Research and Structural Optimizationof Hydrogel-based Desiccant-coated Heat Exchanger

Abstract

Desiccant-coated heat exchangers (DCHE) play a very important role in the field of dehumidification. However, due to a lack of structural optimization and selection of operating conditions, the efficiency of current dehumidification technology needs to be improved. Therefore, this paper developed an efficient hydrogel composite material, set up a dehumidification experimental platform, and established a physical model of hydrogel-based desiccant-coated heat exchanger in COMSOL based on material characteristics. Three structural parameters, adsorbent coating thickness, fin spacing, and air channel length, were extracted, and the dehumidification performance was optimized and verified by experiments. The study found that the hydrogel-based desiccant heat exchanger had the best desiccant performance when the coating thickness was 0.4mm, the fin spacing was 2.2mm, and the air passage length was 20mm. Unlike other models, this model considers the coupling of multiple physical fields, including the humidity field, adsorbent adsorption volume field, and fluid temperature field in the heat exchanger, and the average desiccant amount increased by 10.35g/kg and the average desiccant rate was improved by 48.65% after structural optimization. This provides a feasible solution for efficient and energy-saving desiccant.

Keywords

• DCHE
• hydrogel adsorbent
• heat and mass transfer
• dehumidification