COMPOSITE PHASE CHANGE MATERIAL WITH METAL FOAM IN SHELL AND CONVERGENT TUBE THERMAL ENERGY STORAGE SYSTEMS

In order to decrease the negative effects on the environment and to handle the problem of a temporal and methodological mismatch between the energy required and the energy produced, energy storage systems have become highly relevant. In the proposed investigation, a simulation on a vertical shell and convergent tube geometry at different inclination angles composed of metal foam filled with a phase change material (PCM) is performed. The aluminum foam is used as porous media filled with pure paraffin wax as the PCM. The top, bottom, and external surfaces of the hollow cylinder are thought to be adiabatic, whereas the inner surface temperature is supposed to be constantly above the PCM melting point. Darcy-Forchheimer model is used to analyze the aluminum foam saturated with paraffin under the assumption of the local thermal non-equilibrium (LTNE), while the enthalpy-porosity theory is used to represent the phase change process in paraffin wax. Ansys-Fluent commercial code is used to perform the numerical solutions of the governing equations. The results of numerical simulations are shown as a function of time and are reported in terms of melting time, average temperature, and specific enthalpy. They show that the higher is the inclination angle, the faster is the system to reach the maximum energy stored. The converging system reaches the maximum energy storable faster than the diverging one.