Finite Element Analysis And Research Of Axial Dynamic And Static Clearance Of Supercritical Steam Turbine

Supercritical steam turbine is one of the three major equipments of a thermal powerunit, its structure is complex, and its price is high. If the turbine shutdown for accidents, itmay cause the fatal loss of economic. Axial dynamic and static clearance is only from submillimeter to tens of millimeters. The excessive axial dynamic and static clearances causethe decrease of turbine efficiency; inadequate security remainder may lead to accidents,such as contact rubbing, shutdown and so on. These accidents have great influence on thesafe operation of units. How to accurately calculate axial dynamic and static clearance ofsupercritical steam turbine under the rated and start-stop condition is still a nodus for thedesign of structure of steam turbines.The high&intermediate pressure cylinder of a supercritical steam-turbine was studiedon axial dynamic and static clearance by ANSYS. The calculating method of high&intermediate pressure cylinder’s axial dynamic and static clearance under the ratedcondition is provided in the paper, and the results are obtained. These results are consistentwith the results coming from simplified method. The differences are analyzed between theresults of two methods.A recycle of start and stop consists of a cold start and a sliding-parameter shutdown, itcan show the changes in the axial dynamic and static clearance of the high&intermediatepressure cylinder under start and stop condition. Through calculation, there are13unqualified locations are found, and the corresponding improvement measures areproposed.The study of this thesis is of great significance from both optimization of structureand control of steam temperature for steam turbine, and ensures steam turbine long periodsafety.