TWI644868B - Devices for desalination of seawater used solar energy in combination with thermoelectric module - Google Patents

Abstract

A seawater desalination device combined with solar energy and thermoelectric modules can convert salt water into fresh drinking water only by combining solar panels and thermoelectric devices, and does not require an extra large amount of heat to boil seawater into water vapor, and then condense into water for use. The conversion of solar light into electricity and thermoelectric devices is combined, and the heat of solar energy conversion is not wasted. Together with the high temperature side of the thermoelectric device, the heat exchanger is used as the heating seawater, and the temperature of the solar module can be lowered to improve the power generation efficiency. .

Description

Seawater desalination device combined with solar energy and thermoelectric modules

The invention relates to a seawater desalination device, in particular to a seawater desalination device which is used in combination with a solar energy and a thermoelectric module.

Water is the source of life. As the world's population continues to grow and economic globalization develops, the living environment in which people live is deteriorating. Among them, especially fresh water resources are in short supply. The depletion of freshwater resources and the reduction of potable water are one of the serious challenges facing humanity. More than half of the world's population is expected to face a water shortage crisis by 2025.

On the other hand, it is well known that the Earth's sea water resources are very rich, and seawater accounts for 71% of the Earth's surface area. In contrast, freshwater resources account for only 2.5% of all water resources. Although the sea water resources are very rich, the sea water is salty and bitter and cannot be used directly. Therefore, seawater desalination techniques using seawater desalination to fresh water have been proposed.

The earliest seawater desalination method was to use a distillation method to boil the brine, and then obtain water vapor, which was condensed into fresh water through a condensing coil. Distillation has a long history and is still in use today. There are some drawbacks. For example, it requires complex facilities and equipment, and requires a large amount of heat to evaporate seawater, so the energy efficiency is relatively low. If you operate a seawater distillation unit, energy accounts for half of the cost.

Electrodialysis, distillation, reverse osmosis, ion exchange and other methods are currently the mainstream of industrial wastewater purification and seawater desalination, but expensive material costs, running costs and high energy consumption limit the popularity of these methods.

Fig. 1 is a schematic view showing a porous film seawater desalination apparatus disclosed in the World Intellectual Property Organization publication WO 2016/135701 A1. Among them, PVDF membrane is used as a filter medium and heated by a heater. The high-temperature seawater flows into the water inlet of the seawater desalination device, and is evaporated into water vapor by the high-temperature seawater of the polyvinylidene fluoride film, and the water vapor is condensed into fresh water by natural cooling, and flows out from the other side of the water outlet. Compared to the conventional distillation method, since the seawater is boiled without a large amount of heat energy to obtain the required water vapor, less energy is consumed. However, since the energy is continuously lost from the hot side of the polyvinylidene fluoride film to the cold side, the overall energy efficiency is not high, since the seawater is heated before the polyvinylidene fluoride film seawater desalination device is required to be heated. Therefore, the actual energy consumption cost is still very high.

Therefore, how to develop new technologies for seawater desalination or sewage purification to solve the shortage of fresh water resources and meet the requirements of economy and sustainability is imperative. Desalination methods and devices have higher requirements for low cost and low energy consumption. In other words, in order to meet the following objectives: seawater desalination methods and devices that are efficient, inexpensive, portable, and do not require additional power, will be more likely to cause market attention and demand.

In order to solve the above technical problem, the present invention discloses a seawater desalination device for use in combination of a solar energy and a thermoelectric module, comprising: a water inlet to receive seawater; a solar panel, including a front surface of the solar power panel, a back surface of the solar power panel, and a positive power terminal of the solar power source. And a solar power output negative terminal; wherein the solar power panel receives sunlight, and the heat exchanger is coupled to the water inlet, including the heat exchanger front surface and the heat exchanger back surface, and the seawater is evaporated and separated into high temperature water vapor. And the seawater that is not completely evaporated; wherein the heat exchanger is coupled in parallel with a solar vacuum heat collecting tube; the thermoelectric module includes a high temperature heating end, a low temperature cooling end, a positive power input end of the thermoelectric module, and a negative power input end; The high-temperature heating end of the thermoelectric module is connected with the seawater evaporating heat exchanger; the positive power input end and the negative power input end of the thermoelectric module are respectively connected to the positive power output end of the solar power generating board and the negative output end of the power output; the liquid-gas separator, Used to separate water vapor from seawater that has not completely evaporated, and to discharge seawater that has not completely evaporated Discharge; seawater condensing heat exchanger coupled to the low temperature refrigerating end of the thermoelectric module for condensing water vapor into liquid water; and a water outlet coupled to the condenser to collect liquid water for output and use; a pressurizing motor for Driving seawater circulation system use.

