Thermal High Performance Storages for use in vehicle applications

Abstract

To overcome the restrictions on electric vehicles ranges on winter term conditions, due to the heating demand of the interior, the use of a Thermal High Performance Storage with metallic Phase Change Materials is one possible solution. A new storage concept, using a so called Heat Transport System, enabling the heat transfer from the storage to a vehicles cooling fluid by evaporation and condensation of a working fluid within a closed circle, is introduced in this study. The influence of the storage on an electric vehicles range is exemplary shown for DLR´s Urban Modular Vehicle Concept for a motorway cycle by theoretical investigations. An increase of range by 36,3 km resp. 18,4 % for an ambient temperature of -10 °C and 46 km resp. 26,7 % for an ambient temperature of -20 °C could be reached. The energy densities of the designed storages reach values of more than 220 Wh/kg resp. more than 310 Wh/l. The cost estimations for those storage systems are approx. 445 € resp. 660 €. A comparison between the thermal energy storage and a conventional heating system consisting out of a PTC-Heater and a battery show, that the conventional heating system has a mass which is about two thirds higher, a volume which is more than one third higher and a quadrupled price compared to the thermal energy storage.