阅读说明：本技术 一种毛细管阵列供水光热界面蒸发结构和方法 (Capillary array water supply photo-thermal interface evaporation structure and method ) 是由 骆周扬 申震 刘春红 祁志福 陈彪 吴恒刚 吴善宏 于 2020-04-30 设计创作，主要内容包括：本发明涉及毛细管阵列供水光热界面蒸发结构,包括水源、隔热材料、毛细管、光热转化材料和光源；隔热材料固定或漂浮于水源上方,毛细管排列成阵列结构嵌入隔热材料中,毛细管下端接触水源,毛细管上端与光热转化材料接触；水源中的液体通过毛细管进入光热材料蒸发界面,在光源照射下蒸发。本发明的有益效果是：本发明利用毛细管阵列嵌入隔热材料中,为光热转化材料供水,同时实现良好的汲水和隔热效果,并且具有更精确简单的供水-热损失平衡的调节性能,实现高效的光-热界面蒸发,获得更高的太阳能利用效率。(The invention relates to a capillary array water supply photo-thermal interface evaporation structure, which comprises a water source, a heat insulation material, a capillary, a photo-thermal conversion material and a light source; the heat insulating material is fixed or floats above the water source, the capillaries are arranged into an array structure and embedded into the heat insulating material, the lower ends of the capillaries are contacted with the water source, and the upper ends of the capillaries are contacted with the photothermal conversion material; liquid in the water source enters the evaporation interface of the photo-thermal material through the capillary tube and is evaporated under the irradiation of the light source. The invention has the beneficial effects that: the invention utilizes the capillary array to be embedded into the heat insulation material to supply water for the photothermal conversion material, simultaneously realizes good water absorption and heat insulation effects, has more accurate and simple water supply-heat loss balance adjusting performance, realizes high-efficiency light-heat interface evaporation, and obtains higher solar energy utilization efficiency.)

1. The utility model provides a capillary array supplies water light and heat interface evaporation structure which characterized in that: comprises a water source (1), a heat insulation material (2), a capillary tube (3), a photothermal conversion material (4) and a light source (5); the heat insulation material (2) is fixed or floats above the water source (1), the capillaries (3) are arranged into an array structure and embedded into the heat insulation material (2), the lower ends of the capillaries (3) are contacted with the water source (1), and the upper ends of the capillaries (3) are contacted with the photothermal conversion material (4).

2. The capillary array water-supplying photothermal interface evaporation structure of claim 1, wherein: the water source (1) comprises seawater free of suspended particulate matter, fresh water, non-corrosive industrial waste water or non-corrosive organic reagents.

3. The capillary array water-supplying photothermal interface evaporation structure of claim 1, wherein: the heat insulation material (2) comprises polystyrene, polyurethane hydrophobic white foam or aerosol; the thickness of the heat insulation material (2) is 1-6 cm.

4. The capillary array water-supplying photothermal interface evaporation structure of claim 1, wherein: the capillary tube (3) comprises a glass tube, a plastic tube or a ceramic tube with hydrophilic inner wall surface; the length of the capillary tube (3) is 1-2cm greater than the thickness of the heat insulating material (2), and the radius r of the capillary tube satisfies the formulaWherein gamma is the surface tension coefficient of a water source, theta is the contact angle of liquid and the capillary, rho is the density of the liquid, g is the acceleration of gravity, and h is the length of the capillary.

5. The capillary array water-supplying photothermal interface evaporation structure of claim 1, wherein: the photothermal conversion material (4) comprises single-layer or multi-layer black dyeing fiber cloth with the light absorption rate of more than or equal to 80%, carbon-based material deposition cloth, plasma deposition cloth or carbon-based material blending gel.

6. The capillary array water-supplying photothermal interface evaporation structure of claim 1, wherein: the light source (5) comprises simulated sunlight, sunlight under natural conditions or concentrated sunlight obtained by a light-concentrating device, and the illumination area range of the light source is larger than that of the photothermal interface evaporation area.

