Holistic thermal management in electric vehicles
The available energy in electric vehicles – in particular under winter conditions – is needed in approximately the same extent for propulsion and air conditioning. The achievable range of electric vehicles is a key factor for their attractiveness. Therefore, new components are required, allowing optimum distribution of thermal energy in the vehicle with minimum electrical power consumption. This paper will show how to minimize the consumption of electric power for vehicle air conditioning compared to current solutions. The objective of the presented work is an efficient cooling and air conditioning system which is based on an indirect heat-pump with an optimized valve concept. Thereby a reliable, cost-effective and energy-efficient air conditioning of the passenger compartment is possible. The system costs are kept low by a modular design strategy, applicable both to new and to conventional drive systems. A further reduction of the power consumption of the HVAC system and thus potential decrease of the battery costs of this system can be achieved, among others, by an increase of the portion of recirculating air. However, due to the recirculation of the air the moisture emission of the passengers is removed to a lesser extent. The resulting increased tendency to fogging on the vehicle windows is detected by a novel fogging detector and thus free visibility and safety is guaranteed.
The heat exchangers of the indirect heat pump system were researched and experimentally investigated at MAHLE. The coolant valves used in the heat pump system were researched at Bosch. The heat balance of the passenger compartment and the increase of the portion of recirculating air in heating modes were examined by Daimler. The results of these studies have been used by sitronic to investigate the fogging sensor. To provide the evidence of the effectiveness of the measures in thermal management an overall vehicle simulation is carried out at FKFS.
This paper is a summary of the results of the project “Ganzheitliches Thermomanagement im E-Fahrzeug – GaTE (Holistic Thermal Management in E-Vehicles)” within the framework of the Cluster of Excellence “Electromobility South-West”.
KeywordsElectric Vehicle Heat Pump Driving Cycle Electrical Power Consumption Heat Pump System
Unable to display preview. Download preview PDF.