Axial Flow Compressor, Gas Turbine System Having the Axial Flow Compressor and Method of Modifying the Axial Flow Compressor

A gas turbine system, comprising:

• a combustor that mixes a compressed air with a fuel, burns the mixture, and generate a combustion gas;
• a turbine rotated by the combustion gas;
• an axial flow compressor and a load device which are driven by a rotating power of the turbine,
• wherein three or more stator vanes are disposed downstream of a last-stage rotor blade of the axial flow compressor,
• wherein a blade loading on a first stator vane disposed at the most upstream side among the stator vanes is set to be larger than a blade loading of a third stator vane disposed at the most downstream side, and
• wherein a blade loading on a second stator vane disposed downstream of the first stator vane by one row is set to be larger than the blade loading on the first stator vane.

A method of distributing a load to stator vanes disposed downstream of a last-stage rotor blade in an axial flow compressor in which, an annular flow passage is formed by a rotor having a multiple of rotor blades fitted thereto and a casing having a multiple of stator vanes fitted thereto, and three or, more stator vanes are disposed downstream of the last-stage rotor blade of the annular flow passage,

• wherein a blade loading on a first stator vane disposed downstream of the last-stage rotor blade by one vane row is set to be equal to or lower than 1.3 times as large as a blade loading on a third stator vane disposed at the most downstream side, and
• wherein a blade loading on a second stator vane is set to be larger than the blade loading on the first stator vane, and to be 1.3 to 1.6 times as large as the blade loading on the third stator vane 8. A method of modifying a stator vane in an axial flow compressor having two or more stator vanes downstream of a last-stage rotor blade disposed at the most downstream side in a flow direction of an operating fluid, the method comprising the steps of:
• rotating a first stator vane disposed at the most upstream side among the stator vanes about a center of gravity of the vanes so as to increase a stagger angle;
• and
• bending a blade leading edge and a blade trailing edge of a second stator vane disposed downstream of the first stator vane by one vane row toward a pressure surface side to increase camber angle.