Experimental study of an aqueous desiccant mixture system: Air dehumidification and desiccant regeneration

Abstract

This article presents the results of an experimental study on the performance of a structured packing dehumidifier and the regenerator system. The system is tested using different proportions of an aqueous desiccant mixture of calcium chloride and lithium chloride solutions with an overall concentration of 40 wt%. The instantaneous effectiveness and the time-average effectiveness of the dehumidification process as well as the regeneration process are defined for the hybrid cooling system. It is found that as the lithium chloride content in the solution increases, the effectiveness of the dehumidifier as well as the regenerator increases. Moreover, the regeneration of the lithium chloride solution is found to be more effective than that of calcium chloride solution. The dehumidifier effectiveness using the desiccant mixture of 20 wt% CaCl 2 and 20 wt% LiCl is found to be close to that of 45 wt% solution of calcium chloride and improves by 80 per cent over the 40 wt% solution of calcium chloride.

Economic and Experimental Assessment of KCOOH Hybrid Liquid Desiccant-Vapor Compression System

“…Dai et al [7] experimentally investigated a hybrid LDAC system comprised of a VCS, a liquid desiccant system, and an evaporative cooler, and the COP was found to be 1.513, 1.862, and 1.745 while using VCS, VCS + desiccant dehumidification, and VCS + desiccant dehumidification + evaporative cooling, respectively. Al-Farayedhi et al [8] suggested a system consisting of a packed-bed dehumidifier with a five-ton capacity VCS while employing CaCl 2 as liquid desiccant, and results revealed that temperature of the air was reduced from 48 to 38 • C and the value of outlet-to-inlet absolute humidity was found to be 0.6. The COP hybrid was calculated in three different regeneration modes: 1.164 (while heating desiccant), 1.616 (while heating air), and 1.4221 (while heating both air and desiccant), and the COP of the standalone VCS was 0.989.…”