| 摘要 |
<p>1,133,592. Gas turbine fuel systems. GENERAL ELECTRIC CO. Sept. 29, 1966 [Oct. 22, 1965], No. 43488/66. Heading F1G. [Also in Division G3] In a system for controlling the speed of a gas turbine engine which is insensitive to ambient temperature variations, a pneumatic signal generator 20 driven by the engine generates two sinusoidal signals, one of which enters a resonator 22 which generates a reference signal which is fed to decoupler 24 and amplifiers 26, 28togenerate signals P r , P r <SP>1</SP>, which are 180 degrees out of phase. When the reference signal frequency equals the resonant frequency of resonator 22, the signals P r , P r <SP>1</SP>, when matched against the other signal Pg of generator 20 by phase discriminator 30, produce equal outputs from the latter to transducer 32. If the speed changes, the signal frequency from generator 20 will change and the discriminator will provide a differential output to vary the fuel-flow to the engine via control unit 34. The resonant frequency of resonator 22 is varied by varying the volume thereof by means of piston 42. Since the resonant frequency is also a function of temperature, the resonator is continually flushed with a gas maintained at constant temperature. The gas is supplied from plenum chamber 66 which receives a mixture of relatively cool air from the compressor and hot gas from the combustion chamber, these streams being directed to the plenum chamber via respective monostable fluid switches 50, 52 Fig. 2 (not shown) and vortex restrictors 94 under the control of bi-metal flapper 82 contained in the plenum chamber.</p> |
