Thermal Storage Improvement through the Melting Process of PCMs in Triplex Tube Heat Exchangers with Different Fin Materials

This study explores the melting dynamics of paraffin wax, a phase change material (PCM), within a Triplex Tube Heat Exchanger (THEX) equipped with internal fins, using numerical simulations. The primary objective is to evaluate the impact of fin materials—aluminum, copper, carbon, and steel—on the PCM melting rate under controlled conditions of 300 K ambient temperature and 373 K steam temperature. The results demonstrate that fins significantly enhance the melting rate by improving thermal conduction within the PCM. Aluminum, copper, and carbon fins exhibited superior performance, with aluminum fins achieving the greatest reduction in melting time, approximately 41% compared to the finless configuration. Steel fins, limited by lower thermal conductivity, reduced melting time by about 26%, reflecting a moderate improvement. Increasing the steam temperature to 383 K further accelerated melting across all cases, with the no-fin configuration showing a 10% reduction in melting time and finned configurations averaging a 5.3% reduction. These findings highlight the critical role of high-conductivity fin materials in optimizing thermal energy storage systems, particularly for thermal condenser applications, offering valuable insights for enhancing system efficiency.