216 is still much higher than the external environment. At this time, although the temperature of the bottom and side wall of the condensation unit 23 is also high, it is relatively low compared to the evaporation space 216; at the same time, because the specific heat capacity of seawater is much greater than that of air, the temperature of the seawater layer 213 is lower than the temperature of the bottom and side wall of the condensation unit 23, so in this case, the water vapor in the condensation unit 23 will condense into condensed water when it encounters cold on the entire inner wall of the condensation unit 23.

[0083] Further, as long as the temperature in the evaporation space 216 is higher than the external environment, the inner surface temperature of the double-layer ETFE film 211 is higher than the outer surface temperature of the double-layer ETFE film 211, and the water vapor in the evaporation space 216 will condense into condensed water when it encounters cold on the inner surface of the double-layer ETFE film 211. The second side of the evaporation space 216 of the present invention is provided with a first fresh water drain port 216a, and the first side is higher in the vertical direction than the second side, so the condensed water will slide to the first fresh water drain port 216a under the action of gravity, and the condensed water discharged from the first fresh water drain port 216a can be collected to obtain fresh water. It is only during the day when the external environment temperature is high, under the diversion effect of the fan 22a, the water vapor in the evaporation space 216 will be quickly diverted to the condensation unit 23, so the condensed water at the first fresh water drain port 216a will be less.

[0084] According to the present invention, the seawater desalination device is located in a different location with different sunshine environments. The seawater desalination device is moved to a suitable location (e.g., an open beach without any obstructions) by adjusting the adjustment module 3, and the tilt angle θ of the seawater desalination device is adjusted by adjusting the adjustment module 3. The tilt angle θ is as follows: Figure 1 as shown in .

[0085] In this embodiment, the value range of the tilt angle θ is 0≤θ≤45°.

[0086] Fresh water can be obtained by discharging condensed water from the first fresh water outlet 216a and the second fresh water outlet 23a. According to the test by the technicians, the salt ion concentration in the condensed water discharged from the first fresh water outlet 216a and the second fresh water outlet 23a meets the WHO drinking water standard.

[0087] In the process of desalinating seawater, the seawater desalination device of the present invention mainly performs solar interface evaporation in the evaporation unit 21 during the day when there is sunlight, and condensed water is obtained in the condensation unit 23; at night when there is no sun, evaporation can still be performed in the evaporation unit 21, and condensed water is obtained in the condensation unit 23, so the seawater desalination device of the present invention can desalinate seawater around the clock.

[0088] In the process of desalinating seawater, if all power-consuming components such as the fan 22a, the air pump 211b and the sensor are stopped, the seawater can still be desalinated without consuming any electricity; if all power-consuming components such as the fan 22a, the air pump 211b and the sensor are started, only a small amount of electricity is consumed, and the seawater desalination efficiency can be greatly improved. Compared with multi-stage distillation for seawater desalination, the present invention has low energy consumption and is very energy-saving and environmentally friendly.

[0089] In the seawater desalination device of the present invention, the upper surface of the condensation unit 23 is arranged in close contact with the lower surface of the seawater layer 213, and the lower surface of the condensation unit 23 and the outside of the side wall are the external environment. By utilizing the huge difference in specific heat capacity between air and seawater, no matter under what circumstances, there can be a place in the condensation unit 23 that is low in temperature relative to water vapor, so that as long as the water vapor enters the condensation unit 23, it can be smoothly condensed into condensed water when it encounters cold.

[0090] When water vapor turns into condensed water on the upper surface of the condensation unit 23, the latent heat of the water vapor is transferred to the lower surface of the seawater layer 213 which is in close contact with the upper surface of the condensation unit 23, thereby increasing the temperature of the seawater layer 213 and further promoting the evaporation of seawater in the seawater layer 213 into the evaporation space 216, while also reducing energy loss.

[0091] The top of the evaporation unit 21 of the present invention adopts a double-layer ETFE film 211 with good thermal insulation performance and flexibly adjustable light transmittance. When there is sunlight during the day, the inflation volume of the double-layer ETFE film 211 is adjusted to ensure that the double-layer ETFE film 211 maintains a high light transmittance under the lighting conditions at that time. In this way, the seawater desalination device of the present invention can desalinate seawater efficiently for a long time during the day.

