The main goal of this work is to numerically simulate convection phenomena insolid-liquid phase change processes and its application in the analysis of a thermalenergy storage system with phase change materials.First two chapters consist in the resolution of two well-known numerical problemsused as an introduction to the governing equations of uid ows and heat transfer.Here, the necessary tools for discretizing and solving these equations are brieydescribed.Third chapter speci cally deals with the problem of modelling solid-liquid phasechange and its application into the simulation of a special thermal storage system.