7. A capillary array arrangement method of the capillary array water-supplied photothermal interface evaporation structure according to claim 1, comprising the steps of:

step 1), arranging the capillary arrays into corresponding polar coordinate equidistant divergence circles or rectangular coordinate equidistant rectangles according to the photo-thermal interface evaporation plane shape;

step 2), the number and the spacing of the capillaries in the array are adjusted according to the photothermal evaporation water supply-heat loss balance: the number of capillaries is increased and the spacing is reduced when the water supply demand is high; if the heat loss is too high, the number of capillaries is reduced, and the spacing is increased;

step 3), regulating and controlling the phenomenon of salt deposition on the photo-thermal interface: setting an initial interval; when the salt accumulation phenomenon is not generated in the photo-thermal evaporation process, the number of the capillaries is reduced according to the multiplying power, and the spacing is increased at equal intervals until the salt accumulation phenomenon is generated.

8. The evaporation method of the capillary array water-supplied photothermal interface evaporation structure of claim 1, wherein: liquid in the water source (1) is drawn into the photothermal conversion material (4) through the capillary (3) and undergoes photothermal interface evaporation under the irradiation of the light source (5).

Technical Field

The invention relates to the field of seawater desalination and photothermal evaporation, in particular to a capillary array water supply photothermal interface evaporation structure and a method.

Background

The solar seawater desalination thermal method technology mainly utilizes solar photo-thermal resources to heat seawater, phase change evaporation is carried out on the seawater, and fresh water is obtained through condensation and collection. The photo-thermal solar seawater desalination technology has the advantages of high efficiency, low cost, simple maintenance and the like, and is the mainstream solar seawater desalination technology at present. In the traditional seawater desalination or solar distiller adopting multilevel evaporation and other thermal methods, a heat absorbing medium comprises seawater and a substrate, so that water in an evaporation part is heated, and finally discharged concentrated water is heated. Although the heated concentrated water can be subjected to heat recovery through a heat exchanger or the water body is preheated by using latent heat of condensation in a large-scale seawater desalination facility, the problem of heat loss of the concentrated water is inevitable; in a small-sized seawater desalination plant, the heat loss ratio brought by directly discharging concentrated water is almost equivalent to the concentrated water-evaporation flow ratio. The interface evaporation method is that light absorbing material is arranged at the interface between sea water and air, the thin liquid layer at the interface is heated and evaporated, and the sea water is continuously absorbed to the heating interface by the water absorbing core or the floating water absorbing material, so that the photo-thermal evaporation process is continuously carried out. The heating mode effectively applies the heat energy converted from sunlight to the thin liquid layer at the interface, and can greatly reduce the heat loss in the evaporation process, thereby improving the evaporation temperature and efficiency. The relevant documents are: zhang Xuan radium, Bo Yuan and Liu Qiang in electric power science and engineering, 2017,33(12):1-8, published "New technical development State of solar seawater desalination" [ J ]; solar-drive interfacial deployment, published in Nat energy3, 1031-1041 (2018), by Tao, p., Ni, g, Song, c.

The main characteristic and advantage of the light-heat interface evaporation technology is that the heat loss in the evaporation heating process is reduced, and particularly the heat leakage loss to seawater is reduced. The technology therefore requires separating the photo-thermal material from the seawater by an insulating material, drawing water from the seawater to the heating interface with as small an area of water conducting channel as possible. However, this technique also requires a comprehensive balance of the water supply-heat loss relationship: if the area of the water guide channel is too small or the water guide efficiency is not high, although the heat leakage loss of the photo-thermal material can be reduced, the evaporation interface is not supplied with water sufficiently, the photo-thermal evaporation efficiency is reduced, a serious salt accumulation phenomenon is caused, the light receiving area is reduced, and the photo-thermal evaporation efficiency is further reduced. The prior art adopts cotton cloth, gauze and other fiber cloth as a water absorption unit, and has the defects of low water absorption efficiency, high heat loss rate, uncontrollable water absorption channel area adjustment and the like. The relevant documents are: ni, G., Zandavi, SH., et al, Energy environ, Sci, 2018,11,1510-1519, A salt-requiring flowing plastic for low-cost evaluation.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a capillary array water supply photo-thermal interface evaporation structure and a method.

The capillary array water supply photo-thermal interface evaporation structure comprises a water source, a heat insulation material, a capillary, a photo-thermal conversion material and a light source; the heat insulating material is fixed or floats above the water source, the capillaries are arranged into an array structure and embedded into the heat insulating material, the lower ends of the capillaries are contacted with the water source, and the upper ends of the capillaries are contacted with the photothermal conversion material; liquid in the water source enters the evaporation interface of the photo-thermal material through the capillary tube and is evaporated under the irradiation of the light source.

