GB667022A - Improvements relating to gas-turbine engine fuel systems - Google Patents

Abstract

667,022. Gas turbine plant; centrifugal pumps. ROLLS-ROYCE, Ltd. March 1, 1950. [March 10, 1949] No. 6600/49. Classes 110(i) and 110(iii). A gas turbine power plant installationhaving a fuel supply tank remote from the engine or engines and main or auxiliary fuel supply systems has a fuel pump located adjacent to or incorporated in the fuel supply tank driven by an air motor, such as a turbine, which motor is supplied with compressed air from the compressor system of a gas turbine engine. The fuel to a gas turbine engine, Fig. 2, is supplied by an engine driven pump 24 supplied in turn by a booster pump 19 driven by an air turbine 21 which receives air from the compressor 11 system of the gas turbine engine. An electrically driven pump 19a is provided for starting purposes. In a modification, the pump 19 is used to boost a second engine driven pump supplying fuel-to reheat burners in the turbine exhaust pipe. In another modification, Fig. 4, two air turbine driven pumps 30, 31 are provided. The pump 30 is used to boost the engine driven pump 24 supplying fuel to the main burners 16 and the pump 31 supplying fuel to the reheat burners 25. Arrangements are made to connect the valve 38 controlling the air supply to the turbine 35 with the valve 37 in the discharge of the pump 31. The pump 30 may rotate at a slower speed than that of the pump 31. In a further modification, two pumps are arranged hydraulically in series to supply fuel to the reheat burners 25. These pumps are driven by a common turbine, the low pressure pump being driven through gearing at a lower speed than the high pressure pump. An air turbine driven pump, Fig. 6, comprises a plate 51 made integral with the lower half 63a of the centrifugal pump casing and the upper O1 exhaust half 52 of the turbine casing. A turbine nozzle plate 59 is clamped between the two halves of the casing 52, 58. A legging 66 prevents leakage of fuel along the shaft 54. The plate 51 is bolted to the fuel tank 50 so that the centrifugal pump is submerged. To avoid icing of the turbine due to the expansion of the air, the operating air may be taken from the space between the flame tube and outer air casing of each combustion chamber. The air motor may be of the piston or vane type and the pumps of the gear or reciprocating type. The term "fuel" is stated to include additional liquids such as a watermethanol mixture which may be injected into the compressor. Specification 608,963 is referred to.