METHOD FOR PREVENTING DEFORMATION OF A GAS TURBINE CASING, A PURGE DEVICE FOR EXECUTING SAME, AND A GAS TURBINE PROVIDED WITH PURGE DEVICE

摘要

In this method of preventing deformation in a turbine casing of a gas turbine, in a turbine casing 10 there is arranged a buffer tank 30. In this buffer tank 30 there are formed a stagnation part agitation air opening 52 which ejects part of the air from an air compressor 21 as stagnation part agitation air Ga2 toward a stagnation part 19 within the turbine casing, and an overall agitation air opening 51 which ejects overall agitation air Ga1 for agitating gas held in an upper space within the turbine casing. In the buffer tank 30 there is provided a partition wall 36 with through holes 53 formed therein serving to resist air from the air compressor 21, in order to make the ejection speed of the overall agitation air lower than the ejection speed of the stagnation part agitation air.