基于表面改性的光伏组件冷凝除尘特性研究

INVESTIGATION OF CONDENSATION-INDUCED DUST REMOVAL ON MODIFIED SURFACE FOR PV MODULE

制备5种不同润湿性表面,并在冷凝条件下进行光伏组件表面灰尘自清洁实验,分析不同表面冷凝除尘的过程、机理以及除尘效果。结果表明:在实验条件下,超亲水表面、亲水表面和疏水表面均无法实现冷凝除尘,而超疏水表面和超滑表面上冷凝液滴以滚动方式除去表面76%以上的灰尘。相较于亲水型表面,疏水型表面冷凝干燥后能有效减少表面灰尘相对覆盖率,进而减少灰尘遮挡对光伏发电的影响。超疏水表面滚动液滴较小且速度快,除尘更早发生;而超滑表面滚动液滴较大且速度慢,但与表面接触面积大,清扫范围广。冷凝除尘主要依靠灰尘颗粒与冷凝水之间的界面力,液滴发生运动的临界直径越小越有利于除尘。

Five surfaces with different wettabilities are prepared. Then,the self-cleaning of PV module surface is investigated under condensing conditions. The condensation-induced dust removal process,mechanism and dust removal performance of different surfaces were analyzed. The results show that the super-hydrophilic surface,hydrophilic surface and hydrophobic surface cannot achieve dust removal,while the condensate droplets on the superhydrophobic surface(SHS)and hydrophobic slippery surface(HPO-SLIP)can removemore than 76% dust of the surface in a rolling manner. Compared with the hydrophilic surface,the hydrophobic surface can effectively reduce the relative coverage of dust on the surface after condensation and drying,thus reducing the impact of the shielding effect of dust on photovoltaic system. On the SHS,rolling droplets are smaller and faster,and dust removal occurs earlier. In contrast,rolling droplets on the HPO-SLIP are larger and slower,but the contact area with the surface is large,resulting in a wider cleaning range. The condensation-induced dust removal mainly relies on the interface force between dust particles and condensate. The smaller the critical diameter of droplet detachment,the more conducive dust can be removed.