SYSTEMS AND METHODS FOR A SPLIT EXHAUST ENGINE SYSTEM

• US 20180171886A1
• Filed: 12/16/2016
• Published: 06/21/2018
• 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, Leiby, James
• Granted Patent: US 10,145,315 B2
• Time in Patent Office: Days
• CPC Class Codes: F01N 13/107 More than one exhaust manifold or exhaust collector
• CPC Class Codes: F01N 2410/00 By-passing, at least partially, exhaust from inlet to outlet of apparatus, to atmosphere or to other device
• 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: F02B 25/145 with intake and exhaust valves exclusively in the cylinder head
• CPC Class Codes: F02B 37/00 Engines characterised by provision of pumps driven at least for part of the time by exhaust
• CPC Class Codes: F02B 39/10 electric
• CPC Class Codes: F02D 13/0215 changing the valve timing only
• CPC Class Codes: F02D 13/0234 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 13/0276 Actuation of an additional valve for a special application, e.g. for decompression, exhaust gas recirculation or cylinder scavenging
• CPC Class Codes: F02D 2041/001 for engines with variable valve actuation
• CPC Class Codes: F02D 2200/0414 Air temperature
• CPC Class Codes: F02D 2200/0418 Air humidity
• CPC Class Codes: F02D 23/00 Controlling engines characterised by their being supercharged
• CPC Class Codes: F02D 41/0007 for control of turbo-charged or super-charged engines control of the pumps per se F02B37/12
• CPC Class Codes: F02D 41/005 according to engine operating conditions
• 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: F02D 41/123 the fuel injection being cut-off
• CPC Class Codes: F02D 41/14 : Introducing closed-loop corrections
• CPC Class Codes: F02D 41/26 : using computer, e.g. microprocessor
• 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 26/06 : Low pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust downstream of the turbocharger turbine and reintroduced into the intake system upstream of the compressor
• CPC Class Codes: F02M 26/07 : Mixed pressure loops, i.e. wherein recirculated exhaust gas is either taken out upstream of the turbine and reintroduced upstream of the compressor, or is taken out downstream of the turbine and reintroduced downstream of the compressor
• CPC Class Codes: F02M 26/09 : Constructional details, e.g. structural combinations of EGR systems and supercharger systems; Arrangement of the EGR and supercharger systems with respect to the engine
• CPC Class Codes: F02M 26/14 : in relation to the exhaust system
• CPC Class Codes: F02M 26/15 : in relation to engine exhaust purifying apparatus
• CPC Class Codes: F02M 26/17 : in relation to the intake system
• CPC Class Codes: F02M 26/23 : Layout, e.g. schematics
• CPC Class Codes: F02M 26/38 : with two or more EGR valves disposed in parallel
• CPC Class Codes: F02M 26/41 : characterised by the arrangement of the recirculation passage in relation to the engine, e.g. to cylinder heads, liners, spark plugs or manifolds; characterised by the arrangement of the recirculation passage in relation to specially adapted combustion chambers
• CPC Class Codes: F02M 26/42 : having two or more EGR passages; EGR systems specially adapted for engines having two or more cylinders
• CPC Class Codes: F02M 26/53 : using electric actuators, e.g. solenoids
• 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, an intake valve timing, exhaust valve timing of a first set of exhaust valves coupled to the first exhaust manifold, and a position of an exhaust gas recirculation (EGR) valve in an EGR passage may be adjusted in coordination with one another in response to a condition at a compressor. The EGR passage may be coupled between the intake passage, upstream of the compressor, and the first exhaust manifold.

Claims

1. A method, comprising:

adjusting, in coordination, an intake valve timing, exhaust valve timing of a first set of exhaust valves, and a position of an exhaust gas recirculation (EGR) valve in an EGR passage in response to a condition at a compressor, where the EGR passage is coupled between an intake passage, upstream of the compressor, and a first exhaust manifold coupled to the first set of exhaust valves.

2. The method of claim 1, wherein adjusting in coordination includes first adjusting the exhaust valve timing and then adjusting one of the intake valve timing or the position of the EGR valve in response to the exhaust valve timing reaching a maximum amount of adjustment and based on the condition at the compressor and a current intake valve timing.

3. The method of claim 2, wherein the condition at the compressor includes one or more of condensate forming at the compressor and an inlet temperature of the compressor being below a threshold inlet temperature, where the threshold inlet temperature is based on a temperature at which condensate forms at the compressor.

4. The method of claim 1, wherein adjusting in coordination includes modulating the position of the EGR valve, and during the modulating, adjusting each of the intake valve timing and the exhaust valve timing based on the condition at the compressor.

5. The method of claim 4, wherein the condition at the compressor includes a compressor outlet temperature greater than a threshold outlet temperature.

