Solar interface evaporation seawater desalination device and seawater desalination method

Abstract

The application belongs to the technical field of seawater desalination, and particularly relates to a solar interface seawater desalination device and a seawater desalination method. The solar interface evaporation seawater desalination device comprises a water source module, and further comprises a desalination water module, the desalination water module comprising an evaporation unit, an air guide pipe and a condensation unit, the condensation unit being attached to the lower bottom surface of the evaporation unit, the evaporation unit being communicated with the condensation unit through the air guide pipe, seawater in the water source module flowing out and flowing into the evaporation unit to be evaporated into water vapor, the water vapor entering the condensation unit to be condensed into condensed water, and the desalination water being obtained by collecting the condensed water. The seawater desalination device can desalinate seawater in a low energy consumption, clean and environmentally-friendly and high-efficiency manner.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of seawater desalination, and particularly relates to a solar interface seawater desalination device and a seawater desalination method. BACKGROUND

[0002] Water resources have an important influence on the sustainable development of human society. Although 71% of the earth's area is covered by water, only 0.3% of the total water can be directly used by humans. And due to population growth, climate change and water pollution, many areas are facing water resource shortages and water quality decline, which seriously threatens safe drinking water and environmental health.

[0003] Using a multi-stage distillation method to desalinate seawater is an effective way to obtain fresh water.

[0004] However, each stage of multi-stage distillation requires the provision of heat energy to achieve evaporation and condensation, which is extremely energy-consuming. And multi-stage distillation requires stable heat supply, otherwise the temperature difference during evaporation 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, so a large amount of electricity is needed to provide stable heat in multi-stage distillation, and clean energy can only assist power supply, which is very environmentally unfriendly. Therefore, there is an urgent need for a seawater desalination device with low energy consumption, clean and environmentally friendly, and high desalination efficiency. SUMMARY

[0005] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide a solar interface evaporation seawater desalination device that can desalinate seawater with low energy consumption, clean and environmentally friendly, and high efficiency.

[0006] To achieve the above purpose, the application adopts the following technical solutions:

[0007] A solar interface seawater desalination device, comprising a water source module, further comprising a desalination water module, the desalination water module comprising an evaporation unit, an air guide pipe and a condensation unit, the condensation unit being attached to the lower bottom surface of the evaporation unit, the evaporation unit being in communication with the condensation unit through the air guide pipe, seawater in the water source module flowing out and flowing into the evaporation unit to be evaporated into water vapor, the water vapor entering the condensation unit and condensing into condensed water when cooled, and the condensed water being collected to obtain fresh water.

[0008] Preferably, the evaporation unit comprises a double-layer ETFE film, a box body arranged obliquely, a seawater layer and an evaporation space. The box body is composed of a bottom and a side wall. The double-layer ETFE film is fixedly arranged on the top of the box body. The seawater layer is located at the bottom of the box body. The evaporation space is the space in the box body between the seawater layer and the double-layer ETFE film. The outer part of the side wall of the box body is covered with thermal insulation material. The water source module is connected with the seawater layer. 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 body. The upper surface of the condensation unit is fixedly arranged on the lower surface of the seawater layer. The gas guide pipe is connected with the evaporation space and the condensation unit. The bottom and the outer part of the side wall of the condensation unit are the external environment.

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

[0010] Preferably, the two opposite sides of the seawater layer are respectively provided with a seawater inlet and a seawater outlet. The water source module comprises a water tank, a float ball valve and a water pipe. The water tank contains seawater. The float ball valve is arranged in the water tank and is used to control the amount of seawater contained in the water tank. One end of the water pipe is connected with the bottom of the water tank. The other end of the water pipe is connected with the seawater inlet. The height in the vertical direction is arranged in descending order as the bottom of the water tank, the seawater inlet and the seawater outlet.

[0011] Preferably, the gas guide pipe is provided with a fan. The air inlet side of the fan faces the evaporation space. The air outlet side of the fan faces the condensation unit.

[0012] Preferably, the two opposite sides of the evaporation space are respectively provided with a water vapor outlet and a first fresh water outlet. The two opposite sides of the condensation unit are respectively provided with a second fresh water outlet and a water vapor inlet. The two ends of the gas guide pipe are respectively connected with the water vapor outlet and the water vapor inlet. The fan is arranged close to the water vapor outlet. The height in the vertical direction is arranged in descending order as the water vapor outlet, the first fresh water outlet, the water vapor inlet and the second fresh water outlet.

