GB824467A - Fuel controls for gas turbine power plants - Google Patents

Abstract

824,467. Gas turbine plant. UNITED AIRCRAFT CORPORATION. Sept. 26, 1957, No. 30214/57. Class 110 (3). [Also in Group XXIX] Fuel is supplied to the nozzles 56 of a gasturbine engine by an engine-driven pump 26 via a metering valve 32, a conduit 52 and a manifold 54; the valve 32 consists of a fixed liner 38, with one or more inlet and outlet ports 36, 48, and an axially and rotatably movable cylinder 42 with one or more inlet and outlet ports 40, 46, the two sets of outlet ports 46, 48 being rectangular. The pressure drop across the valve 32 is held constant by means of a spring-loaded piston 60 controlling a by-pass 68 across the pump. Axial movement of the cylinder 42 is effected by a speed governor 76 driven by the engine compressor 14 whilst the governor datum is adjusted from the throttle lever 82 by a threedimensional cam 86 and a liner 90 that controls the loading of the governor speeder spring 94. The speed selection is modified by rotating the cam 86 by a rack 136 connected to a piston 130 supplied with fluid from pump 26 through a restriction 144, the piston position being determined by a hinged leak-off valve 120 controlled by an evacuated bellows 112 in a chamber 110 subjected to compressor inlet pressure; the piston 130 is loaded by a spring 128 the other end of which abuts a plate 126 connected to the lever 116 of the valve 120. The lever 116 is loaded by a spring 240 which tends to close valve 120 when the difference between the pressures in bellows 112 and chamber 110 is small so ensuring a sufficient force under all conditions for moving the piston 130. Rotation of the cylinder 42 is done through a rack 162 and a pinion operated by a servomotor 160, similar to that for rotating cam 86, which is responsive to compressor discharge pressure. The upper spindle 166 of the cylinder 42 has an abutment 172 which co-operates with stops 168, 170 that limit the opening of the metering valve 32. The position of stop 170 is controlled by a bellows 176, responsive to compressor inlet temperature, an axially movable shaft 178 connected thereto, and a crank 236. On shaft 178 is a pinion 210 and a three-dimensional cam 180, the pinion being engaged by a rack 198 actuated by a servomotor 196 similar to that for rotating cam 86 but sensitive to compressor speed through a governor 184; rotation and/or translation of cam 180 is transmitted by a liner 214 and a shaft 218 as an axial motion to another three-dimensional cam 220, the rotation of which is effected by another servomotor similar to that for rotating cam 86 but responsive to compressor inlet pressure. Cam 220 adjusts the stop 168 via a lever 230.