Optimization of patterned-fins for enhancing charging performances of phase change materials-based thermal energy storage systems

摘要

Structures and dimensions of highly conductive metal fins applied to reinforce the charging performances of organic phase change materials (PCM) such as paraffin wax have not been systematically analyzed and accurately designed yet. Therefore, an optimization of the patterned metal fins for enhancing the charging performances of PCM-based thermal energy storage systems is numerically conducted using the enthalpy-porosity method by adjusting the areas of the convection-controlled and conduction-controlled regions through the patterned-fins dimensions during the charging process. Two optimization arrangements are conducted and the optimum patterned-fins are respectively obtained in this study. The results demonstrate that the optimum patterned-fins can obviously shorten the total charging time thus greatly enhance the charging performance of the poorly conductive PCM-based thermal energy storage system compared to the completely vertical triple-fin system through perfectly integrating the convection-controlled and conduction-controlled regions during the charging process. About 63.7%, 48.5% and 42.7% enhancements can be respectively obtained by the optimum patterned-fins under the heating temperatures of 85 °C, 90 °C and 95 °C via optimization arrangement Ⅰ. Moreover, around 61.9%, 44.1% and 38.4% enhancements can be achieved by optimization arrangement Ⅱ, which is a bit lower than that induced by optimization arrangement I due to the weaker convection effect using optimization arrangement Ⅱ. The results provide an effective guideline and database for designing the optimum patterned-fins to enhance the average charging performances of lowly conductive PCM-based thermal energy storage and thus expanding their applications.