Start flow measurement
AssigneePratt & Whitney Canada Corp.
InventorKevin Allan Dooley
Life of this patent
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Abstract
A method and apparatus for measuring a start fuel flow to a pilot nozzle of a fuel system of a gas turbine engine using pressure differential between fuel passages leading to fuel nozzles.
Claims16
A method for measuring a start fuel flow to a pilot nozzle in a fuel system of a gas turbine engine for ignition in a combustion chamber during an engine start procedure, the fuel system including a first fuel passage leading to the pilot nozzle and a second fuel passage leading to a main manifold, both the pilot nozzle and main manifold being in fluid communication with the combustion chamber, the method comprising:
- a) measuring a pressure differential between the first fuel passage and the second fuel passage while the start fuel flow is being directed through the first fuel passage to the pilot nozzle, until a light-up condition of the pilot nozzle is detected;
- and
- b) calculating the start fuel flow using a flow number of the pilot nozzle and a measured value of the pressure differential.
An apparatus for determining a start fuel flow to a pilot nozzle of a fuel system for ignition in a combustion chamber of a gas turbine engine, the apparatus comprising:
- a differential pressure transducer connected between first and second fuel passages of the fuel system, the first fuel passage leading to the pilot nozzle and the second fuel passage leading to a main manifold, both the pilot nozzle and the main manifold being in fluid communication with the combustion chamber;
- and
- means for calculating the start fuel flow using a known flow number of the pilot nozzle and a measured value of the differential pressure transducer.
A fuel system of a gas turbine engine, comprising:
- a fuel pump for pressurizing fuel from a fuel source;
- at least a first nozzle in fluidic communication with a combustion chamber of the engine;
- at least a second nozzle in fluidic communication with the combustion chamber of the engine;
- a fluidic connection extending from the fuel pump and dividing into at least first and second passages leading to the respective first and second nozzles;
- a differential pressure transducer connected between the first and second passages of the fluidic connection for measuring a pressure differential between the first and second passages;
- and
- a control unit in contact with the fluidic connection for controllably operating the fuel system, the control unit including a device for using a measured value of the differential pressure transducer to calculate a start fuel flow through the first passage before a light-up condition of the first nozzle is detected.
Dependencies are inferred from the claim text.