[0013] Preferably, the application further comprises an adjusting module. The adjusting module is arranged at the bottom of the desalination water module. The adjusting module is used to adjust the inclination angle and the height of the desalination water module.

[0014] Preferably, one end of the double-layer ETFE film is an air inlet. The other end is an air outlet. An air pump is arranged in the air inlet. The double-layer ETFE film is provided with a solar radiation sensor. A salinity sensor is arranged near the seawater outlet in the seawater layer. A gas pressure sensor is further arranged in the evaporation space.

[0015] The application further provides a seawater desalination method applied to the solar interface evaporation seawater desalination device.

[0016] During the day:

[0017] S1, moving the solar interface seawater desalination device to a place with sufficient sunlight, and adjusting the inclination angle θ of the seawater desalination device according to the geographical position;

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

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

[0020] Preferably, the air volume in the double-layer ETFE film is adjusted in a time manner, and the method further comprises sub-steps S21-S24:

[0021] S21, starting the current period, opening the air outlet, and deflating the double-layer ETFE film until the internal pressure P of the film is the first sag pressure P1, and then closing the air outlet;

[0022] S22, starting the air pump, inflating the double-layer ETFE film until the internal pressure P of the film is the second sag pressure P2, and then closing the air pump, and the solar radiation sensor records the solar radiation value change range R corresponding to the increase of the internal pressure P of the film from the first sag pressure P1 to the second sag pressure P2, and the internal pressure corresponding to the maximum solar radiation value in the solar radiation value change range R is recorded as the third sag pressure P3, wherein P1≤P3<1.05P3≤P2;

[0023] S23, during the current period, if the internal pressure P of the film is greater than 1.05P3, the air outlet is opened until the internal pressure P of the film is P3≤P≤1.05P3, and then the air outlet is closed; if the internal pressure P of the film is P3≤P≤1.05P3, neither the air outlet nor the air pump is actuated; if the internal pressure P of the film is less than P3, the air pump is started until the internal pressure P of the film is P3≤P≤1.05P3, and then the air pump is closed, and the duration of each period is t;

[0024] S24, when the current period ends, returning to S21 to start the adjustment of the air volume in the double-layer ETFE film in the next period.

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

[0026] (1) The seawater desalination device of the present application can desalinate seawater all day long, because in the process of desalinating seawater, in the daytime with sunlight, the evaporation unit mainly performs solar interface evaporation, and then condensed water is obtained in the condensation unit; at night without sunlight, evaporation can still be carried out in the evaporation unit, and condensed water is obtained in the condensation unit.

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

[0028] (3) In the seawater desalination device of the present application, the upper surface of the condensation unit is arranged close to the lower surface of the seawater layer, and the lower surface of the condensation unit and the outer wall are the external environment. By utilizing the large difference in specific heat capacity between air and seawater, a low-temperature place for water vapor can be formed in the condensation unit under any condition, so that water vapor can be condensed into condensed water as soon as it enters the condensation unit.

[0029] (4) The evaporation unit in the seawater desalination device of the present application adopts a double-layer ETFE film with good heat preservation performance and adjustable light transmittance. When there is sunlight in the daytime, the air volume of the double-layer ETFE film is adjusted to ensure that the double-layer ETFE film maintains high light transmittance under the current light conditions. Thus, the seawater desalination device of the present application can efficiently desalinate seawater for a long time during the day.

[0030] (5) The seawater desalination device of the present application can be moved flexibly, has small footprint and high site utilization rate. The amount of fresh water obtained can be increased by increasing the number of seawater desalination devices of the present application. As many seawater desalination devices as possible can be arranged 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 application, the air volume in the double-layer ETFE film is adjusted at regular intervals, so that the average light transmittance of the double-layer ETFE film in each cycle can be maintained at a high value, which greatly improves the seawater desalination efficiency in each cycle. The seawater desalination method of the present application can desalinate seawater with low energy consumption, clean and environmentally friendly, and high efficiency, and has high flexibility in the process of desalinating seawater.

[0032] (7) The seawater desalination method of the present application can further improve the rate of producing fresh water by the seawater desalination device of the present application and improve the desalination efficiency of the seawater desalination device. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 It is a structural schematic diagram of a solar interface evaporation seawater desalination device of the present application.

