Internal combustion engine system and a method of operating an internal combustion system

Patent metadata

Field	Value
Publication number	US-11698010-B2
Application number	US-202017601071-A
Country	US
Kind code	B2
Filing date	Mar 27, 2020
Priority date	Apr 4, 2019
Publication date	Jul 11, 2023
Grant date	Jul 11, 2023

Abstract

Provided are a method and an ICE system, including an internal combustion engine including a first and a second set of cylinders. A first and a second EGR valve control flow of exhaust gas from the cylinders to an EGR conduit. A controller controls the closing of the second EGR valve, thereby preventing flow of exhaust gas from the second set of cylinders to the EGR conduit. The second EGR valve is upstream of a turbine. The controller is configured to activate a fuel injector for late post injection of fuel into the second set of cylinders when the second EGR valve is closed, so that at least a part of the fuel that exits the second set of cylinders is uncombusted. An exhaust gas aftertreatment system receives and treats exhaust gas which is not recirculated in the EGR conduit, and includes an oxidation catalyst for combustion.

First claim

The invention claimed is:

1. An internal combustion engine system, comprising:
an internal combustion engine comprising a first set of one or more cylinders and a second set of one or more cylinders which is separate from the first set,
an exhaust gas recirculation (EGR) conduit for recirculating exhaust gas from the first and second sets of cylinders to an inlet of the internal combustion engine,
an EGR cooler provided in the EGR conduit,
a first EGR valve for controlling flow of exhaust gas from the first set of cylinders to the EGR conduit, the first EGR valve fluidly connected to the EGR conduit downstream of the EGR cooler
a fuel injector for injection of fuel into at least one cylinder of the second set of cylinders,
a second EGR valve for controlling flow of exhaust gas from the second set of cylinders to the EGR conduit,
a controller configured to control the closing of the second EGR valve, thereby preventing flow of exhaust gas from the second set of cylinders to the EGR conduit, and configured to activate the fuel injector for late post injection of fuel into at least one cylinder of the second set of cylinders when the second EGR valve is closed, so that at least a part of the fuel that exits the second set of cylinders is uncombusted,
a turbine arranged to receive and be driven by exhaust gas which is not recirculated in the EGR conduit, and
an exhaust gas aftertreatment system arranged to receive and treat exhaust gas which is not recirculated in the EGR conduit, the exhaust gas aftertreatment system comprising an oxidation catalyst for combustion of the late post injected fuel or derivates thereof,
wherein, for the exhaust gas flowing from the second set of cylinders, the second EGR valve is located upstream of the turbine, and
wherein the second EGR valve additionally configured to control flow of exhaust gas from the first set of cylinders to the EGR conduit.

2. The internal combustion engine system according to claim 1 , wherein the controller is configured to determine a desired EGR flow and to control the opening of the first EGR valve so that the desired EGR flow is recirculated from the first set of cylinders to the inlet of the internal combustion engine.

3. The internal combustion engine system according to claim 1 , wherein the flow of recirculated exhaust gas delivered from the EGR conduit to said inlet continues to flow from said inlet to both the first and second sets of cylinders.

4. The internal combustion engine system according to claim 1 , wherein the controller is configured to control the first and second EGR valves so that a desired ratio of recirculated flow of exhaust gas to the EGR conduit relative to the amount of air entering the inlet of the internal combustion engine is obtained.

5. The internal combustion engine system according to claim 1 , wherein when the second EGR valve is closed all exhaust gas from the second set of cylinders flows to the exhaust gas aftertreatment system.

6. The internal combustion engine system according to claim 1 , wherein the oxidation catalyst is an electrically heated oxidation catalyst.

7. The internal combustion engine system according to claim 6 , wherein the controller is configured to heat the oxidation catalyst to the light-off temperature for hydrocarbons present in the injected fuel.