The invention also discloses a seawater desalination device which is used together with a solar energy and a thermoelectric module, and considers that the solar photoelectric conversion is an unstable power source, especially on a cloudy day with low illumination, and is connected with a solar vacuum heat collecting tube coupled to the seawater inlet. The nozzle is parallel to the solar power board and the heat exchanger, and can replace the heating function of the solar power to drive the thermoelectric module; the surface of the vacuum heat pipe coated with the nano carbon black heat absorbing material can enhance the absorption of the solar radiant heat energy; the sea water passes the solar vacuum set At the inlet of the heat pipe, the seawater evaporates into high-temperature water vapor, and the outlet collects the water vapor and is connected to the liquid-gas separator; when the sunlight is insufficient (nighttime, cloudy or rainy days), the solar vacuum heat collecting tube collects heat energy more efficiently than solar power generation. Driving the high-temperature heating of the thermoelectric module; driving the seawater circulation system requires a pressurized motor, the motor power is from the solar panel power, considering that the solar photoelectric conversion is an unstable power source, and the pressure motor includes an energy storage battery to store and stabilize the power source.

The invention discloses a seawater desalination device which is combined with a solar energy and a thermoelectric module, and is arranged as follows, comprising: a water inlet, receiving seawater; a solar power generation panel, comprising a solar power generation panel and a vacuum heat collecting tube, a solar power panel power supply output positive end, and solar power generation a power supply output negative end; wherein the solar power panel receives sunlight energy into electrical power output, the solar vacuum heat collecting tube directly receives solar radiation heat energy; the seawater evaporation heat exchanger and the water vapor condensation heat exchanger; wherein the seawater evaporation heat exchange The device is coupled to the seawater inlet to evaporate and separate the seawater into water vapor and incompletely evaporated seawater; the thermoelectric module includes a high temperature heating end, a low temperature refrigerating end, a thermoelectric module power input positive end, and a thermoelectric module power input negative end. The high-temperature heating end of the thermoelectric module is connected with the seawater evaporating heat exchanger; the positive input end of the thermoelectric module power supply and the negative end of the power input of the thermoelectric module are respectively connected to the positive output end of the solar power board and the negative end of the power output of the solar power board; Vacuum collector tube coupled to seawater inlet, parallel to solar energy Evaporation of sea water between the plate and the heat exchanger; wherein the vacuum tube Bu Naimi coated carbon black substance absorbing solar radiation absorbed by the heat, when the auxiliary drive is insufficient sunlight thermoelectric power generation module, and the solar panels to the thermoelectric The module jointly supplies the evaporated seawater to the liquid-gas separator, separates the water vapor from the incompletely evaporated seawater, and discharges the incompletely evaporated seawater to the lower seawater storage tank via the liquid-gas separator; the water vapor passes through the condensation heat exchange The condensing heat exchanger is connected to the low temperature refrigerating end of the thermoelectric module for condensing the water vapor into a liquid fresh water; the fresh water outlet provides an output for use.

