Title: Exergy analysis of electric vehicle battery thermal management systems using transcritical CO₂ vapour compression cycle

Authors: H.S. Hamut

Addresses: The Scientific and Technological Research Council of Turkey (TUBITAK), Marmara Research Center, Energy Institute, TÜBİTAK Gebze Yerleşkesi, Barış Mah. Dr. Zeki Acar Cad. No. 1, 41470 Kocaeli, Turkey

Abstract: In this paper, performance analysis of a transcritical CO₂-based electric vehicle battery thermal management system (EV BTMS) is investigated in a basic single-stage vapour compression cycle along with its various modifications that include internal heat exchanger (IHX), two-stage vapour compression and an intercooler. The system is compared against conventional cycles with various commercial refrigerants including R152a, R134a, R290, R600, R600a, R1234yf and Dimethylether and evaluated with respect to exergy-based thermodynamic, economic and environmental considerations. In the study, the efficiencies of each system and its components are calculated under various conditions and input parameters, and the corresponding component and exergy destruction-based costs and environmental impacts are determined. Based on the analyses, it is found that the exergy efficiency of the transcritical CO₂-based system can be improved by up to 22% with two-stage compression and IHX. However, the efficiency of the improved system is still found out to be lower than the compared system using the studied refrigerants.

Keywords: carbon dioxide; CO2 vapour compression cycle; exergy efficiency; exergoeconomic analysis; exergoenvironmental analysis; electric vehicles; battery thermal management; exergy analysis; internal heat exchangers; intercoolers; two-stage compression; refrigerants.

DOI: 10.1504/IJEX.2015.072169

International Journal of Exergy, 2015 Vol.18 No.2, pp.214 - 233

Received: 25 Aug 2014
Accepted: 14 Oct 2014
Published online: 02 Oct 2015 *

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