A novel thermal management system for battery packs in hybrid electrical vehicles utilising waste heat recovery

Thermal management system generally ensures the safe operating conditions and heat resilience of bat-tery packs in hybrid electric vehicles (HEVs). The current study raised a novel approach to reduce fire risks related to HEVs through a novel battery thermal management system powered by low-grade com-bustion waste heat running on steam ejectors for the first time. In this paper, an ejector operating at a low temperature under 100 degrees C for HEV's battery thermal management system is proposed and investi-gated. An in-house wet-steam model considering the condensation effect has been developed to charac-terise the ejector's internal flow structure and further analyse its feasibility as a thermal management system. The results show that the model considering the condensation process is more feasible in evalu-ating the performance of the steam ejector than the dry gas assumption. To improve the performance of the proposed ejector battery thermal management system, the effect of superheating of primary steam has been investigated. The results showed that an optimum point exists with 11 K superheating between improvement of entrainment ratio, the system's coefficient of performance and the power efficiency for the current case. The entrainment ratio at that point reaches around 0.45, while the coefficient of perfor-mance reaches 0.225. (c) 2022 Published by Elsevier Ltd.

Automated summary

This study proposes a novel battery thermal management system powered by low-grade combustion waste heat to reduce fire risks in hybrid electric vehicles (HEVs). The study analyzes the internal flow structure and performance of the system using a wet-steam model and investigates the effect of superheating of the primary steam. The results show that the proposed system can achieve improved performance with the optimal superheating conditions.