Improving the performance of thermal management system for electric and hybrid electric vehicles by adding an ejector

• Published in: Energy conversion and management Vol. 201; p. 112133
• Main Authors: Alkhulaifi, Yousif M., Qasem, Naef A.A., Zubair, Syed M.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.12.2019; Elsevier Science Ltd
• Subjects: batteries; Battery thermal management system; Capacitors; Cooling; COP; Ejection; Ejector; Electric vehicles; Evaporative cooling; Evaporators; heat; Hybrid electric vehicles; Hybrid systems; Inlet pressure; management systems; mixing; Operating temperature; Refrigerants; temperature; Thermal management; vehicles (equipment); Electric vehicles; Ejector; Cooling; Performance; COP; Battery thermal management system
• ISSN: 0196-8904; 1879-2227
• DOI: 10.1016/j.enconman.2019.112133

•A novel thermal management system for electric vehicles is introduced.•Various configurations are studied to explore performance subject to various conditions.•All the systems are investigated under different operating conditions.•It is demonstrated that the ejector can efficiently be used to improve the performance of thermal management system.•The refrigerant charge and rejected heat by the condenser decrease by 12% and 14.4%, respectively. For electric and hybrid electric vehicles, a battery thermal management system (BTMS) is an essential component to maintain a proper operating temperature for the battery pack. In this paper, a modern BTMS involving an evaporator (for cooling passenger cabinet) and a chiller (for cooling battery pack) is investigated under different cooling temperatures. Three systems are studied in which (a) the refrigerant lines coming from the chiller and evaporator have the same temperature (for the basic system), or they have different temperatures to be connected by (b) the mixing chamber, or (c) an ejector for a suggested novel system. For a mixing-chamber based system, the results show that the refrigerant charge decreases by 12% compared to the basic system leading to improving the coefficient of performance (COP) by 4.7%. Alternatively, the ejector can efficiently be used instead of the mixing chamber. One of the advantages for the use of ejector is to increase the inlet pressure of the compressor, resulting in minimizing the required power input. Therefore, COP improvement is found to be in a range of 7.17%–77.9%, compared to the basic system under the investigated conditions. The refrigerant charge and the rejected heat by the condenser decrease by 12% and 14.4%, respectively.