Air water taking device based on temperature-sensitive hydrogel and semiconductor refrigeration and application of air water taking device

Abstract

The invention provides an air water-taking device based on temperature-sensitive hydrogel and semiconductor refrigeration and application thereof.The air water-taking device comprises a solar power supply module used for providing part of electric energy for the whole air water-taking device; the temperature-sensitive hydrogel adsorption bed is used for adsorbing the introduced high-humidity gas to obtain moisture; the semiconductor chilling plate provides low-temperature and high-temperature surfaces required by desorption and condensation at the same time; the desorption side is located on the heating side of the semiconductor chilling plate and connected with the fin type adsorption bed coated with the temperature-sensitive hydrogel, and the condensation chamber is located on the refrigeration side and used for condensing desorbed water vapor into liquid water and finally collecting the liquid water into the water storage tank. The desorption and condensation processes in the air water taking process can be achieved at the same time through cold energy and heat energy generated in the working process of the semiconductor chilling plate, the energy utilization efficiency in the air water taking process is greatly improved, and the device is suitable for providing stable water source supply for high-humidity areas such as hot and tropical islands and ocean vessels.

Description

Technical Field

[0001] The present invention relates to the technical field of unconventional water extraction, and in particular to an air water extraction device based on temperature-sensitive hydrogel and semiconductor refrigeration and applications thereof. Background Art

[0002] With the increase in population and the development of industry, mankind is facing an unprecedented shortage of fresh water resources. According to relevant surveys, there are currently about 2.1 billion people in the world who cannot access safe drinking water. It is estimated that by 2023, there will be a gap of more than 40% between the demand and supply of fresh water. Taking my country as an example, the per capita water resources in China are only 2,100 cubic meters, which is only 28% of the world's per capita level. China is one of the most water-scarce countries in the world.

[0003] At present, the main sources of fresh water supply in most areas are underground and surface water resources, and some inland areas also store rainwater as an unconventional source. However, these water extraction methods are affected by factors such as climate and geographical location, and are not suitable for all water-scarce areas. Large-scale water supply facilities and power supply are also required. However, in environments such as offshore islands and ocean-going ships, the existing conventional water extraction technology cannot fully meet human needs. Therefore, humans urgently need to develop unconventional water source acquisition technologies to increase water supply flexibility.

[0004] The total amount of fresh water resources on Earth is approximately 35 million km 3 , of which there are 24 million km 3 (68.7%) is stored in Antarctica, the Arctic and the plateau in the form of glaciers or snow. The total amount of fresh water resources available to humans is only 1 million km 3 . However, there are abundant water vapor resources in the earth's atmosphere. The development of atmospheric water harvesting (AWH) technology is expected to greatly improve the water shortage problem in some areas. At present, atmospheric water harvesting technologies mainly include surface cooling technology and adsorption water collection technology. Surface cooling technology mainly uses condensation to obtain water, which is suitable for high humidity areas. Adsorption water collection technology has lower requirements for air humidity, but because it goes through the three processes of adsorption-desorption-condensation (desorption absorbs heat, condensation releases heat), it consumes more energy.

[0005] In recent years, semiconductor refrigeration technology has developed rapidly. Its basic principle is that by applying direct current between PN semiconductors, a cooling effect can be generated at one end and a heating effect can be generated at the other end. This type of refrigeration sheet can respond quickly to achieve precise temperature control, and the cooling and heating modes can be switched by changing the direction of the current. In the field of air-to-water extraction, semiconductor refrigeration sheets are often used as cold sources in surface cooling technology or the condensation process of air-to-water extraction to obtain fresh water, but this also means that the heat generated at the hot end is not utilized and dissipated in the external environment.

[0006] Therefore, the existing technology needs to be further optimized and developed. Summary of the invention

[0007] Aiming at the deficiencies of existing air water extraction devices in high humidity areas, the present invention provides an air water extraction device based on temperature-sensitive hydrogel and semiconductor refrigeration and an application method thereof.

[0008] According to the present invention, an air water extraction device based on thermosensitive hydrogel and semiconductor refrigeration includes a solar power supply module, a thermosensitive hydrogel adsorption bed, a semiconductor refrigeration sheet (desorption side, located on the heating side of the semiconductor refrigeration sheet; condensation chamber, located on the cooling side of the semiconductor refrigeration sheet), a control module, an air filter module and a water storage tank. The solar power supply system includes a solar photovoltaic panel, a photovoltaic inverter and a battery; the thermosensitive hydrogel adsorption bed includes a fin-type heat sink and a hygroscopic hydrogel; the semiconductor refrigeration sheet is connected to the fins installed on the desorption side and the cooling side; the control module is composed of a temperature and humidity sensor connected to the heat sink and the front side of the adsorption bed and a control circuit; the water collection tank is arranged below the fin-type refrigeration fins to receive the liquid water obtained by condensation; the refrigeration fins and the thermosensitive hydrogel adsorption bed are placed horizontally and parallel, and the two are separated by a semiconductor refrigeration sheet and an insulating guide plate.

