Experimental Study of Capillary Assisted Textured Plastic Plate for Liquid Desiccant Dehumidification

Thermally activated liquid desiccant air-dehumidification systems (LDDS) offer a viable energy-efficient alternative to traditional vapor compression systems. Plastics, being inexpensive and corrosion-resistant is an attractive option for the fabrication of LDDS. However, their inherently hydrophobic nature poses a major challenge, causing rapid shrinking and breaking of the desiccant film, thereby reducing the overall performance. This study proposed a cost-effective, capillary-assisted vertical grooved polypropylene plate, designed through surface modification to improve wetting characteristics of the plastic surface. The dimension of the rectangular groove is optimized using the capillary flow concept to promote continuous liquid film formation. The vertical groove plate performance is experimentally tested and compared with that of plain and modified plastic surfaces reported in the past study. Under the tested conditions, vertical grooved plate improved the dehumidification rate and effectiveness of the plain plate by 51.5% and 62.1%, respectively. It also outperformed the horizontal inclined grooved plate dehumidification rate and effectiveness by 12.3% and 14.1%, respectively, under specific desiccant solution operating conditions. Furthermore, its performance was compared with a polypropylene hollow fiber membrane dehumidifier under close operating conditions, showing equivalent performance. The findings of the current study are promising for advancing the development of plastic LDDS for thermal comfort.