The Diagnosis of Turbine Component Degradation: Case Histories

In this paper several cases of steam and gas turbine components wearing-out are described. The wearing-out of the steam path components were identified during operation of the machine and verified during overhaul. The diagnosis of the wearing out principally of the blades and seals was carried out before the overhauls. The diagnosis results were useful to indicate major problems to the personal of the plants. The estimation of degrees of wearing-out of the steam turbine components was conducted applying a simplified flow equation [1] considering three key pressures. As far as the gas turbine is concerned the output capacity and pressures, temperature and air and gas flow were measured and analyzed. The results obtained during on-line analysis were confirmed by measurements of the dimensions of wearied-out components during the overhaul which were treated as an input data to a program which calculated losses. Also, the results obtained from a special computer program proved the usefulness of the applied methods.