[0034] Figure 2 It is an enlarged schematic diagram of A in Figure 1

[0035] Figure 3 It is an enlarged schematic diagram of B in Figure 1

[0036] The actual correspondence between each reference sign and component name of the present application is as follows:

[0037] 1, water source module; 11, water tank; 12, floating ball valve; 13, water pipe;

[0038] 2, desalination water module;

[0039] 21, evaporation unit; 211, double-layer ETFE film; 211a, air inlet; 211b, air charging pump; 211c, air outlet; 211d, solar radiation sensor; 212, box body; 213, seawater layer; 213a, seawater inlet; 213b, seawater outlet; 213c, salinity sensor; 214, capillary layer; 215, photothermal layer; 216, evaporation space; 216a, first fresh water drain outlet; 216b, water vapor air outlet; 216c, air pressure sensor;

[0040] 22, air guide pipe; 22a, fan;

[0041] 23, condensation unit; 23a, second fresh water drain outlet; 23b, water vapor air inlet;

[0042] 3, adjustment module; 31, telescopic support; 32, universal wheel. DETAILED DESCRIPTION

[0043] In order to make the technical solutions of the present application clearer and more explicit, the present application will be described in detail below in conjunction with the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. The technical features of the technical solutions of the present application obtained by equivalent replacement and routine inference by those skilled in the art without creative labor fall within the protection scope of the present application.

[0044] Example 1

[0045] As Figures 1-3 ​​As shown, it is a solar interface evaporation seawater desalination device, comprising a water source module 1, a desalination water module 2 and an adjusting module 3, the adjusting module 3 is arranged at the bottom of the desalination water module 2, and is used for moving the desalination water module 2 or adjusting the inclination angle and height of the desalination water module 2; the desalination water module 2 comprises an evaporation unit 21 and a condensation unit 23, the evaporation unit 21 and the condensation unit 23 are communicated, seawater flows out from 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 to condense into condensed water, and the desalination water is obtained by collecting the condensed water.

[0046] The water source module 2 comprises a water tank 11, a floating ball valve 12 and a water pipe 13, the floating ball valve 12 is arranged in the water tank 11, the water tank 11 contains seawater, one end of the water pipe 13 is communicated with the bottom of the water tank 11, and the other end of the water pipe 13 is communicated with the evaporation unit 21. The floating ball valve 12 is used for controlling the filling amount of seawater in the water tank 11, when the seawater in the water tank 11 is too little, the ball of the floating ball valve 12 sinks to drive the opening degree of the water inlet valve of the water tank 11 to increase, and the water inlet amount of the water tank 11 increases; when the seawater in the water tank 11 is relatively much, the ball of the floating ball valve 12 rises to drive the opening degree of the water inlet valve of the water tank 11 to decrease or close, and the water inlet amount of the water tank 11 decreases or no longer inlets water. The water inlet valve of the water tank 11 is not shown in the figure.

[0047] The evaporation unit 21 comprises a double-layer ETFE film 211, a box body 212, a seawater layer 213, a capillary layer 214, a photo-thermal layer 215 and an evaporation space 216. The double-layer ETFE film 211 is fixedly arranged at the top of the box body 212, and the inside of the box body 212 is sequentially provided with the evaporation space 216, the photo-thermal layer 215, the capillary layer 214 and the seawater layer 213 from top to bottom.

[0048] The box body 212 only has a bottom and a side wall, and does not have a top, and the double-layer ETFE film 211 is fixedly arranged at the top of the box body 212. The side wall of the box body 212 is made of heat preservation material, or the side wall of the box body 212 is coated with heat preservation material.

[0049] The double-layer ETFE film 211 is a double-layer air pillow structure, and is filled with air, nitrogen or inert gas in the middle. One end of the double-layer ETFE film 211 is an inflation port 211a, the other end is an air outlet 211c, and an inflation pump 211b is arranged in the inflation 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 inflation amount in the double-layer ETFE film 211, the maximum light transmittance of the double-layer ETFE film 211 is also greater than that of glass, and as long as the double-layer ETFE film 211 has a certain inflation amount, the heat preservation effect of the double-layer ETFE film 211 far exceeds that of glass. Generally, the double-layer ETFE film 211 has a certain inflation amount, and does not have no air at all.

[0050] Optionally, the solar radiation sensor 211d is arranged at the side of the double-layer ETFE film 211, so that the solar radiation value can be measured through the double-layer ETFE film 211, and the double-layer ETFE film 211 and the top of the box 212 are not blocked.

