Effect of blade tip leakage flow on erosion of a radial inflow turbine for compressed air energy storage system

摘要

The erosion caused by sand particles significantly influences the safety of radial inflow turbine in Compressed Air Energy Storage (CAES) system which operated in desert area. In present study, effects of tip leakage flow on erosion of a CAES radial inflow turbine are investigated at different tip clearances and total pressure ratios. A CFD model coupling Tabakoff and Grant erosion model is utilized for the analysis. Results illustrate that the trailing edge of stator, the leading edge of rotor blades, the shroud and hub surfaces near inlet of rotor cause more severe erosion at each tip clearance. Therefore, wear-resistant coating should be adopted. The severe erosion can also be found at blade tip of rotor. However, it is gradually suppressed with the increase of tip clearance. With the increase of total pressure ratio, the region with higher erosion rate on the shroud of rotor gradually extends to downstream. However, the erosion rate at leading edge of rotor blades is decreased obviously. In conclusion, the erosion effect can be alleviated remarkably when the tip clearance size is of 2% and total pressure ratio is more than 1.84, while the isentropic efficiency is almost kept the same. (C) 2019 Elsevier Ltd. All rights reserved.