Venturi mixing system for exhaust gas recirculation (EGR)

• US 7,032,578 B2
• Filed: 09/21/2004
• Issued: 04/25/2006
• Est. Priority Date: 09/21/2004
• Status: Active Grant

• Current Assignee: International Engine Intellectual Property Company, LLC (Volkswagen AG)
• Original Assignee: International Engine Intellectual Property Company, LLC (Volkswagen AG)
• Inventors: Chang, Timothy, Liu, Zhengbai, Ricart-Ugaz, Laura M., Zhu, Yuanxian
• Primary Examiner(s): Gimie, Mahmoud
• Application Number:
  US10/945,618
• Publication Number:
  US 20060060172A1
• Time in Patent Office: 581 Days
• Field of Search: 123/568.15, 123/568.17, 123/568.18
• US Class Current: 123/568.15
• 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 35/10118 with variable cross-sections of intake ducts along their length; Venturis; Diffusers
• CPC Class Codes: F02M 35/10157 Supercharged engines
• CPC Class Codes: F02M 35/10222 Exhaust gas recirculation [EGR]; Positive crankcase ventilation [PCV]; Additional air admission, lubricant or fuel vapour admission

Abstract

A venturi mixing system mixes intake air with exhaust gases for exhaust gas recirculation (EGR) in an internal combustion engine. The venturi mixing system has a venturi disposed in a mixing conduit. The venturi is connected to an intake air conduit and a supply conduit. The venturi and mixing conduit form an annular cavity connected to an EGR conduit. The venturi forms a mixing chamber. One or more inset conduits connect to the venturi and extend into the mixing chamber. Each inset conduit has an end outlet and one or more side outlets. The venturi generates a lower pressure region in the intake air. The inset conduits generate a turbulence field in the lower pressure region. The inset conduits direct intake air into the turbulence field. The inset conduits direct exhaust gases through the end and side outlets into the turbulence field. The exhaust gases mix with the intake air in the turbulence field to form a combustion gas for combustion of fuel in the engine. The venturi provides the combustion gas to the supply conduit.

Claims

1. A venturi mixing system for exhaust gas recirculation (EGR) in an internal combustion engine, comprising:

a venturi mixing device;

an intake air conduit connected to the venturi mixing device;

a supply conduit connected to the venturi mixing device;

at least two inset conduits connected to the venturi mixing device;

an EGR conduit connected to an annular cavity of the venturi mixing device;

where the venturi mixing device generates a lower pressure region in intake air from the intake air conduit;

where the at least two inset conduits are in fluid communication with the annular cavity;

where the at least two inset conduits generate a turbulence field in the lower pressure region;

where the venturi mixing device directs exhaust gases from the EGR conduit into the turbulence field; and

where the venturi mixing device provides a combustion gas to the supply conduit.

2. The venturi mixing system of claim 1, where the venturi mixing device directs intake air into the turbulence field.

3. The venturi mixing system of claim 1,

where the venturi mixing device generates a minimum pressure zone in the lower pressure region;

and

where the venturi mixing device directs the exhaust gases from the EGR conduit into the minimum pressure zone.

4. The venturi mixing system of claim 1, where the combustion gas has a selected concentration of exhaust gases in the intake air.

5. The venturi mixing system of claim 1, further comprising:

a mixing conduit connected to the intake air conduit and to the supply conduit;

a venturi disposed in the mixing conduit, where venturi and the mixing conduit form an annular cavity, where the EGR conduit is connected to the annular cavity;

where the venturi forms a mixing chamber; and

where the at least one inset conduit extends into the mixing chamber, where the at least one inset conduit forms an end outlet, where the at least one inset conduit forms at least one side outlet on a downstream side, and where the end outlet and the at least one side outlet direct the exhaust gases into the at least one turbulent flow location.

6. The venturi mixing system of claim 5, where the at least one inset conduit produces a flow surface, and where the flow surface directs intake air into the turbulence field.

7. The venturi mixing system of claim 5, where the at least one side outlet is an orifice.

8. The venturi mixing system of claim 5, where the at least one side outlet is a slot.

9. The venturi mixing system of claim 5, where the at least one inset conduit has a cylindrical configuration.

10. The venturi mixing system of claim 5, where the at least one inset conduit has an airfoil configuration.

11. A venturi mixing system for exhaust gas recirculation (EGR) in an internal combustion engine, comprising:

a mixing conduit;

a venturi disposed in the mixing conduit, where the venturi and the mixing conduit form an annular cavity, where the venturi forms a mixing chamber;

an intake air conduit connected to the venturi;

a supply conduit connected to the venturi;

an EGR conduit connected to the annular cavity; and

at least two inset conduits in fluid communication with the annular cavity, where the at least two inset conduits generate at least one turbulent flow location in intake air from the intake air conduit, where the at least two inset conduits extend into the mixing chamber, where the at least two inset conduits each form an end outlet, where each of the at least two inset conduits form at least one side outlet on a downstream side.