[0051] Inside the box 212, the evaporation space 216 refers to the space inside 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 referred to as the first side and the second side, and the water vapor outlet 216b is arranged on the first side of the evaporation space 216.

[0052] Optionally, the first fresh water outlet 216a is arranged on the second side of the evaporation space 216, and the height of the first side in the vertical direction is higher than that of the second side.

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

[0054] The photothermal layer 215 is fixedly arranged on the upper surface of the capillary layer 214, the side wall of the capillary layer 214 is fixedly arranged on the inner side wall of the box 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 is 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 referred to as the third side and the fourth side, the seawater inlet 213a is arranged on the third side of the seawater layer 213, the seawater outlet 213b is arranged on the fourth side of the seawater layer 213, and the height of the seawater inlet 213a in the vertical direction is always higher than that of the seawater outlet 213b. Valves for controlling the flow of water are arranged in the seawater inlet 213a and the seawater outlet 213b.

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

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

[0058] The photothermal layer 215 is one of a metal nano material, a semiconductor-based material or a carbon-based material, which functions 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, which functions to absorb the seawater in the seawater layer 213 to the photothermal layer 215 for evaporation, and the photothermal layer 215 uses heat energy to accelerate the evaporation of seawater in the photothermal layer 215 to obtain water vapor, which 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 bottom and the outer wall of the condensing unit 23 are the external environment, i.e. the bottom and the outer wall of the condensing unit 23 are directly in contact with the external air. The two opposite sides of the condensing unit 23 are respectively referred to as the fifth side and the sixth side, and the second fresh water outlet 23a is arranged on the sixth side of the condensing unit 23, and the water vapor inlet 23b is arranged on the fifth side of the condensing unit 23, and the height of the water vapor inlet 23b in the vertical direction is higher than that of the second fresh water outlet 23a.

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

[0062] Optionally, the air guide pipe 22 is provided with a fan 22a, and 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 arranged close to the water vapor outlet 216b.

[0064] The adjusting module 3 comprises a telescopic support 31 arranged on the lower surface of the condensing unit 23, and the telescopic support 31 comprises two adjusting rods, one of which is arranged close to the fifth side of the condensing unit 23, and the other of which is arranged close to the sixth side of the condensing unit 23. The two adjusting rods can be adjusted to different heights respectively, so that the condensing unit 23 is inclined 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 fifth side of the condensation unit 23 is higher than the height of the sixth side of the condensation unit 23 in the vertical direction by making the height of the top of the adjusting rod near the fifth side of the condensation unit 23 higher than the height of the top of the adjusting rod near the sixth side of the condensation unit 23. The height of the first side of the evaporation space 216 is higher than the height of the second side of the evaporation space 216 in the vertical direction, and the height of the third side of the seawater layer 213 is higher than the height of the fourth side of the seawater layer 213 in the vertical direction.

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

[0067] Optionally, the adjusting module 3 further comprises universal wheels 32 arranged below the telescopic supports 31, which facilitates the movement of the seawater desalination device.

[0068] The principle of the seawater desalination device will be described below.

[0069] The floating ball valve 12 can ensure that there is always seawater in the water source module 2, and the presence of the floating ball valve 12 can automatically adjust the water inflow of the water source module 2 according to the real-time water level of the seawater in the water source module 2, so that the water level of the seawater contained in the water source module 2 is not too low. The technical personnel do 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 opened, 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. 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 of 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 wetted by seawater. The capillary layer 214 absorbs seawater from the seawater layer 214 into the photothermal layer 215.

[0071] Whether the seawater layer 213 is horizontal or inclined, the skilled person can adjust the valve opening 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, but does not accumulate excessively inside the box 212, so that no seawater level formed by seawater accumulation is formed in the evaporation space 216.

[0072] The solar radiation penetrates the double-layer ETFE film 211 to reach the photothermal layer 215 and is converted into heat 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 good heat preservation effect, the temperature in the entire evaporation space 216 is also relatively high, which accelerates 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, which is gaseous fresh water.

