Liquid and/or gaseous fuel delivery system and methods thereof

Patent metadata

Field	Value
Publication number	US-11293336-B2
Application number	US-202016811945-A
Country	US
Kind code	B2
Filing date	Mar 6, 2020
Priority date	Mar 6, 2020
Publication date	Apr 5, 2022
Grant date	Apr 5, 2022

Abstract

Methods and systems are provided for reducing wall-wetting and improving mixing of air and fuel within a pre-chamber system of an engine. In one example, a method comprises supplying an air flow to the pre-chamber system via an air injector system while a piston associated with a main chamber is undergoing reciprocating motion. In this way, a rotating or swirling flow of fuel exiting a pre-chamber fuel injector of the pre-chamber system may be induced, which may reduce wall-wetting and improve air and fuel mixing, and when fuel is not being injected to the pre-chamber system the air flow may pressurize the pre-chamber system to reduce an amount of residuals from the main chamber to the pre-chamber system.

First claim

The invention claimed is:

1. A method comprising:
determining conditions for pre-chamber pressurization are met; and
responsive to determining the conditions for pre-chamber pressurization are met, supplying an air flow to a pre-chamber system of an engine via an air injector system at a first predetermined time while a piston of a main chamber of the engine is undergoing reciprocating motion, the pre-chamber system including a pre-chamber fuel injector and a spark plug for igniting an air-fuel mixture within the pre-chamber system, and one or more pre-chamber orifices that fluidically couple the pre-chamber system to the main chamber.

2. The method of claim 1 , wherein supplying the air flow further comprises controlling a duty cycle of an air injection control valve included in an air injector line of the air injector system.

3. The method of claim 1 , further comprising supplying a first fuel to the main chamber via a main chamber fuel injector at a second predetermined time while the piston of the main chamber is undergoing reciprocating motion.

4. The method of claim 3 , further comprising supplying the first fuel via port injection to the main chamber.

5. The method of claim 1 , further comprising determining that the conditions for pre-chamber pressurization are not met, and responsive to determining the conditions for pre-chamber pressurization are not met, supplying a first fuel via direct injection to the main chamber and generating a curtain of air around the first fuel via the air injector system.

6. The method of claim 3 , wherein the first predetermined time includes a time when fuel injection via one or both of the pre-chamber fuel injector and the main chamber fuel injector is discontinued.

7. The method of claim 1 , further comprising supplying a second fuel to the pre-chamber system via the pre-chamber fuel injector at a third predetermined time while the piston of the main chamber is undergoing reciprocating motion.

8. The method of claim 7 , wherein the first predetermined time is within a threshold time before the third predetermined time; and
wherein the air flow is continued to be supplied at the third predetermined time when the second fuel is supplied to the pre-chamber system via the pre-chamber fuel injector.

9. The method of claim 7 , further comprising supplying the second fuel at a predetermined angle with respect to a central axis of the pre-chamber fuel injector.

10. The method of claim 1 , further comprising providing a spark to the pre-chamber system at a fourth predetermined time.

11. A system for an engine, comprising:
a pre-chamber system that includes a pre-chamber fuel injector, a spark plug, a pre-chamber and an air injector each included within a pre-chamber housing;
an air injector control valve for regulating a supply of air to the air injector;
a main chamber that includes at least a piston and an associated main chamber fuel injector, the main chamber fluidically coupled to the pre-chamber housing by one or more pre-chamber orifices; and
a controller with computer readable instructions stored on non-transitory memory that when executed, cause the controller to:
responsive to determining that conditions for pressurizing the pre-chamber housing are met, with the piston undergoing reciprocating motion, inject an air flow to the pre-chamber system at a position between a tip of the pre-chamber fuel injector and the main chamber by controlling a duty cycle of the air injector control valve to pressurize the pre-chamber housing.

12. The system of claim 11 , wherein the tip of the pre-chamber fuel injector includes a single spray hole for providing fuel to the pre-chamber system; and
wherein the single spray hole is of a diameter within a range of 50-70 microns.

13. The system of claim 12 , wherein fuel exits the single spray hole at a predetermined angle with respect to a central axis of the pre-chamber fuel injector.

14. The system of claim 11 , wherein the air injector includes an air injector scaffold and a plurality of air injector orifices extending from the air injector scaffold, the air injector scaffold and the plurality of air injector orifices positioned directly between the tip of the pre-chamber fuel injector and the main chamber; and
wherein the air injector scaffold and the plurality of air injector orifices extend generally circumferentially around at least part of an outer perimeter of the tip of the pre-chamber fuel injector so as to introduce a swirling or rotating pattern of the air flow.

15. The system of claim 14 , further comprising a ring-like venturi element positioned just below the plurality of air injector orifices between the plurality of air injector orifices and the main chamber, the ring-like venturi element configured to further encourage the swirling or rotating pattern of the air flow exiting the plurality of air injector orifices.

16. The system of claim 11 , further comprising an air injector line that extends from the air injector and which receives air from an air supply system; and
wherein the air injector control valve is included within the air injector line.

17. A method comprising:
determining pre-chamber pressurization conditions are met; and
responsive to determining the pre-chamber pressurization conditions are pressurizing a pre-chamber of a pre-chamber system that is fluidically coupled to a main chamber of an engine that includes a piston by supplying an air flow to the pre-chamber system, to reduce a flow of residual material from the main chamber back to the pre-chamber under conditions where the piston is undergoing a reciprocating motion, wherein the pre-chamber pressurization conditions are different than air injection conditions for fuel combustion events.

18. The method of claim 17 , wherein pressurizing the pre-chamber includes supplying an air flow to the pre-chamber via an air injector that includes one or more air injector orifices.

19. The method of claim 18 , wherein pressurizing the pre-chamber further comprises controlling a duty cycle of an air injector control valve positioned within an air injector line that stems from the air injector.

20. The method of claim 17 , further comprising pressurizing the pre-chamber at least when the piston is traveling from a bottom dead center position to a top dead center position.

Assignees

• Ford Global Tech Llc

Inventors

• Basmaji Joseph F
• Wicks Christopher Donald
• Meinhart Mark

Classifications

• F02D41/0025

  Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures · CPC title

• F02D41/3094 Primary

  the fuel injection being effected by at least two different injectors, e.g. one in the intake manifold and one in the cylinder · CPC title

• Y02T10/12

  Improving ICE efficiencies · CPC title

• F02M23/04

  with automatic control · CPC title

• F02B19/12

  with positive ignition (engines with non-timed positive ignition, and with incandescent chambers F02B9/08) · CPC title