10‧‧‧Solar power panels

10-1‧‧‧Back of solar panel

10-2‧‧‧ Solar power board front

10-3‧‧‧Solar power panel power output positive terminal

10-4‧‧‧Solar power panel power output negative terminal

20‧‧‧Thermal module

20-1‧‧‧Cryogenic refrigeration end

20-2‧‧‧High temperature heating end

20-3‧‧‧Thermal module power input positive terminal

20-4‧‧‧Thermal module power input negative terminal

30‧‧‧Seawater Evaporation Heat Exchanger

30-1‧‧‧Back of seawater evaporation heat exchanger

30-2‧‧‧Seawater Evaporation Heat Exchanger Front

40‧‧‧Water vapor condenser

50‧‧‧ water inlet

60‧‧‧Water Vapor

70‧‧‧Liquid gas separator

70-1‧‧‧Liquid gas separator discharge pipe

80‧‧‧Seawater that has not completely evaporated

90‧‧‧Water outlet

100‧‧‧Solar vacuum collector

110‧‧‧Auxiliary power supply system

200‧‧‧Seawater desalination device for solar energy and thermoelectric module according to the first embodiment of the present invention

300‧‧‧Seawater desalination device for solar energy and thermoelectric module according to the second embodiment of the present invention

400‧‧‧Seawater desalination device for solar energy and thermoelectric module according to a third embodiment of the present invention

Figure 1 is a schematic view of a conventional polyvinylidene fluoride film seawater desalination apparatus.

2 is a seawater desalination apparatus used in combination with a solar energy and a thermoelectric module according to a first embodiment of the present invention.

3 is a seawater desalination apparatus used in combination with a solar energy and a thermoelectric module according to a second embodiment of the present invention.

Fig. 4 is a seawater desalination apparatus used in combination with a solar energy and a thermoelectric module according to a third embodiment of the present invention.

A detailed description of the embodiments of the present invention will be given below. While the invention will be described in conjunction with the embodiments, it is understood that the invention is not limited to the embodiments. Rather, the invention is to cover various modifications, equivalents, and equivalents of the invention as defined by the scope of the appended claims. It should be understood that the illustrations are not drawn to scale, and only a

Fig. 2 shows a seawater desalination apparatus 200 for use in combination with a solar energy and a thermoelectric module according to a first embodiment of the present invention. Seawater desalination device combined with solar energy and thermoelectric modules 200 includes a solar panel 10, a thermoelectric device 20, a seawater evaporation heat exchanger 30, a water vapor condensation heat exchanger 40, a liquid gas separator 70, a seawater inlet 50 and a fresh water outlet 90.

The solar panel 10 includes a solar panel front surface 10-2 and a solar panel back surface 10-1, a solar power source output terminal 20-3, and a solar power source output negative terminal 20-4. When the sunlight illuminates the front surface 10-2 of the solar panel, there is a voltage difference between the solar power output positive end 20-3 and the solar power output negative end 20-4, and the temperature absorbing the solar radiant heat is higher than the solar back 10 -1. The technical field in which the solar panel absorbs the electric power generated by the solar radiation and the temperature rise due to the radiant heat is a conventional technique, and will not be further described herein. At the latitude of Taiwan, the tilt angle of solar photovoltaic panels in summer and autumn is 23.5 degrees. The highest temperature in summer can often reach 50 degrees Celsius or above, that is, every 1 degree °C, the power generation will drop by 0.3~0.5%. .

The thermoelectric module 20 includes a high temperature heating end 20-2 and a low temperature refrigerating end 20-1, a thermoelectric module power input positive end 20-3, and a thermoelectric module power input negative end 20-4. When the thermoelectric module power input positive terminal 20-3 of the thermoelectric module device 20 has a voltage difference from the thermoelectric module power input negative terminal 20-4, a current will pass through the thermoelectric module 20, and then at the high temperature heating end 20- 2 A temperature difference is generated with the low temperature refrigerating end 20-1. The technical scope of the thermoelectric module 20 to generate the temperature difference is a conventional technique, and will not be further described herein.

The solar power panel power output positive terminal 20-3 and the solar power panel power output negative terminal 20-4 are respectively coupled to the thermoelectric module power input positive terminal 20-3 and the thermoelectric module power input negative terminal 20-4. In an embodiment, when the sunlight illuminates the front surface 10-2 of the solar power panel, the solar power panel 10-2 can maintain a high temperature of 50 ° C or higher, and the high temperature and thermoelectric module of the front surface of the solar power panel 10-2 The temperature difference of the low temperature refrigerating end 20-1 is about 42.3 ° C, which is enough to drive the temperature difference required by the desalination device.

