Air-cooled exhaust gas casing for a gas turbine.

摘要

PROBLEM TO BE SOLVED: To reduce the thermal stress of the wall of a gas turbine emission wheel chamber.;SOLUTION: A cooling air channel is provided by boring in the wall of an emission wheel chamber 5 that is connected with a turbine wheel chamber 3 of a gas turbine 1, where cooling air is supplied from the vicinity of the end part of the downstream side. The cooling air flows through a cooling air channel 20 in an emission wheel chamber wall 5a, and after cooling the wall of the emission wheel chamber, is admitted into a turbine stage cavity 35 at the most downstream side of the turbine wheel chamber 3, after which the cooling air passes from the cavity 35 through a stationary blade ring 25 into a turbine stator blade 23 cooling the stator blade, to be emitted into the combustion gas that passes through the turbine stage. The emission wheel chamber wall 5a is cooled by the cooling air and the temperature of the wall in the vicinity of the joint part with the turbine wheel chamber drops. Furthermore, the cooling air with increased temperature having cooled the wall of the emission wheel chamber is supplied to the cavity 35, which causes a rise in temperature on the wall of the turbine wheel chamber in the vicinity of the joint, thus reducing the difference in temperatures between the wall of the turbine wheel chamber in the vicinity of the joint and the wall of the emission wheel chamber, thereby reducing a thermal stress that occurs on the wall of the emission wheel chamber.;COPYRIGHT: (C)2002,JPO