Performance evaluation of a hybrid solar powered rotary desiccant wheel air conditioning system for low latitude isolated islands

Abstract Low latitude isolated islands have the climate characteristic of high temperature and high humidity, but in short of conventional energy. This study proposes a novel hybrid solar powered rotary desiccant wheel air conditioning (SRDAC) system to improve the indoor temperature of buildings on low latitude isolated islands. The SRDAC system combines photovoltaic power generation, solar thermal collector, vapor compressed cooling system and a two stage rotary desiccant wheel system. In this study, mathematical models of the subsystems of the SRDAC system are established firstly. MATLAB was used to analyze the performance of the SRDAC system, which includes the dehumidification capacity, cooling capacity, condensation heat quantity and thermodynamic performance coefficient. Then, the photovoltaic area and solar thermal collector area of the SRDAC system were matched and optimized based on meteorological parameters of low latitude isolated islands. Finally, the SRDAC system’s economic performance was analyzed. The results show that, for every 10 ℃ increase in regeneration temperature, the dehumidification capacity and cooling capacity increase by 0.9 g/kg-2.7 g/kg and 0.4 kW-1.9 kW, respectively. For every 1g/kg increase of outdoor air moisture content, the total installed area increased by 2.2%-2.3%. The SRDAC system shows a good operating performance, can better adapt to the climate characteristics of low latitude isolated islands, and effectively reduces the temperature and moisture content of the air. This study serves as a reference for the application of SRDAC system in extremely hot and humid climates.