Experimental Investigation of Sinusoidal Tube in Triplex-Tube Heat Exchanger during Charging and Discharging Processes Using Phase Change Materials

In this experiment effect of two full and half width sinusoidal inner tubes in triplex-tube heat exchanger with phase change material (PCM) was investigated. Length and diameter of the tubes have been chosen such that the area of each tube to be the same. Charging and discharging processes were carried out by inner tube, outer tube and both. Results indicated, PCM melting and solidification time for the full width sinusoidal inner tube, in the processes of charging and discharging from the inner tube, outer tube and two sides were shorter than the half width sinusoidal inner tube. Comparing the charging and discharging processes of these tubes with a straight inner tube indicated significant improvement in the amount and reduction in time of PCM melting. The melting mode in the straight tube process was incomplete after about 32.5 hours, however in the case of full and half width sinusoidal inner tube, the melting times were 8 and 10 hours, respectively. Moreover, it was an improvement of 54% in melting time from the outer tube in the full width sinusoidal tube and 35.8% in the half width sinusoidal tube.