Investigations of Influential Factors on the Aerodynamic Performance of a Steam Turbine Exhaust System

Abstract

The purpose of this paper is to investigate the influences of different parameters on the three-dimensional flow fields in the low-pressure steam turbine exhaust hood of a typical power station. The complex flows in both small-scale and full-scale turbine exhaust systems under different inlet flow conditions were simulated. The effects of inlet Reynolds number, inlet Mach number and fluid properties on the aerodynamic performance and flow fields in the exhaust systems were analyzed. The influential rules of inlet tangential flow angle distributions in the radial direction for a low speed small-scale model and a full speed full-scale exhaust system were summarized and compared. It is found that the inlet tangential flow angle at different radial position has different effects on the aerodynamic performance for both small-scale and full-scale exhaust systems. The influences of inlet Reynolds number on the aerodynamic performance depend on the inflow swirl conditions. The changing of inlet Mach number leads to the flow pattern variations in the exhaust system. The influences of fluid properties on the exhaust system performance are small.