ISSN Online: 2379-1748
ISBN Flash Drive: 978-1-56700-469-4
ISBN Online: 978-1-56700-470-0
Second Thermal and Fluids Engineering Conference
LIMITS OF LATENT HEAT STORAGE CHARGING
Abstract
Charging latent heat storages is limited by the low thermal conductivity of Phase Change Materials (PCMs). In the present work, a combined numerical-analytical study reveals the limits of PCM charging in terms of the governing non-dimensional properties. A Pareto front between energy and power density is obtained, presenting the trade-off between storage capacity and charging rate for these idealised limits. The results show that the characteristic length, i.e. the maximum distance between PCM material and a heat exchanging surface, should be reduced as much as possible in order to reach the highest performance. The Pareto front reveals that, depending on the PCM/metal combination, the maximal metal volume fraction should not exceed 70 to 95%. Furthermore, the optimal metal volume fraction depends on energy density versus charging power
requirements. The performance of existing latent heat storages are situated in the developed framework for charge limits.