Investigation of the effect of thermal comfort-focused autonomous air conditioning system design on energy efficiency in electric vehicles

One of the biggest obstacles to the widespread use of electric cars is range anxiety. One of the most important factors that reduces range is the air conditioning unit. These units cooling more than necessary leads to energy loss. In this study, an autonomous air conditioning unit focused on thermal comfort was designed in order to eliminate the energy loss caused by the air conditioning unit. Additionally, the contributions of vent locations to thermal comfort and energy savings were investigated. PMV was used as thermal comfort index. This study was carried out experimentally and numerically on the Renault Safrane brand vehicle. The autonomous air conditioning system was operated with three different vent positions. The effects of vent locations and autonomous air conditioning system on energy saving were investigated. Additionally, the air conditioning unit operating at fixed compressor and fan levels, which are traditionally accepted, was also tested in these positions. In the comparisons made, it was seen that the autonomous air conditioning system provides 83.5% energy savings compared to the traditional system. Autonomous air conditioning system, vent positions, compressor level and fan level were used as parameters. An artificial radiation stand was set up to ensure the same boundary conditions in the experiments. ANSYS CFX program was used for numerical analysis. Numerical analysis was validated by experimental study. This analysis was used to obtain values such as temperature contours, streamline graphics and cabin volume temperature inside the vehicle. The numerical and experimental results obtained are explained and examined in detail. Based on the results of the study, various recommendations have been made to electric vehicle manufacturers.