Convective Heat Transfer and Thermal Performance in a Circular Tube Heat Exchanger Inserted with U-Shaped Baffle

Abstract

Numerical investigations on flow structure and heat transfer characteristic in a heat exchanger tube fitted with U-shaped baffle are presented. The U-shaped baffle is created from the concepts of orifice and inclined baffle. The influences of the baffle height (b/D = 0.05, 0.10, 0.15, 0.20 and 0.25) and flow attack angle (α = 20°, 30° and 45°) of the U-shaped baffle on heat transfer, pressure loss and thermal performance are considered. The finite volume method with SIMPLE algorithm is selected to solve the present problem. The numerical results are reported in terms of flow visualization and heat transfer behavior. The performance analysis for the tube heat exchanger inserted with the U-shaped baffle is also reported. As the numerical result, it is found that the insertion of the U-shaped baffle help to improve the heat transfer rate and thermal performance higher than the smooth tube with no baffle. The increments of heat transfer rate and pressure loss are around 1–8.7 and 1–29 times over the smooth tube, respectively. Additionally, it is detected that the 45° U-shaped baffle with the BR = 0.2 gives the highest thermal enhancement factor around 2.9 at the highest Reynolds number, Re = 1200.