Patent ID: 7997062
Filing Date: 2011-08-16
Classification: F01D,F02C,F02K,F28D,F28F,Y02T

Abstract:
1. An aircraft gas turbine engine having a fuel-oil heat exchange system, the system comprising: a primary fuel-oil heat exchanger; a secondary fuel-oil heat exchanger; a primary oil passage for directing a primary hot oil flow to pass through the primary fuel-oil heat exchanger; a secondary oil passage for selectively directing a secondary hot oil flow to pass through the secondary fuel-oil heat exchanger, the primary oil passage and the secondary oil passage being connected in a parallel relationship one to another; a bypass oil passage for selectively directing the secondary hot oil flow to bypass the secondary fuel-oil heat exchanger; a thermal valve connecting the bypass oil passage to the secondary oil passage upstream of the secondary fuel-oil heat exchanger, the thermal valve being switchable between a first position in which the bypass oil passage is closed and the secondary hot oil flow is directed to pass through the secondary fuel-oil heat exchanger and a second position in which the secondary oil passage is closed and the secondary hot oil flow is directed through the bypass oil passage; and a fuel flow connection including the primary and secondary fuel-oil heat exchangers that direct a fuel flow to pass through the primary and secondary fuel-oil heat exchangers and supply to a combustor of the gas turbine engine, wherein the secondary hot oil flow bypasses the secondary fuel-oil heat exchanger according to a temperature change of the fuel flow.