US 12,071,894 B2
Aircraft heat management
Craig W Bemment, Derby (GB); Benjamin J Keeler, Chesterfield (GB); Christopher P Madden, Derby (GB); Andrea Minelli, Derby (GB); Peter Swann, Derby (GB); and Martin K Yates, Derby (GB)
Assigned to ROLLS-ROYCE plc, London (GB)
Filed by ROLLS-ROYCE PLC, London (GB)
Filed on Jun. 20, 2023, as Appl. No. 18/337,519.
Prior Publication US 2024/0209779 A1, Jun. 27, 2024
Int. Cl. F02C 7/14 (2006.01); F02C 7/06 (2006.01); F02C 7/10 (2006.01); F02C 7/224 (2006.01); F02C 7/36 (2006.01)
CPC F02C 7/14 (2013.01) [F02C 7/06 (2013.01); F02C 7/10 (2013.01); F02C 7/224 (2013.01); F02C 7/36 (2013.01); F05D 2220/323 (2013.01); F05D 2260/205 (2013.01); F05D 2260/213 (2013.01); F05D 2260/98 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of operating a gas turbine engine, the gas turbine engine comprising:
an engine core comprising a turbine, a compressor, a combustor arranged to combust a fuel, and a core shaft connecting the turbine to the compressor;
a fan located upstream of the engine core;
a fan shaft;
a main gearbox that receives an input from the core shaft and outputs drive to the fan via the fan shaft, the gearbox comprising gears and journal bearings;
a recirculating lubrication system arranged to supply oil to lubricate the gears and journal bearings, the lubrication system comprising a first oil tank arranged to supply oil to the gears and journal bearings and a second oil tank arranged to supply oil to the journal bearings only; and
a heat exchange system arranged to transfer heat between the oil and the fuel,
wherein the method comprises, at cruise conditions:
controlling the heat exchange system so as to transfer 200-600 kJ/m3 of heat to the fuel from the oil; and
providing cooler oil to the journal bearings than to the gears.