| 摘要 |
PURPOSE:To reduce thrust force generated at the time of starting so as to increase the turbine speed up to the rated number of revolution in a short time by communicating together a turbine blade side and a brake fan side provided respectively on both ends of a main shaft through a bypass circuit and providing a control means for opening and closing the circuit. CONSTITUTION:High pressure gas from a compressor is supplied to an introducing unit 35 through a piping 34 and flowed to a turbine blade 32 of one end of a main shaft 24. While, a portion of the gas in the introducing unit 35 is flowed from an inlet 60b to a bypass circuit 55 and from an outlet 60a to a working gas introducing passage 38 for a brake fan 31 on the other end of the main shaft 24. This time, a breaking valve 53 limits gas flow amount so that the difference between the outlet pressure of a turbine blade 32 and the pressure of the brake fan introducing passage 38 becomes less than the predetermined differential pressure. And when the main shaft 24 starts to rotate, a portion of the high pressure gas of the inlet of the nozzle 33 is flowed by the bypass circuit 55, then said pressure difference becomes a constant pressure corresponding to the pressure of the inlet of the nozzle 33 and rapid and upward thrust force will not be generated. |
