Axial Compressor, Gas Turbine with Axial Compressor, and its Remodeling Method

An axial compressor comprising:

• a rotor as a rotational shaft;
• a plurality of rotor blades mounted on the rotor;
• a compressor casing that covers the rotor and the rotor blades;
• a plurality of stator vanes mounted on the compressor casing, the rotor blades and the stator vanes being each disposed in a circumferential direction of the rotational shaft to form a rotor-blade cascade and a stator-vane cascade, respectively;
• the rotor-blade cascade and the stator-vane cascade being arranged in plural rows, respectively, in an axial direction of the rotational shaft;
• wherein
• the stator vane has a plurality of dovetails relative to the axial direction of the rotational shaft as a base for supporting a vane section, the compressor casing has a plurality of dovetail grooves extending in the circumferential direction of the rotational shaft, the dovetail grooves receiving the dovetail inserted therein to fix the stator vanes;
• and
• the stator vanes are disposed across the dovetail grooves formed in the axial direction of the rotational shaft.

A method of remodeling an axial compressor, the axial compressor comprising:

• a rotor as a rotational shaft;
• a plurality of rotor blades mounted on the rotor;
• a compressor casing that covers the rotor and the rotor blades;
• a plurality of stator vanes mounted on the compressor casing;
• and
• a plurality of dovetails as bases for supporting the stator vanes, the compressor casing having a plurality of dovetail grooves extending in a circumferential direction of the rotational shaft, the dovetail grooves receiving the dovetails inserted therein to fix the stator vanes, the rotor blades and the stator vanes being each disposed in the circumferential direction of the rotational shaft to form a rotor-blade cascade and a stator-vane cascade, respectively;
• the rotor-blade cascade and the stator-vane cascade being arranged in plural rows, respectively, in an axial direction of the rotational shaft, the method comprising:
• machining the compressor casing by cutting a bulkhead that separates the dovetail grooves juxtaposed back and forth in the axial direction of the rotational shaft to thereby provide communication between the dovetail grooves.