6. The method of claim 1, further comprising opening the first set of exhaust valves at a different timing than a second set of exhaust valves coupled to a second exhaust manifold, the second exhaust manifold coupled to an exhaust passage including a turbine.

7. The method of claim 1, wherein the condition at the compressor includes an inlet temperature of the compressor below a threshold inlet temperature, where the threshold inlet temperature is based on a temperature at which condensate forms at the compressor, and wherein the adjusting includes retarding the exhaust valve timing.

8. The method of claim 7, further comprising, in response to the exhaust valve timing reaching a maximum amount of retard while the inlet temperature of the compressor is below the threshold inlet temperature, first advancing the intake valve timing and, if the intake valve timing is fully advanced, closing the EGR valve.

9. The method of claim 8, further comprising opening a bypass valve disposed in a bypass passage coupled between the first exhaust manifold and an exhaust passage, where the exhaust passage is coupled to a second exhaust manifold coupled to a second set of exhaust valves.

10. The method of claim 1, wherein the condition at the compressor includes an outlet temperature of the compressor being greater than a threshold outlet temperature and wherein the adjusting includes modulating a position of the EGR valve to reduce flow through the EGR passage to a first level, advancing the intake valve timing, and retarding the exhaust valve timing to further decrease the flow through the EGR passage to a lower, second level.

11. The method of claim 10, further comprising increasing cold recirculation via opening the EGR valve.

12. The method of claim 10, further comprising opening a bypass valve disposed in a bypass passage coupled between the first exhaust manifold and an exhaust passage, where the exhaust passage is coupled to a second exhaust manifold coupled to a second set of exhaust valves, and adjusting the opening of the bypass valve based on the modulating of the EGR valve.

13. The method of claim 1, wherein adjusting the exhaust valve timing includes actuating a cam to adjust a timing of the first set of exhaust valves and a second set of exhaust valves together, where an opening timing of the first set of exhaust valves is different than the second set of exhaust valves, and where the second set of exhaust valves are coupled to a second exhaust manifold, the second exhaust manifold coupled to an exhaust passage including a turbine.

14. The method of claim 1, further comprising, in response to a temperature and speed of the compressor operating between set upper and lower thresholds, adjusting the intake valve timing, exhaust valve timing, and the position of the EGR valve based on fuel economy thresholds and a demanded torque level.

15. A method, comprising:

during a first condition, adjusting each of an exhaust valve timing of a first set of exhaust valves, an intake valve timing, and a position of an exhaust gas recirculation (EGR) valve disposed in an EGR passage based on a demanded torque level and a timing for best fuel economy, where the EGR passage is coupled between an intake passage, upstream of a compressor, and a first exhaust manifold coupled to the first set of exhaust valves; and

during a second condition, adjusting each of the exhaust valve timing, intake valve timing, and position of the EGR valve based on a condition at the compressor and not based on the demanded torque level and fuel economy setting.

16. The method of claim 15, further comprising opening the first set of exhaust valves at a different timing than a second set of exhaust valves coupled to a second exhaust manifold, the second exhaust manifold coupled to an exhaust passage including a turbine.

17. The method of claim 15, wherein the second condition includes one or more of when an inlet temperature of the compressor is below a lower threshold temperature, condensate is detected at the compressor, an outlet temperature of the compressor is greater than an upper threshold temperature, and a speed of the compressor is above a threshold speed and wherein the first condition includes when the inlet temperature of the compressor is above the lower threshold temperature, condensate is not detected at the compressor, the outlet temperature of the compressor is less than the upper threshold temperature, and the speed of the compressor is below threshold speed.

18. The method of claim 15, wherein adjusting each of the exhaust valve timing, intake valve timing, and position of the EGR valve during the second condition includes modulating the position of the EGR valve to reduce EGR flow through the EGR passage, advancing the intake valve timing, and retarding the exhaust valve timing to further decrease the EGR flow.

19. A system for an engine, comprising:

a first exhaust manifold coupled to a first set of cylinder exhaust valves and an intake passage, upstream of a compressor, via an exhaust gas recirculation (EGR) passage including an EGR valve;

a second exhaust manifold coupled to a second set of cylinder exhaust valves and an exhaust passage including a turbine;

a plurality of cylinder intake valves; and

a controller including memory with computer-readable instructions for;

adjusting each of a timing of the first set of cylinder exhaust valves, a timing of the plurality of cylinder intake valves, and a position of the EGR valve in response to a condition of the compressor reaching an operational threshold and wherein an amount and order of adjustment is based on the operational threshold.

20. The system of claim 19, wherein the condition of the compressor reaching the operational threshold includes one or more of condensate forming at the compressor, an inlet temperature of the compressor decreasing below a lower threshold temperature, and an outlet temperature of the compressor increasing above an upper threshold temperature.