Numerical Simulation of Suction Slot Structure on the LP Last Stage Stationary Blades of Steam Turbine

To open suction slots in arc and back-arc face of hollow stationary blade at suitable place, using the pressure difference between inside and outside of the slot, is one of the most direct and effective to protect the moving blades from water erosion. By using the FLUENT software, this article conducted the numerical simulation to the steam flow field of LP last stage, which is opened with a suction slot at the relative width of 0.2 and 0.7 in arc and back-arc face of hollow stationary blade when the opening angle is 45°. Comparative analysis was conducted to the dewetting effect and its impact on the steam flow field between the slot rounding or not and different width from 2 to 5 mm. Results show that rounding suction slot with a 4 mm wide with opening angle of 45° is optimal.