Fuel injection system for aircraft engine

Patent metadata

Field	Value
Publication number	US-11111848-B1
Application number	US-202016890660-A
Country	US
Kind code	B1
Filing date	Jun 2, 2020
Priority date	Jun 2, 2020
Publication date	Sep 7, 2021
Grant date	Sep 7, 2021

Abstract

A fuel injection system for an aircraft engine has: a first fuel injector having a first actuation inlet, a first fuel inlet connected to a fuel source, and a first fuel outlet connected to the at least one combustion chamber, the first fuel injector defining a first pressure ratio; a second fuel injector having a second actuation inlet, a second fuel inlet connected to the fuel source, and a second fuel outlet connected to the at least one combustion chamber, the second fuel injector defining a second pressure ratio; and an actuation fluid system having a circuit connected to the first actuation inlet and to the second actuation inlet, the first outlet pressure different than the second outlet pressure by having one or both of the first pressure ratio different than the second pressure ratio and a first actuation pressure different than a second actuation pressure.

First claim

The invention claimed is:

1. A fuel injection system for an aircraft engine having at least one combustion chamber of varying volume, comprising:
a first fuel injector having a first actuation inlet, a first fuel inlet hydraulically connected to a fuel source, and a first fuel outlet hydraulically connected to the at least one combustion chamber, the first fuel injector defining a first pressure ratio defined as a first outlet pressure at the first fuel outlet to a first inlet pressure at the first fuel inlet;
a second fuel injector having a second actuation inlet, a second fuel inlet hydraulically connected to the fuel source, and a second fuel outlet hydraulically connected to the at least one combustion chamber, the second fuel injector defining a second pressure ratio defined as a second outlet pressure at the second fuel outlet to a second inlet pressure at the second fuel inlet; and
an actuation fluid system having a circuit hydraulically connected to the first actuation inlet and to the second actuation inlet,
wherein the first fuel injector and the second fuel injector are structurally configured such that the first pressure ratio is different than the second pressure ratio and the first outlet pressure is different than the second outlet pressure, and/or the actuation fluid system includes a first pressure regulating valve hydraulically connected to the first actuation inlet and a second pressure regulating valve hydraulically connected to the second actuation inlet and configured to regulate a first actuation pressure from the actuation fluid system to be different than a second actuation pressure from the actuation fluid system such that the first outlet pressure is different than the second outlet pressure.

2. The fuel injection system of claim 1 , wherein the actuation fluid system contains a first and second actuation fluid, wherein the first actuation fluid and the second actuation fluid are lubricant from a source of the lubricant.

3. The fuel injection system of claim 1 , wherein each injector of the first injector and the second injector has a body, a nozzle defining a fuel outlet of the injector and protruding from the body, and a needle slidingly received within the nozzle, the needle movable from an engaged position in which the needle is sealingly engaged to the nozzle and a disengaged position in which the needle allows fuel to exit the injector.

4. The fuel injection system of claim 3 , wherein the body of the each injector defines an actuation chamber hydraulically connected to the circuit and an injection chamber hydraulically connected to the fuel source, a first piston slidingly received within the actuation chamber, a second piston slidingly received within the injection chamber and connected to the needle, movement of the first piston upon reception of a first or second actuation fluid within the actuation chamber pushing the fuel received via the first or second fuel inlet into the injection chamber thereby pushing on the second piston to move the needle from the engaged position toward the disengaged position.

5. The fuel injection system of claim 1 , comprising a high-pressure pump hydraulically connected to both of the first actuation inlet and the second actuation inlet, the first pressure ratio different than the second pressure ratio.

6. The fuel injection system of claim 5 , wherein the first actuation pressure is equal to the second actuation pressure.

