All-weather working solar membrane distillation device

Abstract

The utility model discloses an all-weather working solar membrane distillation device. The all-weather working solar membrane distillation device comprises a photo-thermal assembly, a phase change assembly and a membrane distillation assembly from top to bottom, the photo-thermal assembly comprises a heat insulation layer, a photo-thermal layer and a first heat conduction layer which are arranged from top to bottom. The membrane distillation assembly comprises a heat conduction layer II, an evaporation layer, a hydrophobic membrane, a water supply layer, a condenser and a water storage chamber; the evaporation layer is located between the second heat conduction layer and the hydrophobic film, and the water supply layer communicates with the evaporation layer. The phase change assembly is located between the first heat conduction layer and the second heat conduction layer. The solar energy and phase change energy storage technology is utilized, all-weather efficient operation is guaranteed, and a new scheme is provided for reasonable and efficient utilization and sustainable development of water resources and solar energy resources.

Description

Technical Field

[0001] The utility model relates to the field of solar energy seawater desalination, in particular to a solar energy membrane distillation device working around the clock. Background Art

[0002] With the rapid development of social economy, the increasing urgency of fresh water and energy has become a global concern. Seawater desalination is considered one of the most effective solutions to solve the problem of water shortage. Compared with the mature seawater desalination technology that relies on fossil energy on the market, using the abundant clean renewable solar energy on the earth for seawater desalination can effectively alleviate the shortage of fresh water and energy.

[0003] Photothermal membrane distillation is a new hybrid technology that uses photothermal materials and membranes with integrated light absorption to collect solar energy through photothermal reactions to drive the membrane distillation process. Compared with traditional membrane distillation, a higher transmembrane temperature difference and a stronger driving force for vapor transfer are maintained, which improves the energy efficiency of membrane distillation. Photothermal membrane distillation can provide clean water in a more flexible configuration and compact modules, so it has application potential in some specific scenarios, such as small households and remote areas. It provides clean water in a cheap, modular, convenient and decentralized manner. Summary of the invention

[0004] The utility model aims to provide a solar membrane distillation device which works around the clock to make up for the shortcomings of the prior art.

[0005] Research on the design and preparation of solar membrane distillation devices that can operate around the clock without heat input at night has not yet been carried out.

[0006] The photothermal material in the utility model efficiently absorbs solar energy and converts it into thermal energy, driving the membrane distillation device to desalinate seawater; the phase change material stores the heat converted from photothermal energy, and releases the heat to drive the device to produce fresh water when there is no heat source input at night, thereby achieving all-weather operation and maximum application of solar energy.

[0007] In order to achieve the above purpose, the specific technical solution adopted by the utility model is:

[0008] A solar membrane distillation device that works around the clock, comprising from top to bottom: a photothermal component, a phase change component and a membrane distillation component; the photothermal component comprises a heat insulation layer, a photothermal layer and a heat conduction layer 1 arranged from top to bottom; the membrane distillation component comprises a heat conduction layer 2, an evaporation layer, a hydrophobic membrane, a water supply layer and a condenser, and a water storage chamber; the evaporation layer is located between the heat conduction layer 2 and the hydrophobic membrane, and the water supply layer is connected to the evaporation layer; the phase change component is located between the heat conduction layer 1 and the heat conduction layer 2; the water supply layer transports seawater to the evaporation layer through capillary action; the seawater in the evaporation layer evaporates under the action of heat, and the water vapor is condensed in the bottom condenser through the hydrophobic membrane, and the condensed fresh water is collected in the water storage chamber.

[0009] Furthermore, the solar membrane distillation device is provided with a shell on the outside, which is a frame body and can be a 3D printed frame.

[0010] Furthermore, the condenser is a fence-type condensation component.

[0011] Furthermore, the water supply layer and the evaporation layer are configured as an integrated structure.

[0012] Furthermore, the thermal insulation layer is a transparent silica aerogel, which has ultra-low thermal conductivity and high infrared opacity, and suppresses heat loss of the photothermal layer through conduction, convection and radiation.

[0013] Furthermore, the photothermal layer is a graphene and polypropylene slurry, which has high absorptivity and low emissivity in the infrared band to maximize energy input and achieve a high absorbance of 98.0% in the wavelength range of 200-2500 nm.

[0014] Furthermore, the first heat conduction layer and the second heat conduction layer are ultra-thin aluminum sheets, whose thermal conductivity is higher than 100 W / (m·K) and whose thickness is less than 1 mm.

[0015] Furthermore, the phase change component uses paraffin as the phase change material. During the day, the paraffin absorbs heat and stores energy, and at night, the paraffin releases heat to drive membrane distillation. At the same time, paraffin has good heat storage capacity, is simple to manufacture, and is cost-effective.

[0016] Furthermore, the water supply layer and the evaporation layer are both fiber membranes with good hydrophilicity and low thermal conductivity, which can be but not limited to natural or synthetic fiber membranes; preferably, they are super-hydrophilic nanocellulose membranes with a porosity higher than 95% and an average fiber diameter of 5-20 μm.

