A Review on Desiccant Coated Heat Exchangers

Abstract

Fixed bed and rotatory desiccant systems have been widely studied and used for dehumidification; they suffer from decreasing sorption capacity as the desiccant’s temperature increases due to the released heat of adsorption. The desiccant coated heat exchangers (DCHX) overcome this limitation. Such heat exchangers are able to deliver combined heat and mass transfer between the process air and the working fluid. The process air can be cooled and dehumidified simultaneously by pumping cooling water/refrigerant in the DCHX. The DCHX has to be heated cyclically to regenerate the desiccant material. This paper presents a review on the studies conducted on air-to-liquid DCHX. It summarizes various modeling approaches used to simulate the performance of DCHX as well as the experimental studies conducted to validate these models. It also reviews the current and potential applications of these heat exchangers. Current work in this field consists of experiments conducted on the DCHX as standalone equipment (i.e. component level) as well as an integrated component into cooling and dehumidification systems (system level). The integration of the DCHX in such systems was found to improve the COP, leading to energy savings.