阅读说明：本技术 一种用于太阳能光热蒸发海水淡化的多级梯型蒸馏器及方法 (Multistage ladder-shaped distiller and method for solar photo-thermal evaporation seawater desalination ) 是由 骆周扬 申震 刘春红 祁志福 高强生 王莞珏 蒋狄希 于 2020-05-11 设计创作，主要内容包括：本发明涉及用于太阳能光热蒸发海水淡化的多级梯型蒸馏器,包括隔热材料、光热转化材料、多级蒸发冷凝室、玻璃盖板和透明蓄热材料；第一级蒸发冷凝室底部的海水上方铺设有在隔热材料和光热转化材料；梯型的蒸发冷凝室竖向由倾斜的玻璃盖板分隔形成多级蒸发冷凝室；玻璃盖板上下端分别设有进水口和出水口。本发明的有益效果是：本发明的梯型蒸馏器由倾斜的玻璃盖板分隔出多级蒸发冷凝室,光热转化材料受光照加热海水蒸发,蒸汽通过倾斜的玻璃盖板进行热交换冷凝成淡水收集,冷凝潜热加热上一级海水再次蒸发得到蒸汽,在上一级玻璃盖板进行热交换冷凝成淡水收集,实现太阳能光热多级蒸发海水淡化,获得更高的太阳能利用效率。(The invention relates to a multistage ladder-shaped distiller for solar photothermal evaporation seawater desalination, which comprises a heat insulating material, a photothermal conversion material, a multistage evaporation condensing chamber, a glass cover plate and a transparent heat storage material; a heat insulating material and a photothermal conversion material are laid above the seawater at the bottom of the first-stage evaporation and condensation chamber; the ladder-shaped evaporation and condensation chamber is vertically divided by an inclined glass cover plate to form a multi-stage evaporation and condensation chamber; the upper end and the lower end of the glass cover plate are respectively provided with a water inlet and a water outlet. The invention has the beneficial effects that: the ladder-type distiller provided by the invention is characterized in that a multistage evaporation and condensation chamber is separated by the inclined glass cover plate, a photothermal conversion material is heated by illumination to evaporate seawater, steam is subjected to heat exchange and condensation through the inclined glass cover plate to be collected as fresh water, latent heat of condensation heats the previous stage of seawater to be evaporated again to obtain steam, the previous stage of glass cover plate is subjected to heat exchange and condensation to be collected as fresh water, solar photothermal multistage evaporation seawater desalination is realized, and higher solar energy utilization efficiency is obtained.)

1. The utility model provides a multistage ladder type distiller for solar photothermal evaporation sea water desalination which characterized in that: comprises a heat insulating material (2), a photothermal conversion material (3), a multi-stage evaporation and condensation chamber, a glass cover plate (5) and a transparent heat storage material (6); a heat insulating material (2) and a photothermal conversion material (3) are laid above the seawater (1) at the bottom of the first-stage evaporation and condensation chamber (4); the trapezoidal evaporation and condensation chamber is vertically divided by an inclined glass cover plate (5) to form a multi-stage evaporation and condensation chamber; the upper end and the lower end of the glass cover plate (5) are respectively provided with a water inlet and a water outlet, and the lower end of the glass cover plate (5) is also provided with a condensed fresh water collecting tank; the bottom of the first-stage evaporation and condensation chamber (4) is provided with a water inlet and a water outlet.

2. The multi-stage ladder distiller for solar photothermal evaporation seawater desalination of claim 1, wherein: the heat insulation material (2) comprises polystyrene, polyurethane hydrophobic white foam or aerosol; the heat insulation material (2) covers the outer surface of the distiller except the glass cover plate and the space between the photothermal conversion material (3) and the seawater (1) in the distiller; the thickness of the heat insulation material (2) is 1-6 cm.

3. The multi-stage ladder distiller for solar photothermal evaporation seawater desalination of claim 1, wherein: the photothermal conversion material (3) comprises single-layer or multi-layer black dyed fiber cloth, carbon-based material deposition cloth, plasma deposition cloth or carbon-based material blending gel; the lower end of the partial area of the photothermal conversion material passes through the heat insulation material (2) to be contacted with the seawater (1).

4. The multi-stage ladder distiller for solar photothermal evaporation seawater desalination of claim 1, wherein: the glass cover plate (5) comprises super white glass with the light transmittance of more than 95 percent, and the thickness of the super white glass is 3-8 mm; the inclination angle of the glass cover plate (5) is 10-30 degrees.

