Dehumidification Performance Improvement of a Cross-Flow Liquid Desiccant Dehumidifier through Physical Dimensions Modification

Abstract

The configuration of the dehumidifier plays an important role in the dehumidification performance of the liquid desiccant system. In this study, a parametric analysis of each geometric parameter on dehumidification performance was conducted to investigate the dehumidifier configuration for improving the dehumidification performance of a cross-flow liquid desiccant dehumidifier. To analyze the effects of the geometrical parameters (i.e., packing height, length, width, and air/solution side aspect ratio) on dehumidification performance, the air-desiccant contacting area estimation method and a two-dimensional heat and mass transfer numerical model was adopted. Two performance indices, the dehumidification effectiveness and pressure drop, were calculated via a series of simulations. Based on the simulation process, parametric analysis of each geometrical parameter on dehumidification performance were conducted. From the parametric analysis conducted using the proposed numerical model, it is clear that the solution side mass transfer area has a more significant effect on the dehumidification performance compared with that of the air side. In addition, increasing the packing length achieves higher dehumidification effectiveness compared with increasing the packing width. Consequently, it may be concluded that the cross-flow liquid desiccant dehumidifier can have a high dehumidification performance comparable to that of the counter-flow dehumidifier, achieved by modifying the physical dimensions of the packing tower, especially the packing length.