Analysis of heat and mass transfer characteristics of desiccant dehumidifier system with honeycomb configuration

Adjusting the heat and moisture of a conditioned space is important to maintain the comfort of the air. Adding or removing heat and moisture depends mainly on the heat and mass transfer characteristics within the system. In this study, the heat and mass transfer characteristics, in the form of the Nusselt number (Nu) and the Sherwood number (Sh), of a honeycomb desiccant dehumidifier (HDDH) were investigated experimentally. The HDDH was driven by using the honeycomb desiccant configuration, which was constructed from a polymer adsorbent material. The adsorption temperature (Tads) was considered as an adjustable parameter using values of 20 °C, 25 °C, and 35 °C. Each adsorption temperature was evaluated under the time intervals for the desorption and adsorption processes (switching time: τ) of 60:60 min, 60:90 min, 60:120 min, and 90:120 min. For the given parameters, the desorption temperature and mass flow rate of the air were kept unchanged at 55 °C and 0.1 kg/s, respectively. The results showed that the Nu and Sh are more evenly responsive to change of adsorption temperature than switching time. Low desorption temperature results in high values of Nu and Sh. However, variation of switching time produces little change in Nu and Sh. Empirical correlations were also developed in this study. The empirical correlations matched the experimental data well.