Numerical study of a latent heat storage system adapted to concentrated solar power (CSP) plants at medium temperatures

摘要

Latent Heat Storage (LHS) is a promising solution to overcome the intermittent nature of solar energy for concentrated solar power (CSP) plants. In fact, it matches at a relatively low cost between the electricity produced by these plants and the periods of demand. Moreover, LHS systems have higher energy density compared to Sensible Heat Storage (SHS) ones. However, their inorganic materials have low thermal conductivity, which reduces the dynamics of the storage system with respect to the limitation of operating conditions of a CSP plant. One of the effective ways to resolve this problem is the use of extending surfaces such as fins. The present work evaluates the viability of this LHS applied to the case study of a heat exchanger with and without fins. A Computational fluid dynamics (CFD) model of the studied system was built in the COMSOL-Multyphysics environment. Furthermore, it was succefully validated against the available experimental results. Overall, the obtained simulation results show a considerable enhancement of the global dynamic performances of the LHS: the charging period and the phase change duration were decreased by 30.5% and 44.64% respectively.