Numerical Investigation of the Effect of Baffle Orientation on Heat Transfer and Pressure Drop in a Shell and Tube Heat Exchanger With Leakage Flows

Abstract

The commercial CFD code FLUENT is used to investigate the effect of baffle orientation and of viscosity of the working fluid on the heat transfer and pressure drop in a shell-and-tube heat exchanger in the domain of turbulent flow. The shell-and-tube heat exchanger considered follows the TEMA standards and consists of 76 plane tubes with fixed outside diameter, which are arranged in a triangular pitch. Two baffle orientations as well as leakage flows are considered. In order to determine the effect of viscosity on heat transfer and pressure drop, simulations are performed for the working fluids air, water, and engine oil with Prandtl numbers in the range of 0.7 to 206. For each baffle orientation and working fluid, simulations are performed using different flow velocities at the inlet nozzle. Heat transfer and pressure drop are reported in order to describe the performance of vertically and horizontally baffled shell-and-tube heat exchangers. The heat transfer coefficient is described as modified shell-side Nusselt number, which is defined similar to the VDI method.

Acknowledgments

This scientific work has been sponsored by Heat Transfer Research, Inc. (HTRI), under contract 1566.1. The authors gratefully acknowledge this support.