The seawater evaporation heat exchanger 30 includes a heat exchanger front surface 30-2 and a heat exchanger back surface 30-1. The heat exchanger front surface 30-2 is coupled to the back surface 10-1 of the solar power generation panel 10 with a thermal conductive adhesive to absorb the high temperature generated by the solar radiation radiant heat on the solar panel 10. The heat exchanger back surface 30-2 is coupled to the high temperature heating end 20-2 of the thermoelectric module 20 to suck The high temperature generated by the heat generating module 20 on the high temperature heating end 20-2.

The water vapor condensing heat exchanger 40 is coupled to the low temperature refrigerating end 20-1 of the thermoelectric module 20 to condense the water vapor 60. In one embodiment, seawater enters the seawater evaporation heat exchanger 30 via the water inlet 50 to produce water vapor 60 and a portion of the seawater 80 that is not fully vaporized. During this process, salts or bacteria or most of the contaminant bodies in some of the water that are not completely evaporated do not evaporate. When the salinity in the water exceeds 26.3 wt.%, the salt of the solid precipitates and settles.

A liquid-gas separator (Solid-Gas Separator) 70 separates the water vapor 60 from the partially incompletely evaporated seawater 80, and discharges a portion of the incompletely evaporated seawater 80 through the liquid-gas separator discharge pipe 70-1. The steam 60 passes through the steam condensing heat exchanger 40 to condense the water vapor 60 into fresh water, and is discharged from the fresh water outlet 90.

In one embodiment, the seawater desalination apparatus of the present invention can produce 0.1 liters of fresh water per square meter in one hour, and the electrical energy required by the thermoelectric module is 0.032 kilowatt hours, which is equivalent to the energy consumption of 0.3 kilowatt hours per liter of fresh water. This part is used to generate electricity from the solar panels to the thermoelectric modules.

Compared with the conventional seawater desalination device, the device of the present invention uses the high temperature generated by receiving solar radiation and the high temperature heating end of the thermoelectric module to increase the ability of seawater to evaporate into fresh water, and simultaneously uses the low temperature refrigerating end of the thermoelectric module. Lower the temperature to improve the effect of water vapor condensation on fresh water. Therefore, the apparatus of the present invention is improved in increasing the production efficiency of producing fresh water and reducing the energy consumption.

In one embodiment, the outlet of the seawater evaporation heat exchanger 30 further includes a heat exchange outlet thermometer (not shown) for measuring the temperature and pressure of the conditioning water vapor 60. The condensation temperature of the water vapor 60 is determined by the temperature and pressure of the water vapor saturation state. The pressure of water vapor is in the range of 0.006~1 atmosphere, and the condensation temperature ranges from 0.0008 to 100 degrees Celsius. Therefore, the temperature of the high temperature heating end side of the thermoelectric module can be increased to increase the water vapor condensation temperature of the low temperature refrigerating end side of the thermoelectric module, or the water vapor pressure can be increased to increase the water vapor condensation temperature. In an embodiment, the thermoelectric The water vapor condensation temperature of the low temperature refrigerating end of the module can be adjusted by the temperature of the high temperature heating end of the thermoelectric module or the pressure of the high temperature water vapor.

Fig. 3 shows a seawater desalination apparatus 300 for use in combination with a solar energy and a thermoelectric module according to a second embodiment of the present invention. The seawater desalination apparatus 300 for solar energy and thermoelectric modules further includes a solar vacuum heat collecting tube 100 coupled between the solar panel 10 and the heat exchanger 30, as compared with the seawater desalination apparatus 200 used in combination with the solar energy and the thermoelectric module. The surface of the solar vacuum heat collecting tube 100 is coated with a nano carbon black heat absorbing material to further absorb solar radiant heat. In this way, in addition to increasing the pressure of the water vapor 60, the temperature of the water vapor 60 and the partially incompletely evaporated seawater 80 can be increased to 80 ° C to 130 ° C.

