Steam turbine rotor blade and corresponding steam turbine

摘要

In a steam turbine including a turbine rotor (7); a moving blade (1) secured to the turbine rotor (7); a shroud (3) provided on an outer circumferential side distal end of the moving blade (1); and an outer circumferential side stationary wall (4) internally embracing the turbine rotor (7) and forming an outer circumferential side passage wall of a steam path, the shroud (3) has an inner circumferential surface (14) so formed that a moving blade outlet flare angle (α3) is greater than a moving blade inlet flare angle (α2); an angle (α1) formed between the outer circumferential side stationary wall (4) adjacently provided on the upstream side of the moving blade (1) and the turbine central axis (50) is generally equal to the moving blade inlet flare angle (α2); and an angle (α4) formed between the outer circumferential side stationary wall adjacently provided on the downstream side of the moving blade and the turbine central axis (50) and an turbine central axis (50) is generally equal to the moving blade outlet flare angle (α3).