| 摘要 |
PROBLEM TO BE SOLVED: To prevent the generation of crack due to thermal fatigue by disposing a support rail for supporting a shroud which is located on the outer periphery of the shroud and in circumferential direction of the shroud, connecting both ends of the rail at the inner periphery side surface of the rail, and providing a slit for forming a circumferential clearance in the inner periphery side surface. SOLUTION: A turbine portion of a gas turbine is provided with a turbine casing 1. A plurality of shroud blocks which form an outer periphery wall of a passage for high temperature high pressure gas are provided along an entire circumference. The shroud blocks are fittingly fixed to shroud rails 3 provided in circuferential direction of the inner periphery side of the casing 1. In this case a slit 5 is provided on the inner periphery side of the shroud rail 3 for forming a clearance which connects both ends of the shroud rail 3. This relieves the restraint on heat deformation in circumferential direction, and reduces the thermal stress generated in the circumferential direction of the shroud rail upon activation and stop. Accordingly, the generation of cracks due to thermal fatigue is prevented. |
