COOLING STRUCTURE OF TURBINE BLADE

摘要

A cooling structure of a turbine airfoil cools a turbine airfoil (10) exposed to hot gas (1), using cooling air (2) of a temperature lower than that of the hot gas. The turbine airfoil (10) includes an external surface (11), an internal surface (12) opposite to the external surface, a plurality of film-cooling holes (13) blowing the cooling air from the internal surface toward the external surface to film-cool the external surface, and a plurality of heat-transfer promoting projections (14) integrally formed with the internal surface and protruding inwardly from the internal surface. The turbine airfoil further includes a hollow cylindrical insert (20) which is positioned inside the internal surface of the turbine airfoil and to which the cooling air is supplied. The insert has a plurality of impingement holes (21) for impingement-cooling the internal surface (12).