Systems and methods for a split exhaust engine system

• US 10,132,235 B2
• Filed: 12/16/2016
• Issued: 11/20/2018
• Est. Priority Date: 12/16/2016
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Ulrey, Joseph Norman, Madison, Daniel Paul, Boyer, Brad Alan
• Primary Examiner(s): MOULIS, THOMAS N
• Application Number:
  US15/382,548
• Publication Number:
  US 20180171867A1
• Time in Patent Office: 704 Days
• CPC Class Codes: F01N 13/107 More than one exhaust manifold or exhaust collector
• CPC Class Codes: F01N 2900/04 Methods of control or diagnosing
• CPC Class Codes: F01N 3/021 by means of filters
• CPC Class Codes: F01N 3/10 by thermal or catalytic conversion of noxious components of exhaust by using other chemical processes, chemical aspects of catalytic conversion, e.g. using specified catalysts, B01D53/34
• CPC Class Codes: F01N 3/20 specially adapted for catalytic conversion F01N3/22 takes precedence; Methods of operation or control of catalytic converters
• CPC Class Codes: F02B 25/145 with intake and exhaust valves exclusively in the cylinder head
• CPC Class Codes: F02B 37/025 Multiple scrolls or multiple gas passages guiding the gas to the pump drive
• CPC Class Codes: F02B 37/18 by bypassing exhaust from the inlet to the outlet of turbine or to the atmosphere
• CPC Class Codes: F02B 37/183 Arrangements of bypass valves or actuators therefor
• CPC Class Codes: F02D 13/0215 changing the valve timing only
• CPC Class Codes: F02D 13/0249 changing the valve timing only
• CPC Class Codes: F02D 13/0257 Independent control of two or more intake or exhaust valves respectively, i.e. one of two intake valves remains closed or is opened partially while the other is fully opened
• CPC Class Codes: F02D 13/0261 Controlling the valve overlap
• CPC Class Codes: F02D 2200/0414 Air temperature
• CPC Class Codes: F02D 2200/0418 Air humidity
• CPC Class Codes: F02D 41/0077 Control of the EGR valve or actuator, e.g. duty cycle, closed loop control of position EGR valve position sensor F02M26/48
• CPC Class Codes: F02M 26/14 in relation to the exhaust system
• CPC Class Codes: F02M 26/20 Feeding recirculated exhaust gases directly into the combustion chambers or into the intake runners
• CPC Class Codes: F02M 26/43 in which exhaust from only one cylinder or only a group of cylinders is directed to the intake of the engine
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 : Engine management systems

Abstract

Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation to an intake passage via a first exhaust manifold and exhaust gas to an exhaust passage via a second exhaust manifold. In one example, the split exhaust engine system may include a first set of exhaust valves fluidly coupled to the exhaust passage, upstream of a turbocharger turbine, a first emission control device (ECD), and a second ECD disposed within the exhaust passage, the second ECD positioned downstream of the first ECD. The system may further include a second set of exhaust valves fluidly coupled to the intake passage and the exhaust passage, between the first ECD and the second ECD.

Claims

1. A system for an engine, comprising:

a first set of exhaust valves fluidly coupled to an exhaust passage, upstream of a turbocharger turbine, a first emission control device (ECD), and a second ECD disposed within the exhaust passage, the second ECD positioned downstream of the first ECD; and

a second set of exhaust valves fluidly coupled to an intake passage and the exhaust passage, between the first ECD and the second ECD.

2. The system of claim 1, wherein the first set of exhaust valves is fluidly coupled to both the first ECD and the second ECD via a first exhaust manifold exclusively coupled to the first set of exhaust valves.

3. The system of claim 2, wherein the second set of exhaust valves is fluidly coupled to the exhaust passage, between the first ECD and the second ECD, via a flow passage, a first end of the flow passage coupled to a second exhaust manifold exclusively coupled to the second set of exhaust valves and a second end of the flow passage coupled to the exhaust passage, between the first ECD and the second ECD.

