Aircraft engine fuel system and method

Patent metadata

Field	Value
Publication number	US-11230979-B2
Application number	US-201916296988-A
Country	US
Kind code	B2
Filing date	Mar 8, 2019
Priority date	Mar 8, 2019
Publication date	Jan 25, 2022
Grant date	Jan 25, 2022

Abstract

A liquid fuel system for an aircraft engine includes a first fuel supply conduit hydraulically connected to a fuel source, a second fuel supply conduit hydraulically connected to the engine, a fuel return conduit hydraulically connected to the second fuel supply conduit, and a fuel pump. The fuel pump has a main inlet hydraulically connected to the first fuel supply conduit, an outlet hydraulically connected to the second fuel supply conduit, and an intermediate inlet hydraulically connected to the fuel return conduit. The intermediate inlet is located between the main inlet and the outlet and in use has a pressure between the main inlet pressure and the outlet pressure. A method of supplying a liquid fuel to an aircraft engine is also described.

First claim

The invention claimed is:

1. A liquid fuel system for an aircraft engine, the fuel system comprising:
a first fuel supply conduit hydraulically connected to a fuel source,
a second fuel supply conduit hydraulically connected to the engine,
a fuel return conduit hydraulically connected to the second fuel supply conduit, and
a fuel pump having a main inlet hydraulically connected to the first fuel supply conduit, an outlet hydraulically connected to the second fuel supply conduit, and an intermediate inlet hydraulically connected to the fuel return conduit, the intermediate inlet located between the main inlet and the outlet and in use having a pressure between a pressure at the main inlet and a pressure at the outlet, the intermediate inlet movable relative to the main inlet about a rotation axis of the fuel pump between a lower return pressure position and a higher return pressure position.

2. The fuel system of claim 1 , wherein the fuel pump is a regenerative rotodynamic fuel pump having a housing defining an impeller cavity therein, the main inlet, the intermediate inlet, and the outlet, at least part of an impeller disposed in the impeller cavity and rotatable about the rotation axis to pump fuel from the main inlet to the outlet.

3. The fuel system of claim 2 , wherein the intermediate inlet is movable about the rotation axis of the impeller relative to the main inlet between the lower return pressure position and the higher return pressure position.

4. The fuel system of claim 2 , wherein the housing includes a fixed housing portion defining the outlet therein and a movable housing portion defining the intermediate inlet therein, the movable housing portion being movable relative to the fixed housing portion to move the intermediate inlet between the lower return pressure position and the higher return pressure position.

5. The fuel system of claim 2 , wherein the housing includes a fixed housing portion defining the outlet therein, and a movable housing portion defining the main inlet therein, the movable housing portion being movable relative to the fixed housing portion to move the main inlet between the lower return pressure position and the higher return pressure position.

6. The fuel system of claim 2 , wherein the housing includes a fixed housing portion defining the outlet therein, a first movable housing portion defining the main inlet therein, and a second movable housing portion defining the intermediate inlet therein, and the first movable housing portion and the second movable housing portion are movable relative to each other and relative to the fixed housing portion.

7. The fuel system of claim 1 , further comprising an actuator operatively connected to the intermediate inlet, the actuator being operable to move the intermediate inlet between the lower return pressure position and the higher return pressure position.

8. The fuel system of claim 7 , further comprising a controller communicatively coupled to the actuator, the controller being operable to operate the actuator in response to changes in pressure in the fuel return conduit to selectively move the intermediate inlet between the lower return pressure position and the higher return pressure position to regulate a fluid pressure toward an intermediate return pressure setpoint.

9. The fuel system of claim 8 , wherein the controller is a proportional-integral-derivative (PID) controller.

10. A liquid fuel system for an aircraft engine, the fuel system comprising:
a first fuel supply conduit adapted to be hydraulically connected to a fuel source,
a second fuel supply conduit adapted to be hydraulically connected to a combustion chamber,
a fuel return conduit adapted to be hydraulically connected to the second fuel supply conduit for returning at least some fuel directed toward the combustion chamber, and
a fuel pump comprising:
a main inlet hydraulically connected to the first fuel supply conduit,
an outlet hydraulically connected to the second fuel supply conduit, and

an intermediate inlet hydraulically connected to the fuel return conduit, the intermediate inlet being hydraulically connected to the main inlet and the outlet downstream of the main inlet and upstream of the outlet, the intermediate inlet movable relative to the main inlet about a rotation axis of the fuel pump.

11. The fuel system of claim 10 , further comprising an actuator operatively connected to the fuel pump, the actuator being operable to move the intermediate inlet relative to the main inlet in response to changes in pressure in the fuel return conduit.

12. The fuel system of claim 11 , further comprising a controller communicatively coupled to the actuator, the controller being operable to operate the actuator in response to the changes in the pressure in the fuel return conduit.

13. A method of supplying a liquid fuel to an aircraft engine, comprising:
operating a fuel pump to pump the fuel from a main inlet of the fuel pump toward the engine via an outlet of the pump,
returning at least some of the fuel from downstream of the outlet to the fuel pump via an intermediate inlet of the fuel pump at a location of the fuel pump that is downstream of the main inlet and upstream of the outlet relative to a direction of fuel flow through the pump, and
varying a distance by rotating about a rotation axis of the fuel pump between the intermediate inlet and the main inlet during the operating the fuel pump in response to a variation in pressure in the intermediate inlet.

14. The method of claim 13 , wherein the aircraft engine is a gas turbine engine having a combustion chamber, and the operating the fuel pump to pump the fuel to the engine includes operating the fuel pump to pump the fuel toward the combustion chamber.

15. The method of claim 13 , wherein the varying the distance includes decreasing the distance in response to the pressure exceeding an intermediate return pressure setpoint, and increasing the distance in response to the pressure falling below the intermediate return pressure setpoint.

16. The method of claim 13 , wherein the varying the distance includes moving a first part of a housing of the fuel pump that defines at least in part an impeller cavity of the fuel pump, at least part of an impeller disposed in the impeller cavity, relative to a second part of the housing, one of the intermediate inlet and the main inlet being in the first part of the housing, and other one of the intermediate inlet and the main inlet being in the second part of the housing.

17. The method of claim 16 , further comprising receiving a signal at a controller, the signal being indicative of the pressure, and operating, by the controller, an actuator to move the first part of the housing relative to the second part of the housing in response to changes in the pressure to regulate the pressure in the intermediate inlet toward an intermediate return pressure setpoint.

Assignees

• Pratt & Whitney Canada

Inventors

• Waddleton David
• Renaud Benjamin
• Bergeron Sebastien
• Plamondon Etienne
• Gauvreau Jean-Gabriel

Classifications

• F05D2220/323

  for aircraft propulsion, e.g. jet engines · CPC title

• F04D27/006

  by influencing fluid temperatures · CPC title

• F02C9/36

  characterised by returning of fuel to sump (F02C9/38 takes precedence) · CPC title

• F04D29/406

  especially adapted for liquid pumps · CPC title

• F04D15/005

  the pumps being of the circumferential flow type · CPC title