[0009] Furthermore, the solar power supply system is used to provide part of the electric energy for the semiconductor cooling plate, the axial flow fan and the control unit. The input current of the solar photovoltaic panel is stored in the battery through the photovoltaic inverter.

[0010] Furthermore, the photovoltaic inverter in the solar power supply system is an MPPT inverter.

[0011] Furthermore, the thermosensitive hydrogel adsorption bed is arranged on the fin part of the heating side, and the thermosensitive hydrogel adsorbent has good adhesion with the heat dissipation fin, ensuring close contact with the heat-conducting copper plate. The number of adsorption beds ranges from 10 to 30, and the thickness of the adsorption bed is between 0.5 and 3 mm.

[0012] Furthermore, the semiconductor refrigeration sheet is connected to the fins on the cooling side and the heat dissipation side through thermal grease to increase heat transfer efficiency and reduce heat loss.

[0013] Furthermore, the input voltage range of the semiconductor refrigeration chip is 3-48 V, the operating temperature range of the cooling side surface is -15-20°C, and the operating temperature range of the heat dissipation side surface is 30-60°C. Different desorption and cooling temperatures are maintained by adjusting the input voltage.

[0014] Furthermore, the plate spacing of the finned adsorption bed is 3mm, which fully contacts the wet air flowing through it and increases the water production. In addition, the cooling plate and the hydrophobic surface are both environmentally friendly materials, avoiding secondary pollution of liquid water.

[0015] Furthermore, heat-insulating guide plates are provided between the heat-dissipating fins and the semiconductor refrigeration fins and at the redundant parts of the fins to reduce the influence of the heat-dissipating section of the semiconductor refrigeration fins on the condensation and water extraction.

[0016] Furthermore, an axial flow fan is provided inside the cabin of the air water intake device, which can introduce external humid air into one side of the adsorption bed, thereby increasing the air flow speed, improving the desorption and condensation effects, and reducing the overall energy consumption.

[0017] Furthermore, the control unit is mainly composed of a temperature and humidity sensor and an intermediate relay controller. The patch thermocouple in the temperature control module is connected below the temperature-sensitive hydrogel adsorption bed to detect the temperature of the adsorption bed on the desorption side. The temperature sensor is arranged on the inlet and outlet sides and inputs the signal to the intermediate relay controller; the intermediate relay is connected to the semiconductor refrigeration sheet, and when the heating side of the semiconductor refrigeration sheet reaches the preset temperature for a certain period of time, the relay disconnects from the power supply circuit.

[0018] Furthermore, the air filter module is composed of a low-resistance H12-level HEPA filter. The air introduced by the axial flow fan is purified through the air filter module, thereby preventing harmful substances such as germs, dust, and heavy metals from entering the system and contaminating the obtained fresh water.

[0019] Furthermore, the method for preparing the salt-loaded salt gel adsorption bed comprises the following steps: Step S1, dissolving a certain mass of N-isopropylacrylamide, acrylic acid, N,N-methylenebisacrylamide, and ammonium persulfate in water in a certain ratio to prepare a gel precursor solution, wherein the corresponding mass ratio is 50:50:10~1:5~1.

[0020] Step S2, pouring the gel precursor solution into the mold, heating to 50°C-70°C, and reacting for 5-12 hours until gelation.

[0021] Step S3, freeze-drying the obtained gel for 12 to 24 hours to obtain a porous gel.

[0022] Step S4, soaking the obtained porous gel in a 5-37.5 wt % lithium chloride aqueous solution for 12-24 h, and drying at 90° C. to obtain a thermosensitive hygroscopic hydrogel.

[0023] Furthermore, the present invention collects water vapor in high-humidity air through a thermosensitive hygroscopic adsorbent adsorption bed, and desorbs it through the high temperature of the heating side of the semiconductor refrigeration plate. The desorbed high-humidity airflow passes through the cooling side on the other side to condense into liquid water, and is collected through the water collection tank below to complete the air water extraction process.

