BLADE GROOVE COOLING STRUCTURE OF INTERMEDIATE PRESSURE STAGE MOVING BLADE IN HIGH-INTERMEDIATE PRESSURE STEAM TURBINE

摘要

PROBLEM TO BE SOLVED: To restrain the deterioration of turbine performance, and perform expected cooling by arranging a central hole in a central part of a rotor, and arranging communicating holes to guide speed control stage outlet steam of a high pressure turbine to the central hole and communicating holes to communicate blade grooves of at least first and second stage moving blades among intermediate pressure stage moving blades with the central hole. ;SOLUTION: A central hole 2 extending in the shaft direction is arranged in the center of a rotor 1 of a high-intermediate pressure steam turbine, and communicating holes 5 to communicate with the central hole 2 from a peripheral space part 4 in which a nozzle 3 is installed, are arranged in a plurality in a radial shape around the central hole 2. Communicating holes 7A to 7C are arranged to connect blade grooves, formed at the respective blade roots of intermediate pressure stage moving blades 6A to 6C, to the central hole 2. Cooling steam passes through the communicating holes 5 and the central hole 2 through the space part 4 after coming out of the nozzle 3 of a speed control stage, and is dispersed by the communicating holes 7A top 7C, and reaches the respective blade grooves of the medium pressure stage moving blades 6A to 6C, and flows so as to directly cool these, so that an optimal quantity of cooling steam can be supplied to the intermediate pressure stage moving blades 6A to 6C.;COPYRIGHT: (C)1998,JPO