Numerical investigations of heat transfer enhancement in a latent heat storage exchanger with paraffin/graphite foam

Abstract

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.The discrepancy between energy supply and demand can be overcome by the implementation of a proper energy storage system. The latent heat thermal energy storage employing a PCM is the most effective way of the thermal energy storage due to its advantages of high energy storage density and its isothermal operating characteristics during solidification and melting processes. Here high conductivity porosity materialgraphite foam is proposed to enhance the phase change materials (PCM), paraffin, in order to solve the problem of its low conductivity in the latent heat storage exchanger (LHSE). The LHSE suggested is like shell-and-tube heat exchanger, which HTF (water) is flowing in the tube while paraffin/graphite foam is in the shell side. And two-dimensional numerical investigations are conducted to predict the heat transfer performance of the PCM/graphite foam for LHSE by CFD software. The results show that graphite foam can improve heat transfer rate effectively, and a series of numerical calculations have been done in order to analyze the influence of several HTF operating conditions on the melting process of the paraffin/ graphite foam in LHSE, which will provide guidelines of thermal performance and design optimization for LHSE.