12. The venturi mixing system of claim 11,

where the venturi has an inlet section connected by a throat section to an outlet section;

where the inlet section forms a venturi inlet, where the inlet section has an inlet length from the throat section to the venturi inlet, where the venturi inlet has a venturi inlet diameter;

where the throat section has a throat diameter; and

where the outlet section forms a venturi outlet, where the outlet section has an outlet length from the throat section to the venturi outlet.

13. The venturi mixing system of claim 12,

where the ratio of the throat diameter to the venturi inlet diameter is greater than about 0.45;

and

where the ratio of the throat diameter to the venturi inlet diameter is less than about 0.95.

14. The venturi mixing system of claim 13, where the ratio of the throat diameter to the venturi inlet diameter is about 0.71.

15. The venturi mixing system of claim 12,

where the ratio of the inlet length to the venturi inlet diameter is greater than about 0.5;

and

where the ratio of the inlet length to the venturi inlet diameter is less than about 2.0.

16. The venturi mixing system of claim 15, where the ratio of the inlet length to the venturi inlet diameter is about 1.0.

17. The venturi mixing system of claim 12,

where the ratio of the outlet length to the venturi inlet diameter is greater than about 1.5;

and

where the ratio of the outlet length to the venturi inlet diameter is less than about 5.0.

18. The venturi mixing system of claim 17, where the ratio of the outlet length to the venturi inlet diameter is about 2.5.

19. The venturi mixing system of claim 12,

where the at least one inset conduit has an inset diameter;

where the ratio of the inset diameter to the venturi inlet diameter is greater than about 0.125; and

where the ratio of the inset diameter to the venturi inlet diameter is less than about 0.55.

20. The venturi mixing system of claim 19, where the ratio of the inset diameter to the venturi inlet diameter is about 0.25.

21. The venturi mixing system of claim 12, where the end outlet produces a flow surface at an offset distance from an axis of the mixing chamber, and where the flow surface forms a guide angle with the axis.

22. The venturi mixing system of claim 21,

where the ratio of the offset distance to the inset diameter is greater than about 1.0;

and

where the ratio of the offset distance to the inset diameter is less than about 1.5.

23. The venturi mixing system of claim 22, where the ratio of the offset distance to the inset diameter is about 1.1.

24. The venturi mixing system of claim 21, where the guide angle is equal to about zero.

25. The venturi mixing system of claim 21, where the guide angle is greater than about zero, and where the guide angle is less than about 45 degrees.

26. The venturi mixing system of claim 12, where each of the at least one side outlets is an orifice.

27. The venturi mixing system of claim 26,

where the orifice has an orifice diameter;

where the ratio of the orifice diameter to the venturi inlet diameter is greater than about 0.025; and

where the ratio of the orifice diameter to the venturi inlet diameter is less than about 0.25.

28. The venturi mixing device of claim 27, where the ratio of the orifice diameter to the venturi inlet diameter is about 0.12.

29. The venturi mixing system of claim 12, where each of the at least one side outlets is a slot.

30. The venturi mixing system of claim 29,

where the slot has a slot width;

where the at least one inset conduit has an inset diameter;

where the ratio of the slot width to the inset diameter is greater than about 0.2; and

where the ratio of the slot width to the inset diameter is less than about 0.9.

31. The venturi mixing system of claim 16, where the ratio of the slot width to the inset diameter is about 0.25.

32. The venturi mixing system of claim 12,

where the EGR conduit has an EGR conduit diameter;

where the ratio of the EGR conduit diameter to the venturi inlet diameter is greater than about 0.25; and

where the ratio of the EGR conduit diameter to the venturi inlet diameter is less than about 0.75.

33. The venturi mixing system of claim 32, where the ratio of the EGR conduit diameter to the venturi inlet diameter is about 0.5.

34. The venturi mixing system of claim 11, where each of the at least two inset conduits has a cylindrical configuration.

35. The venturi mixing system of claim 11, where each of the at least two inset conduits has an airfoil configuration.

36. The venturi mixing system of claim 11, further comprising:

an exhaust conduit connected to the EGR conduit;

an exhaust manifold connected to the exhaust conduit; and

an intake manifold connected to the supply conduit.

