Melting process of paraffin wax inside plate heat exchanger: experimental and numerical study

In this paper, an experimental and numerical study has been performed on melting process of commercial Iranian paraffin wax, with melting temperature of about 60 °C, inside a plate heat exchanger. A 500 × 100 mm plate thermal storage system and 22 mm thick phase change material has been designed. Experimental and numerical results are compared with each other in three different inlet temperatures of heat transfer fluid (HTF), which are 343, 348, and 353 K, and three different volume flow rates, which are 15, 30, are 45 L min⁻¹. The temperature contours of paraffin wax at various time steps are presented to investigate the conduction and convection effects of melting process with respect to time. It has been shown that the melting rate of paraffin wax is higher at the upper part of the system due to the presence of natural convection. Results showed that increasing HTF temperature enhances the amount of heat transfer and reduces the melting time up to 37%. Also, by increasing volume flow rate of HTF, the melting time reduced up to 0.9%.