Advanced Indirect Dew-Point Evaporative Cooling System Under High-Humidity Environments
Abstract
Conventional dew-point evaporative cooling (DPEC) systems are constrained by two critical bottlenecks: insufficient humidification efficiency and pronounced performance degradation under high-humidity conditions. To address these limitations, this study proposes and experimentally characterizes a novel ultrasonic spray-humidified DPEC system integrated with a 3D-printed PA (polyamide)-supported LiCl-PAAS (lithium chloride–sodium polyacrylate) composite sorbent coating. In this system, a 3D-printed porous sorbent module with a high specific surface area is embedded in the drying chamber to dehumidify the working air. Under the standard operating condition of 36 °C and 50% RH (relative humidity), the improved system achieves a product air dry-bulb temperature of 21.5–4.1 °C lower than that of the counterpart without a sorbent coating—alongside an 84% improvement in COPe (electrical coefficient of performance, accounting only for fan and ultrasonic humidifier power, excluding regeneration heat). Under the high-humidity condition of 90% RH, the cooling performance degradation rate is reduced from 91.97% for the conventional system to 63.81% for the proposed design. This work validates the synergistic enhancement effect of precooling-assisted dehumidification coupled with centralized humidification in a small-scale proof-of-principle prototype, and provides preliminary experimental evidence for future exploration of DPEC technology in high-temperature and high-humidity climate zones; scale-up and long-term field validation remain to be conducted.