Ducted combustion systems utilizing Venturi ducts

Patent metadata

Field	Value
Publication number	US-9915190-B2
Application number	US-201514798140-A
Country	US
Kind code	B2
Filing date	Jul 13, 2015
Priority date	Jul 13, 2015
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

A ducted combustion system is disclosed. The ducted combustion system may include a combustion chamber, which is defined as an enclosure bound at a first end by a flame deck surface of a cylinder head of an internal combustion engine and bound at a second end by a piston top surface of a piston disposed within the internal combustion engine. The system may further include a fuel injector, having at least one orifice, injecting fuel into the combustion chamber as at least one fuel jet. The system may further include at least one Venturi duct disposed within the combustion chamber between the flame deck surface and the piston top surface, the at least one Venturi duct being disposed such that each of the at least one fuel jet, at least partially, enters the at least one Venturi duct structure upon being injected into the combustion chamber.

First claim

What is claimed is:

1. A ducted combustion system, comprising:
a combustion chamber defined as an enclosure bound at a first end by a flame deck surface of a cylinder head of an internal combustion engine, and bound at a second end by a piston top surface of a piston disposed within the internal combustion engine, and forming a cylindrical bore in which a main combustion event occurs which provides work on the piston;
a fuel injector in fluid connection with the combustion chamber and including at least one orifice opening from an injector tip of the fuel injector, the at least one orifice injecting fuel into the combustion chamber as at least one fuel jet; and
at least one Venturi duct structure disposed totally within the combustion chamber between the flame deck surface and the piston top surface and being disposed such that the at least one fuel jet, at least partially, enters a duct opening of the at least one Venturi duct structure upon being injected into the combustion chamber, and exits a duct outlet of the at least one Venturi duct structure, wherein the at least one Venturi duct structure defines a first section, a second section, and a throat section disposed between the first section and the second section, and wherein a wall of the Venturi duct structure defines one or more holes at the throat section, the one or more holes being configured to draw ambient air from the combustion chamber into the at least one fuel jet as the at least one fuel jet passes through the throat section.

2. The ducted combustion system of claim 1 , wherein the at least one fuel jet enters the first section at an opening of the at least one Venturi duct structure and the at least one fuel jet exits the at least one Venturi duct structure through the second section.

3. The ducted combustion system of claim 1 , wherein the first section is generally converging in shape and converges in a flow direction of the at least one fuel jet.

4. The ducted combustion system of claim 1 , wherein the second section is generally diverging and diverges in a flow direction of the at least one fuel jet.

5. The ducted combustion system of claim 1 , wherein the first section is greater, in length, than the second section.

6. The ducted combustion system of claim 1 , wherein the second section is greater, in length, than the first section.

7. A method for operating a combustion system, comprising:
injecting a fuel jet into a combustion chamber of an internal combustion engine, the combustion chamber defined as an enclosure bound at a first end by a flame deck of a cylinder of an internal combustion engine, and bound at a second end by a piston top surface of a piston disposed within the internal combustion engine, and forming a cylindrical bore in which a main combustion event occurs which provides work on the piston;
directing the fuel jet into an opening of a duct, the duct being disposed totally within the combustion chamber between the flame deck surface and the piston top surface;
directing the fuel jet through a converging section of the duct, the converging section of the duct being proximate to the opening;
directing the fuel jet through a throat section of the duct, the throat section of the duct being downstream of the converging section;
drawing in outside air from the combustion chamber into the duct at the throat section via one or more holes defined by a wall of the duct proximate to the throat section;
mixing fuel of the fuel jet and the outside air from the combustion chamber at the throat section of the duct; and
directing the mixed fuel jet through a diverging section of the duct and through a duct outlet, the diverging section of the duct being downstream of the throat section.

8. The method of claim 7 , further comprising preventing entrainment of recirculated combustion products from a downstream region of the fuel jet to a upstream region of the fuel jet by substantially containing a segment of the fuel jet within the duct.

9. The method of claim 7 , wherein directing the fuel jet through a converging section of the duct includes directing the fuel jet through the converging section in a flow direction of the fuel jet, wherein radii of the converging section decrease in the flow direction.

10. The method of claim 7 , wherein directing the fuel jet through the diverging section of the duct includes directing the fuel jet through the diverging section in a flow direction of the fuel jet, wherein radii of the diverging section increase in the flow direction.

11. An internal combustion engine, comprising:
an engine block having at least one cylinder bore;
a cylinder head having a flame deck surface disposed at one end of the cylinder bore;
a piston connected to a crankshaft and configured to reciprocate within the cylinder bore, the piston having a piston top surface facing the flame deck surface such that a combustion chamber is defined within the cylinder bore bound at a first end by the flame deck surface and at a second end by the piston top surface, and forming a cylindrical bore in which a main combustion event occurs which provides work on the piston;
a fuel injector in fluid connection with the combustion chamber and including at least one orifice opening from an injector tip of the fuel injector, the at least one orifice injecting fuel into the combustion chamber as at least one fuel jet; and
at least one Venturi duct structure disposed totally within the combustion chamber between the flame deck surface and the piston top surface, the at least one Venturi duct structure being disposed such that the at least one fuel jet, at least partially, enters a duct opening of the at least one Venturi duct structure upon being injected into the combustion chamber, and exits a duct outlet of the at least one Venturi duct structure, the at least one Venturi duct structure including a first section, a second section, and a throat section disposed between the first section and the second section, wherein a wall of the at least one Venturi duct structure defines one or more holes at the throat section.

12. The internal combustion engine of claim 11 , wherein the first section has a generally converging shaped structure, the generally converging shaped structure converging in a flow direction of the at least one fuel jet, and wherein the second section has a generally diverging shaped structure, the generally diverging shaped structure diverging in a flow direction of the at least one fuel jet.

Assignees

• Caterpillar Inc

Inventors

• Koci Chad

Classifications

• F02B23/10 Primary

  with separate admission of air and fuel into cylinder · CPC title

• F02B23/02 Primary

  with compression ignition · CPC title

• F02F1/24

  Cylinder heads · CPC title

• Y02T10/125

  Cross-Sectional Technologies · mapped topic

• Y02T10/12

  Improving ICE efficiencies · CPC title