GB693218A - Improvements in or relating to means for feeding fuel to gas turbines - Google Patents

Abstract

693,218. Gas turbine plant. SZYDLOWSKI, J. Jan. 2, 1950 [Jan. 4, 1949], No. 33/50. Class 110(iii) [Also in Group XXXIII] A gas turbine fuel supply system comprises a fuel pump, a first by-pass connecting the inlet and outlet of the pump containing an adjustable control valve to limit the pressure at the pump discharge, a fixed orifice through which fuel is supplied to the burners, a second by-pass leading from the main fuel supply pipe between the first by-pass and the fixed orifice to the inlet of the pump containing a cock controlled by a barometric capsule and an adjustable constant speed governor acting on the pitch of an airscrew driven by the turbine, the operative speed of which is determined by the pressure on the second by-pass after the barometrically controlled cock. The discharge pressure of a fuel pump 9 which delivers fuel to the burners of a gas turbine engine through an orifice 12a is controlled by an adjustable valve 11 inserted in a by-pass 10 connecting the inlet and discharge of the pump. The pressure defined by the valve 11 may be adjusted by a lever 15. To prevent sudden variations of the fuel supply during acceleration, a damping element 17 constituted by an air-filled chamber or a yielding diaphragm is connected to the main fuel supply conduit before the orifice 12a. To ensure an adequate fuel supply at starting, a second damping element 18 may be inserted in the fuel supply line between the orifice 12a and the shut off cock 19, or a valve 20 in the by-pass line 10 closed to prevent the control valve 11 operating. To adjust the speed of rotation of the airscrew 21 to the required power, a variable speed governor 14 acts on the pitch of the propeller. The controlled speed of the governor is determined by a spring 22 the loading of which is determined by a piston 23. The cylinder of the piston 23 is connected to a second by-pass 16 around the pump between a cock 24 controlled by a barometric capsule 25 and a fixed orifice 26. The by-pass 16 is connected to the main fuel supply pipe between the by-pass 10 and fixed orifice 12a. The pressure on the piston 23 and consequently the controlled speed will therefore be proportional to the pressure of the fuel supply to the engine as modified by the barometrically controlled cock 24. Specifications 686,908 and 693,217 are referred to.