[0073] The solar radiation sensor 211d collects the value of the solar radiation to adjust the light transmittance of the double-layer ETFE film 211, that is, to adjust the air 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 into the condensation unit 23. At the same time, the opening of the fan 22a reduces 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 the seawater evaporates, the salinity of the seawater in the seawater layer 213 increases, which is not conducive to the evaporation of seawater, so the seawater desalination device of the present application 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 issue an alarm to inform the technician to increase the valve opening of the seawater outlet 213b and the seawater inlet 213a to increase the flow rate of seawater in the seawater layer 213, so that the salinity of seawater flowing in the seawater layer 213 is reduced to an appropriate concentration range, so as to avoid slowing down the evaporation rate of seawater; at the same time, it also avoids the precipitation of crystalline salt in the seawater layer 213.

[0076] When the seawater layer 213 is inclined, the salt concentration is highest at the relatively low point in the vertical direction, and the position where the salinity sensor 213c of the present application is arranged, that is, the position of 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 salinity in the seawater layer 213 as the basis for adjusting the flow rate of seawater in the seawater layer 213.

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

[0078] The water vapor enters the condensing unit 23 through the air duct 22 from the water vapor inlet 23b, and condenses into condensed water in the condensing unit because the height of the water vapor inlet 23b in the vertical direction is higher than that of the second fresh water outlet 23a. Therefore, the condensed water is collected at the second fresh water outlet 23a and discharged from the second fresh water outlet 23a. The condensed water collected from the second fresh water outlet 23a is fresh water. The opening of the fan 22a increases the air pressure in the condensing unit 23, and the water vapor in the condensing unit 23 is more likely to condense into condensed water.

[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 double-layer ETFE film 211 and the good heat preservation performance of the side wall of the box 212 make the temperature in the evaporation space 216 higher than the outside environment. The upper surface of the condensing unit 23 is closely arranged below the lower surface of the seawater layer 213. Because the specific heat capacity of seawater is much larger than that of air, the temperature of the seawater layer 213 is also relatively high. However, the bottom and the side wall of the condensing unit 23 are exposed to the outside environment, so the temperature is relatively low. Therefore, in this case, the water vapor in the condensing unit 23 mainly condenses into condensed water on the bottom and the side wall of the condensing unit 23.

[0081] When the outside environment temperature is low at night, the double-layer ETFE film 211 and the good heat preservation performance of the side wall of the box 212 make the temperature in the evaporation space 216 higher than the outside environment. The upper surface of the condensing unit 23 is closely arranged below the lower surface of the seawater layer 213. Because the specific heat capacity of seawater is much larger than that of air, the temperature of the seawater layer 213 is also relatively high. However, the bottom and the side wall of the condensing unit 23 are exposed to the outside environment, so the temperature is relatively low. Therefore, in this case, the water vapor in the condensing unit 23 mainly condenses into condensed water on the bottom and the side wall of the condensing unit 23.

[0082] When the ambient temperature is high during the day, the temperature in the evaporation space 216 is still much higher than the ambient temperature due to the good heat preservation performance of the double ETFE film 211 and the box 212 sidewall and the further increase of the temperature in the evaporation space 216 due to the conversion of sunlight into heat by the light-heat layer 215. At this time, the temperature of the bottom and the sidewall of the condensation unit 23 is also relatively high, but it is lower than the temperature in the evaporation space 216. At the same time, the temperature of the seawater layer 213 is lower than the temperature of the bottom and the sidewall of the condensation unit 23 due to the much larger specific heat capacity of seawater, so in this case, the water vapor in the condensation unit 23 will condense into condensed water 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 ambient temperature, the temperature of the inner surface of the double ETFE film 211 is higher than the temperature of the outer surface of the double ETFE film 211, and the water vapor in the evaporation space 216 will condense into condensed water on the inner surface of the double ETFE film 211. The second side of the evaporation space 216 is provided with a first freshwater drainage port 216a, and the height of the first side in the vertical direction is higher than that of the second side, so the condensed water will slide to the first freshwater drainage port 216a under the action of gravity, and the condensed water collected from the first freshwater drainage port 216a can be obtained as freshwater. However, when the ambient temperature is high during the day, the water vapor in the evaporation space 216 will be quickly guided to the condensation unit 23 under the guiding action of the fan 22a, so there will be less condensed water at the first freshwater drainage port 216a.

