Influence of solid particle erosion (SPE) on safety and economy of steam turbines

Highlights: • The influence of the SPE on the rotor due to the notch eroded was analyzed. • The total pressure loss coefficient at nozzle outlet change with notch shape. • The steam angle at nozzle outlet increases when the nozzle erodes seriously. • For the 20 mm E-type notch, the isentropic efficiency declining by 4.06%. -- Abstract: At present, the economic deterioration of the unit due to solid particle erosion (SPE) at the governing stage has attracted widespread attention. Based on the Euler-Lagrange equation and the Finnie erosion model, the influence of SPE on the safety and the efficiency of the unit are numerically analyzed for different types of notches in the governing stage of a 1000 MW ultra-supercritical steam turbine in this article. The results indicate that the total pressure loss coefficient and the outlet steam angle increase as the depth of the notch goes up. And with the rising of the notch depth, the erosion at the rear edge of the rotor blade increases and the isentropic efficiency decreases rapidly. Furthermore, the decline trend of efficiency differs when notch type is different. When the notch depth is 20 mm, the maximum decline of entropy efficiency is 4.06%.