| 摘要 |
A steam or air cooled combined cycle gas turbine includes first and second turbine stages (12,14) and a second nozzle stage (16). During start-up, cooling air is supplied radially inwardly through the second stage nozzle for flow into the gas flow through the turbine and for combining with cooling air flowing radially outwardly from a high pressure compressor port. The combined air flow flows radially outwardly through the turbine blades. In normal operation, steam in lieu of air flows radially inwardly through the second nozzle stage and radially outwardly between the turbine wheels and spacer therebetween. Part of the steam through the nozzle stage combines with the radially outwardly flowing steam for cooling the turbine blades. The balance of the steam flows into the gas flow through the turbine. Combined steam/air cooling is effected for abnormally high turbine blade temperatures by combining cooling air from the high pressure discharge port of the compressor with the steam flowing radially outwardly through the turbine blades. <IMAGE> |
