Highly efficient heat pump with desiccant coated evaporator and condenser: principle and application.

Abstract

Nowadays, comfortable and efficient heating, ventilation, and air conditioning (HVAC) systems in buildings are highly desirable. Traditional vapor-compression devices exhibit a low coefficient of performance (COP) (typically 2.8–3.6) due to the cooling-based dehumidification. Temperature-and humidity-independent control (THIC) systems have been proposed to overcome the challenges; however, their COP is hindered by the sorption heat effect. Here, we report on a solid desiccant heat pump (SDHP) based on desiccant coated evaporators/condensers (DCEs/DCCs). The desiccants adsorb moisture almost isothermally and can be regenerated by the condensation heat. With the optimized refrigerant and desiccant, our proposed DCCs/DCEs feature a weakly-coupled heat and mass transfer. The system exhibits a COP of 6~7, doubling the efficiency of heat pumps currently used in household, which opens a window for the future development of HVAC systems and also a broad range of THIC applications.