Numerical Investigation of the Effects of the Baffles Added in a Concentric Pipe Heat Exchanger

Abstract

In this numerical work, the effects of baffles added in a Concentric Tube Heat Exchanger are studied, using a commercial software CFD (Computational Fluid Dynamics) package. The CFD model is made to grab all the physical phenomena such as heat transfer rating, temperature, velocity and pressure distributions within the computational domain. First the simplest model, the Heat Exchanger without baffles, is considered. Due to its limited capacity, baffles are added into the domain to investigate the heat transfer enhancement while observing pressure loss that is a direct indication of the pumping power for a given flow rate. A sufficiently high detailed geometry and fine mesh characteristics are adopted taking into account the computation resources and time, yet satisfactory enough to show that the numerical model can be validated using the analytical solutions relying on empirical heat transfer formulas. This gives researches working in Heat Exchanger area the opportunity to design their systems using CFD, without depending on a prototype that needs to be tested before the actual product is marketed. Normally, a new type of heat exchanger with a different tube diameter and baffle lay-out has to be manufactured using general a heat exchanger calculation approach that will most of the time require the revision of the preliminary design.