Preferably, the method comprises the following steps: the water source comprises seawater free of suspended particulate matter, fresh water, non-corrosive industrial waste water or non-corrosive organic reagents.

Preferably, the method comprises the following steps: the heat insulating material comprises polystyrene with the thermal conductivity coefficient less than or equal to 0.1W/(m.K), polyurethane hydrophobic white foam or aerosol; the thickness of the heat insulation material is 1-6 cm.

Preferably, the method comprises the following steps: the capillary tube comprises a glass tube, a plastic tube or a ceramic tube with hydrophilic inner wall surface; the length of the capillary tube is 1-2cm greater than the thickness of the heat insulating material, and the radius r of the capillary tube satisfies the formula(where γ is the water source surface tension coefficient, θ is the contact angle of the liquid and the capillary, ρ is the liquid density, g is the gravitational acceleration, and h is the capillary length).

Preferably, the method comprises the following steps: the photothermal conversion material comprises single-layer or multi-layer black dyed fiber cloth with the light absorption rate of more than or equal to 80 percent, carbon-based material deposition cloth such as activated carbon, graphene and carbon nano tubes, plasma deposition cloth such as nano gold and silver, and carbon-based material blending gel.

Preferably, the method comprises the following steps: the light source comprises simulated sunlight, sunlight under natural conditions or concentrated sunlight obtained by a light concentrating device, and the illumination area range of the light source is larger than that of the photothermal interface evaporation area.

The capillary array arrangement method of the capillary array water supply photo-thermal interface evaporation structure comprises the following steps:

step 1), arranging the capillary arrays into corresponding polar coordinate equidistant divergence circles or rectangular coordinate equidistant rectangles according to the photo-thermal interface evaporation plane shape;

step 2), the number and the spacing of the capillaries in the array are adjusted according to the photothermal evaporation water supply-heat loss balance: the number of capillaries is increased and the spacing is reduced when the water supply demand is high; if the heat loss is too high, the number of capillaries is reduced, and the spacing is increased;

step 3), regulating and controlling the phenomenon of salt deposition on the photo-thermal interface: setting an initial interval; when the salt accumulation phenomenon is not generated in the photo-thermal evaporation process, the number of the capillaries is reduced according to the multiplying power, and the spacing is increased at equal intervals until the salt accumulation phenomenon is generated.

The capillary array water supply photothermal interface evaporation structure evaporation method comprises the steps of drawing liquid in a water source into a photothermal conversion material through a capillary, and performing photothermal interface evaporation under the irradiation of a light source.

The invention has the beneficial effects that: the invention utilizes the capillary array to be embedded into the heat insulation material to supply water for the photothermal conversion material, simultaneously realizes good water absorption and heat insulation effects, has more accurate and simple water supply-heat loss balance adjusting performance, realizes high-efficiency light-heat interface evaporation, and obtains higher solar energy utilization efficiency.

Drawings

FIG. 1 is a schematic view of a capillary array water supply photothermal interface evaporation structure according to the present invention;

FIG. 2 is a schematic view of the evaporation process of the seawater photothermal interface of the present invention;

FIG. 3 is a schematic view of the photo-thermal interface evaporation method for capillary array water supply regulation in the present invention.

Description of reference numerals: a water source 1, a heat insulation material 2, a capillary tube 3, a photothermal conversion material 4 and a light source 5.

Detailed Description

The present invention will be further described with reference to the following examples. The following examples are set forth merely to aid in the understanding of the invention. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

The capillary array embedded in the heat insulation material is used as a water guide channel, so that a good water drawing effect can be realized by utilizing the capillary phenomenon, the capillary array has higher water guide efficiency and relatively lower heat loss rate in unit area, has more accurate and simple water supply-heat loss balance adjusting performance, and is expected to be applied to the light-heat interface evaporation technology to obtain higher solar energy utilization efficiency.

As shown in fig. 1, the capillary array water supply photothermal interface evaporation structure comprises heat insulation foam floating above seawater and having low thermal conductivity, capillary glass tubes are arranged at intervals in a matrix structure and embedded in the heat insulation foam, the lower ends of the capillary glass tubes are contacted with seawater, the upper ends of the capillary glass tubes are contacted with a photothermal conversion material, and the seawater passes through the heat insulation foam through capillary glass tube channels, enters a photothermal conversion material evaporation interface and is evaporated under sunlight irradiation.

