多功能木材表面太阳能海水淡化装置性能的研究

目的 研究不同处理工艺下蒸发器的蒸发性能,开发一种多功能木材表面的木质太阳能界面蒸发器.方法 采用化学处理和冷冻干燥技术,使木块通道内形成互联的纤维素纤维网络,室温下,通过原位聚合法,在木块表面制备海藻酸钠/聚丙烯酰胺(SA/PAM)作为有机骨架的光热吸水层,再利用激光雕刻法构筑减反层.用扫描电子显微镜和能谱仪(SEM-EDS)、X射线衍射仪(XRD)对不同样品的微观形貌、物相及元素分布进行表征分析.通过傅立叶红外光谱仪(FT-IR)、紫外可见分光光度计,分别记录不同样品的表面官能团以及透射光谱和反射光谱.利用红外相机分析不同处理工艺在热定位方面的影响.结果 六组不同处理工艺下的蒸发器中,CSE-wood蒸发器表现出更加优异的性能.在1个太阳强度下,蒸发率最大值为2.456 kg/(m2·h),蒸发效率为92.3％.结论 均匀构筑在光热吸水层上的减反层的毛细作用与马兰戈尼效应协同,实现了蒸发所需水分的快速输送,木块内部形成的纤维网络起到隔热的作用.另外,在基底表面制备光热涂层或吸水层,并构筑减反层时,可促进较宽波长范围的光吸收和光程延伸,使蒸发器表面温度迅速上升,实现热局域化,提高了光热转换效率和蒸发速率.这种木质太阳能界面蒸发器可应用在海水淡化、水净化等方面.

Performance of Solar Seawater Desalination Device of Multi-functional Wood Surface

The work aims to research the evaporation performance of evaporator under different treatment processes, and develop a multifunctional wood surface for wood solar interface evaporators. Chemical treatment and freeze drying were used to form interconnected cellulose fiber networks in the wood block channels, and a photothermal water absorption layer based on sodium alginate (SA)/polyacrylamide (PAM) as organic skeleton was prepared by in-situ polymerization at room temperature on the surface of wood block. The antireflective layer was constructed by laser engraving. The microscopic morphology, phase and element distribution of different samples were characterized and analyzed by scanning electron microscope and energy spectrometer (SEM-EDS) and X-ray diffractometer (XRD). The surface functional groups, transmission and reflection spectra of different samples were recorded by fourier infrared spectrometer (FT-IR) and UV-vis spectrophotometer, respectively. The effects of different treatment processes on thermal localization were analyzed using infrared camera. Among the six groups of evaporators under different treatment processes, CSE-wood evaporator shows more excellent performance. The maximum evaporation rate of 2.456 kg/(m2.h) and the evaporation efficiency of 92.3% at 1 solar intensity. Capillary action of the antireflection layer uniformly constructed on the photothermal water absorption layer and the Marangoni effect realize the rapid transportation of water needed for evaporation, and the fiber network formed inside the wood block plays a role of thermal insulation. In addition, the preparation of photothermal coating or water absorption layer on the substrate surface and the construction of antireflective layer can promote light absorption and optical path extension in a wider wavelength range, resulting in a rapid rise in the surface temperature of the evaporator to achieve thermal localization, which improves the efficiency of photothermal conversion and evaporation rate. It can be used in seawater desalination, water purification and so on.