Greenhouse dehumidification by zeolite-based desiccant coated heat exchanger

Abstract

Desiccant-coated heat exchanger (DC-HX) is a promising technology for greenhouse dehumidification since both latent and sensible loads can be addressed simultaneously. DC-HX can be operated using low-grade heat, with temperatures less than 90 °C, from renewable energy sources, which makes them attractive from environmental and operating cost perspectives. In this study, a new DC-HX coated with AQSOA™-FAM-Z02 is built and studied experimentally and theoretically under typical greenhouse conditions for the first time. For this purpose, a custom-built experimental setup is developed to examine the dehumidification performance of the proposed DC-HX. The effects of greenhouse airflow rate, temperature, and relative humidity (RH), as well as regeneration and cooling heat transfer fluid (HTF) temperatures, on the average moisture removal capacity (MRC) and thermal coefficient of performance (COP) are analyzed. Moreover, the contributions of the removed latent and sensible heats by the present DC-HX are discussed. It is found that the custom-built DC-HX can achieve cyclic MRC and COP in the range of 2.5–4.0 and 0.18–0.3, thereby providing satisfactory dehumidification performance for greenhouse applications. Moreover, optimal operating parameters to maximize COP and MRC are determined by performing a multi-objective optimization using genetic algorithm approach.