Research and Structural Optimization of Hydrogel-Based Desiccant-Coated Heat Exchanger

Desiccant-coated heat exchangers (DCHEs) play an important role in dehumidification. However, considering the ineffective structural optimization and selection of operating conditions, the efficiency of the current dehumidification technology needs improvement. Therefore, in this study, an efficient hydrogel composite material was developed, a dehumidification experimental platform was established, and a physical model of a hydrogel-based desiccant-coated heat exchanger was developed in COMSOL based on the material characteristics. Three structural parameters, including adsorbent coating thickness, fin spacing, and air channel length, were extracted. The dehumidification performance was optimized and experimentally verified. The study determined that the hydrogel-based desiccant heat exchanger had the best dehumidification performance when the coating thickness was 0.4 mm, fin spacing was 2.2 mm, and air passage length was 20 mm. Unlike other models, this model considers the coupling of multiple physical fields, including the humidity field, adsorbed water fraction field, and fluid temperature field in the heat exchanger. The moisture removal capacity increased by 10.35 g/kg (dry air), and the moisture removal rate improved by 48.65% after structural optimization.