Performance analysis of an electric vehicle heat pump system with a desiccant dehumidifier

•An additional heat exchanger is applied to heat recovery of an electric vehicle.•A desiccant coated heat exchanger is utilized for defogging and heat recovery.•A novel dehumidification system is regenerated by waste heat recovery.•The proposed system shows 20% energy reduction by dehumidification and heat recovery. A battery-electric-vehicle (BEV) relies on the state of charge (SoC) of the built-in battery system because it exclusively uses electric energy stored in rechargeable battery packs. The EV's mileage would be reduced due to the electricity consumption when the mobile heat pump system (MHP) is operated. In the case of the the winter season, the heat pump system operates not only for heating the cabin to achieve thermal comfort but also for defogging to maintain driving safety. To ensure the EV’s driving range, the energy consumption of MHP should be minimized as much as possible by recovering waste heat and applying a dehumidifier. For these purposes, the desiccant coated heat exchanger (DCHE) is introduced into the system, which is able to simultaneously transfer heat and mass (water vapor). In this study, the MHP and cabin thermal load models were made, and the DCHE model was validated by experiments using the unit DCHE. Based on the models, the energy consumption of the EV MHP with the DCHE was conducted, and compared to the conventional system, the proposed system required less energy.