5. The multi-stage ladder distiller for solar photothermal evaporation seawater desalination of claim 1, wherein: the upper surface of the glass cover plate (5) is covered with a transparent heat storage material (6), the transparent heat storage material (6) comprises polyvinyl alcohol group, sodium polyacrylate group or polyacrylate, and the thickness of the transparent heat storage material (6) is 0.1-5 cm.

6. The evaporative condensation method of the multistage ladder-type distiller for solar photothermal evaporation seawater desalination of claim 1, characterized in that: the photothermal conversion material (3) is irradiated by light to heat the seawater (1) for evaporation, the steam is subjected to heat exchange and condensation through the inclined glass cover plate (5) to form fresh water, the released condensation latent heat heats running water under a flowing water cooling method or a transparent heat storage material (6) under a heat storage cooling method, the seawater at the upper stage is evaporated again to obtain steam, the heat exchange and condensation are performed on the glass cover plate (5) at the upper stage to form fresh water for collection, and the solar photothermal multistage evaporation seawater desalination is realized.

7. The evaporative condensation method of the multistage ladder-type distiller for solar photothermal evaporation seawater desalination of claim 6, wherein: the running water cooling method is characterized in that seawater is dripped into the upper end of the inclined glass cover plate (5) in a dripping mode, so that a uniform water film is formed on the surface of the glass cover plate (5), the surface temperature of the glass cover plate (5) is reduced, and evaporation is carried out by utilizing latent heat of condensation; the flowing water mode is a circulating reciprocating type or a direct discharging type, and the flowing water flow is adjusted according to the multi-stage condensation latent heat recovery rate.

8. The evaporative condensation method of the multistage ladder-type distiller for solar photothermal evaporation seawater desalination of claim 6, wherein: the heat storage cooling method is characterized in that the surface of the glass cover plate (5) is kept at a low temperature through the transparent heat storage material (6) laid on the glass cover plate (5), water in the transparent heat storage material (6) is evaporated by using latent heat of condensation, and fresh water is generated by still utilizing heat storage for evaporation at night; the water in the transparent heat storage material (6) is supplemented in a dripping mode, and the heat storage material amount is adjusted according to the seawater desalination efficiency all day long.

Technical Field

The invention relates to the field of seawater desalination and photothermal evaporation, in particular to a multistage ladder-type distiller and a method for solar photothermal evaporation seawater desalination.

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. The thermal method solar seawater desalination can be divided into solar-assisted multiple-effect evaporation, multi-stage flash evaporation, heat pump seawater desalination, membrane distillation, humidification and dehumidification and a solar distiller according to different evaporation and condensation modes, wherein the solar distiller occupies a small area and is independent, and the requirement of the application of unit distributed small seawater desalination can be met. The solar still can be divided into three parts according to energy conversion and material change: the light-heat conversion section, the evaporation section and the condensation section correspond to the conversion of energy and material from "light" to "heat", "sea water" to "steam" and "steam" to "fresh water", respectively. The traditional solar distiller is an integrated solar distiller, sunlight passes through glass to be absorbed by seawater and a substrate, the seawater is condensed on the inner wall of the glass after being evaporated and flows to a collecting tank to obtain fresh water, and the light-heat conversion, the evaporation and the condensation are all realized in a container. Although the solar still has a simple structure and is easy to manufacture, the efficiency of water production is low due to the influence of condensed water on light absorption, light reflection from water surfaces and glass surfaces, heat loss of large-volume water and the solar still and the like, and the influence factors need to be optimized and improved in a targeted manner.

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 ]; xiao, G., Wang, X., Ni, M., et al, applied Energy103, 642-652 (2013), A review on synthetic rods for knitting administration; xu, Z, Zhang, L, Zhao, L, et al, Ultrahigh-efficiency depletion via thermal-localized multistep solar still, published in Energy & Environmental Science 13, 830-839 (2020).

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a multistage ladder-type distiller and a method for solar photo-thermal evaporation seawater desalination.

The multistage ladder-shaped distiller for solar photothermal evaporation seawater desalination comprises a heat insulation material, a photothermal conversion material, a multistage evaporation and condensation chamber, a glass cover plate and a transparent heat storage material; a heat insulating material and a photothermal conversion material are laid above the seawater at the bottom of the first-stage evaporation and condensation chamber; the ladder-shaped evaporation and condensation chamber is vertically divided by an inclined glass cover plate to form a multi-stage evaporation and condensation chamber; the upper end and the lower end of the glass cover plate are respectively provided with a water inlet and a water outlet, and the lower end of the glass cover plate is also provided with a condensed fresh water collecting tank; the bottom of the first-stage evaporation and condensation chamber is provided with a water inlet and a water outlet. The photothermal conversion material is heated by illumination to evaporate seawater, steam is subjected to heat exchange and condensation through the inclined glass cover plate to be collected as fresh water, seawater in the upper stage evaporation and condensation chamber is heated by using latent heat of condensation to be evaporated again to obtain steam, and the glass cover plate at the top of the upper stage evaporation and condensation chamber is subjected to heat exchange and condensation to be collected as fresh water, so that solar photothermal multistage evaporation seawater desalination is realized. (the upper level mentioned here describes the upper and lower levels of orientation)

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 heat insulation material covers the outer surface of the distiller except the glass cover plate and the space between the photothermal conversion material and the seawater inside the distiller; the thickness of the heat insulating material is 1-6 cm.

