A novel air-conditioning system with cascading desiccant wheel and liquid desiccant dehumidifier for low-humidity industrial environments

Abstract

Numerous industrial workshops require low-humidity environments, including lithium battery production, chip fabrication, some pharmaceutical manufacturing, etc. The desiccant wheel system is the conventional air-conditioning system for maintaining the low-humidity environments. However, only high-humidity outdoor air can be used for desiccant regeneration in some mechanical workshops requiring no mechanical ventilation, which leads to a high regeneration temperature and a poor system energy performance. To enhance the performance, a novel air-conditioning system with cascading desiccant wheel and liquid desiccant dehumidifier for low-humidity industrial workshops is proposed in this study. Solid desiccant and liquid desiccant are innovatively integrated in the proposed system for achieving a supply air dew point temperature below −10 °C. When dehumidifying process air from 5 to 1 g/kg in the basic case, the proposed system shows a competitive COP of 1.6. Under weather conditions in Guangzhou, subtropical China, the proposed system consumes 19.6 % and 58.0 % lower electricity during the summer, compared to the integrated system using outdoor air for regeneration and the desiccant wheel based system, respectively. The proposed system particularly applies to low-humidity industrial workshops in tropical and subtropical regions in summer, where there is a huge air humidity difference between indoors and outdoors. It is anticipated that this study could provide reference for energy saving and carbon emission reduction in low-humidity industrial production process.