STEAM TURBINE

摘要

PROBLEM TO BE SOLVED: To provide a steam turbine capable of contributing to shortening an operation stop period by curbing a difference in thermal expansion between a rotor and a casing.SOLUTION: A steam turbine comprises: a casing 10 which has annular concave sections 11 arranged in a direction of a turbine shaft on an inner peripheral surface thereof; a plurality of diaphragm outer rings 23 which contact with corresponding concave sections 11 of the casing 10 in the direction of the turbine shaft; nozzles 22 which are fixed to the inner peripheral sections of respective diaphragm outer rings 23; a rotor 30 which has blades 32 facing opposite to the corresponding nozzles 22 in the direction of the turbine shaft on an outer peripheral section thereof; and steam flow passages 53 which connect spaces at an outer peripheral side and at an inner peripheral side of contact surfaces 52 between the casing 10 and the diaphragm outer rings 23.