Design strategies of conventional and modified closed-air open-water humidification dehumidification systems

摘要

Humidification dehumidification (HDH) systems are robust and known to withstand a wide range of saline water without the need of complex maintenance. In this study, the closed-air open-water (CAOW) HDH arrangement is examined, which can easily be integrated with solar or other renewable resources. Also, this system is modified by incorporating heat recovery options for low performing units. The heat recovery process is executed through two approaches, (i) a mixing chamber and, (ii) by a heat exchanger. Thermal balancing through air extraction is evaluated for the basic as well as the modified cycles, particularly for high performing units. Zero, single and double extractions models are evaluated for the conventional CAOW water heated cycle. The performance of the systems is characterized into three operating regions (high, moderate and low) based on the effectiveness of the components. Based on the results of this evaluation, an operating scheme is then developed to decide where to use the conventional or the modified systems with or without extraction.