xEV용 냉난방 시스템 기술 개발 동향 연구

The objective of this study is to explain the development trend of A/C system for xEV. Because the electrical energy must be spent for cooling and heating of the cabin for xEV(Electric-driven Vehicle, HEV, PHEV, FCEV, BEV) unlike ICEV(Internal Combustion Engine Vehicle), driving range per a charge of electric vehicles is reduced due to A/C conditioning system operation according to previous study. Especially, since heating system influences more than cooling system, efficient heating system is required to be development. Therefore, heat pump system has been considered as a substitute on behalf of electric heater. Because heat pump system with the air as a heat source has had some barriers to apply the vehicle, such as dehumidification of the cabin, frost concern of exterior heat exchanger as an evaporator when operating under lower ambient conditions, and unbalance heat capacity between exterior and interior heat exchanger due to different specifications, technical approaches have been studied, such as the heat pump with the coolant as a heat source, gas/liquid injection techniques. Even though heat pump systems have been investigated to deal with heat loads under the various operating conditions, electric heaters need to add deficient heat capacity under freezing conditions due to working fluid’s physical characteristics. Then, various electric heaters have been studied, such as air heating and coolant heating. To improve heating performance, various heating methods have been developed to find out optimum system.