Simulation for influence of Y-shape fin on phase change of paraffin inside triplex pipe with using Al₂O₃ nanoparticles

Solidification phenomena within a chamber with different arrangement of fins were investigated in this article. The homogeneous mixture of paraffin (RT82) and Al₂O₃ were assumed as NEPCM (nanoparticle enhanced phase change material). Different cases have been simulated to show the impact of concentration of alumina, arrangement of fins and their height and thickness. Numerical technique with structure grid was utilized for simulation of this transient modeling. For selection of time step and grid size, different cases were analyzed and finally the optimum values were selected to reduce the computing price. For verification examination, empirical data was tested and nice accommodations were reported. The cases with outer arrangement of fins have better efficiency in view of solidification. After 900 s, the liquid fraction of case 8 reaches to 0.023 while this value for case 3 is 0.12. The third case has longest time and all NEPCM solidifies after 1582.2 s. The case 8 has minimum time of freezing and after 1072s, the process finishes. Changing NEPCM instead of pure RT82, causes the required time to decline about 13.71%, 11.98%, 13.75% and 11.71% for cases 1, 2, 3 and 4, respectively. With replacement of fins with b = 0.38in, t = 0.02in to outer wall, solidification time decreases about 14.45%.