[0024] According to the present invention, an air water extraction device based on temperature-sensitive hydrogel and semiconductor refrigeration and an application method thereof are provided, and the specific working process thereof includes: Step S1, the photovoltaic panel receives sunlight to obtain electrical energy and stores it in the battery. When the system needs electricity, the battery discharges it to ensure the normal operation of the system; Step S2, the axial flow fan is started to introduce external air into the cabin of the air water intake device. After the high-humidity air flows through the temperature-sensitive hydrogel adsorption bed, the water vapor is captured by the adsorbent, and the remaining air is discharged from the device; Step S3, when the relative humidity RH (Relative Humidity) received at the inlet side is less than the relative humidity at the outlet side, the axial flow fan stops working and the semiconductor cooling sheet starts working; Step S4, when the temperature of the temperature sensor on the heating side of the semiconductor refrigeration plate reaches the set temperature, the cavity air inlet is closed; Step S5, when the working time of the semiconductor refrigeration plate reaches the set time, the axial flow fan starts to work, and the desorbed saturated humidity water vapor is brought into the condensation fins of the semiconductor refrigeration plate, and the water vapor is condensed into liquid water.

[0025] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention enriches water vapor through a thermosensitive hygroscopic hydrogel adsorbent, and the desorption energy required by the adsorbent is relatively low, so that low-energy atmospheric water collection can be achieved; 2. The design adopted by the present invention is ingenious and occupies a small area. It can rely on solar energy or directly use electric energy to realize the process of air water extraction. The energy source is wide and the overall compatibility of the system is strong; 3. The present invention utilizes both the cold source and the heat source in the refrigeration process of the semiconductor refrigeration sheet, with high energy utilization rate, and is suitable for use on offshore islands and ships; 4. The present invention utilizes a high-efficiency moisture absorbent and a semiconductor refrigeration sheet to solve the problems of low water intake per unit mass of the adsorbent and long system regeneration time in the existing water intake device, thereby greatly improving the efficiency of preparing pure water per unit mass of the adsorbent; 5. The present invention adopts PID circuit and program automation control to ensure the efficient operation of the overall device. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is an appearance diagram of an air water extraction device based on temperature-sensitive hydrogel and semiconductor refrigeration provided by the present invention.

[0027] Figure 2 A front view of an air water extraction device based on temperature-sensitive hydrogel and semiconductor refrigeration provided by the present invention.

[0028] Figure 3 A side view of an air water extraction device based on temperature-sensitive hydrogel and semiconductor refrigeration provided by the present invention.

[0029] Figure 4 A top view of an air water extraction device based on temperature-sensitive hydrogel and semiconductor refrigeration provided by the present invention.

[0030] Figure 5 A side cross-sectional view of an air water extraction device based on temperature-sensitive hydrogel and semiconductor refrigeration provided by the present invention.

[0031] As shown in the figure: 1. Air water intake device cabin 2. Water collection tank 3. Cooling end thermal fins 4. Semiconductor cooling plate 5 Heating section thermal fins 6. Air filter module 7. Temperature and humidity sensor 8. Axial fan 9. Integrated control panel 10. Heat insulation guide plate DETAILED DESCRIPTION

[0032] This specification will elaborate the present invention through specific embodiments. These embodiments are intended to enable professionals in the relevant technical field to have a deeper understanding of the essence and characteristics of the present invention, but do not constitute any limitation to the present invention. It should be emphasized that for those skilled in the art, various modifications and optimizations can be made without departing from the core concept of the present invention. These modifications and optimizations are also considered to be within the scope of protection of the present invention.

[0033] In order to facilitate the understanding of the embodiments of the present invention, the following will be further explained with reference to the drawings by taking specific implementation modes as examples, and each implementation mode does not constitute a limitation on the embodiments of the present invention.

[0034] Specific implementation method 1: Figure 1 As shown, an air water extraction device based on thermosensitive hydrogel and semiconductor refrigeration is provided according to the present invention. It includes a solar power supply module, a thermosensitive hydrogel adsorption bed, a semiconductor refrigeration sheet (desorption side, located on the heating side of the semiconductor refrigeration sheet; condensation chamber, located on the cooling side of the semiconductor refrigeration sheet), a control module, an air filter module and a water storage tank.

[0035] The solar power supply system includes a solar photovoltaic panel, an MPPT photovoltaic inverter and a battery.

[0036] like Figure 5 As shown, the air water extraction device cavity (1) is divided into two parts by a semiconductor cooling plate (4), the temperature-sensitive hydrogel adsorption bed is arranged on the heating side (5) of the semiconductor cooling plate, and is distributed in parallel with the cooling heat-conducting fins (3) on the other side, and the water collection tank (2) is located directly below the cooling heat-conducting fins.

