Solar regenerated carbon-based composite desiccant coated heat exchangers for air dehumidification

Desiccant dehumidification can realize decoupling of latent and sensible heat loads in dehumidified air conditioning, thereby reducing energy consumption. This paper proposes a solar regenerated carbon-based composite desiccant coated heat exchangers (DCHE) for air dehumidification. Carbon-based composite desiccant is electrostatically sprayed onto the surface of the heat exchanger to form a dehumidification coating. An experimental system for evaluating the dehumidification and regeneration performance of DCHE is established. The Taguchi method is employed to evaluate the impact of operating parameters such as air velocity, water flow rate, and regeneration temperature on the dehumidification and regeneration efficiency of DCHE. The result shows that air velocity is the primary factor impacting the dehumidification performance of DCHE, with regeneration temperature and cooling water flow rate following in importance. With the faster air velocity and the lower cooling water flow rate, DCHE shows the better dehumidification performance. Moreover, excessively both high and low regeneration temperatures can result in a degradation in the dehumidification performance of DCHE. Under optimal operating conditions, the dehumidification rate (EDE) and thermal coefficient of performance (COPth) of DCHE can reach 7.5 kg/h and 2.3, respectively. The moisture content of the air reduces from 19.6 g/kg to 8.0 g/kg. •A solar regenerated carbon-based composite desiccant coated heat exchanger (DCHE) is proposed.•Dehumidification process of DCHE can reduce the influence of adsorption heat of desiccant.•DCHE solve the high humidity problem in direct evaporative cooling supply air.•Equilibrium adsorption capacity of carbon-based composite desiccant is 6.8 times than activated carbon.