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Electric Vehicle Thermal Management System For Hot Climate Regions
ISSN: 0148-7191, e-ISSN: 2688-3627
To be published on November 21, 2019 by SAE International in United States
Event: NuGen Summit
ELECTRIC VEHICLE THERMAL MANAGEMENT SYSTEM FOR HOT CLIMATE REGIONS Rana Tarun*, Yamamoto Yuji, Kumar Ritesh, Bhagatkar Shubhada Pranav Vikas India Private Limited, India Key Words Electric Vehicles (EV); Battery Thermal Management System (BTMS); COP; Electric Vehicle Thermal Management System (EVTMS); BTMS and HVAC System Integration; Thermal System Performance Comparison; Active Liquid Cooling; EV Battery Cooling Research and/or Engineering Questions/Objective Electric Vehicles is the need of time to limit global warming and it is in application at a wide scale in colder or mild climate regions where ambient temperature is limited to mild or moderate level. Its application (Heat pump, CO2) is constrained to cold climates only due to securing better COP for heating function, sacrificing cooling COP of the existing system when operated in Hot Climate Regions, thus limiting its application to nearly half of the automotive user-base. This study is aimed to develop a new Electric Vehicle Thermal Management System (EVTMS) limited to active liquid cooling for application of Electric Vehicle in Hot Climate Regions with higher system COP targets when compared to existing EVTMS subjected to hot climate regions. Methodology In current EV’s there is separate HVAC System and BTMS sharing electric compressor and cooling unit only. Evaporator and Chiller are used for HVAC Cooling and Battery Cooling respectively. An exclusive Heat Pump system is used for HVAC Heating. For battery heating a separate electric heater is used which in turn is powered from Battery itself, decreasing Battery SOC to keep Battery in a healthy operating temperature zone. To overcome this inefficiency and existing design limitation, this study is proposing a complete integration of BTMS and HVAC System. This integrated Thermal Management Systems has lesser number of pipes and valve connection in comparison to conventional EVTMS which decreases refrigerant pressure drop resulting in optimized cooling COP of EVTMS even sacrificing heating COP if pre-heating is required optionally. This concept proposes a heat recovery system also which contributes to improve in Thermal System COP of the EVTMS dedicated to Hot Climate Regions. This system will be simulated using 1-D simulation tool and thus performance analysis and comparison will be carried out. Results In this paper 1-D simulation results will be presented considering Thermal System COP of the EVTMS as the key parameter. Waste Heat Recovery and decrement in refrigerant pressure drop due to lesser number of parts in the proposed EVTMS in comparison to conventional EVTMS resulting in better cooling COP of the EVTMS dedicated to hot climate region with a little compromise to heating COP of EVTMS concept. Simulation for system performance in different climatic (ambient) condition and different cooling load requirement of BTMS will be presented in this study. A comparison between Thermal System COP of this EVTMS concept and existing best EVTMS dedicated to Hot Climate Regions will also be presented in this paper. Limitations Testing of the proposed design in a System Calorimeter Bench integrated with Battery Conditioning System to validate the simulation results is missing in study which will be an extension of this study. What does the paper offer that is new in the field including in comparison to other work by the authors? The existing research works provide a suitable solution for thermal management of Electric Vehicles used in Cold or Mild climatic region. But there is no extensive study done to provide a solution for BTMS requirements along-with HVAC System Requirements of Electric Vehicles for application in Hot Climate Regions. This study provides a solution to the existing design limitations and widens the scope of Electric Vehicle application to Hot Climate Regions also. Conclusion An ideal solution for application of EVTMS in hot climate regions has been conceptualized. It was found that EVTMS would be beneficial for moderate region also where does not have so severe cold winter.