[0092] Compared with large-scale multi-stage distillation equipment, the seawater desalination device of the present invention can be flexibly moved, occupies a small area, and has a high site utilization rate. Not only can the amount of fresh water obtained be increased by increasing the number of seawater desalination devices of the present invention; but also as many seawater desalination devices as possible can be set according to the use area of ​​the site to obtain as much fresh water as possible.

[0093] Example 2

[0094] The present invention also provides a seawater desalination method, which is applied to a solar interface evaporation seawater desalination device as described in Example 1, and comprises the following contents:

[0095] daytime:

[0096] S1, move the solar interface evaporation desalination device to a site with sufficient sunlight, and adjust the tilt angle θ of the desalination device according to the geographical location;

[0097] S2, regularly adjust the inflation volume in the double-layer ETFE membrane 211, and at the same time adjust the valve openings of the seawater inlet 213a and the seawater outlet 213b to ensure that the salinity measured by the salinity sensor 213c is lower than the first salinity threshold; at the same time, adjust the wind speed of the fan 22a to ensure that the air pressure measured by the air pressure sensor 216c is lower than the first air pressure threshold; collect condensed water flowing out of the first fresh water drain 216a and the second fresh water drain 23a.

[0098] At night: fill the double-layer ETFE membrane 211 with air, and adjust the valve openings of the seawater inlet 213a and the seawater outlet 213b at the same time to ensure that the salinity measured by the salinity sensor 213c is lower than the first salinity threshold; at the same time, adjust the wind speed of the fan 22a to ensure that the air pressure measured by the air pressure sensor 216c is lower than the first air pressure threshold; collect condensed water flowing out of the first fresh water drain 216a and the second fresh water drain 23a.

[0099] The double-layer ETFE film 211 is filled with air at night, which is beneficial for keeping the evaporation space 216 warm.

[0100] In this embodiment, the first salinity threshold is 4%, and the first air pressure threshold is 1.01 atmospheres.

[0101] The air pump 211b includes an air pressure sensor.

[0102] In S2, the inflation amount in the double-layer ETFE film 211 is adjusted in a timely manner, and sub-steps S21 to S24 are also included:

[0103] S21, the current cycle starts, the air outlet 211c is opened, the double-layer ETFE film 211 is deflated until the pressure P inside the film reaches the first vertical height pressure P1, and the air outlet 211c is closed;

[0104] S22, the air pump 211b is started, and the double-layer ETFE film 211 is inflated until the pressure P inside the film is the second vector height pressure P2, and then the air pump 211b is turned off, and the solar radiation sensor 211d records the solar radiation value variation range R corresponding to the increase of the pressure P inside the film from the first vector height pressure P1 to the second vector height pressure P2, and the pressure inside the film corresponding to the maximum solar radiation value in the solar radiation value variation range R is recorded as the third vector height pressure P3, where P1≤P3<1.05P3≤P2;

[0105] S23, in the current cycle, if the pressure inside the membrane P>1.05P3, the air outlet 211c is opened until the pressure inside the membrane is P3≤P≤1.05P3, and the air outlet 211c is closed; if the pressure inside the membrane is P3≤P≤1.05P3, the air outlet 211c and the air pump 211b are inoperative; if the pressure inside the membrane is P3≤P≤1.05P3, the air pump 211b is started until the pressure inside the membrane is P3≤P≤1.05P3, and the air pump 211b is closed. The duration of each cycle is t.

[0106] S24, when the current cycle ends, return to S21 and start the next cycle to adjust the inflation amount in the double-layer ETFE film 211.

[0107] In this embodiment, t=10 min.

[0108] In the sub-step S2, the inflation volume in the double-layer ETFE film 211 is adjusted regularly, so that the average light transmittance of the double-layer ETFE film 211 in each cycle can be maintained at a relatively high value, thereby greatly improving the seawater desalination efficiency in each cycle.

[0109] A seawater desalination method of the present embodiment can desalinate seawater with low energy consumption, cleanness, environmental protection and high efficiency, and has high flexibility in the seawater desalination process.

