Heat Transfer and Friction Performance of Plate Fin and Tube Heat Exchangers at Low Reynolds Numbers : 2nd Report. Characteristics of Multi-Row

Abstract

In the former paper the authors presented experimental data showing the effects of fin spacing, tube spacing and other geometric parameters on the heat transfer and friction performance of single row plate fin and tube heat exchangers. This paper describes the results of a continuation of that earlier study. Heat transfer and pressure drop measurements have been made for 24 plate fin and tube heat exchangers in which the primary physical variable is the flow depth, which varied from 2 to 5 tube rows. The experimental results revealed that the performance of multi row heat exchangers was affected by vortices generated from the outerwall of the tube, and the vortices are activated and strengthened with increasing Reynolds number. Dimensionless equations for the performance of multi row plate fin and tube heat exchangers were obtained.