Investigation of the improvement methods in terms of performance and the energy usage of the hvac system of electric vehicles

In internal combustion engine vehicles, the heat demand of the vehicle is provided by utilizing the waste heat of the engine. But in electric vehicles, due to the inadequate waste heat of the vehicle, some solutions are developed such as heat pump systems. Although electrical heaters show fast warm-up performances, they consume proportionally too much energy from the limited battery capacity and cause a significant decrease in the vehicle range. On the other hand, conventional air source heat pump systems cannot satisfy the heat demand of the vehicle. In this study, to overcome the deficiencies, a one-dimensional vehicle HVAC system model was developed. This model also utilizes the waste heat of electric vehicle and was performed under the NEDC driving cycle. In addition, a one-dimensional conventional vehicle air conditioning and heat pump systems were modeled by using conventional HVAC system components. The results showed that, a hybrid heating system consists of a heat pump system and electrical heaters can be used for the heating electric vehicle cabin. The hybrid system has lower energy consumption than electrical heaters. They can provide the heat demand of the vehicle at low ambient temperature conditions and they can utilize the waste heat of the vehicle.