Multistage, axial-flow gas turbine - has rotor blade roots enclosing rotor cooling air passages on outside

摘要

The gas turbine has axial cooling passages at the blade roots of the individual stages, through which pressurised cooling air flows. Annular grooves between the rows of rotor blades accommodate rings on the inner ends of the guide vanes, so as to give a smooth surface for the gas flows. The U-shaped annular chamber so formed in each case is connected to the gas flow by narrow axial gaps, and at its smallest dia. is a radial labyrinth seal. The cooling passages of successive stages are connected together via the U-shaped chambers, part of the cooling air passing into the gas flow via the gaps, with its pressure higher than that of the gas flowing parallel to it. The blade roots (3) enclose the cooling air passages (9) on the outside, and the axial gaps are sealed by radial labyrinth seals (7). PS.