Latent thermal energy storage (LTES) heat exchangers are being applied in a wide range of energy systems. However, there is no analytical method to determine the outlet temperature of LTES heat exchangers from its operational conditions. This hinders experimental data reduction and sizing of these components for specific energy systems. The present paper develops an analytical model for the overall phase fraction and outlet heat transfer fluid temperature for planar LTES heat exchangers. The method is developed with solutions of the Stefan problem. The analytical results are validated based on a numerical model using the same assumptions as the analytical model. The analytical solution can be reduced to a limited set of parameters which are a dimensionless time and heat exchanger surface area. This limited set of parameters can form the basis for experimental data reduction of LTES heat exchangers.
