Capacity evaluation of mechanical dehumidification systems: A theoretical framework

Abstract

Vapor compression cycle-based mechanical dehumidification systems are common and have undergone extensive research to augment their dehumidification capacity. Traditional methodologies typically validate these enhancements via experimentation or simulation. In contrast, this study leverages an analytical perspective, developing a theoretical framework to evaluate system capacity. This is achieved through the analysis of the dehumidifying heat exchanger's performance or the impact of the air state entering the heat exchanger. Analytical solutions specific to the finned-tube heat exchanger are derived, establishing evaluation criteria for two distinct cases. These cases are visually represented as dividing lines on the psychrometric chart, fostering a more direct understanding of how system capacity changes with the incoming air state. The soundness of this theoretical framework is confirmed through numerical simulations and experiments and is subsequently applied to analyze various modifications to the traditional mechanical dehumidification system. These include the Cromer cycle, heat pipe, air-to-air heat exchanger, and evaporative cooling. The feasibility of these modifications is explained, and their relative strengths and weaknesses in theory are compared. The proposed framework provides insights into existing technologies and has the potential to stimulate the conception of innovative designs.