Multi-objective optimization under the mixed utilization strategy of heat pump and electric drive waste heat of electric vehicles

• Published in: Applied thermal engineering 2025-01, Vol.259, p.124900, Article 124900
• Main Authors: Zhang, Yan, Zhao, Donggang, Wu, Limin, He, Liange, Huang, Jianglu, Zhao, Yu
• Format: Article
• Language: English
• Subjects: Electric drive system; Electric vehicle; Heat pump air conditioning; Hybrid utilization; Waste heat recovery
• ISSN: 1359-4311
• DOI: 10.1016/j.applthermaleng.2024.124900

•A new EDS waste heat recovery structure was constructed and efficiently utilized.•Utilizing EDS waste heat to reduce the probability of OHE frosting and increase cell temperature.•Improve the COP of MHP and enhance the heating efficiency of EV in low temperature environment.•Optimize compressor energy consumption and effectively reduce the energy consumption of electric vehicles while driving. Low-temperature conditions can lead to problems such as easy frosting of the outdoor heat exchanger (OHE) of the vehicle heat pump air conditioner (MHP) in electric vehicles (EVs), inefficient use of waste heat in the electric drive system (EDS), and poor performance of the power battery. A hybrid utilization structure of EDS waste heat recovery (WHR) and MHP is proposed, and a corresponding WHR control strategy is developed. The strategy utilizes the EDS waste heat for the power battery to increase the operating temperature, and improves the heat production performance of the MHP to suppress the occurrence of outdoor heat exchanger frost. The results show that at ambient temperatures of −10 °C and −5°C, the strategy not only effectively utilizes the waste heat of the EDS to rapidly raise the power battery to the target temperature of 20 °C, but also warms the inlet of the outdoor heat exchanger of the MHP to above 0 °C, effectively preventing frosting. The Coefficient of Performance (COP) of MHP is increased by 21.98 % and 20.73 %, respectively, and the state of charge (SOC) can be saved by 0.86 % and 3.3 %, respectively, from full power to depletion. The energy consumption of the compressor is reduced by 0.52 % and 2.45 % respectively.