GB746050A - Fuel control system for turbine engines, particularly engines utilizing afterburning - Google Patents

Abstract

746,050. Centrifugal pumps; jet propulsion plant. BENDIX AVIATION CORPORATION. June 4, 1953 [July 28, 1952], No. 15473/53. Classes 110(1) and 110(3) [Also in Group XXIX] In a re-heat fuel system for gas turbines' in which fuel is supplied by a centrifugal pump 36 driven by an air turbine 39 supplied by a compressor 14 driven by the main turbine 15, the air supply to the turbine 39 is controlled by a throttle member such as the valve 53 itself controlled by a pilot valve 59 responsive to the pressure rise across the compressor 14. The re-heat burners 44 are supplied by the pump 36 through a pipe 41 and the nozzle chamber 51 of the turbine 39 is supplied with air from the compressor 14 through a pipe 49. The inlet of the chamber 51 is controlled by the valve 53 on the end of an actuating bellows 54 to the inside of which air taker from the compressor discharge is admitted by a pipe 57 controlled by a valve 59. The valve 59 is urged by a spring 61 against a piston 60 subject to compressor dischargethrough the pipe 57 and a passage 65 and to compressor inlet pressure through a pipe 67. The piston'60 is rigidly connected with a diaphragm 68 responsive through passages 70, 74 containing restrictions to the pressure drop across a metering restriction 42 in the pipe 41. The. pressure drop due to the varying fuel flow through the restriction 42 is thus balanced against the pressure rise across the compressor and the valve 59 is positioned by the net force acting on the piston 60 and the diaphragm. A dash-pot action is provided by a restricted by-pass 76 across the diaphragm 68. A further stabilizing action is provided by allowing a certain amount of air from the nozzle chamber 51 to bleed into the bellows 54 through a restricted passage 78 on opening a solenoid operated valve 83. A "bullet" valve 19 in the end of the tail pipe 17 is retracted during afterburning by a servopiston 21 controlled by a valve 23 operated by a solenoid 25 The solenoid 25 is energized through an electronic amplifier 28 responsive to the temperature in the tail pipe as sensed by thermocouples 29, 30. The amplifier 28 is connected in a circuit 46, 47, controlled by a starting switch 48 and including also the solenoid 84 which opens the valve 83, an igniting device' 33, and a solenoid 45 which opens a cut-off valve 45 in the supply pipe 41. Specifications 708,732 and 733,356 are referred to: