Study on the solid particle erosion characteristic of top gas pressure recovery turbine under variable working condition

Abstract

Aiming at the problem of particle erosion in top gas pressure recovery turbines, the physical and chemical properties of the sampled gas dust particles are tested in this paper, and particle motion behavior and erosion characteristics in the turbine cascade are investigated by employing a validated numerical method. On this basis, the influence mechanism of adjustable stator angle and rotate speed on the erosion characteristics of blades under variable working conditions is quantitatively explored. Results show that the erosion damage of the first-stage stator S1 and rotor R1 are mainly initiated by particles with different size. The change of adjustable stator angle will change the load and gas enthalpy drop distribution of the cascade, which then affects the impingement velocity and position of the particles. When adjustable stator angle reduces from 44.2 to 25% opening, erosion of S1 trailing edge grows about 20%, while the erosion of R1 trailing edge reduces by 50%. The change of rotating speed will change the relative magnitude of the particle centrifugal force and airflow drag force, which in turn affects the particle’s trajectory and impingement velocity. When rotate speed increases from 3,000 to 4,500 r/min, both the particle impingement velocity and escape rate increase, resulting in doubling of the erosion on blade leading edge and halving of the erosion on blade trailing edge. Finally, for the high rotation speed TRT operating under variable working conditions, some insightful suggestions are given to minimize the erosion damage of the turbine blades.