[0037] In this embodiment, the thermosensitive hydrogel adsorption bed is composed of N-isopropylacrylamide, acrylic acid, N,N-methylenebisacrylamide, ammonium persulfate and lithium chloride. 1g of the thermosensitive hydrogel adsorbent can absorb 1.2g of water vapor under 70%RH, and the desorption temperature is 40-60°C.

[0038] Specifically, the air water-taking hydrogel prepared by the present invention is mainly aimed at the temperature difference requirements between high-humidity areas and the two sides of the semiconductor refrigeration plate, so the present invention adopts a thermosensitive and efficient hygroscopic hydrogel composed of N-isopropylacrylamide, acrylic acid, N,N-methylenebisacrylamide, ammonium persulfate and lithium chloride. This thermosensitive hydrogel has the advantages of good hygroscopicity under high humidity conditions, low critical solution temperature (LCST), low desorption temperature and small desorption energy. When combined with a semiconductor refrigeration plate and a solar power supply system, it can effectively increase the water production efficiency.

[0039] Furthermore, the method for preparing the air water extraction hydrogel packed bed used in the present invention comprises the following steps.

[0040] The preparation method of the adsorbent packed bed (7) whose filling adsorption material is agar hydrogel + LiCl composite adsorption material comprises the following steps: Step S1, dissolving 3 g of N-isopropylacrylamide, 3 g of acrylic acid, 0.5 g of N,N-methylenebisacrylamide, and 0.2 g of ammonium persulfate in water according to a certain ratio to prepare a gel precursor solution; Step S2, pouring the gel precursor solution into a prefabricated mold, heating to 70° C., and reacting for 12 hours until gelation; Step S3, freeze-drying the obtained gel for 24 hours to obtain a porous gel; Step S4, soaking the obtained porous gel in a 20 wt % lithium chloride aqueous solution for 12 h, and drying at 90° C. to obtain a thermosensitive hygroscopic hydrogel.

[0041] In this embodiment, the control system is a PID circuit, which is composed of a temperature sensor and a humidity sensor (7) connected to the cooling side and the heat dissipation side and a control circuit.

[0042] Furthermore, in order to prevent the leakage of salt solution during the moisture absorption process of the air-water gel prepared by the present invention, a hydrophobic porous fiber membrane is used to encapsulate the thermosensitive hydrogel adsorption bed in this embodiment.

[0043] Specifically, the fiber membrane material can be produced by electrospinning, biaxial stretching, melt spinning and the like. The fiber membrane has the advantages of large specific surface area, good air permeability and large contact area, and thus will not affect the adsorption and desorption rates of the hydrogel adsorbent.

[0044] An induced draft fan is arranged in the cavity of the air water intake device, and the induced draft fan adopts an axial flow fan (8). Through the above-mentioned unitized arrangement, the air water intake device of this embodiment forms an internal gas flow system connected to the external air, and is coordinated by the control system.

[0045] After the PID control unit receives input signals from the inlet temperature and humidity sensor and the outlet temperature and humidity sensor (8), the temperature and humidity sensing signal output ends of the sensors are connected to the controller in the control circuit, and then the output signal of the controller is connected to the semiconductor cooling plate, thereby determining the adsorption and desorption state of the air water intake device.

[0046] In the embodiment described in this invention, an air water extraction device based on thermosensitive hydrogel and semiconductor refrigeration and its application can timely and accurately monitor the working state of the thermosensitive hydrogel adsorption bed through the temperature and humidity sensors at the inlet and outlet. When the outlet humidity is greater than or equal to the inlet humidity, the semiconductor refrigeration sheet starts to work, and the adsorbent desorbs a large amount of high-humidity water vapor. At the same time, it contacts the low-temperature heat-conducting fins on the condensation side, liquefies and is collected by the water collection tank. The present invention adopts PID circuit control, and the air water extraction device can work independently, run for a long time, and achieve continuous water production.

[0047] In this embodiment, the heat insulating guide plate (10) is made of a ceramic plate with a thickness of 4 mm.

[0048] In this embodiment, the spacing between the heat-conducting fins on the heating side connected to the semiconductor refrigeration plate is 10 mm, the number is 10, and the fin material is copper. The spacing between the heat-conducting fins on the condensing side connected to the semiconductor refrigeration plate is 5 mm, the number is 20, and the fin material is aluminum.

[0049] In this embodiment, the air water intake device prepared by the present invention is provided with an air filter module, and the HEPA filter used is of H12 grade, and the filtration efficiency for PM0.3 particles is above 99.9%, and the material is melt-blown electret fiber.

