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US 7,997,062 B2Granted
Dual channel regulated fuel-oil heat exchanger
AssigneePratt & Whitney Canada Corp.
InventorsJu Sun, Brian Lee, Adam Logan
Life of this patent
Estimating the term…
Abstract
A gas turbine engine includes a fuel-oil heat exchange system in which the fuel is continuously heated by a primary hot oil flow in a primary fuel-oil heat exchanger and the fuel is selectively heated in a secondary fuel-oil heat exchanger by a secondary hot oil flow selectively passing through or bypassing a secondary fuel-oil heat exchanger, controlled by a thermal valve.
Claims17
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.
5 more elements
An aircraft gas turbine engine having a fuel-oil heat exchange apparatus, the apparatus comprising:
- a primary fuel-oil heat exchanger and a secondary fuel-oil heat exchanger, the primary and secondary fuel-oil heat exchangers being connected in a fuel flow connection to direct the fuel flow to a combustor of the gas turbine engine;
- means for directing a first portion of a main hot oil flow to continuously pass through the primary fuel-oil heat exchanger;
- means for directing a secondary portion of the main hot oil flow to pass through the secondary fuel-oil heat exchanger, means for directing the first portion and means for directing a secondary portion being connected in a parallel relationship one to another;
- and
- means for directing the secondary portion of the main oil flow to bypass the secondary fuel-oil heat exchanger according to a temperature change of the fuel flow.
2 more elements
A method for regulating a temperature of a fuel flow heated by hot oil in a gas turbine engine, comprising steps of:
- a) directing the fuel flow to be heated, to pass through a primary fuel-oil heat exchanger and a secondary fuel-oil heat exchanger;
- b) directing a primary hot oil flow to continuously pass through a primary oil passage of the primary fuel-oil heat exchanger in order to continuously heat at least a first portion of the fuel flow;
- and
- c) directing a secondary hot oil flow to pass through a secondary oil passage of the secondary fuel-oil heat exchanger when a temperature of the heated fuel flow is below a first predetermined temperature and directing the secondary hot oil flow to bypass the secondary fuel-oil heat exchanger when the temperature of the heated fuel flow is above a second predetermined temperature, to thereby selectively heat at least a second portion of the fuel flow in response to temperature changes of the heated fuel flow measured after step (a), wherein the primary oil passage and the secondary oil passage being connected in a parallel relationship one to another.
1 more element
Dependencies are inferred from the claim text.