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 nano silver, and carbon-based material blending gel; the lower end of the partial area of the photothermal conversion material passes through the heat insulation material to be contacted with seawater, and the seawater is drawn through the capillary action of the fiber cloth.

Preferably, the method comprises the following steps: the multi-stage evaporation and condensation chamber comprises a first stage evaporation and condensation chamber for bearing seawater, a heat insulation material and a photothermal conversion material, and a second stage evaporation and condensation chamber, a third stage evaporation and condensation chamber and more than the third stage evaporation and condensation chamber for recycling latent heat by adopting a running water cooling method or a heat storage cooling method.

Preferably, the method comprises the following steps: the glass cover plate comprises ultra-white glass with the light transmittance of more than 95%, the thickness of the glass cover plate meets the structural rigidity, and the thickness of the glass cover plate is as thin as possible, so that the thermal conductivity coefficient of the glass cover plate is as large as possible, and the thickness is usually 3-8 mm; the inclination angle of the glass cover plate is 10-30 degrees, so that condensed water can be conveniently collected.

Preferably, the method comprises the following steps: the upper surface of the glass cover plate is covered with a transparent heat storage material, the transparent heat storage material comprises transparent hydrogel materials such as polyvinyl alcohol group, sodium polyacrylate group and polyacrylate, and the thickness of the transparent heat storage material can be 0.1-5cm according to the heat storage performance requirement.

The evaporation and condensation method of the multistage ladder-type distiller for solar photo-thermal evaporation seawater desalination comprises the following steps: the photothermal conversion material is heated by illumination to evaporate seawater, the steam is subjected to heat exchange and condensation through the inclined glass cover plate to form fresh water, the released condensation latent heat heats flowing water under a flowing water cooling method or a transparent heat storage material under a heat storage cooling method, the previous stage of seawater is evaporated again to obtain steam, the heat exchange and condensation are carried out on the previous stage of glass cover plate to form fresh water, and the fresh water is collected, so that the solar photothermal multistage evaporation seawater desalination is realized.

Preferably, the method comprises the following steps: the flowing water cooling method is characterized in that seawater is dripped into the upper end of an inclined glass cover plate, so that a uniform water film is formed on the surface of the glass cover plate, the surface temperature of the glass cover plate is reduced, and evaporation is carried out by utilizing latent heat of condensation; the flowing water mode is a circulating reciprocating type or a direct discharge type, and the flowing water flow can be adjusted according to the multi-stage condensation latent heat recovery rate.

Preferably, the method comprises the following steps: the heat storage cooling method is that the surface of the glass cover plate is kept at a low temperature by the transparent heat storage material paved on the glass cover plate, water in the transparent heat storage material is evaporated by using latent heat of condensation, and the heat storage can still be used for evaporation to generate fresh water at night; the water in the transparent heat storage material can be supplemented in a dripping mode, and the heat storage material amount can be adjusted according to the seawater desalination efficiency all day long.

The invention has the beneficial effects that: the ladder-type distiller provided by the invention is characterized in that a multistage evaporation and condensation chamber is separated by the inclined glass cover plate, a photothermal conversion material is heated by illumination to evaporate seawater, steam is subjected to heat exchange and condensation through the inclined glass cover plate to be collected as fresh water, latent heat of condensation heats the previous stage of seawater to be evaporated again to obtain steam, the previous stage of glass cover plate is subjected to heat exchange and condensation to be collected as fresh water, solar photothermal multistage evaporation seawater desalination is realized, and higher solar energy utilization efficiency is obtained.

Drawings

FIG. 1 is a schematic structural diagram of a multistage ladder-type distiller for solar photo-thermal evaporation seawater desalination;

FIG. 2 is a schematic flow diagram of seawater evaporation, condensation and desalination in a multi-stage ladder-type distiller.

