The diagnosis of turbine component degradation––case histories

Four case histories of steam and gas turbine components degradation identified during operation and verified during overhaul are presented. The diagnosis was carried out before the overhauls to indicate major problems to the personal of the plants. The estimation of degrees of degradation of the steam turbine components was carried out applying simplified flow equation considering three key pressures. In the case of the gas turbine the output capacity and pressures, temperature and air and gas flow were analyzed. The results obtained during on-line analysis were confirmed by measurements of the dimensions of degraded components during an overhaul. Also, the results obtained from a sophisticated computer program proved the usefulness of the applied methods.