Internal combustion engine utilizing two independent flow paths to a dedicated exhaust gas recirculation cylinder

Patent metadata

Field	Value
Publication number	US-9657692-B2
Application number	US-201514851890-A
Country	US
Kind code	B2
Filing date	Sep 11, 2015
Priority date	Sep 11, 2015
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

An exhaust gas recirculation (EGR) system and corresponding method for improved combustion efficiency of an internal combustion engine having a number of cylinders, comprising one or more main cylinders connected to an intake manifold and one or more cylinders operable as a dedicated EGR cylinder(s). The dedicated EGR cylinder(s) have two independent intake flow paths for where one flow path provides only intake air and one flow path provides air and recirculated exhaust gas. The exhaust gas output of the one or more dedicated EGR cylinders are connected to an exhaust gas recirculation loop which delivers the exhaust gas output to the main cylinder intake manifold.

First claim

The invention claimed is:

1. An exhaust gas recirculation (EGR) system for improved combustion efficiency of an internal combustion engine having a number of cylinders, comprising:
one or more main cylinders connected to an intake manifold;
one or more cylinders operable as a dedicated EGR cylinder(s), having two independent intake flow paths for said dedicated cylinder(s) where one flow path provides only intake air including a first intercooler in the flow path and one flow path provides air and recirculated exhaust gas including a second intercooler in the flow path, the exhaust gas output of said one or more dedicated EGR cylinders connected to an exhaust gas recirculation loop which delivers said exhaust gas output to said main cylinder intake manifold.

2. The exhaust gas recirculation system of claim 1 wherein said intake manifold includes a pathway for introducing said air and recirculated exhaust gas to said one or more cylinders operable as a dedicated EGR cylinder(s).

3. The exhaust gas recirculation system of claim 1 wherein said flow path providing only intake air to said one or more dedicated EGR cylinder(s) includes a cylinder throttle.

4. The exhaust gas recirculation system of claim 1 wherein said one or more dedicated EGR cylinder(s) has a single exhaust port which is connected to said EGR loop.

5. The exhaust gas recirculation system of claim 1 wherein the EGR rate in said one or more cylinders operable as a dedicated EGR cylinder(s) is about 14.29%.

6. The exhaust gas recirculation system of claim 1 wherein said one or more dedicated EGR cylinders are run rich.

7. The exhaust gas recirculation system of claim 1 including a first cylinder valve on said flow path that provides only intake air to said one or more dedicated cylinder(s) and a second cylinder valve on said flow path that provides air and recirculated exhaust gas to said one or more dedicated cylinder(s).

8. The exhaust gas recirculation system of claim 1 wherein said one flow path providing only intake air to said one or more dedicated EGR cylinder(s) includes a port valve.

9. A method of using exhaust gas recirculation (EGR) to improve the combustion efficiency of an internal combustion engine comprising:
operating one or more main cylinders as non-dedicated EGR cylinders, which main cylinders are connected to an intake manifold;
operating one or more cylinders as dedicated EGR cylinder(s) such that its exhaust, during all or some engine cycles, is recirculated via an EGR loop as EGR gas, wherein said one or more EGR cylinder(s) have two independent intake flow paths where one flow path including a first intercooler provides only intake air and one flow path including a second intercooler provides air and recirculated exhaust gas, the exhaust gas output of said one or more dedicated EGR cylinders connected to an exhaust gas recirculation loop which delivers said exhaust gas output to said main cylinder intake manifold; and
cooling said air in said flow path providing only intake air to said one or more dedicated EGR cylinder(s) with said first intercooler and cooling said air in said flow path providing air and recirculated exhaust gas with said second intercooler, wherein said first and second intercoolers allow independent temperature control.

10. The method of claim 9 wherein said intake manifold includes a pathway for introducing said air and recirculated exhaust gas to said one or more cylinders operable as a dedicated EGR cylinder(s).

11. The method of claim 9 including operating a first cylinder valve on said flow path that provides only intake air to said one or more dedicated cylinder(s) and operating a second cylinder valve on said flow path that provides air and recirculated exhaust gas to said one or more dedicated cylinder(s).

12. The method of claim 9 wherein the EGR rate is said one or more cylinders operating as a dedicated EGR cylinder(s) is about 14.29%.

13. The method of claim 9 wherein said one or more dedicated EGR cylinders are run rich.

14. The method of claim 9 further comprising controlling intake air flow in said one flow path providing only intake air to said one or more dedicated EGR cylinder(s) with a port valve.

Assignees

• Southwest Res Inst

Inventors

• Chiu James P

Classifications

• F02M26/43 Primary

  in which exhaust from only one cylinder or only a group of cylinders is directed to the intake of the engine · CPC title

• F02M26/27

  with air-cooled heat exchangers · CPC title

• F02M26/28

  with liquid-cooled heat exchangers · CPC title

• F02D9/02

  concerning induction conduits (throttle valves, or arrangements thereof in conduits F02D9/08) · CPC title

• F02M26/14

  in relation to the exhaust system · CPC title