This paper aims to perform the entropy analysis and thermal performance evaluation of a wavy-channels
triplex-tube latent heat storage heat exchanger (LHSHE) during melting and solidification mechanisms.
The system with different wave amplitudes was examined for different temperatures and Reynolds
numbers of the heat transfer fluid (HTF). Water is passed in the inner and outer tubes in opposite directions
and the PCM is placed in the middle tube. The heat exchanger was analyzed based on the
temperature, liquid fraction and velocity of the PCM as well as thermal (S000
T ) and frictional (S000
f ) entropy
generation rates. The results show that for a higher wave amplitude, shorter melting and solidification
times are achieved. Both frictional and thermal entropy generation rates increase to the maximum values
and then decrease during the melting and solidification. The frictional entropy generation rate reaches
almost zero quickly during the solidification. For both melting and solidification, the magnitude of S000
T is
significantly higher than S000
f in the phase change problem. The maximum values of S000
T are 0.05 and
0.13 W/Km3 for the melting and solidification mechanisms, respectively, for the dimensionless wave
amplitude of 0.3. The results show the crucial role of entropy generation on the performance of the
LHSHE.