Performance analysis of the CO 2 heat pump-combined desiccant air-conditioning systems applied to dedicated outdoor air systems

A desiccant air-conditioning system has been suggested as being suitable to improve indoor air quality due to its superior humidity control. However, this system has the drawback of being less energy efficient, so it is typically used in conjunction with co-generation systems or solar heating systems to improve its energy efficiency. In previous studies, we proposed a new type of desiccant air-conditioning system combined with a CO2 heat pump, and studied its applicability through experiments and simplified calculations. In this system, the CO2 heat pump can provide the desiccant air-conditioning system with a steady heat source for both cooling and heating (regeneration). In this paper, the combined system is assumed to be applied to the dedicated outdoor air system of a hotel, and theoretical calculations were carried out to study the system performance. As a result, we propose a system whose overall coefficient of performance is higher than conventional air-conditioning systems.