New method for designing an effective finned heat exchanger

Abstract

This paper presents a computational analysis of the heat transfer and pressure drop in a finned tube heat exchanger. The main objectives are to develop a method for designing an effective finned heat exchanger through changing the arrangement of the fins and tubes so that the tubes can be bent in a zigzag shape. Thus, they present an angle of less than 90° to the vertical fins. Consequently, the fin block forms a zigzag shape. The construction and the dimensions of the developed alternative heat exchanger are comprehensively presented. This new design is characterized by smaller dimensions of the heat exchanger and allows an increase of the heat transfer on the surface of the fins. Furthermore, a slight increase in the fan and pump power can result, which is very small compared with the recovered heat transfer. However, an effective model is analyzed by means of the computational fluid dynamics (CFD), FLUENT code, which is used to solve the equation for the heat transfer and pressure drop. The major results of the work show an increase in the heat transfer value of 59.13% in comparison to the existing old model. This increase is also accompanied by an increase in the ratio between the total power consumption and the amount of heat transfer obtained of 3.84% compared to 0.8% in the old model.