Antisurge system adapted to prevent the stalling of turbine aero-engines

摘要

1,56,811. Fluid-pressure servomotor systems. SOC. NATIONALE D'ETUDE ET DE CONSTRUCTION DE MOTEURS D'AVIATION. Jan. 15, 1964 [Jan. 16, 1963], No.1764/64. Heading G3P. [Also in Division F1] Means for preventing surging and stalling of an aircraft turbojet engine comprises a pair of diaphragms 2, 58 rigidly interconnected by a member 62 and defining a chamber 3 connected by passages 11, 12 or by a restriction 59 with an engine pressure that fluctuates in the event of an incipient stall, e.g. the pressure at the compressor discharge or in the combustion chamber, a chamber 4 connected through a restriction 5 also with the pressure P2, and a chamber 60 open through a passage 61 to atmosphere. Normally, the pressures in the chambers 3, 4 are equal and the diaphragm assembly is positioned as shown, with a valve head 65 permitting communication through the passage 12. As surging commences the pressure P2 falls and, due to the restriction 5, the diaphragm assembly is moved to the right to operate a spring-loaded abutment 66 which unloads the combustion chamber through a transmission comprising an electric switch and relay etc., or a hydraulic or pneumatic leak. The unloading may be effected by opening a fuel by-pass valve, reaction jet nozzle, or compressor unloading valves, or by adjusting the angular setting of the engine stator blades. The rightward movement of the diaphragm assembly also closes the valve head 65 and opens a valve head 63 which allows atmospheric pressure to become effective, through passages 68, 69, 70, in the chamber 3 to cause the diaphragm assembly to remain in the rightward position until, after a time lag or in response to action by the pilot, fluid pressure is applied to a chamber 73 to close a valve 76 in the passage 70 so that P2 pressure is again effective in the chamber 3 through the restriction 59 to reset the diaphragm assembly to its normal position. Release of the pressure in the chamber 73 prepares the apparatus for subsequent operation.