Effect of Turbine Capacity Increase on Comparative Excitability of Different Forms of Vibrations of Rotor Blades.

Variations of comparative excitability of different forms of vibrations, related to the increase in turbine capacities, are considered. The effects of changes in the number of stator blades on the level of dynamic stresses in turbine rotor blades are analyzed. It is concluded that the growth of the turbine capacites, accompanied by a decrease in the number of rotor and stator blades (faster for the rotor blades) and of the number of blades in a packet, results in an increased danger of synphase vibrations with the frequency of nz (n - turbine rotation frequency, z - number of stator blades), compared with the intra-packet vibrations. The use of diaphragms with a ″great″ number of nozzles can help to reduce considerably the level of dynamic stresses in rotor blades.