Description of reference numerals: seawater 1, a heat insulating material 2, a photothermal conversion material 3, a first-stage evaporation and condensation chamber 4, a glass cover plate 5, a transparent heat storage material 6, a second-stage evaporation and condensation chamber 7 and an nth-stage evaporation and condensation chamber 8.

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.

This patent adopts multistage ladder distiller, can be so that condensation interface has sufficient cooling temperature difference on the one hand for the inside evaporation and condensation rate of distiller, on the other hand can make full use of condensation latent heat, provides extra multistage evaporation condensation fresh water. The interface evaporation structure is adopted, a light absorption material is arranged at the interface between seawater and air, a thin liquid layer at the interface is heated and evaporated, the seawater is continuously absorbed to the heating interface by utilizing a water absorption core or a floating water absorption material, the photo-thermal evaporation process is continuously carried out, the heat loss in the evaporation process is greatly reduced, and the evaporation temperature and efficiency are improved. The heat storage structure is adopted, heat converted in the daytime is stored to be slowly released at night, on one hand, a cold source with stable temperature can be provided in the daytime, the condensation effect is enhanced, heat loss caused by overhigh temperature is reduced, and on the other hand, the time window at night can be utilized to release the stored heat for evaporation and condensation.

As shown in fig. 1, in the multistage ladder distiller for solar photothermal evaporation seawater desalination, a photothermal conversion material 3 covers above a heat insulation foam floating above seawater 1, the photothermal conversion material 3 is heated by illumination to evaporate seawater, steam is subjected to heat exchange and condensation through an inclined glass cover plate 5 in a first stage evaporation and condensation chamber 4 to be collected as fresh water, latent heat of condensation is absorbed by a transparent heat storage material 6, seawater in a second stage evaporation and condensation chamber 7 is heated to be evaporated again to obtain steam, the glass cover plate 5 on the top of the second stage evaporation and condensation chamber 7 is subjected to heat exchange and condensation to be collected as fresh water, the latent heat of condensation is used for continuously heating seawater to evaporate, and the process is repeated until an nth stage evaporation and condensation chamber 8, so that solar photothermal multistage evaporation seawater desalination is realized.

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 1 to 2 cm.

The photothermal conversion material is: the light absorption rate of 50 x 50cm multilayer black dyed fiber cotton gauze in the solar spectrum range is 93%, and the gauze penetrates through the heat insulation foam at intervals of 5cm to be contacted with seawater to absorb the seawater.

The multi-stage evaporation condensing chamber is as follows: the device comprises a first-stage evaporation and condensation chamber 4 for bearing seawater, heat insulation materials and photothermal conversion materials, and a second-stage evaporation and condensation chamber 7 for recycling latent heat by adopting a heat storage cooling method;

the glass cover plate is as follows: the super-white toughened glass with the light transmittance of more than 95 percent has the thickness of 5 mm; the inclination angle of the glass cover plate is 20 degrees.

The transparent heat storage material is as follows: the polyvinyl alcohol-based transparent hydrogel material has the water content of 95% and the thickness of 2 cm;

the process of seawater evaporation, condensation and desalination in the multistage ladder-type distiller for solar photo-thermal evaporation seawater desalination comprises the following steps: as shown in fig. 2, seawater 1 enters the distiller through a water inlet at the bottom of the first-stage evaporation and condensation chamber 4, absorbs heat to evaporate on the photothermal conversion material 3, and is condensed at the glass cover plate 5 to a condensed fresh water collecting tank for collection; the latent heat of condensation continues to heat the transparent heat storage material 6 in the second stage evaporation and condensation chamber 7, and the seawater therein is condensed and collected at the glass cover plate 5 on the top of the second stage evaporation and condensation chamber 7.

The operation example of the multistage ladder-type distiller device for solar photothermal evaporation seawater desalination comprises a two-stage ladder-type distiller device with a base size of 50 × 50cm, wherein the height of a short-side vertical plate of a first-stage evaporation and condensation chamber is 10cm, the height of a long-side vertical plate of the first-stage evaporation and condensation chamber is 28.2cm, so that the included angle between the inclined plane of a glass cover plate and the horizontal plane is 20 degrees, the heights of the vertical plates at two ends of a second-stage evaporation and condensation chamber are 10cm, the included angle between the inclined plane of the glass cover plate and the horizontal plane is 20 degrees, and under the sunshine irradiation condition that the spring of a coastal city in south China is clear, the environmental temperature is 12-20 ℃, and the equivalent standard sunshine hours is 3.5 hours, the daily average total water yield of the multistage ladder-type²Day, wherein the daytime water production is 1.5kg/m²The water yield is 0.5kg/m at night due to the heat release of the transparent heat storage material, evaporation and condensation²The overall efficiency was 38%.