[0110] Press the cut wood with a length, width and height of 5*5*1cm on a high-temperature hot plate at 500℃ for 1 minute to form a carbonized layer on the top surface, and the bottom is still the untreated natural wood part. The top carbonized layer is the photothermal layer 215 used for photothermal conversion, and the bottom natural wood is the capillary layer 214. The shape and scale of the wood and the simple production of the carbonized layer can be replicated to achieve large-area use effects. Under the same lighting conditions during the day, during the outdoor measurement of 1h, using the seawater desalination device described in Example 1, when all power-consuming components are powered off, the fresh water production rate is about 630ml / m 2 The desalination method of this embodiment is used on the desalination device described in Example 1. The solar radiation collected by the solar radiation sensor 211d is stable at about 710W, and the fresh water production rate is about 910ml / m 2That is, the seawater desalination method of this embodiment can further increase the rate at which the seawater desalination device produces fresh water, and improve the desalination efficiency of the seawater desalination device.

[0111] The technology, shape, and structure parts not described in detail in the present invention are all well-known technologies. It should also be pointed out that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. The components or steps in the embodiments of the present invention can be decomposed and / or recombined, and these decompositions and / or recombinations should be regarded as equivalent solutions of the present application and should fall within the protection scope of the present invention.

Claims

1. A solar interface evaporation seawater desalination device, comprising a water source module (1), characterized in that: The invention also comprises a desalinated water module (2), the desalinated water module (2) comprising an evaporation unit (21), an air guide pipe (22) and a condensation unit (23), the condensation unit (23) being arranged in close contact with the bottom surface of the evaporation unit (21), the evaporation unit (21) being connected to the condensation unit (23) via the air guide pipe (22), the seawater in the water source module (1) flowing out and flowing into the evaporation unit (21) to be evaporated into water vapor, the water vapor entering the condensation unit (23) condenses into condensed water when it encounters cold, and the condensed water is collected to obtain fresh water.

2. A solar interface evaporation seawater desalination device according to claim 1, characterized in that: The evaporation unit (21) comprises a double-layer ETFE film (211), an inclined box (212), a seawater layer (213) and an evaporation space (216); the box (212) comprises a bottom and a side wall; the double-layer ETFE film (211) is fixedly arranged on the top of the box (212); the seawater layer (213) is located at the bottom of the box (212); and the evaporation space (216) is a space in the box (212) between the seawater layer (213) and the double-layer ETFE film (211). The side wall of the housing (212) is coated with a heat-insulating material; the water source module (1) is connected to the seawater layer (213), and seawater flows from the water source module (1) into the seawater layer (213); the lower surface of the seawater layer (213) is the lower surface of the bottom of the housing (212); the upper surface of the condensation unit (23) is fixedly attached to the lower surface of the seawater layer (213); the air guide pipe (22) connects the evaporation space (216) and the condensation unit (23); and the outside of the bottom and side wall of the condensation unit (23) is the external environment.

3. The solar interface evaporation seawater desalination device according to claim 2, characterized in that: The evaporation unit (21) further comprises a capillary layer (214) and a photothermal layer (215) arranged in the housing (212); the lower surface of the capillary layer (214) is immersed in seawater of the seawater layer (213); the photothermal layer (215) is fixedly arranged on the upper surface of the capillary layer (214); and the evaporation space (216) is located between the photothermal layer (215) and the double-layer ETFE film (211).

4. The solar interface evaporation seawater desalination device according to claim 2, characterized in that: A seawater inlet (213a) and a seawater outlet (213b) are respectively arranged on two opposite sides of the seawater layer (213); the water source module (1) comprises a water tank (11), a float valve (12) and a water pipe (13); the water tank (11) contains seawater; the float valve (12) is arranged in the water tank (11) and is used to control the amount of seawater contained in the water tank (11); one end of the water pipe (13) is connected to the bottom of the water tank (11); the other end of the water pipe (13) is connected to the seawater inlet (213a); and the water pipes (213b) are arranged in descending order of height in the vertical direction: the bottom of the water tank (11), the seawater inlet (213a), and the seawater outlet (213b).

5. The solar interface evaporation seawater desalination device according to claim 2, characterized in that: A fan (22a) is arranged in the air guide pipe (22), the air intake side of the fan (22a) faces the evaporation space (216), and the air exhaust side of the fan (22a) faces the condensation unit (23).