Fig. 4 shows a seawater desalination apparatus 400 for use in combination with a solar energy and a thermoelectric module according to a third embodiment of the present invention. The seawater desalination device 400 used in combination with the solar energy and the thermoelectric module further includes an auxiliary power supply system 110 electrically coupled to the positive end of the solar power output 20-3. With the solar power output negative terminal 20-4. When the sunlight is insufficient (night, cloudy or rainy), it is used to supply power to the thermoelectric module 20 together with the solar panel 10. Further improved thermoelectric symbiosis design and system efficiency optimization can be achieved by integrating the vacuum collector tubes of parallel fish solar panels to absorb solar energy and thermal energy with an auxiliary power supply system 110.

The device of the invention completely changes the seawater desalination treatment technology, and only needs to combine the solar panel and the thermoelectric module to convert the brine into fresh drinkable fresh water, without additionally consuming a large amount of heat energy to boil the seawater into water vapor, and then condensing into fresh water for use. Since solar energy photoelectric conversion and photothermal conversion are combined with electric energy and thermoelectric modules, the heat of solar radiation is not wasted. Together with the high temperature heating end of the thermoelectric device, the heat exchanger is used as a heat source for heating seawater, and the solar mode can be reduced. The temperature of the group further increases the power generation efficiency.

The above detailed description and the accompanying drawings are only typical embodiments of the invention. It is apparent that various additions, modifications and substitutions are possible without departing from the spirit and scope of the invention as defined by the appended claims. Those skilled in the art will appreciate that the present invention In practical applications, the form, structure, layout, proportion, materials, elements, components and other aspects may be changed according to the specific environment and work requirements without departing from the invention criteria. The presently disclosed embodiments are, however, to be construed as limited in

Claims (7)

A seawater desalination device combined with a solar energy and a thermoelectric module, comprising: a water inlet, receiving a seawater; a solar power panel comprising a solar power panel front surface, a solar power panel back surface, a solar power panel power output positive end, and a solar power panel power output negative end; wherein the solar panel power generating board receives a sunlight on the front side; a seawater evaporation heat exchanger coupled to the water inlet, including a seawater evaporation heat exchanger front surface and a seawater Evaporating the back of the heat exchanger to separate the seawater into a water vapor and an incompletely evaporated seawater; wherein the seawater evaporation heat exchanger has a front surface coupled to the back surface of the solar power panel; and a thermoelectric module including a high temperature heating a low temperature refrigerating end, a thermoelectric module power input positive end and a thermoelectric module power input negative end; wherein the high temperature heating end is coupled to the back of the seawater evaporating heat exchanger; the thermoelectric module power input positive end And the negative end of the power input of the thermoelectric module is respectively coupled to the positive end of the power output of the solar power board and the power supply of the solar power board a negative liquid end; a liquid-gas separator separating the water vapor and the incompletely evaporated seawater, and discharging the incompletely evaporated seawater through a liquid-gas separator discharge pipe; a water vapor condenser, and the thermoelectric mold The low temperature refrigerating end of the group is coupled to condense the water vapor into a liquid fresh water; and a water outlet is coupled to the water vapor condenser to collect and output the liquid fresh water. The apparatus of claim 1, wherein the front side of the seawater evaporation heat exchanger and the back side of the solar power generation panel are coated with a thermal conductive adhesive. The apparatus of claim 1, wherein the seawater evaporation heat exchanger further comprises a water outlet, wherein the water outlet further comprises an outlet thermometer and an outlet pressure gauge for respectively measuring the water vapor. Temperature and pressure. The device of claim 1, wherein the temperature difference between the high temperature heating end and the low temperature refrigerating end is up to 42.3 °C. The device of claim 4, wherein the temperature of the low temperature refrigerating end is adjustable according to the temperature of the high temperature heating end or the pressure of the water vapor. The apparatus of any one of claims 1 to 5, further comprising: a solar vacuum heat collecting tube coupled in parallel between the solar power generation panel and the seawater evaporation heat exchanger, wherein the vacuum heat pipe surface The nanocarbon black heat absorbing material is coated to absorb the radiant heat of the sunlight. The device of claim 6, further comprising: an auxiliary power supply system electrically coupled to the positive end of the solar power panel power output and the negative end of the solar power panel power output, wherein when the sunlight is insufficient The auxiliary power supply system is configured to supply power to the thermoelectric module together with the solar power panel.