8. The internal combustion engine system according to claim 1 , comprising an exhaust throttle, wherein
the exhaust throttle is provided downstream of the turbine, or
the exhaust throttle is provided in an exhaust conduit downstream of the first and second EGR valves and upstream of the turbine,
wherein the controller is configured to control the exhaust throttle for further controlling the flow to the EGR conduit.

9. The internal combustion engine system according to claim 1 , comprising a compressor or pump fluidly connected to the EGR conduit, wherein the controller is configured to control the compressor or pump for controlling the flow in the EGR conduit.

10. A vehicle comprising an internal combustion engine system according to claim 1 .

11. A method of operating an internal combustion engine system which comprises:
an internal combustion engine comprising a first set of one or more cylinders and a second set of one or more cylinders which is separate from the first set,
an exhaust gas recirculation (EGR) conduit for recirculating exhaust gas from the first and second sets of cylinders to an inlet of the internal combustion engine,
an EGR cooler provided in the EGR conduit,
a first EGR valve for controlling flow of exhaust gas from the first set of cylinders to the EGR conduit, the first EGR valve fluidly connected to the EGR conduit downstream of the EGR cooler,
a second EGR valve for controlling flow of exhaust gas from the second set of cylinders to the EGR conduit,
a fuel injector for injection of fuel into at least one cylinder of the second set of cylinders,
a turbine arranged to receive and be driven by exhaust gas which is not recirculated in the EGR conduit, and
an exhaust gas aftertreatment system arranged to receive and treat exhaust gas which is not recirculated in the EGR conduit, the exhaust gas aftertreatment system comprising an oxidation catalyst for combustion of fuel and/or fuel derivates,
wherein, for the exhaust gas flowing from the second set of cylinders, the second EGR valve is located upstream of the turbine, and
wherein the second EGR valve additionally configured to control flow of exhaust gas from the first set of cylinders to the EGR conduit,
the method comprising :
closing the second EGR valve, thereby preventing flow of exhaust gas from the second set of cylinders to the EGR conduit without preventing flow of exhaust gas to the exhaust gas aftertreatment system, and
activating the fuel injector for late post injection of fuel into at least one cylinder of the second set of cylinders when the second EGR valve is closed, so that at least a part of the fuel that exits the second set of cylinders is uncombusted.

12. The method according to claim 11 , further comprising the:
determining a desired EGR flow, and
controlling the opening of the first EGR valve so that the desired EGR flow is recirculated from the first set of cylinders to the inlet of the internal combustion engine.

13. The method according to claim 11 , wherein the exhaust gas aftertreatment system comprises an electrically heated oxidation catalyst, wherein the method further comprises :
electrically heating the oxidation catalyst to the light-off temperature for hydrocarbons present in the injected fuel.

14. The method according to claim 11 , wherein the internal combustion engine system comprises an exhaust throttle provided downstream of the turbine, the method further comprises :
controlling the exhaust throttle for further controlling the flow to the EGR conduit.

15. The method according to claim 11 , wherein the internal combustion engine system comprises an exhaust throttle provided in an exhaust conduit downstream of the first and second EGR valves and upstream of the turbine, the method further comprising :
controlling the exhaust throttle for balancing the flow to the turbine, and/or
controlling the exhaust throttle for further controlling the flow to the EGR conduit.

16. The method according to claim 11 , wherein the internal combustion engine system comprises a compressor or pump fluidly connected to the EGR conduit, the method further comprising :
controlling the compressor or pump for controlling the flow in the EGR conduit.

17. A computer program comprising pro

Assignees

• Volvo Truck Corp

Inventors

• Ehleskog Malin
• Andersson Lennart

Classifications

• F02D41/0082

  per groups or banks (F02D41/0087 takes precedence) · CPC title

• F02D9/04

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

• F02D41/0055

  Special engine operating conditions, e.g. for regeneration of exhaust gas treatment apparatus · CPC title

• F02M26/16

  with EGR valves located at or near the connection to the exhaust system · CPC title

• F02M26/42

  having two or more EGR passages; EGR systems specially adapted for engines having two or more cylinders · CPC title