A comparative analysis of the performance of LHTES systems-case study: Cylindrical exchanger with and without annular fins

The Thermal Energy Storage (TES) occupied an important role in the reasonable use of energy, because it allows the decoupling between the production and the energy demand in the applications with intermittent energy production. In recent years, many researchers have highlighted the use of Latent Heat Thermal Energy Storage (LHTES) systems, this is especially because the high energy density can be stored during phase change. Notwithstanding this great potential, the feasibility of LHTES with PCM is still limited, mainly due to a low thermal conductivity. In this sense, the exchanger with fins is the most effective proposal which is based on the increase of the exchange surface. After a review of recent advances in LHS systems with a focus on methods for improving the thermal conductivity of MCPs, and a selection methodology (Exchanger + PCM) adequate. The main objective of this paper is to develop, perform and compare a numerical study of a new finned exchanger (double pipe with Longitudinal fins on the external pipe, Phase Change Material in the annular space between the two pipes and HTF in the inner pipe) with a classic exchanger without fins. This comparative study was done according to the process of heat transfer during melting (charging) at average temperature (180-280°C). In addition, the results obtained were adapted for an implementation of Fresnel solar power installed at Green Energy Park (1 MWe) in Morocco. This study has shown that the first exchanger has a good compactness, can store enough latent energy, and significantly overcome the problem of low thermal conductivity related to the second heat exchanger.