Numerical Investigation on the Effect of Cooling Steam on the Erosion to the Flue Gas Turbine Impeller Based on CFD

In this study, the numerical study was conducted to investigate the effect of cooling stream on the erosion to the flue gas turbine impeller by using the commercial CFD software NUMECA. The Spalart-Allamaras turbulence model was employed in this computation. It was found that with increasing the inlet pressure or the mass flow of the cooling steam, the erosion at the tip region of the impeller caused by the vortex could be alleviated. On the other hand, the erosion caused by the catalyst particles inside the cooling steam flowing passage can be also prevented. However, it is important to be noticed that increasing the inlet pressure and the mass flow may decrease the efficiency of the flue gas turbine´s main flow. Therefore, it can be conclude that there must exit a critical point for inlet pressure and mass flow, at which the flue gas turbine can reach the optimal condition. The systemic research of the optimal design is should still needed in further study.