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.

Suitability of aluminium copper silicon eutectic as a phase change material for thermal storage applications: Thermophysical properties and compatibility

“…Our group at the German Aerospace Centre (DLR) has been investigating Al-based alloys for vehicle applications since 2016. 3 The binary eutectic Al-12.7 wt% Si has been previously investigated with a melting temperature of 577 C. [4][5][6][7] The ternary Al-Cu-Si system has been selected as it has comparable thermal properties to the binary Al-Si with a lower melting temperature of about 522 C. 2 Additionally, this ternary system has showed superior corrosion resistance compared to Al-Cu and Al-Si alloys. 8 Our previous findings show the Al-25.4% Cu-6.1% Si (wt%) (rounded to Al-25% Cu-6% Si [wt%] in the rest of the article) eutectic to be optimal in energy density (both gravimetric and volumetric) and in cost per kWh of latent heat for the temperature range 508 C to 548 C. 2 Given its apparent optimal properties for a temperature range relevant to many applications, the thermal properties and compatibility of the eutectic should be determined to enable implementation.…”

Thermal Battery for Electric Vehicles: High-Temperature Heating System for Solid Media Based Thermal Energy Storages

“…So far, several studies have been performed for thermal storage systems based on phase change materials (PCM) for heat supply [14][15][16], for preheating of catalysts [17], for combustion engines [18] and for cooling applications [19]. New ways for thermal management concepts based on thermochemical energy storage systems (solid/gas reaction) are described in [20], offering an alternative heat and cold supply especially for fuel cell vehicles.…”

Simulative Investigation of Thermal Capacity Analysis Methods for Metallic Latent Thermal Energy Storage Systems

“…The driving range can be maintained under these conditions by adding thermal energy storage (TES) in addition to the electrochemical energy storage. Carefully designed TES can save mass, space, cost and rare raw materials compared to a larger battery [4,5]. Thermal energy can be stored latently in a phase transition of a phase change material (PCM) at constant temperature.…”

“…Storage with high thermal input and output can be termed thermal high-performance storage (THS). Kraft et al first proposed a THS design for a battery electric subcompact car with a defined reference scenario for ambient temperatures up to −20 • C [5]. The design was based on the mPCM Al-12wt% Si, with an operating temperature up to 600 • C. Charging power of 11 kW and thermal output of 5.1 kW were suggested.…”