[0084] According to the different sunlight environments of the geographical location of the seawater desalination device, the seawater desalination device is moved to a suitable position (for example, an open beach without shelter) by the adjusting module 3, and the inclination angle θ of the seawater desalination device is adjusted by the adjusting module 3. The inclination angle θ is as shown in Figure 1

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

[0086] The condensed water discharged from the first freshwater drainage port 216a and the second freshwater drainage port 23a can be obtained as freshwater. According to the detection of the technical personnel, the salt ion concentration in the condensed water discharged from the first freshwater drainage port 216a and the second freshwater drainage port 23a meets the WHO drinking water standard.

[0087] ​The seawater desalination device of the present application can desalinate seawater all day long.

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

[0089] In the seawater desalination device of the present application, the upper surface of the condensing unit 23 is closely attached to the lower surface of the seawater layer 213, and the lower surface of the condensing unit 23 and the outside of the side wall are the external environment. By utilizing the large difference in specific heat capacity between air and seawater, a place with low temperature relative to water vapor can exist in the condensing unit 23 in any case, so that water vapor can be condensed into condensed water as soon as it enters the condensing unit 23.

[0090] When the water vapor becomes condensed water on the upper surface of the condensing unit 23, the latent heat of the water vapor is transferred to the lower surface of the seawater layer 213 closely attached to the upper surface of the condensing unit 23, which increases the temperature of the seawater layer 213 and further promotes the evaporation of seawater in the seawater layer 213 into the evaporation space 216, while reducing the loss of energy.

[0091] The top of the evaporation unit 21 of the present application adopts a double-layer ETFE film 211 with good heat preservation performance and flexible light transmittance adjustment. When there is sunlight during the day, the air volume of the double-layer ETFE film 211 is adjusted to ensure that the double-layer ETFE film 211 maintains high light transmittance under the current light conditions, so that the seawater desalination device of the present application can desalinate seawater efficiently for a long time during the day.

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

[0093] Example 2

[0094] The application also provides a seawater desalination method applied to the solar interface evaporation seawater desalination device as described in Embodiment 1, and includes the following contents:

[0095] Day:

[0096] S1, the solar interface evaporation seawater desalination device is moved to a place with sufficient light, and the inclination angle θ of the seawater desalination device is adjusted according to the geographical position;

[0097] S2, the air volume in the double-layer ETFE film 211 is adjusted at a fixed time, and the valve opening degree of the seawater inlet 213a and the seawater outlet 213b is adjusted at the same time, so as to ensure that the salinity measured by the salinity sensor 213c is lower than the first salinity threshold; at the same time, the air speed of the adjusting fan 22a is adjusted, so as to ensure that the air pressure measured by the air pressure sensor 216c is lower than the first air pressure threshold; and the condensed water flowing out of the first fresh water outlet 216a and the second fresh water outlet 23a is collected.

[0098] Night: the double-layer ETFE film 211 is filled with air, and the valve opening degree of the seawater inlet 213a and the seawater outlet 213b is adjusted at the same time, so as to ensure that the salinity measured by the salinity sensor 213c is lower than the first salinity threshold; at the same time, the air speed of the adjusting fan 22a is adjusted, so as to ensure that the air pressure measured by the air pressure sensor 216c is lower than the first air pressure threshold; and the condensed water flowing out of the first fresh water outlet 216a and the second fresh water outlet 23a is collected.

[0099] The double-layer ETFE film 211 filled with air at night is beneficial to heat preservation of the evaporation space 216.

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

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

[0102] In S2, the air volume in the double-layer ETFE film 211 is adjusted at a fixed time, and the air volume in the double-layer ETFE film 211 is adjusted at a fixed time, and the valve opening degree of the seawater inlet 213a and the seawater outlet 213b is adjusted at the same time, so as to ensure that the salinity measured by the salinity sensor 213c is lower than the first salinity threshold; at the same time, the air speed of the adjusting fan 22a is adjusted, so as to ensure that the air pressure measured by the air pressure sensor 216c is lower than the first air pressure threshold; and the condensed water flowing out of the first fresh water outlet 216a and the second fresh water outlet 23a is collected.

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

[0104] S22, the inflation pump 211b is started, the double-layer ETFE film 211 is inflated to the second sag pressure P2, the inflation pump 211b is closed, the solar radiation sensor 211d records the solar radiation value change range R corresponding to the increase of the film internal pressure P from the first sag pressure P1 to the second sag pressure P2, the film internal pressure corresponding to the maximum solar radiation value in the solar radiation value change range R is recorded as the third sag pressure P3, wherein P1≤P3<1.05P3≤P2;

[0105] S23, in the current period, if the film internal pressure P>1.05P3, the air outlet 211c is opened until the film internal pressure P3≤P≤1.05P3, the air outlet 211c is closed; if the film internal pressure P3≤P≤1.05P3, neither the air outlet 211c nor the inflation pump 211b is actuated; if the film internal pressure P

[0106] S24, at the end of the current period, return to S21 to start the next period of adjustment of the inflation amount in the double-layer ETFE film 211.

