Innovation project: Intelligent heat transfer for efficient electric vehicles
Electric vehicles guarantee personal mobility without depending on fossil fuels, and have low CO2 emissions. However, their efficiency is far behind that of vehicles with an internal combustion engine; this can be clearly seen, for example, by their limited range. One reason behind this is the limited capacity of energy accumulators, the efficiency of which depends to a great degree on the temperature level. In addition, energy consumption is higher for the vehicle’s standard thermal management. On the other hand, there is a significant amount of heat loss during several process sequences – such as motor operation – which, up to now, has been transferred to the environment via the cooling system, which wastes energy. This dissipated heat can be used for targeted, needs-based temperature control, e.g. for the storage battery.
The aim of the research project is to develop a self-regulating thermal management system for electric vehicles. It is intended that the system be able to adjust itself adequately and appropriately to changes in surplus or required heat, and to divert and distribute the heat flow accordingly.
The first step is to determine the demands on the thermal management system, for example the temperature control requirements and the heat losses that arise. This forms the basis for developing innovative heat pipe concepts, known as loop heat pipes. In these, the heat lost through evaporation is automatically transferred without the need for additional electric pumps. The next step is to design an intelligent control system to interconnect the individual heat pipes and ensure that heat is distributed as needed to the parts of the vehicle that require temperature control. A model simulating the workings of the heat pipes and their control system will be developed for the system design. This involves drawing on the results of cross-functional projects in intelligent networking and energy efficiency. Finally, the system will be tested under real conditions using demonstration models, and integrated into an electric vehicle.
The innovation project will increase the performance and efficiency of electric vehicles. The aim is to increase energy efficiency by 4%. This will make a further contribution towards establishing electromobility, particularly as it is expected that there will be a 20% reduction in the cost of thermal management. The approach is transferable to other areas of application, such as cooling systems for power electronics in industrial machinery and in local passenger transit services.
01 July 2014 - 30 June 2017