Investigation on the performance enhancement of electric vehicle heat pump system with air-to-air regenerative heat exchanger in cold condition

• Published in: Sustainable energy technologies and assessments 2022-03, Vol.50, p.101791, Article 101791
• Main Authors: Lee, Sangwook, Chung, Yoong, Jeong, Yeonwoo, Kim, Min Soo
• Format: Article
• Language: English
• Subjects: Air recirculation; ARXH (air-to-air regenerative heat exchanger); EV (electric vehicle); Heating and dehumidification load; Ventilation load
• ISSN: 2213-1388
• DOI: 10.1016/j.seta.2021.101791

•Electric vehicle heat pump model with thermal load of cabin is established.•Performance of heat pump system with air-to-air regenerative heat exchanger is assessed.•Heating, dehumidification load, and resultant power consumption are reduced with air-to-air regenerative heat exchanger.•Air-to-air regenerative heat exchanger enhances the performance of the heat pump system in both recirculation mode and outdoor air mode. Since the heat pump operation in low ambient temperature requires considerable amount of electric energy, electric vehicles (EVs) suffer from the significant range loss problem in cold regions. In this study, heat pump system with air-to-air regenerative heat exchanger (ARHX) is suggested as a way to improve the energy inefficiency in the ventilation or dehumidification process. In recirculation mode, ARHX reduces heating and dehumidification load by utilizing the temperature difference of two air streams, occurring in the subsequent dehumidification and heating process. In outdoor air mode, ARHX enhances heating performance by recovering the heat from the preconditioned cabin air, which is exhausted to the environment in conventional heat pump system. Heat pump model was built upon an experimentally validated component model and thermal load model. Based on this heat pump model, performance enhancement of the proposed system is investigated in both recirculation and outdoor air mode with various climate conditions. Results confirm that suggested heat pump system decreases heating load and dehumidification load up to 12.3% and 12.9% in recirculation mode and the heating load reduction reaches 20.2% in outdoor air mode. Power consumption of the compressor is saved up to 10.6% in recirculation mode and 55% in outdoor air mode.