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

[0108] The inflation amount in the double-layer ETFE film 211 is adjusted in the sub-step of S2, so that the average light transmittance of the double-layer ETFE film 211 can be maintained at a high value in each period, and the seawater desalination efficiency in each period can be greatly improved.

[0109] The seawater desalination method of this embodiment can desalinate seawater in a low-energy, clean, environmentally friendly and efficient manner, and has high flexibility in the process of desalinating seawater.

[0110] The cut wood with a length, width and height of 5*5*1cm is pressed on a high-temperature hot plate at 500℃ for 1min to form a top carbonized layer, and the bottom is still a natural wood part that has not been treated. The top carbonized layer is the photothermal layer 215 for light-heat conversion, and the bottom natural wood is the capillary layer 214. The wood shape and size are simple to make carbonized layers, which can be replicated to achieve large-area use effect. Under the same light conditions during the day, the outdoor measurement for 1h, using the seawater desalination device described in embodiment 1, in the case that all power consumption components are powered off, the fresh water production rate is about 630ml / m 2 ; using the seawater desalination method of this embodiment on the seawater desalination device described in embodiment 1, the solar radiation collected by the solar radiation sensor 211d is stabilized at about 710W, and the fresh water production rate is about 910ml / m 2That is, the seawater desalination method of the embodiment can further improve the rate of producing fresh water by the seawater desalination device and improve the desalination efficiency of the seawater desalination device.

[0111] The techniques, shapes, and structural parts not described in detail in the present application are well-known techniques. It should also be noted that the above is only a preferred embodiment of the present application and is not intended to limit the present application. The components or steps in the embodiment of the present application can be decomposed and / or recombined, and these decompositions and / or recombinationsshould be considered as equivalent solutions of the present application and should fall within the protection scope of the present application.

Claims

1. A method of desalination of sea water, characterized in that, Be applied to a kind of solar interface evaporation seawater desalination device, including the following contents: the solar interface evaporation seawater desalination device, including water source module (1), still including desalination water module (2), desalination water module (2) includes evaporation unit (21), air duct (22) and condensing unit (23), condensing unit (23) is attached to the lower bottom of evaporation unit (21), evaporation unit (21) is communicated with condensing unit (23) by air duct (22), seawater in water source module (1) flows out and flows into evaporation unit (21) and is evaporated into water vapor, water vapor enters condensing unit (23) and condenses into condensed water, and the condensed water is collected to obtain fresh water; Evaporation unit (21) includes double-layer ETFE film (211), obliquely arranged box (212), seawater layer (213) and evaporation space (216), box (212) is composed of bottom and side wall, double-layer ETFE film (211) is fixedly arranged at the top of box (212), seawater layer (213) is located at the bottom in box (212), and evaporation space (216) is the space in box (212) between seawater layer (213) and double-layer ETFE film (211); Seawater inlet (213a) and seawater outlet (213b) are respectively arranged on two opposite sides of seawater layer (213); fan (22a) is arranged in air duct (22); water vapor outlet (216b) and first fresh water drain (216a) are respectively arranged on two opposite sides of evaporation space (216), and second fresh water drain (23a) and water vapor inlet (23b) are respectively arranged on two opposite sides of condensing unit (23); One end of double-layer ETFE film (211) is inflation port (211a), the other end is gas outlet (211c), inflation pump (211b) is arranged in inflation port (211a), and solar radiation sensor (211d) is arranged in the film of double-layer ETFE film (211); salinity sensor (213c) is arranged in seawater layer (213); air pressure sensor (216c) is further arranged in evaporation space (216); During the day: S1, the solar interface evaporation seawater desalination device is moved to the site with sufficient light, and the inclination angle θ of the seawater desalination device is adjusted according to geographical position; S2, the inflation amount in double-layer ETFE film (211) is adjusted at regular intervals, and the valve opening degree of seawater inlet (213a) and seawater outlet (213b) is adjusted simultaneously, so that the salinity measured by salinity sensor (213c) is lower than the first salinity threshold value;The air speed of fan (22a) is adjusted simultaneously, so that the air pressure measured by air pressure sensor (216c) is lower than the first air pressure threshold value;The condensed water flowing out of first fresh water drain (216a) and second fresh water drain (23a) is collected; At night: fill the double ETFE membrane (211) with air, and adjust the valve opening degree 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 air speed of the adjusting fan (22a) to ensure that the air pressure measured by the air pressure sensor (216c) is lower than the first air pressure threshold; collect the condensed water flowing out of the first fresh water outlet (216a) and the second fresh water outlet (23a); The timing adjusts the amount of air in the double ETFE membrane (211), which also includes sub-steps S21-S24: S21, at the beginning of the current period, the air outlet (211c) is opened, and the double ETFE membrane (211) is deflated until the internal pressure P of the membrane is the first sag pressure P1, and the air outlet (211c) is closed; S22, the inflation pump (211b) is started, the double ETFE membrane (211) is inflated until the internal pressure P of the membrane is the second sag pressure P2, the inflation pump (211b) is closed, the solar radiation sensor (211d) records the solar radiation value change range R corresponding to the increase of the internal pressure P of the membrane from the first sag pressure P1 to the second sag pressure P2, and the internal pressure corresponding to the maximum solar radiation value in the solar radiation value change range R is recorded as the third sag pressure P3, wherein P1≤P3<1.05P3≤P2; S23, during the current period, if the internal pressure P of the membrane is greater than 1.05P3, the air outlet (211c) is opened until the internal pressure P of the membrane is P3≤P≤1.05P3, and the air outlet (211c) is closed; if the internal pressure P of the membrane is P3≤P≤1.05P3, neither the air outlet (211c) nor the inflation pump (211b) is actuated; if the internal pressure P of the membrane is less than P3, the inflation pump (211b) is started until the internal pressure P of the membrane is P3≤P≤1.05P3, and the inflation pump (211b) is closed; the duration of each period is t; S24, at the end of the current period, return to S21 to start the next period of adjustment of the amount of air in the double ETFE membrane (211).

