10th European Conference on Turbomachinery Fluid dynamics & Thermodynamics
Extraction modules allow the regulated extraction of large steam quantities on certain enthalpy levels. While extraction steam is lead out of the turbine with an outlet flange, the remaining steam flows through control valves and adjacent diffusers into an annular inlet chamber. Depending on the valve lift, the compact and asymmetric design of the extraction module causes a strongly disturbed incoming flow of the following guide vanes. The current work focusses on improving the inflow of the subsequent guide vanes with regard to uniformity of mass flux and flow inlet angle. As the simulation results illustrate, modification of horizontal as well as vertical valve position can lead to significant variations in distribution of mass flux and flow inlet angle. Furthermore, intense contouring of the vane carrier can minimize the influence of the turbulent steam jet, if compact design is required.