Performance assessment of heat exchanger coated with encapsulated ultra-high salt content desiccant

Abstract

Desiccant coated heat exchanger (DCHE) provides an effective way to decouple the sensible and latent heat loads and improves the energy efficiency by raising the evaporation temperature of air conditioning system. In this paper, a new encapsulation of porous membrane is adopted to fabricate the ultra-high salt content composite desiccant, AFLi30@P, whose salt content can reach over 85w %. Its adsorption capacity can be as high as 3.8 g g−1 at 27 °C and 70 % humidity. And then, DCHE based on AFLi30@P is developed. Experiments on both desiccant and DCHE levels are conducted to investigate the effects of temperature and humidity conditions on the dehumidification performance. The results reveal that, different from air temperature and dehumidification temperature, air humidity and regeneration temperature has positive effects on the DCHE dehumidification performance. Comparison between vertical and horizontal placements presents that horizontal placement of AFLi30@P on DCHE can avoid the effect of gravity to realize more uniform adsorption and heat transfer capacity. Dehumidification capacity of AFLi30@P DCHE can reach 1.08 g g−1 under the conditions of 27 °C air temperature, 70 % air humidity, 30 °C dehumidification temperature and 60 °C regeneration temperature.