This thesis uses computational fluid dynamics to investigate the effect of erosion-corrosion on the 2nd, 3rd, 4th and final headers of the 1:5 scale model of a shell and tube heat exchanger in the mechanical engineering department, at the University of Queensland.
Queensland Alumina Limited (QAL) at Gladstone, have suffered severe erosion-corrosion damage with its inlet header, and previous studies have primarily looked at erosion-corrosion damage within this header using computational and experimental studies. From these studies it has been demonstrated that computational fluid dynamics is an excellent tool in predicting the fluid flow and erosion-corrosion within the inlet header.
In obtaining these computational results for the various headers grid refinement study and convergence criteria study were conducted to obtain the optimal mesh and convergence criteria. Also a comparison of turbulence models was conducted between the κ-ε standard turbulence model and the κ-ε RNG turbulence model. It was found that the κ-ε RNG modeled the flow accurately for a convergence criteria of 1e-3, yet when this was decreased to 1e-4 the results appeared to be incorrect. Therefore, the study concluded that the κ-ε standard turbulence model was the most reliable turbulence model.
The operation of the 2nd, 3rd, 4th and final headers of QAL’s shell and tube heat exchanger have demonstrated that they do not suffer from erosion-corrosion. As a result, the investigation has shown that turbulent kinetic energy experienced in the 2nd, 3rd, 4th and final headers appears to be significantly lower than that experienced in the inlet header, possibly demonstrating why erosion-corrosion damage is minimal.