7. The fuel injection system of claim 5 , wherein the first pressure ratio is 5 and the second pressure ratio is 10.

8. The fuel injection system of claim 1 , comprising a high-pressure pump hydraulically connected to both of the first actuation inlet and the second actuation inlet, the first actuation inlet hydraulically connected to the high-pressure pump via a first pressure regulating valve and the second actuation inlet hydraulically connected to the high-pressure pump via a second pressure regulating valve, an outlet valve pressure of the first pressure regulating valve different than that of the second pressure regulating valve.

9. The fuel injection system of claim 8 , wherein the first actuation inlet is hydraulically connected to the high-pressure pump via both of the first pressure regulating valve and the second pressure regulating valve.

10. The fuel injection system of claim 8 , wherein the first pressure ratio is equal to the second pressure ratio.

11. The fuel injection system of claim 10 , wherein the first pressure ratio ranges from 1 to 10.

12. A rotary internal combustion engine, comprising:
an outer body defining a rotor cavity;
a rotor rotatable within the rotor cavity and in sealing engagement with walls of the outer body and defining at least one chamber of variable volume in the rotor cavity;
a pilot subchamber defined by the outer body communicating with the rotor cavity;
a main fuel injector having a tip in communication with the rotor cavity at a location spaced apart from the pilot subchamber, the main fuel injector having a main actuation inlet hydraulically connected to a source of an actuation fluid, a main fuel inlet hydraulically connected to a fuel source, and a main fuel outlet hydraulically connected to the at least one combustion chamber, the main fuel injector defines a main pressure ratio defined as a main outlet pressure at the main fuel outlet to a main inlet pressure at the main fuel inlet;
a pilot fuel injector having a tip in communication with the pilot subchamber, the pilot fuel injector having a pilot actuation inlet hydraulically connected to the source of the actuation fluid, a pilot fuel inlet hydraulically connected to the fuel source, and a pilot fuel outlet hydraulically connected to the at least one combustion chamber via the pilot subchamber, the pilot fuel injector defines a pilot pressure ratio defined as a pilot outlet pressure at the pilot fuel outlet to a pilot inlet pressure at the pilot fuel inlet; and
an actuation fluid system having a circuit hydraulically connected to the main actuation inlet and to the pilot actuation inlet;
wherein the actuation fluid system is operable to inject the actuation fluid at a main actuation pressure to the main actuation inlet and to inject the actuation fluid at a pilot actuation pressure to the pilot actuation inlet,
wherein the main fuel injector and the pilot fuel injector are structurally configured such that the main pressure ratio is different than the pilot pressure ratio and the main outlet pressure is different than the pilot outlet pressure, and/or the actuation fluid system includes a first pressure regulating valve hydraulically connected to the main actuation inlet and a second pressure regulating valve hydraulically connected to the pilot actuation inlet and configured to regulate the main actuation pressure from the actuation fluid system to be different than the pilot actuation pressure from the actuation fluid system such that the main outlet pressure is different than the pilot outlet pressure.

13. The rotary internal combustion engine of claim 12 , comprising a high-pressure pump hydraulically connected to both of the main actuation inlet and the pilot actuation inlet, the main pressure ratio different than the pilot pressure ratio.

14. The rotary internal combustion engine of claim 13 , wherein the main actuation pressure is equal to the pilot actuation pressure.

15. The rotary internal combustion engine of claim 12 , comprising an engine control unit (ECU) operatively connected to the main fuel injector and the pilot fuel injector, the ECU having a processing unit and a computer readable medium operatively connected to

Assignees

• Pratt & Whitney Canada

Inventors

• Bergeron Sebastien
• Plamondon Etienne
• Thomassin Jean

Classifications

• Y02T10/12

  Improving ICE efficiencies · CPC title

• F02B41/10

  in exhaust turbines (use of exhaust turbines for charging F02B37/00) · CPC title

• F02B37/00

  Engines characterised by provision of pumps driven at least for part of the time by exhaust · CPC title

• F02B19/1085

  controlling fuel injection · CPC title

• F02M63/0028

  hydraulic · CPC title