Performance analysis and optimization of two-stage desiccant wheel cooling systems in low-latitude island with hot and humid climate

In low-latitude islands characterized by extreme humidity and heat, effective dehumidification and cooling are essential for indoor environmental comfort. However, energy supply challenges persist due to geographical isolation, necessitating energy-efficient systems with stable operation. This study proposes three dehumidification/cooling systems tailored to such climates, utilizing dual solid desiccant wheels. Comparative analysis revealed the solar-powered two-stage desiccant wheel coupled with mechanical refrigeration (SDW-VCR) system as optimal. After optimization, peak thermodynamic performance (COPth = 1.32) was achieved at a 30 % return air ratio and 85 °C regeneration temperature. The system delivers 57.2 kW total cooling capacity, with the refrigeration unit handling 11.6 kW (20.3 %) of sensible heat. Notably, the condenser inlet air temperature approximates ambient conditions due to high evaporation temperatures, yielding a refrigeration COP of 4.85. Regeneration heating demand was reduced by preheating air through condensation heat recovery. These findings establish a reference framework for sustainable thermal environment management in high-humidity tropical islands.