CN-121651476-B - Solar evaporator with double-spiral lateral structure and preparation method thereof

Abstract

The invention relates to the technical fields of interfacial water evaporation, sea water desalination and sewage treatment, and discloses a solar evaporator with a double-spiral lateral structure, which comprises a substrate with a water absorption and transmission function, wherein the outer wall of the substrate is provided with a double-spiral structure capable of actively inducing air micro-convection, the double-spiral structure is a double-spiral groove or a double-spiral bulge extending along the axial direction, in the evaporation process, the double-spiral structure can actively destroy an air stagnation boundary layer, enhance the outward diffusion of water vapor, reduce the saturated vapor pressure of the lateral surface and obviously enhance the evaporation rate of the lateral surface.

Inventors

• LI BO
• WANG JIYUE
• Mao Hanting
• HU XIANLING
• LI YUANSHUO

Assignees

• 浙江工业大学

Dates

Publication Date

20260505

Application Date

20260203

Claims (5)

1. 1. The solar evaporator with the double-spiral lateral structure comprises a substrate with a water absorption and transmission function, and is characterized in that the substrate is a columnar body or a conical body, the lateral outer wall surface of the substrate is provided with the double-spiral lateral structure capable of actively inducing micro air convection, and the double-spiral lateral structure is a double-spiral groove or a double-spiral protrusion axially extending along the lateral surface of the substrate.
2. 2. A solar energy evaporator with double helix lateral structure according to claim 1, wherein the substrate is made of a material with hydrophilic water absorbing function.
3. 3. A solar evaporator with double helix lateral structure according to claim 1 or 2, wherein the top surface and the entire lateral surface of the substrate are provided with a photo-thermal material layer by spraying.
4. 4. A solar energy evaporator with double helix lateral structures according to claim 1, wherein the double helix lateral structures are continuous structures or discontinuous structures extending from the top of the substrate to the bottom of the substrate, or the double helix lateral structures cover a partial area of the substrate side.
5. 5. The preparation method of the solar evaporator with the double-helix lateral structure is characterized by comprising the following steps of: Step 1) preparation of a photo-thermal substance: the photo-thermal material and the binder are mixed according to a proportion to prepare a photo-thermal substance solution; Step 2) preparing a solar evaporator substrate with a double-spiral lateral structure: Processing a material with a hydrophilic water absorption function into a column body or a cone body, and processing a solar evaporator substrate with a double-helix lateral structure on the lateral outer wall of the column body or the cone body in one or more modes including material reduction manufacturing, material addition manufacturing, material manufacturing and the like, wherein the double-helix lateral structure is a double-helix groove or a double-helix protrusion extending axially along the lateral surface of the substrate; Step 3) spraying a photo-thermal functional layer: uniformly spraying the photo-thermal substance prepared in the step 1) on the outer surface of the solar evaporator substrate prepared in the step 2), and airing after spraying, thus obtaining the solar evaporator with the double-spiral lateral structure.

Description

Solar evaporator with double-spiral lateral structure and preparation method thereof Technical Field The invention relates to the technical fields of interfacial water evaporation, sea water desalination, sewage treatment and the like, in particular to a solar evaporator with a double-spiral lateral structure. Background The solar-driven interfacial water evaporation technology is a powerful technical path in the fields of sea water desalination, emergency water supply, industrial wastewater treatment and the like by virtue of renewable energy utilization, simple system structure and potential low running cost. The technology is characterized in that a high-efficiency photo-thermal conversion evaporator is designed and manufactured, so that the solar energy absorption and heat utilization efficiency is maximized, the continuous wetting and high-flux evaporation of an interface are ensured, and the stable water yield per unit area is realized. In order to improve the interface evaporation efficiency, the research in the field has been significantly progressed, and mainly focuses on two layers, namely, one layer is innovation on the material layer, development of a photo-thermal functional material with high light absorption and low heat loss, and the other layer is optimization on an internal micro/nano structure and a water supply system, and a porous network with good capillary transport capacity is constructed through a special preparation process so as to ensure timely replenishment of water. These two technical paths greatly promote the improvement of the basic performance of the evaporator. In terms of device morphology, three-dimensional (3D) structures are widely recognized as effective ways to increase evaporation rate due to their greater exposed evaporation surface area than two-dimensional planes. In order to adapt to engineering production and modularized deployment, three-dimensional forms which are regular and convenient for molding processing, such as rotary or regular symmetrical structures of cylinders, cones and the like are often adopted in practice, and the three-dimensional forms are well-known in the art because the three-dimensional forms are easy to prepare and process, and are convenient for mechanical assembly and stable design of a floating system. However, precisely in these widely adopted basic device configurations, a bottleneck problem that has been ignored for a long time, which has further broken through the limiting performance, is increasingly highlighted. The prior research and engineering implementation usually adopts the classical regular configuration by default, focuses on material and internal microstructure in technical optimization, and systematically optimizes the side morphology of the evaporator, the coupling between the gas-liquid interface and the surrounding air flow field from a macroscopic geometry angle. In actual operation, the lateral surfaces of the device may contribute a considerable evaporation surface area when wetted, but under natural or weak wind conditions, a stagnant and water vapor-rich air boundary layer is often formed near the smooth sidewalls, raising the local vapor pressure at the sides, thereby significantly inhibiting the lateral evaporation flux and becoming a bottleneck limiting overall performance. For this bottleneck, there is an inherent contradiction to increasing the evaporation amount simply by increasing the device height. The height increasing device can prolong the transportation path of water, and when the capillary water supply rate can not timely supplement the water required by high evaporation, local dry spots, insufficient water supply and salting-out phenomenon can occur, thereby reducing the overall water production efficiency and aggravating the maintenance burden. Therefore, merely scaling up cannot fundamentally break boundary layer limitations. In summary, the requirements of engineering and long-term stable operation require a new solution to be provided on the macroscopic geometry level, namely, to maintain the advantages of moldable manufacturing and mass production of rotationally symmetrical devices such as columns/cones, and to introduce a manufacturable and powerful macroscopic texture or turbulence structure on the side surface to internally regulate a gas-phase flow field, thin a steam boundary layer and promote lateral evaporation, and meanwhile, the structure needs to work cooperatively with a high-efficiency water supply system and an anti-salt/self-cleaning strategy to ensure long-term stability and easy maintainability. Therefore, on the premise of not sacrificing the existing engineering advantages, the introduction of a macroscopic functional structure which is convenient for batch preparation, can effectively enhance lateral air convection, reduce boundary layer influence and take account of water supply and salt precipitation resistance on the side surface of the common rotationally symmetrical