Study on heat transfer and dehumidification performance of desiccant coated microchannel heat exchanger

Abstract The desiccant coated heat exchanger is capable of dealing with sensible load and latent load of hot and humid air. The heat and moisture transfer coefficients of the desiccant coated microchannel heat exchanger (DMHE) are derived theoretically and increase with the airflow velocity in the heat exchanger. The microchannel structure optimization is implemented. It is found that the smaller the fin pitch and flat tube pitch are, the greater the heat and moisture transfer coefficients are. The thicker the desiccant coating, the larger the moisture transfer coefficient, the smaller the heat transfer coefficient. The experimental results show that the dehumidification capacity and the thermal performance coefficient of DMHE are 1.59 kgh-1 and 2.09 respectively with the regeneration hot water at 60 ℃. The Taguchi method is employed to evaluate the influence of cooling water temperature, airflow velocity, and water flow rate on the dehumidification performance of DMHE. The airflow velocity is the main factor affecting the dehumidification capacity, where lower cooling water temperatures and faster the airflow velocity increases the dehumidification performance.