To efficiently cool a rotor extending from the upper stream side of a high- pressure turbine first stage blade to an intermediate pressure turbine side by providing a cooling path which exchanges the heat of a bleed steam for a low-temperature steam of a high-pressure stage outlet to cool it, passes it through a rotor central hole via a cooling path, and returns it to the path after a second stage moving blade.
In a high pressure turbine side of a high- and intermediate-pressure integrated steam turbine, main steam entering from a main steam pipe 4 to a nozzle chest 5 flows to a first-stage moving blade 6, a first-stage nozzle 12, and a second-stage moving blade 13 in this order so as to execute an expansion work. Then, the low- temperature steam after the first-stage moving blade 6 is bled through a bleed port 15 as a rotor cooling steam and led to a cooling ventilating port 19 provided in a partition wall casing part of the high- and intermediate-pressure turbine via an heat exchanger 16 and a bypass line 18a. The high- and intermediate-pressure partition wall stator 18 is returned to the path after the two-stage moving blade 13a via a cooling path 21 formed in an extension part which is extended in the bottom part of a nozzle chest 5 to the adjacent to the first-stage disc 7 part so that the cooling efficiency of the rotor 8 is improved.
TSUBOI NOBUYOSHI
YOKOTA OSAMU
ONODA TAKESHI
INOUE SHIGEMICHI
