GB745146A - Fuel feed and power control system for gas turbine engines - Google Patents

Abstract

745,146.. Gas turbine plant. BENDIX AVIATION CORPORATION. Jan. 23, 1953 [March 15. 1952], No. 2058/53. Class 110(3) [Also in Group XXIX] To prevent overheating, flame extinction and compressor surge during acceleration of a gas turbine engine the fuel flow is controlled at a rate proportional to the product of total pressure or ram at the compressor intake, the square roct of the absolute temperature at the entrance to the compressor, and a function of the pressure ratio across the compressor. Fuel is fed to a chamber 24 whence it passes through a valve 39 adjustable by a spring- loaded diaphragm 51 to an orifice 43 the area of which is controlled as a function uf the compressor pressure ratio by a valve member 44. The fuel then flows via a passage 42 to a governor valve 70 actuated by engine-driven centrifugal weights 74 against a manually adjustable spring 79 and thence through a shut-off valve 49 to the burners. The total pressures at the intake and delivery of the compressor are applied respectively to evacuated bellows 90 91 which through a lever 102 pivoted about a roller 99. and a link 112, actuate a lever 114 carrying a valve member 116 which controls a leak-off passage 118 from a bellows 119 fed with fuel under pressure through a restricted passage 120. The bellows operates the valve member 44 through a lever 122, and a feed-back connection 97 from the valve member repositions the fulcrum roller 99. The valve 39 is adjusted by its diaphragm 51 to maintain the pressure difference across the two valves 44. 70 proportional to the square of the total pressure at the compressor intake and to the intake temperature, and to this end the diaphragm 51 is exposed on one side to pressure in a chamber 40 between the valves 39, 44 and on the other side to the pressure downstream of the governor valve 70. the effect of the latter pressure being modified by a needle valve 54 movable by an evacuated bellows 64 subject to ram pressure and by a valve 53 actuated by a bellows 61 responsive to the temperature at the compressor intake. When the engine drives a propeller and its speed is controlled by a propeller governor rather than by the valve 70, control of fuel flow by the pilot is effected through ,a lever 127 which is linked to the pilot's control and operates the valve 44 direct. Reference has been directed by the Comptroller to Specification 700,776.