Experimental and numerical investigation on shell and coil storage unit with biodegradable PCM for modular thermal battery applications

Thermal energy storage (TES) in automotive applications is currently growing in importance. TES can visibly reduce primary energy consumptions, decrease CO2 emission, and improve thermal comfort in electric as well as hybrid vehicles. However, to meet the new ambitious target (15% reduction of CO2 emissions in the new cars until 2025) it is required to use plug-in electric vehicles. For this reason, this paper focuses on the optimization of key coil designing parameters. For the reference geometry, both experimental and CFD results have been presented. The optimization of coil geometrical parameters has been carried out based on numerical modelling. The prototype of TES is proposed as a honeycomb battery of individual modules. The results show that increasing the diameter and pitch of the coil decreases the melting and solidification time by 13.2% and 11.8% respectively for chosen geometry. CFD calculation has also been made for TES with a hexagonal geometry. The best results were obtained for the TES with a cylindrical shell. However, the results for the TES with hexagonal shell were, very similar (the difference was less than 1% of the share of the liquid phase). It is seen that presented coil optimization is also a good fit for TES with hexagonal shell geometry.

Automated summary

Thermal energy storage (TES) is becoming increasingly important in automotive applications, as it can effectively reduce energy consumption, CO2 emissions, and improve thermal comfort in electric and hybrid vehicles. This paper focuses on the optimization of key coil designing parameters for TES in plug-in electric vehicles, in order to meet the ambitious target of reducing CO2 emissions by 15% in new cars by 2025. Both experimental and CFD results were used to optimize coil geometrical parameters, and a prototype of TES in the form of a honeycomb battery of individual modules was proposed. The results showed that increasing the diameter and pitch of the coil reduced melting and solidification time, and the optimization was applicable for TES with hexagonal shell geometry as well.