Computational efficiency in numerical modeling of high temperature latent heat storage: Comparison of selected software tools based on experimental data

In this article, four different numerical models for the investigation of phase change processes within latent heat storage are described and compared concerning accuracy, convergence behavior and computational efficiency. The models are based on different types of discretization, make use of different ways to model phase change and are implemented with C, MATLAB or ANSYS CFX. After a brief introduction into each investigated numerical model, the experimental reference setup is described. It consists of a flat plate latent heat storage with the eutectic mixture NaNO3 (46 wt%)-KNO3 (54 wt%) with a measured melting temperature of 219.5 °C as storage material. Based on the corresponding simulation model developed in this paper, the comparison of the numerical models is achieved. This methodology allows the investigation of the numerical performance of different software tools in the context of high temperature latent heat storage that was not achieved thus far. All four numerical models show good agreement to experimental results but differ significantly in speed and convergence behavior.