GB979061A - Improvements in or relating to fuel-supply systems for gas-turbine engines - Google Patents

Abstract

979,061. Gas turbine plant. PLESSEY CO. Ltd. March 14, 1961 [April 5, 1960], No. 12088/60. Heading F1G. [Also in Division G3] A gas turbine fuel supply system comprises a by-pass valve 4, Fig. 1, of a fuel pump 1, which valve is actuated by gaseous fluid, such as air from the compressor, acting on a diaphragm piston or bellows 8, 9. The servo fluid is supplied through 12 to act on the diaphragm 8 while the pressure on the diaphragm 9 is that between a fined restriction 14 and a leak valve 16 or 15. The housing 17 is rotated at engine speed and the valve 16 opens under centrifugal force against an adjustable loading while the valve 15 opens at a set maximum speed. Instead of opening a by-pass, the valve 4 may control a servo fluid which adjusts a variable displacement fuel pump. The valve 4 may also be opened in response to an increase in fuel flow. In Fig. 3, the valve 4 is controlled as above and may also be actuated in response to torque through control valve 38. The fuel flows from line 5 to the burners past a throttle valve 29 carrying a differential piston 30 subjected to the pressure upstream and downstream of a throttle 34. When the valve 4 closes to increase speed, the pressure on the larger side of the piston increases slowly to increase flow through the valve 29. This increased flow is restricted by a valve 36 subject to the pressure drop across the throttle valve 29.