ABSTRACT: This paper examines a passive thermal management system for electric vehicle batteries, consisting of encapsulated phase change
material (PCM) which melts during a process to absorb the heat generated by a battery. A new configuration for the thermal
management system, using double series PCM shells, is analyzed with finite volume simulations. A combination of computational
fluid dynamics (CFD) and second law analysis is used to evaluate and compare the new system against the single PCM shells.
Using a finite volume method, heat transfer in the battery pack is examined and the results are used to analyse the exergy
losses. The simulations provide design guidelines for the thermal management system to minimize the size and cost of the system.
The thermal conductivity and melting temperature are studied as two important parameters in the configuration of the shells.
Heat transfer from the surroundings to the PCM shell in a non-insulated case is found to be infeasible. For a single PCM system,
the exergy efficiency is below 50%. For the second case for other combinations, the exergy efficiencies ranged from 30–40%.
The second shell content did not have significant influence on the exergy efficiencies. The double PCM shell system showed
higher exergy efficiencies than the single PCM shell system (except a case for type PCM-1). With respect to the reference
environment, it is found that in all cases the exergy efficiencies decreased, when the dead-state temperatures rises, and
the destroyed exergy content increases gradually. For the double shell systems for all dead-state temperatures, the efficiencies
were very similar. Except for a dead-state temperature of 302K, with the other temperatures, the exergy efficiencies for
different combinations are well over 50%. The range of exergy efficiencies vary widely between 15 and 85% for a single shell
system, and between 30–80% for double shell systems.
Heat and Mass Transfer 04/2012; 47(7):777-788. · 0.90 Impact Factor