4. The system of claim 3, further comprising a first valve disposed within the flow passage and configured to adjust an amount of flow from the second exhaust manifold to the exhaust passage, between the first ECD and the second ECD.

5. The system of claim 4, further comprising a second valve disposed in a bypass passage arranged around the turbocharger turbine.

6. The system of claim 5, wherein when the first valve is in an open position, where gases flow from the second exhaust manifold to the exhaust passage, the second valve is in an at least partially closed position where gas flow through the bypass passage is at least partially blocked.

7. The system of claim 5, wherein when the first valve is in an open position, where gases flow from the second exhaust manifold to the exhaust passage and through only the second ECD, the second valve is in a closed position, where gases flow from the first exhaust manifold to the exhaust passage, and through both the first and second ECDs, and not through the bypass passage.

8. The system of claim 3, further comprising an exhaust gas recirculation (EGR) passage, a first end of the EGR passage directly coupled to the intake passage, upstream of a turbocharger compressor, and a second end of the EGR passage directly coupled to the second exhaust manifold.

9. The system of claim 1, further comprising a plurality of engine cylinders, where each engine cylinder of the plurality of engine cylinders includes one of the first set of exhaust valves and one of the second set of exhaust valves.

10. The system of claim 1, wherein the first ECD is a first catalyst and the second ECD is a second catalyst.

11. The system of claim 1, wherein the first ECD is a catalyst and the second ECD is a gasoline particulate filter.

12. A method for an engine, comprising:

while exhaust gases are flowing from a first set of cylinder exhaust valves to an exhaust passage, downstream of a turbocharger turbine, at least partially closing a wastegate valve disposed within a bypass passage disposed around the turbocharger turbine and flowing at least a portion of exhaust gases from a second set of cylinder exhaust valves through the turbocharger turbine; and

flowing the portion of exhaust gases from an outlet of the turbocharger turbine to an emission control device disposed in the exhaust passage, upstream of where the exhaust gases from the first set of cylinder exhaust valves enter the exhaust passage.

13. The method of claim 12, further comprising fully closing the wastegate valve and maintaining the wastegate valve fully closed, even as engine speed and load increase.

14. The method of claim 12, further comprising operating the first set of cylinder exhaust valves at a different timing than the second set of cylinder exhaust valves.

15. The method of claim 12, further comprising flowing exhaust gases from the first set of cylinder exhaust valves to the exhaust passage, downstream of the turbocharger turbine, via opening a valve disposed in a flow passage coupled between a first exhaust manifold exclusively coupled to the first set of cylinder exhaust valves and the exhaust passage, downstream of the turbocharger turbine.

16. The method of claim 15, further comprising flowing a first portion of exhaust gases from the first set of cylinder exhaust valves to the exhaust passage via the flow passage and flowing a remaining, second portion of exhaust gases from the first set of cylinder exhaust valves to an intake passage, upstream of a turbocharger compressor.

17. A method for an engine, comprising:

flowing exhaust gas from a first set of exhaust valves to a turbocharger turbine, an upstream, first catalyst, and a downstream, second catalyst disposed in an exhaust passage;

flowing a first portion of exhaust gas from a second set of exhaust valves to only the second catalyst and not the first catalyst; and

opening the second set of exhaust valves at a different timing in an engine cycle than the first set of exhaust valves.

18. The method of claim 17, further comprising flowing a remaining, second portion of exhaust gas from the second set of exhaust valves to an intake passage.

19. The method of claim 17, wherein flowing exhaust gas from the first set of exhaust valves to the turbocharger turbine, first catalyst, and second catalyst includes flowing the first portion of exhaust gas from the first set of exhaust valves through the turbocharger turbine, first catalyst, and second catalyst and a second portion of exhaust gas from the first set of exhaust valves around the turbocharger turbine and to the first catalyst and second catalyst.

20. The method of claim 17, wherein flowing exhaust gas from the first set of exhaust valves to the turbocharger turbine, first catalyst, and second catalyst includes maintaining a wastegate, arranged in a bypass passage around the turbocharger turbine, in a closed position, even as engine speed increases and decreases.