Passive pumping for recirculating exhaust gas

Patent metadata

Field	Value
Publication number	US-10316803-B2
Application number	US-201715714699-A
Country	US
Kind code	B2
Filing date	Sep 25, 2017
Priority date	Sep 25, 2017
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

An exhaust gas recirculation mixer includes a convergent nozzle in a flow path from an air inlet of the mixer to an outlet of the mixer. The convergent nozzle is oriented converging toward the outlet of the mixer. The nozzle accelerates the flow to high velocity, which is released as a free-jet. The mixer includes an exhaust gas housing having an exhaust gas inlet into an interior of the exhaust gas housing, and a convergent-divergent nozzle having an air-fuel-exhaust gas inlet in fluid communication to receive fluid flow from the convergent nozzle (i.e., the free-jet), the interior of the exhaust gas housing, and a fuel supply into the mixer.

First claim

What is claimed is:

1. An exhaust gas recirculation mixer, the mixer comprising:
a convergent nozzle in a flow path from an air inlet of the mixer to an outlet of the mixer, the convergent nozzle converging toward the outlet of the mixer;
an exhaust gas housing comprising an exhaust gas inlet for allowing exhaust gas into an interior of the exhaust gas housing; and
a convergent-divergent nozzle comprising an air-fuel-exhaust gas inlet in fluid communication to receive fluid flow from the convergent nozzle; and
a fuel supply coupled to the mixer, the fuel supply comprising a fuel supply tube positioned parallel to and centrally within the air flow path, the fuel supply tube configured to supply fuel into the air flow path upstream of the convergent nozzle.

2. The exhaust gas recirculation mixer of claim 1 , where the fuel supply tube comprises a gaseous fuel supply tube.

3. The exhaust gas recirculation mixer of claim 1 , where the fuel supply comprises a fuel supply port upstream of the exhaust gas inlet.

4. The exhaust gas recirculation mixer of claim 3 , where the fuel supply port comprises a gaseous fuel supply port.

5. The exhaust gas recirculation mixer of claim 1 , where the convergent nozzle and the convergent-divergent nozzle are aligned on a same center axis.

6. The exhaust gas recirculation mixer of claim 1 , where the exhaust inlet is upstream of an outlet of the convergent nozzle.

7. The exhaust gas recirculation mixer of claim 1 , where the convergent nozzle is at least partially within the exhaust gas housing.

8. The exhaust gas recirculation mixer of claim 1 , where an inlet of the convergent-divergent nozzle has a greater area than an exit of the convergent nozzle.

9. An engine system comprising:
an intake manifold configured to receive a combustible mixture configured to be combusted within a combustion chamber;
a throttle upstream of the intake manifold, the throttle configured to at least partially regulate an air flow into the intake manifold;
an exhaust manifold configured to receive combustion products from the combustion chamber; and
an exhaust gas recirculation mixer downstream of the throttle and upstream of an intake manifold, the exhaust gas recirculation mixer comprising:
a convergent nozzle in a flow path from an air inlet of the mixer to an outlet of the mixer, the convergent nozzle converging toward the outlet of the mixer;
an exhaust gas housing comprising an exhaust gas inlet into an interior of the exhaust gas housing;
a convergent-divergent nozzle comprising an air-fuel-exhaust gas inlet in fluid communication to receive fluid flow from the convergent nozzle, the interior of the exhaust gas housing, and a fuel supply into the mixer; and
a fuel supply coupled to the mixer, the fuel supply comprising a fuel supply tube positioned parallel to and centrally within the air flow path, the fuel supply tube configured to supply fuel into the air flow path upstream of the convergent nozzle.

10. The engine system of claim 9 , further comprising a compressor upstream of the throttle, the compressor configured to increase a pressure within the air flow path.

11. The engine system of claim 10 , further comprising a turbine downstream of the exhaust manifold, the turbine being coupled to the compressor and configured to rotate the compressor.

12. The engine system of claim 9 , further comprising an exhaust gas cooler positioned within a flow path between the exhaust manifold and the exhaust gas recirculation mixer, the exhaust gas cooler configured to lower a temperature of the exhaust gas prior to the exhaust gas recirculation mixer.

Assignees

• Woodward Inc

Inventors

• Hampson Gregory James
• Chiera Domenico

Classifications

• F02M26/05

  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 title

• F02D9/02

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

• F02M35/10222

  Exhaust gas recirculation [EGR]; Positive crankcase ventilation [PCV]; Additional air admission, lubricant or fuel vapour admission · CPC title

• F02M26/19 Primary

  Means for improving the mixing of air and recirculated exhaust gases, e.g. venturis or multiple openings to the intake system · CPC title

• F02M26/10

  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 title