The heat insulation foam is as follows: extruded polystyrene foam boards (XPS) having a density of 30kg/m³The thermal conductivity is 0.03W/mK, and the thickness is 2 to 3 cm.

The capillary glass tube comprises: the inner wall surface of the capillary glass tube has hydrophilicity, the length of the capillary tube is 3-4 cm, the radius r of the capillary tube is 0.5mm, and the formula is satisfied(wherein gamma is the surface tension coefficient 0.07345 J.m of seawater with salt content of 3.5%^-2Theta is the contact angle between the liquid and the capillary tube of 20 degrees, and rho is the density of the seawater of 1026.2kg · m^-3G is the acceleration of gravity of 9.8 m.s^-2And h is the capillary length).

The array of the capillary glass tubes is that the planar shape of the photothermal interface evaporation is 10 × 10cm square, the distance between capillaries in the array of the capillary glass tubes is 0.5cm, and the number of the array capillaries is 21 × 21.

The photothermal conversion material is 10 × 10cm square double-layer black gauze or activated carbon deposition fiber cotton cloth, and the absorbances in the solar spectrum range are 90% and 93% respectively.

The process of seawater interface evaporation comprises the following steps: as shown in fig. 2, the seawater soaks the capillary glass tube array, is vertically drawn into the photothermal conversion material fiber cloth, and is diffused to the whole evaporation interface through the capillary channel inside the fiber cloth; the photothermal conversion material in the evaporation interface converts the absorbed sunlight into heat, heats the seawater absorbed in the material, and heats and evaporates the seawater.

The method for regulating and controlling the photo-thermal interface evaporation by the capillary glass tube array comprises the following steps: the quantity and the space of the capillary glass tubes and the thickness and the length of the capillary tubes in the array can be adjusted according to the balance of the photo-thermal evaporation water supply and heat loss: as shown in FIG. 3, the capillary material is selected according to the water source type and the thickness of the heat insulation material, and the length and the diameter of the capillary are set; setting the shape of a capillary array and an initial interval according to a photothermal evaporation interface; when the phenomenon of salt accumulation is not generated in the photo-thermal evaporation process, the number of the capillaries is reduced according to the multiplying power, and the spacing is increased at equal intervals until the phenomenon of salt accumulation is generated, so that the heat loss is reduced, and the photo-thermal interface evaporation efficiency is improved.

An example of photothermal interface evaporation with water supplied by a capillary array was that an extruded polystyrene foam board heat insulating material having a diameter of 20cm and a thickness of 2cm was cut out using a die, a square fine glass tube array of 10 × 10cm square was inserted in the middle of the foam, 21 × 21 capillary tubes in the fine glass tube array had a length of 3cm and a distance of 0.5cm from each other, the lower part of the fine glass tubes was contacted with seawater having a salt content of 3.5%, water was transported to a 10 × 10cm square double-layer black gauze or an activated carbon deposition fiber cotton cloth, and the surface thereof absorbed sunlight to effect heated water interface evaporation, and the experimental results showed that the heated water interface evaporation was carried out at 1kW/m²The evaporation rate of the activated carbon deposition cellucotton cloth material is 0.82kg/m under the standard sunlight irradiation condition and the background evaporation under the no-light condition is deducted²H, evaporation rate of the double layer black gauze material was 0.66kg/m²*h。

An example of photo-thermal interfacial evaporation of water supply control by capillary array is that an extruded polystyrene foam board thermal insulation material with a diameter of 20cm and a thickness of 2cm is cut out by a die, a square capillary glass tube array with a thickness of 10 × 10cm is embedded in the middle of foam, 21 × 21 capillaries in the capillary glass tube array are 3cm in length and are spaced from each other by 0.5, 1, 2.5 and 5cm, the lower part of each capillary glass tube is contacted with seawater with a salt content of 3.5%, water is transported to an active carbon deposition fiber cotton cloth with a square thickness of 10 × 10cm, and sunlight is absorbed on the surface of the active carbon deposition fiber cotton cloth to realize interfacial evaporation, and experimental results show that the water is heated by sunlight at a concentration of 1kW/m²The evaporation rates of the activated carbon deposition cellucotton cloth materials with the capillary spacing of 0.5, 1, 2.5 and 5cm are respectively 0.82, 0.85, 0.9 and 0.86kg/m under the standard sunlight irradiation condition, the background evaporation under the non-light condition is deducted²H, wherein the photothermal evaporation process of 5cm spaced capillaries produced salt deposition.