The error of neglecting natural convection in high temperature vertical shell-and-tube latent heat thermal energy storage systems

摘要

There is little understanding of the relative importance of natural convection when designing latent heat thermal energy storage (LHTES) systems based on geometric parameters and/or phase change material (PCM) properties. For high temperature shell-and-tube LHTES systems, this study aims: (i) to determine the error of ignoring natural convection, and (ii) to quantify this error for different geometric parameters and PCM properties. In particular, the study defines the circumstances under which natural convection is important and the error of choosing a 'conduction-only modelling approach'. To do so, the performance of LHTES systems with nine geometric aspect ratios and three commercial PCMs (of different melting points) were analyzed by means of a validated CFD model.