2. A method of desalination of sea water as claimed in claim 1 wherein: The outer wall of the box (212) is coated with thermal insulation material; the water source module (1) is connected with 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 box (212), the upper surface of the condensation unit (23) is fixedly arranged on the lower surface of the seawater layer (213), and the gas guide pipe (22) connects the evaporation space (216) and the condensation unit (23), and the bottom and the outer wall of the condensation unit (23) are the external environment.

3. A method of desalination of sea water as claimed in claim 2 wherein: The evaporation unit (21) further comprises a capillary layer (214) and a photo-thermal layer (215) arranged in the box (212), the lower surface of the capillary layer (214) is immersed in the seawater of the seawater layer (213), the photo-thermal layer (215) is fixedly arranged on the upper surface of the capillary layer (214), and the evaporation space (216) is located between the photo-thermal layer (215) and the double ETFE membrane (211).

4. A method of desalination of sea water as claimed in claim 2 wherein: The water source module (1) comprises a water tank (11), a floating ball valve (12) and a water pipe (13), the water tank (11) is filled with seawater, the floating ball valve (12) is arranged in the water tank (11) and is used for controlling the filling amount of seawater in the water tank (11), one end of the water pipe (13) is communicated with the bottom of the water tank (11), the other end of the water pipe (13) is communicated with a seawater inlet (213a), and the bottom of the water tank (11), the seawater inlet (213a) and a seawater outlet (213b) are arranged in a descending order of height in the vertical direction.

5. A method of desalination of sea water as claimed in claim 2 wherein: The air inlet side of the fan (22a) faces the evaporation space (216), and the air outlet side of the fan (22a) faces the condensation unit (23).

6. A method of desalination of sea water as claimed in claim 5 wherein: The two ends of the air guide pipe (22) are respectively communicated with a water vapor outlet (216b) and a water vapor inlet (23b), the fan (22a) is arranged close to the water vapor outlet (216b), and the water vapor outlet (216b), a first fresh water outlet (216a), the water vapor inlet (23b) and a second fresh water outlet (23a) are arranged in a descending order of height in the vertical direction.

7. A method of desalination of sea water as claimed in claim 1 wherein: The adjusting module (3) is arranged at the bottom of the desalinated water module (2), and is used for adjusting the inclination angle and the height of the desalinated water module (2).

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