Exhaust gas recirculation system in an internal combustion engine and method of using same

• US 6,237,336 B1
• Filed: 11/09/1999
• Issued: 05/29/2001
• Est. Priority Date: 11/09/1999
• Status: Expired due to Term

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Lawrence, Keith E., Feucht, Dennis D.
• Primary Examiner(s): KOCZO JR, MICHAEL
• Application Number:
  US09/437,022
• Time in Patent Office: 567 Days
• Field of Search: 60/605.2, 123/568.17
• US Class Current: 60/605.2
• CPC Class Codes: F02B 29/0425 Air cooled heat exchangers
• CPC Class Codes: F02M 26/05 High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor
• CPC Class Codes: F02M 26/10 having means to increase the pressure difference between the exhaust and intake system, e.g. venturis, variable geometry turbines, check valves using pressure pulsations or throttles in the air intake or exhaust system
• CPC Class Codes: F02M 26/19 Means for improving the mixing of air and recirculated exhaust gases, e.g. venturis or multiple openings to the intake system
• CPC Class Codes: F02M 26/36 with means for adding fluids other than exhaust gas to the recirculation passage; with reformers
• CPC Class Codes: F02M 35/10222 Exhaust gas recirculation [EGR]; Positive crankcase ventilation [PCV]; Additional air admission, lubricant or fuel vapour admission

Abstract

An internal combustion engine including at least one cylinder head defining a plurality of combustion cylinders. Each combustion cylinder has a displacement volume. An exhaust manifold is fluidly connected to each cylinder for transporting exhaust gas therefrom. An intake manifold provides combustion air to each cylinder. A turbocharger is driven by exhaust gas from the exhaust manifold and provides charged combustion air to the intake manifold. A mixing vessel has at least two inlets, at least one outlet and a mixing chamber. One of the inlets is fluidly connected with the exhaust manifold and an other of the inlets is fluidly connected with the turbocharger. The one inlet and the other inlet are connected with the mixing vessel in a parallel manner. The mixing chamber has a volume which is dependent upon a plurality of the displacement volumes.

Claims

1. An internal combustion engine, comprising:

at least one cylinder head defining a plurality of combustion cylinders, each said combustion cylinder having a displacement volume;

an exhaust manifold fluidly connected to each said cylinder for transporting exhaust gas therefrom;

an intake manifold for providing combustion air to each said cylinder;

a turbocharger for providing charged combustion air to said intake manifold;

a mixing vessel having at least two inlets, at least one outlet and a mixing chamber, one of said inlets fluidly connected with said exhaust manifold and an other of said inlets fluidly connected with said turbocharger, said one inlet and said other inlet connected with said mixing vessel in a parallel manner, said mixing chamber having a volume which is approximately equal to the sum of each of said displacement volume.

2. The internal combustion engine of claim 1, wherein said one inlet comprises a fluid conduit extending into said mixing chamber.

3. The internal combustion engine of claim 2, wherein said fluid conduit includes a plurality of radially extending holes which open into said mixing chamber.

4. The internal combustion engine of claim 3, wherein said holes are differently sized.

5. The internal combustion engine of claim 4, wherein said differently sized holes are selected and arranged to provide a substantially uniform flow of exhaust gas from said fluid conduit into said mixing chamber through each of said holes along a length of said fluid conduit.

6. The internal combustion engine of claim 2, wherein said fluid conduit comprises a pipe.

7. The internal combustion engine of claim 2, wherein said mixing vessel has a first longitudinal axis, and wherein said fluid conduit has a second longitudinal axis positioned generally concentrically with said first longitudinal axis.

8. The internal combustion engine of claim 7, wherein each of said mixing vessel and said fluid conduit are generally cylindrical.

9. The internal combustion engine of claim 2, wherein said fluid conduit extends adjacent and is connected to a side of said mixing vessel.

10. A method of recirculating exhaust gas in an internal combustion engine, comprising the steps of:

providing at least one cylinder head defining a plurality of combustion cylinders, each said combustion cylinder having a displacement volume;

providing an exhaust manifold and an intake manifold, each fluidly connected to each said cylinder;

providing a mixing vessel having at least two inlets, at least one outlet and a mixing chamber, one of said inlets fluidly connected with said exhaust manifold and an other of said inlets fluidly connected with a turbocharger, said one inlet and said other inlet connected with said mixing vessel in a parallel manner;

transporting exhaust gas from said exhaust manifold to said one inlet;

transporting combustion air from said turbocharger to said other inlet;

mixing said exhaust gas and said combustion air within said mixing chamber in a volume which is approximately equal to the sum of each of said displacement volume; and

transporting said mixed exhaust gas and combustion air to said intake manifold.

11. The method of claim 10, wherein said one inlet comprises a fluid conduit with a plurality of radially extending and differently sized holes which are in communication with said mixing chamber, and wherein said first transporting step comprises providing a substantially uniform flow of exhaust gas from said exhaust manifold into said mixing chamber along a length of said fluid conduit.