基于仿生陷光结构的太阳能海水蒸发器的界面光热转换特性及蒸发机理研究

Solar seawater evaporator with the interface photothermal conversion principle is a new method for desalination through interface photothermal conversion to increase the temperature and achieve the seawater evaporation. And the photothermal conversion is the key factor that restricts the evaporation efficiency. The gradient structure of the butterfly scale is a natural light-trapping structure that increases the conversion efficiency by dispersing the incident light to various angles to increase the optical path, and its application to solar seawater evaporator can greatly improve the efficiency of photothermal conversion. The porous structure of wood has very high similarity with the gradient structure of the butterfly scales. Therefore, according to the gradient structure of the butterfly scales, a preparation method for constructing bionic light-trapping structures on wood surface is proposed in this paper. Solar seawater evaporator with bionic light-trapping structure is fabricated, and the characteristics and mechanism of interface photothermal conversion and water evaporation are revealed. The main contents cover four aspects: (1) The extraction of the butterfly scale feature and the design of bionic light-trapping structure on wood surface (2) Interface construction method of bionic light-trapping structure on porous wood surface (3) Photothermal conversion characteristics and evaporation characteristics of solar seawater evaporator with bionic light-trapping structure (4) The revealing of the evaporation mechanism of solar seawater evaporator with bionic light-trapping structure. The project aims to propose a new method for solar desalination with the advantages of energy saving, high efficiency, low-carbon, and environmental protection, which also provides a theoretical reference for the improvement of photothermal conversion efficiency.

界面光热转换原理的太阳能海水蒸发器是通过界面光热转换提升温度进行海水蒸发实现海水淡化的新方法，光热转换是制约蒸发效率的关键因素。蝴蝶鳞片的梯度结构是一种天然陷光结构，通过将入射光分散到各个角度增加光程以提高光热转换效率，将其应用于太阳能海水蒸发器可极大提升光热转换效率。木材的多孔结构与蝴蝶鳞片的梯度结构具有极高的相似性。因此，本项目根据蝴蝶鳞片的梯度结构提出一种木材表面构筑仿生陷光结构的制备方法，制造仿生陷光结构的太阳能海水蒸发器，揭示其界面光热转换与水分蒸发的特性及机理。主要内容涵括四个方面：(1)蝴蝶鳞片特征提取与木材表面仿生陷光结构设计(2)仿生陷光结构的多孔木材界面构筑方法(3)仿生陷光结构的太阳能海水蒸发器的光热转换特性与蒸发特性研究(4)仿生陷光结构的太阳能海水蒸发器的蒸发机理揭示。本项目旨在提供一种节能高效、低碳环保的太阳能海水淡化新方法，为光热转换效率提升提供理论参考。

近年来，淡水资源缺乏与全球变暖已成为严峻的全球性问题。受蝴蝶鳞片天然陷光结构具有高效光热转换效率的启发，提出一种用于高效海水淡化的基于多孔木材的仿生陷光结构太阳能海水蒸发器，对于缓解水资源短缺与绿色发展具有重要意义。.通过解剖法与切片实验获取蝴蝶鳞片与多孔木材试样，明确了蝴蝶鳞片的陷光机制与多孔木材的结构特征，给出了木材表面构筑仿生陷光结构的制备工艺方法；对比蝴蝶鳞片陷光结构与木材结构特征关系，给出了在多孔木材上构筑仿生陷光结构的优化设计方案；制造出了木材表面构筑仿生陷光结构的太阳能海水蒸发器，给出了基于仿生陷光结构的太阳能海水蒸发器的光热转换特性与水分蒸发特性，经过优化设计的仿生陷光结构光吸收率达到96.5%，最优的碳化深度为40%，最大蒸发速率可达1.8 Kg·m-2·h-1，最大蒸发效率可达82.3%；通过数值模拟及理论分析的方法，总结归纳得到了仿生陷光结构内部空气对流对水蒸发的影响规律；揭示了基于仿生陷光结构的太阳能海水蒸发器光热转换特性提升蒸发效率的作用机理，即高效的光吸收能力与良好的内部水分运输结构有助于光热转化能力的提升与水蒸气的快速逃逸，进而提高太阳能蒸发器的蒸发效果。.经过本项目相关人员的共同努力，该项目取得了系列进展，突破了传统界面蒸发光热转换效率低与水分运输困难的技术瓶颈，为我国在太阳能海水领域提供理论基础和技术支持。.该项目执行期间，申报国家发明专利4项（已授权4项），共发表学术论文14篇，SCI检索13篇，EI检索1篇；参加国际国内学术会议4次。