37. A venturi mixing device for exhaust gas recirculation (EGR) in an internal combustion engine, comprising:

a mixing conduit;

a venturi disposed in the mixing conduit,

where the venturi and the mixing conduit form an annular cavity,

where the venturi forms a mixing chamber,

where the venturi has an inlet section connected by a throat section to an outlet section,

where the inlet section forms a venturi inlet, where the inlet section has an inlet length from the throat section to the venturi inlet, where the venturi inlet has a venturi inlet diameter,

where the throat section has a throat diameter, and

where the outlet section forms a venturi outlet, where the outlet section has an outlet length from the throat section to the venturi outlet; and

at least two inset conduits in fluid communication with the annular cavity, where the at least two inset conduits generate at least one turbulent flow location in intake air from the venturi inlet, where the at least two inset conduits extend into the mixing chamber, where the at least two inset conduits have an inset diameter, where each of the at least two inset conduits form an end outlet at an offset distance from an axis of the mixing chamber, where each of the end outlets has a guide angle with the axis, and where each of the at least two inset conduits form at least one side outlet on a downstream side.

38. The venturi mixing device of claim 37,

where the ratio of the throat diameter to the venturi inlet diameter is greater than about 0.45 and less than about 0.95;

where the ratio of the inlet length to the venturi inlet diameter is greater than about 0.5 and less than about 2.0;

where the ratio of the outlet length to the venturi inlet diameter is greater than about 1.5 and less than about 5.0;

where the ratio of the inset diameter to the venturi inlet diameter is greater than about 0.125 and less than about 0.55; and

where the ratio of the offset distance to the inset diameter is greater than about 1.0 and less than about 1.5.

39. The venturi mixing device of claim 38, where the guide angle is equal to about zero.

40. The venturi mixing device of claim 38, where the guide angle is greater than about zero, and where the guide angle is less than about 45 degrees.

41. The venturi mixing device of claim 38,

where the at least one side outlet is an orifice;

where the orifice has an orifice diameter; and

where the ratio of the orifice diameter to the venturi inlet diameter is greater than about 0.025 and less than about 0.25.

42. The venturi mixing device of claim 38,

where the at least one side outlet is a slot;

where the slot has a slot width;

where the at least one inset conduit has an inset diameter; and

where the ratio of the slot width to the inset diameter is greater than about 0.2 and less than about 0.9.

43. The venturi mixing device of claim 37,

where the ratio of the throat diameter to the venturi inlet diameter is about 0.71;

where the ratio of the inlet length to the venturi inlet diameter is about 1.0;

where the ratio of the outlet length to the venturi inlet diameter is about 2.5;

where the ratio of the inset diameter to the venturi inlet diameter is about 0.25; and

where the ratio of the offset distance to the inset diameter is about 1.1.

44. The venturi mixing device of claim 43, where the guide angle is equal to about zero.

45. The venturi mixing device of claim 43,

where the guide angle is greater than about zero;

and

where the guide angle is less than about 45 degrees.

46. The venturi mixing device of claim 43,

where the at least one side outlet is an orifice;

where the orifice has an orifice diameter; and

where the ratio of the orifice diameter to the venturi inlet diameter is about 0.12.

47. The venturi mixing device of claim 43,

where the at least one side outlet is a slot;

where the slot has a slot width;

where the at least one inset conduit has an inset diameter; and

where the ratio of the slot width to the inset diameter is about 0.25.

48. The venturi mixing device of claim 37, where each of the at least two inset conduits has a cylindrical configuration.

49. The venturi mixing device of claim 37, where each of the at least two inset conduits has an airfoil configuration.

50. A method for mixing exhaust gases with intake air in an internal combustion engine, comprising:

generating a lower pressure region in intake air;

generating a turbulence field in the lower pressure region with at least two inset conduits; and

directing exhaust gases from an annular cavity into the turbulence field through the at least two inset conduits, wherein the at least two fluid conduits are fluidly communicating with the annular cavity.

51. The method for mixing exhaust gases with intake air of claim 50, further comprising directing intake air into the turbulence field.

52. The method for mixing exhaust gases with intake air of claim 50, further comprising:

generating a minimum pressure zone in the lower pressure region; and

directing the exhaust gases into the minimum pressure zone.

53. The method for mixing exhaust gases with intake air of claim 50, further comprising:

diverting exhaust gases from an exhaust manifold; and

providing combustion gas to an intake manifold.