Effect of inclination angle on the performance of a shell and tube heat storage unit - An experimental study

This study includes experimental investigation on the performance of a shell and tube heat exchanger subjected to inclination angle variation. Paraffin RT35 is used as phase change material (PCM). The investigation was performed for modified Stefan numbers of 0.47, 0.53 and 0.59 and inclination angle rang from 0 degrees to 90 degrees. The Reynolds number is about 770 and the Grashof number is in the range of 4.6 x 10(4)-5.8 x 10(4) which indicated that the flow is laminar. Results show that as the inlet temperature increases melting process accelerates and complete melting time reduces. Results also indicated that the rate of melting process in the first half of the process is more in the horizontal system with respect to the other inclinations. It is also revealed that the angle's variation doesn't affect the rate of heat transfer and the temperature during solidification which is due to the domination of conduction in this process. Results also clarified that during melting, the rate of heat transfer of the horizontal system is more than that of vertical, however the reverse is true for the solidification. It is also concluded that the average temperature of the horizontal heat exchanger sections closer to the inlet is more than the section nearer to outlet. However, when the 30 degrees,60 degrees and 90 degrees cases are considered, the PCM average temperatures of the sections nearer to the outlet are more. (C) 2016 Elsevier Ltd. All rights reserved.