GB1020541A - Apparatus for use in acceleration control of a gas turbine engine - Google Patents

Abstract

1,020,541. Gas turbine plant. JOSEPH LUCAS (INDUSTRIES) Ltd. May 23, 1962 [April 18, 1961], No. 13906/61. Heading FIG. [Also in Division G3] An acceleration control for gas turbine engine of the kind in which the flow of fuel to the engine is governed in part in accordance with a control pressure Pc which is a function of the compressor inlet and outlet pressures P1, P2, and is generated by a mechanism in accordance with a schedule dependant on the particular engine with which the control is employed comprises means for producing a control pressure proportional to P1 when the ratio P2/P1 is below a predetermined value and proportional to P2 when the ratio exceeds the predetermined value. The pressures P1 and P2 are applied to bellows 22, 24 working in conjunction with evacuated bellows 21, 23 at opposite ends of a lever 20 secured to a bellows 30 and carrying a control valve 27. When the engine starts, pressure from the downstream side of the fuel pump 6 is transmitted through a conduit 29 to the bellows 30 to move the lever 20 towards fixed pivots 25, 26 so that when the value of P2/P1 is below the ratio of the lengths of the lever 30 between the bellows 30 and the bellows 22, 24 the lever will engage the pivot 25 while when the value is above the ratio it will engage the pivot 26. The conduit 29 also connects the bellows 30 with the valve 27 and with a bellows 36 controlling a further valve 35 for regulating the main fuel valve 7 which is also controlled in known manner by a governor 8 and a balancing valve 11. The valves 27 and 35 are mounted in casings 18, 19 subjected to the pressure at the fuel pump intake. In a modification the main fuel valve is directly controlled by the valve 27, the valve 35 and bellows 36 being omitted.