Total Thermal Management of Battery Electric Vehicles (BEVs) 2018-37-0026
The key hurdles to achieving wide consumer acceptance of battery electric vehicles (BEVs) are weather-dependent drive range, higher cost, and limited battery life. These translate into a strong need to reduce a significant energy drain and resulting drive range loss due to auxiliary electrical loads the predominant of which is the cabin thermal management load. Studies have shown that thermal sub-system loads can reduce the drive range by as much as 45% under ambient temperatures below −10 °C. Often, cabin heating relies purely on positive temperature coefficient (PTC) resistive heating, contributing to a significant range loss. Reducing this range loss may improve consumer acceptance of BEVs. The authors present a unified thermal management system (UTEMPRA) that satisfies diverse thermal and design needs of the auxiliary loads in BEVs. Demonstrated on a 2015 Fiat 500e BEV, this system integrates a semi-hermetic refrigeration loop with a coolant network and serves three functions: (1) heating and/or cooling vehicle traction components (battery, power electronics, and motor) (2) heating and cooling of the cabin, and (3) waste energy harvesting and re-use. The modes of operation allow a heat pump and air conditioning system to function without reversing the refrigeration cycle to improve thermal efficiency. The refrigeration loop consists of an electric compressor, a thermal expansion valve, a coolant-cooled condenser, and a chiller, the latter two exchanging heat with hot and cold coolant streams that may be directed to various components of the thermal system. The coolant-based heat distribution is adaptable and saves significant amounts of refrigerant per vehicle. Also, a coolant-based system reduces refrigerant emissions by requiring fewer refrigerant pipe joints. The authors present bench-level test data and simulation analysis and describe a preliminary control scheme for this system.
Citation: Chowdhury, S., Leitzel, L., Zima, M., Santacesaria, M. et al., "Total Thermal Management of Battery Electric Vehicles (BEVs)," SAE Technical Paper 2018-37-0026, 2018, https://doi.org/10.4271/2018-37-0026. Download Citation
Author(s):
Sourav Chowdhury, Lindsey Leitzel, Mark Zima, Mark Santacesaria, Gene Titov, Jason Lustbader, John Rugh, Jon Winkler, Aamir Khawaja, Murali Govindarajalu
Affiliated:
Mahle Behr Troy Inc., National Renewable Energy Laboratory, FCA US LLC
Pages: 7
Event:
CO2 Reduction for Transportation Systems Conference
ISSN:
0148-7191
e-ISSN:
2688-3627
Related Topics:
Electric vehicles
Thermal management
Power electronics
Air conditioning
Batteries
Coolants
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