TY - JOUR
TI - Effect of wavy fin usage on thermal performance of heat exchanger used in combi boilers
AU - Yaşar Halit
AU - Erol Gülcan Özel
AU - Durmaz Ufuk
AU - Aydin Ahmet
AU - Kiliç Serhan
AU - Engin Tahsin
JN - Thermal Science
PY - 2020
VL - 24
IS - 2
SP - 693
EP - 700
PT - Article
AB - In this study, performance of a heat exchanger used in combi boilers was  investigated numerically for different fin geometries. Analyses were  performed at the boiler operation conditions. A commercial computational  fluid dynamics (CFD) software package (FLUENT) was used for numerical  simulations. 3-D steady-state turbulent flow field analysis was carried out  and k-ε model was preferred as the turbulence model. In the analysis, it was  assumed that the heat transfer phenomenon occurred both by conduction and  convection. Flat fin geometry was taken as a reference for the  investigation. Variation of the heat transfer and pressure drop values for  the wavy fin were compared with the reference geometry. The wave angle and  wave radius were taken as the parameters for the wavy fins. For different  fin geometries; the outlet temperature of the combustion gases, the heat  transfer to the water and the pressure drop were calculated and the results  were presented. Compared with flat fin, average decrease for the outlet  temperature of hot gases was obtained as 4 K and average increase for the  heat transfer to the water was calculated as 0,68 W. On the other hand, the  average pressure drop in the heat exchanger with wavy fins was about 70%  higher than the flat fin.