Experimental analysis of a latent heat storage unit with multichannel flat tube and copper foam

Abstract

The poor performance of phase change materials (PCMs) in thermal conductivity constrains the widespread application of latent heat storage units (LHSUs) in engineering while the low bulk density and large specificity of copper foam make it an ideal choice to solve this problem. This study proposes a new LHSU which is based on multichannel flat tube and copper foam. With water as the heat transfer fluid (HTF), copper foam is applied to enhance the heat performance of PCM (paraffin). The ratio of the heat exchange area to the PCM volume of this unit is 576.3 1/m, and the compactness factor is 71.8%. In order to evaluate the performance of this unit, a study is conducted on different HTF injection modes, the distribution of PCM temperature at different inlet temperatures and HTF flow rates, charge/discharge power, and the effectiveness of LHSU. According to the results, bottom injection is the optimal HTF injection method in the charge and discharge processes. The average effectiveness during the charge and discharge processes reaches up to 0.383 and 0.409, respectively. Compared with the traditional coil type LHSU, the unit proposed in this research performs better in heat transfer performance.