Windage effect on HP sections of reheat steam turbines

Steam turbines or steam turbine sections, when operated at high speed and little or no steam flow, generate windage due to uncontrolled turbulent flow conditions which can cause high metal temperatures affecting the integrity of steam path components. Indications of blade overheating found in the Belle River 641 MW reheat steam turbines of Detroit Edison Company, have been the cause for addressing this issue. These units were not originally equipped with any preventative measures. This paper will summarize latest findings, investigations and the establishment of guidelines for preventing HP turbine component overheating caused by windage.