6. The solar interface evaporation seawater desalination device according to claim 5, characterized in that: A water vapor outlet (216b) and a first fresh water outlet (216a) are respectively arranged on two opposite sides of the evaporation space (216); a second fresh water outlet (23a) and a water vapor inlet (23b) are respectively arranged on two opposite sides of the condensation unit (23); two ends of the air guide pipe (22) are respectively connected to the water vapor outlet (216b) and the water vapor inlet (23b); a fan (22a) is arranged close to the water vapor outlet (216b); and the water vapor outlet (216b), the first fresh water outlet (216a), the water vapor inlet (23b), and the second fresh water outlet (23a) are arranged in descending order of height in the vertical direction.

7. The solar interface evaporation seawater desalination device according to claim 1, characterized in that: It also comprises an adjustment module (3), which is arranged at the bottom of the desalinated water module (2), and is used to adjust the inclination angle and height of the desalinated water module (2).

8. A solar interface evaporation seawater desalination device according to any one of claims 2 to 5, characterized in that: One end of the double-layer ETFE film (211) is an air filling port (211a), and the other end is an air outlet (211c); an air pump (211b) is arranged in the air filling port (211a); a solar radiation sensor (211d) is arranged in the double-layer ETFE film (211); a salinity sensor (213c) is arranged in the seawater layer (213); and an air pressure sensor (216c) is also arranged in the evaporation space (216).

9. A seawater desalination method, applied to a solar interface evaporation seawater desalination device as claimed in claim 8, comprising the following contents: During the day: S1, move the solar interface evaporation desalination device to a site with sufficient sunlight, and adjust the tilt angle θ of the desalination device according to the geographical location; S2, regularly adjusting the amount of air in the double-layer ETFE film (211), and at the same time adjusting the valve openings of the seawater inlet (213a) and the seawater outlet (213b) to ensure that the salinity measured by the salinity sensor (213c) is lower than a first salinity threshold; at the same time adjusting the wind speed of the fan (22a) to ensure that the air pressure measured by the air pressure sensor (216c) is lower than a first air pressure threshold; collecting condensed water flowing out of the first fresh water outlet (216a) and the second fresh water outlet (23a); At night: the double-layer ETFE membrane (211) is filled with air, and the valve openings of the seawater inlet (213a) and the seawater outlet (213b) are adjusted to ensure that the salinity measured by the salinity sensor (213c) is lower than a first salinity threshold; the wind speed of the fan (22a) is adjusted to ensure that the air pressure measured by the air pressure sensor (216c) is lower than a first air pressure threshold; and condensed water flowing out of the first fresh water outlet (216a) and the second fresh water outlet (23a) is collected.

10. The solar interface evaporation seawater desalination device according to claim 9, characterized in that: The method of time-adjusting the air volume in the double-layer ETFE film (211) further includes sub-steps S21 to S24: S21, the current cycle starts, the air outlet (211c) is opened, the double-layer ETFE film (211) is deflated until the pressure P inside the film reaches the first vertical height pressure P1, and the air outlet (211c) is closed; S22, the air pump (211b) is started, and the double-layer ETFE film (211) is inflated until the pressure P inside the film is the second vector height pressure P2, and then the air pump (211b) is turned off, and the solar radiation sensor (211d) records the solar radiation value variation range R corresponding to the increase of the pressure P inside the film from the first vector height pressure P1 to the second vector height pressure P2, and the pressure inside the film corresponding to the maximum solar radiation value in the solar radiation value variation range R is recorded as the third vector height pressure P3, wherein P1≤P3<1.05P3≤P2; S23, in the current cycle, if the pressure P in the membrane is greater than 1.05P3, the air outlet (211c) is opened until the pressure P3≤P≤1.05P3 is reached, at which time the air outlet (211c) is closed; if the pressure P3≤P≤1.05P3 is reached, the air outlet (211c) and the air pump (211b) are inactive; if the pressure P in the membrane is less than P3, the air pump (211b) is started until the pressure P3≤P≤1.05P3 is reached, at which time the air pump (211b) is closed. The duration of each cycle is t; S24, when the current cycle ends, return to S21 and start the next cycle to adjust the inflation amount in the double-layer ETFE film (211).

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