[0017] Furthermore, the hydrophobic membrane is a polytetrafluoroethylene selective permeable membrane, which allows water vapor molecules to pass through but does not allow liquid water to pass through, thereby achieving the separation of fresh water while preventing salt water or wastewater from penetrating.

[0018] The advantages and beneficial effects of the utility model are:

[0019] (1) Efficient energy utilization: The membrane distillation device uses solar energy to heat water, causing it to evaporate, and then separates the steam and salt through a membrane. Phase change materials can store heat energy when there is sufficient solar energy and release heat when there is insufficient sunlight, allowing the device to operate around the clock and improve energy efficiency.

[0020] (2) Stable water production: Since phase change materials can provide a stable heat supply at night or on cloudy days, the membrane distillation device can maintain a stable distillation temperature and pressure, ensuring a stable water production. This is especially important for application scenarios that require continuous water supply, such as fresh water supply in remote areas and islands.

[0021] (3) Improving water quality: Membrane distillation technology removes impurities from water, including salt, heavy metals, organic pollutants and pathogens, through evaporation and condensation processes. The application of phase change materials ensures the continuity and efficiency of this process, thereby improving the purity and quality of the produced water.

[0022] (4) Reduce thermal stress: During the membrane distillation process, temperature fluctuations will cause thermal stress on the membrane material, affecting the life of the membrane. Phase change materials reduce the thermal stress of the membrane material by maintaining a constant operating temperature, thereby extending the service life and maintenance cycle of the membrane.

[0023] (5) Economical and sustainable: Solar membrane distillation devices mainly use solar energy and phase change materials, do not require a large amount of fossil fuels, have low operating costs, and have good economical efficiency. At the same time, they reduce carbon emissions and environmental pollution, and have significant environmental benefits and sustainability.

[0024] (6) Modular design and flexible application: Membrane distillation units usually have a modular design and can be flexibly scaled according to demand. Combined with the application of phase change materials, the design can be optimized according to different geographical and climatic conditions to meet the water needs of different regions. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the structure of the solar membrane distillation device of the utility model which works around the clock.

[0026] Figure 2 It is a cross-sectional schematic diagram of the utility model's all-weather working solar membrane distillation device.

[0027] Figure 3 This is a front view of the solar membrane distillation device of the utility model that works around the clock.

[0028] Among them, 1-insulation layer, 2-photothermal layer, 3-heat conduction layer 1, 4-housing, 5-phase change component, 6-water supply layer, 7-hydrophobic membrane, 8-condenser, 9-heat conduction layer 2, 10-evaporation layer, 11-water storage chamber. DETAILED DESCRIPTION

[0029] The present invention is further explained and illustrated below through specific embodiments in conjunction with the accompanying drawings.

[0030] Example:

[0031] A solar membrane distillation device that works around the clock, such as Figure 1 As shown, from top to bottom, it includes: a photothermal component, a phase change component and a membrane distillation component, and an outer shell 4 that acts as a protective device; the photothermal component includes an insulating layer 1, a photothermal layer 2 and a heat conduction layer 3 arranged from top to bottom; the membrane distillation component includes a heat conduction layer 2 9, an evaporation layer 10, a hydrophobic membrane 7, a water supply layer 6 and a condenser 8, and a water storage chamber 11; the evaporation layer 10 is located between the heat conduction layer 2 9 and the hydrophobic membrane 7, and the water supply layer 6 is connected to the evaporation layer 10; the phase change component 5 is located between the heat conduction layer 1 3 and the heat conduction layer 2 9; the water supply layer 6 transports seawater to the evaporation layer 10 through capillary action; the seawater in the evaporation layer 10 evaporates under the action of heat, and the water vapor is condensed in the bottom condenser 8 through the hydrophobic membrane 7, and the condensed fresh water is collected in the water storage chamber 11.

[0032] In one embodiment, the thermal insulation layer 1 is a transparent silica aerogel having ultra-low thermal conductivity and high infrared opacity.

[0033] In one embodiment, the overall protective shell 4 of the device is a 3D printed polylactic acid frame with a thermal conductivity of less than 0.03 W / (m·K).

[0034] In one embodiment, the heat conducting layer 1 3 and the heat conducting layer 2 9 are ultra-thin aluminum sheets, the thermal conductivity of which is higher than 100 W / (m·K) and the thickness is less than 1 mm.

[0035] In one embodiment, the water supply layer 6 and the evaporation layer 10 are both fiber membranes with good hydrophilicity and low thermal conductivity, which may be but not limited to natural or synthetic fiber membranes; preferably, they are super-hydrophilic nanocellulose membranes with a porosity higher than 95% and an average fiber diameter of 5-20 μm.

[0036] In one embodiment, the hydrophobic membrane 3 is a polytetrafluoroethylene selective permeable membrane that allows water molecules to pass through but does not allow liquid water to pass through.

