The geometrical parameters have considerable effects on heat transfer and pressure drop on the performance of plate fin and tube heat exchangers. Previous investigators have only studied the effects of geometrical parameters on one row tube of these types of heat exchangers. Therefore, it is the aim of this study to develop the findings of the previous work and extend it to both one and two row tubes in cross flow direction using computational fluid dynamics (CFD). For one row tube heat exchangers, the effect of distance between the fins was investigated. The findings of this work revealed that this parameter has a considerable effect on pressure drop across the heat exchanger. It was also observed that increasing ellipticity of the fin tube would have a positive heat transfer effect. Furthermore, the effects of transverse and longitudinal pitch between the tubes on heat transfer and pressure drop characteristics in two rows have also been investigated. It was found that the transverse pitch has a remarkable effect on pressure drop. On the other hand, an increase in the logitudinal direction enhances the heat transfer characteristics. The finding of the present study also reveals that there is a good agreement with both experimental and numerical studies. It is also worth noting that although the present study has been carried out for one and two row tube heat exchangers, the results could be extended to heat exchangers with more rows tube. Finally, the results of this study could be utilized in designing plate fin and tube heat exchangers.

Keywords