Study of an Efficient Dehumidifying System Utilizingm Phase Change of Intermediate Pressure Refrigerant

This study has proved a new dehumidifying system that aimed to reduce the sensible heat ratio (SHR) of the cooling process without using additional heat to relieve the recently indicated conflict between energy saving and the dehumidification necessary for keeping adequate indoor air quality (IAQ). In this system, intermediate pressure refrigerant in a vapor compression refrigerating cycle is used as the heat transfer medium of a characteristic heat exchanger to precool the process air entering an evaporator as well as to reheat the process air leaving the evaporator. This system has achieved higher moisture removal and consequently higher efficiency of the dehumidifying process. In addition, since this system has the capability of integrating into air-conditioning units (HVAC system), it will be able to accommodate SHR for a wide range of cooling needs. This paper reports technical information, experimental results, and simulation results when applying this system to an HVAC system.