[0037] Sunlight passes through the transparent insulation layer 1 and irradiates the photothermal layer 2. The insulation layer 1 can be used to reduce heat loss and improve the overall thermal efficiency of the device. The photothermal layer 2 absorbs solar energy and converts it into thermal energy. The heat conduction layer 3 transfers the heat energy generated by the photothermal layer 2 to the phase change component 5. Under the action of the heat energy conducted by the photothermal layer 2, the phase change material absorbs heat and melts during the day to store heat energy. At night or when there is no light, the phase change material solidifies and releases the stored heat energy to ensure continuous heat supply and maintain the temperature stability of the evaporation layer. The low thermal conductivity shell 4 provides structural support and optimizes thermal management. The water supply layer 6 uniformly transports seawater to the evaporation layer 10 through capillary action. The seawater in the evaporation layer 10 evaporates under the action of heat to form water vapor. The water vapor passes through the hydrophobic membrane 7 and enters the condenser 8 at the bottom. The condenser 8 includes multiple built-in condensation walls, on which the water vapor condenses into fresh water. The condensed fresh water is collected in the water storage chamber 11 at the bottom of the condenser to form directly usable fresh water for drinking or other purposes.

[0038] The photothermal layer 2 is made of highly efficient light-absorbing materials, such as carbon nanotubes and polypropylene slurry. The heat-conducting layer 3 and the heat-conducting layer 9 have good thermal conductivity, such as copper or aluminum. The water supply layer 6 and the evaporation layer 10 are both made of fiber materials with good hydrophilicity and low thermal conductivity, and can be made of, but not limited to, cotton, sponge, cellulose or non-woven fabrics. Low thermal conductivity can effectively inhibit heat conduction to seawater, while good hydrophilicity can continuously transport seawater to the evaporation layer.

[0039] The bottom condenser 8 comprises a plurality of built-in condensation walls, on which water vapor condenses into liquid water after passing through the hydrophobic membrane. The condensation wall material needs to have good thermal conductivity and corrosion resistance, such as stainless steel or polytetrafluoroethylene-coated aluminum.

[0040] The cross-sectional diagram and main view of the solar membrane distillation device working around the clock are shown in the figure. Figure 2 , Figure 3 As shown, sunlight passes through the transparent heat-insulating layer 1, is absorbed by the photothermal layer 2 and converted into heat, and the heat is conducted to the phase change component 5 through the heat-conducting layer 3. During the day, the phase change component 5 works, the phase change material absorbs heat energy and melts, stores heat and transfers it to the evaporation layer. At night or in the absence of light, the phase change component 5 works, the phase change material solidifies, releases the stored heat, and transfers it to the evaporation layer 10. The evaporation layer 10 maintains a stable temperature to ensure continuous evaporation of seawater. As a heat source for steam generation, a thermal gradient is formed from the phase change component 5 to the condenser 8. The water supply layer 6 transfers seawater to the evaporation layer 10, and the evaporation layer 10 absorbs heat to evaporate the seawater. The generated water vapor passes through the hydrophobic membrane 7, and the water vapor is condensed into fresh water on the multiple condensation walls of the condenser 8 and collected in the water storage chamber 11.

[0041] In this embodiment, the design of the device achieves all-weather seawater desalination through effective photothermal conversion, phase change energy storage technology and membrane distillation process. During the day, the photothermal components efficiently absorb solar energy and store it in the phase change material. At night or in the absence of light, the phase change material releases the stored heat to maintain the continuous evaporation process. The seawater evaporates in the evaporation layer, and the water vapor condenses into fresh water in the condenser through the hydrophobic membrane, thereby achieving the purpose of seawater desalination. The device uses solar energy and phase change energy storage technology to ensure its efficient operation around the clock. The all-weather solar membrane distillation device provides a new solution for the rational and efficient utilization and sustainable development of water resources and solar energy resources.

[0042] Finally, although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A solar membrane distillation device that works around the clock, characterized in that: The device comprises, from top to bottom, a photothermal component, a phase change component and a membrane distillation component; the photothermal component comprises a heat insulation layer (1), a photothermal layer (2) and a first heat conduction layer (3) arranged from top to bottom; the membrane distillation component comprises a second heat conduction layer (9), an evaporation layer (10), a hydrophobic membrane (7), a water supply layer (6) and a condenser (8), and a water storage chamber (11); the evaporation layer (10) is located between the second heat conduction layer (9) and the hydrophobic membrane (7), and the water supply layer (6) is connected to the evaporation layer (10); the phase change component (5) is located between the first heat conduction layer (3) and the second heat conduction layer (9); the water supply layer (6) transports seawater to the evaporation layer (10) through capillary action; the seawater in the evaporation layer (10) evaporates under the action of heat, and the water vapor is condensed in the bottom condenser (8) through the hydrophobic membrane (7), and the condensed fresh water is collected in the water storage chamber (11).

2. The solar membrane distillation device according to claim 1, characterized in that: A shell (4) is provided on the outside of the solar membrane distillation device.

3. The solar membrane distillation device according to claim 1, characterized in that: The condenser (8) is a fence-type condensation component.

4. The solar membrane distillation device according to claim 1, characterized in that: The water supply layer (6) and the evaporation layer (10) are provided as an integrated structure.

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