GB760243A - Improvements in or relating to gas-turbine engines - Google Patents

Abstract

760,243. Gas turbine jet-propulsion plant. ROLLS-ROYCE, Ltd. Oct. 20, 1954 [Nov. 6, 1953], No. 30853/53. Class 110 (3). [Also in Group XXXIV] A lubricating oil system of a gas-turbine engine of a high-speed aircraft comprises a heat exchanger wherein the oil to be cooled is passed in heat exchange with water, the rate of supply of water being such as to result in vaporization of some or all of the water. If all the water in the exchanger is converted to steam this may be delivered to atmosphere, to the combustion equipment of the engine' or to the exhaust assembly. A further oil cooler which may use air or engine fuel as coolant may be provided. As shown in Fig. 1, a gas-turbine jet propulsion engine enclosed in a fairing 10 forming part of an aircraft structure comprises a lubricating system normally housed within the fairing 10 but shown outside for clarity. The system comprises the pump 18 which pumps hot oil from the engine through pipe 19 to a heat exchanger 20 before return by pipe 21 back to the engine. The exchanger receives cooling water pumped from a tank 17 through a variable restrictor 23. The water is converted to steam which may be delivered through a pipe 26 to atmosphere or may be delivered to the combustion equipment 12 or to the exhaust unit 15 of the engine. In the arrangement shown in Fig. 3, two heat exchangers 20, 32 are provided, the exchanger 20 using water supplied from a tank 17, and the exchanger 32 using fuel supplied from a tank 34. The fuel is conveyed to the cooler 32 through a pipe 38 the ends of which are connected to the delivery pipe 39 under control of a valve 40. The valve 40 is coupled to a valve 30 which determines whether the oil to be cooled passes through pipe 19 to the exchanger 20 or through pipe 31 to the exchanger 32. Specification 648,409, [Group XIII], is referred to.