[0050] In summary, in this embodiment, the present invention provides an air water extraction device based on thermosensitive hydrogel and semiconductor refrigeration and its application. Its basic working process is to use an axial fan to let the high-humidity air from the outside enter the cavity of the air water extraction device through the air filter module, and then be adsorbed by the thermosensitive hygroscopic hydrogel. The adsorption bed after adsorption is saturated and desorbed on the heating side of the semiconductor refrigeration plate. At the same time, the desorbed saturated water vapor is contacted and liquefied by the low-temperature heat-conducting fins on the condensation side, so that liquid water is obtained and collected by the water collection tank. The present invention makes full use of the low-temperature desorption temperature of the thermosensitive adsorption bed and the high-temperature and low-temperature interfaces provided by the semiconductor refrigeration plate, greatly improving the energy utilization efficiency of the entire air water extraction device.

[0051] It should be understood that the above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An air water extraction device based on thermosensitive hydrogel and semiconductor refrigeration and its application, which includes a solar power supply module, a thermosensitive hydrogel adsorption bed, a semiconductor refrigeration sheet (desorption side, located on the heating side of the semiconductor refrigeration sheet; condensation chamber, located on the cooling side of the semiconductor refrigeration sheet), a control module, an air filter module and a water storage tank.

2. The air water extraction device according to claim 1, characterized in that The solar power supply system includes a solar photovoltaic panel, a photovoltaic inverter and a battery, which can provide part of the electrical energy for the device.

3. The air water extraction device and its application according to claim 1, characterized in that The air water intake device cavity (1) is divided into two parts by a semiconductor cooling plate (4), the adsorption bed is arranged on the heating side (5) of the semiconductor cooling plate and is distributed in parallel with the cooling heat conducting fins (3) on the other side, and the water collecting tank (2) is located directly below the cooling heat conducting fins.

4. The air water extraction device according to claim 3, characterized in that The adsorption bed is a thermosensitive hydrogel adsorption bed. When the temperature is higher than the LCST temperature, the thermosensitive hydrogel will quickly change from hydrophilicity to hydrophobicity, thereby reducing the difficulty of water vapor desorption.

5. The adsorption bed of the air water extraction device according to claim 4, characterized in that: The preparation method of the salt-loaded water gel adsorption bed comprises the following steps: Step S1, dissolving a certain mass of N-isopropylacrylamide, acrylic acid, N,N-methylenebisacrylamide, and ammonium persulfate in water in a certain ratio to prepare a gel precursor solution. The corresponding mass ratio is 50:50:10~1:5~1; Step S2, pouring the gel precursor solution into a mold, heating to 50°C to 70°C, and reacting for 5 to 12 hours until gelation; Step S3, freeze-drying the obtained gel for 12 to 24 hours to obtain a porous gel; Step S4, soaking the obtained porous gel in a 5-37.5 wt % lithium chloride aqueous solution for 12-24 h, and drying at 90° C. to obtain a thermosensitive hygroscopic hydrogel.

6. The air water extraction device and application thereof according to claim 3, characterized in that: The semiconductor refrigeration sheet is connected to the fins on the cooling side and the heat dissipation side through thermal grease, thereby increasing the heat transfer efficiency and reducing the heat loss.

7. The air water extraction device and application thereof according to claim 3, characterized in that: Heat-insulating guide plates are provided between the heat-dissipating fins and the semiconductor refrigeration sheet and on the redundant parts of the fins to reduce the influence of the heat-dissipating section of the semiconductor refrigeration sheet on the condensation and water extraction.

8. According to the air water extraction device and its application as claimed in claim 3, the input voltage range of the semiconductor refrigeration plate is 3-48 V, the operating temperature range of the cooling side surface is -15-20 ° C, and the operating temperature range of the heat dissipation side surface is 30-60 ° C. Different desorption and cooling temperatures are maintained by adjusting the input voltage.

9. The air water intake device and application thereof according to claim 3, wherein an axial flow fan is provided inside the cabin of the air water intake device.

10. According to the air water extraction device and its application as described in claim 3, the control unit is mainly composed of temperature and humidity sensors and an intermediate relay controller. The patch thermocouple in the temperature control module is connected below the thermosensitive hydrogel adsorption bed to detect the adsorption bed temperature on the desorption side. The temperature sensor is arranged on the inlet and outlet sides and inputs the signal to the intermediate relay controller; the intermediate relay is connected to the semiconductor refrigeration sheet, and when the heating side of the semiconductor refrigeration sheet reaches the preset temperature for a certain period of time, the relay disconnects from the power supply circuit.

11. According to the air water extraction device and application thereof as claimed in claim 3, the air filter module is composed of a low resistance H12 level HEPA filter.

Images