Analysis of Heat and Mass Transfer in the Elements of a Desiccant Evaporative Cooling (DEC) Air Conditioning System

Abstract

The DEC system emerges as a sustainable alternative to conventional air conditioning systems reliant on compressor technology. Distinctively, this system circumvents the use of harmful refrigerants and minimizes electricity consumption. Its operational requirement, namely heat at approximately 70°C, can be sourced from solar collectors or reclaimed from industrial processes. Primarily tasked with air drying followed by cooling through humidification, this study delineates the burgeoning market for DEC and akin devices. Design adaptations catering to diverse weather conditions and operational needs are delineated. Notably, meticulous calculations spotlight mass and heat transfer dynamics within rotary exchangers. An empirical analysis of DEC performance under Polish weather conditions underscores crucial metrics including thermal power consumption, EER coefficient, indoor air parameters, system-wide water flow rates for humidification, and the influence of operational variables such as rotor speed, regeneration air temperature, air mass flow, and external air conditions. While the system effectively achieves desired cooling, it occasionally surpasses upper humidity thresholds during extreme weather conditions. Conclusions drawn from this study prompt potential resolutions to encountered challenges, promising advancements in DEC system optimization.