System and method for reducing engine knock

Patent metadata

Field	Value
Publication number	US-11598277-B2
Application number	US-202117347885-A
Country	US
Kind code	B2
Filing date	Jun 15, 2021
Priority date	Jul 31, 2012
Publication date	Mar 7, 2023
Grant date	Mar 7, 2023

Abstract

A method includes operating a spark ignition engine and flowing low pressure exhaust gas recirculation (EGR) from an exhaust to an inlet of the spark ignition engine. The method includes interpreting a parameter affecting an operation of the spark ignition engine, and determining a knock index value in response to the parameter. The method further includes reducing a likelihood of engine knock in response to the knock index value exceeding a knock threshold value.

First claim

What is claimed is:

1. A method, comprising:
interpreting a parameter affecting an operation of an internal combustion engine receiving a compressed intake air flow;
determining a knock index value in response to the parameter, wherein the knock index value is an incremental indicator of a risk of engine knock occurring during a combustion event; and
reducing an intake manifold temperature to reduce a likelihood of the engine knock occurring during the combustion event in response to the knock index value exceeding a knock threshold value.

2. The method of claim 1 , wherein the reducing the intake manifold temperature comprises reducing an exhaust gas recirculation (EGR) gas temperature.

3. The method of claim 2 , wherein the reducing the EGR gas temperature comprises operating a low temperature EGR cooler.

4. The method of claim 1 , further comprising reducing an engine exhaust backpressure in response to the knock index value exceeding the knock threshold value.

5. The method of claim 4 , wherein the reducing the engine exhaust backpressure comprises at least one operation selected from the operations consisting of reducing an EGR flowing pressure, adjusting an EGR flow route, adjusting a variable geometry turbine position, and adjusting an exhaust throttle position.

6. The method of claim 1 , further comprising adjusting a variable valve timing system in response to the knock index value exceeding the knock threshold value.

7. The method of claim 1 , further comprising fueling the engine at least partially by direct injection in response to the knock index value exceeding the knock threshold value.

8. The method of claim 1 , wherein the reducing an intake manifold temperature comprises operating a charge air cooler bypass.

9. The method of claim 1 , wherein reducing the intake manifold temperature comprises reducing a temperature of an exhaust gas recirculating to an intake system of the internal combustion engine.

10. The method of claim 9 , wherein reducing the temperature comprises selectively coupling one of a high temperature coolant and a low temperature coolant to an exhaust gas recirculation cooler that cools the exhaust gas recirculating to the intake system.

11. The method of claim 1 , further comprising recirculating an exhaust gas from a low pressure exhaust gas recirculation system of the internal combustion engine.

12. The method of claim 11 , wherein low pressure exhaust recirculation system is connected at an intermediate position of a three-way catalyst in an exhaust system of the internal combustion engine.

13. A method, comprising:
interpreting a parameter affecting an operation of an internal combustion engine that receives a compressed intake air flow and a recirculated exhaust gas flow;
determining a knock index value in response to the parameter, wherein the knock index value is an incremental indicator of a risk of engine knock occurring during a combustion event; and
reducing an intake manifold temperature to reduce a likelihood of the engine knock occurring during the combustion event in response to the knock index value exceeding a knock threshold value, wherein reducing the intake manifold temperature includes adjusting a temperature of the recirculated exhaust gas flow by providing a selected amount of high temperature coolant and a selected amount of low temperature coolant to a cooler that cools the recirculated exhaust gas flow.

14. The method of claim 13 , wherein the recirculated exhaust gas flow is fluidly coupled to an intake system of the internal combustion engine at a position upstream of the compressed intake air flow.

15. The method of claim 14 , wherein the recirculated exhaust gas flow is fluidly coupled to an engine exhaust flow at a position downstream of a turbine disposed in the engine exhaust flow.

16. The method of claim 14 , wherein the recirculated exhaust gas flow is fluidly coupled to the engine exhaust flow at a position downstream of a particulate filter disposed in the engine exhaust flow.

17. The method of claim 14 , wherein the recirculated exhaust gas flow is fluidly coupled to the engine exhaust flow at a position intermediate of an aftertreatment component disposed in the engine exhaust flow.

18. The method of claim 17 , wherein the aftertreatment component is a three-way catalyst.

Assignees

• Cummins Inc

Inventors

• Dane Marten H
• Kolhouse J Steven
• Yonushonis Thomas M
• Wills J Stephen
• Geckler Samuel C

Classifications

• F02B29/0425

  Air cooled heat exchangers · CPC title

• F02B29/0418

  the intake air cooler having a bypass or multiple flow paths within the heat exchanger to vary the effective heat transfer surface · CPC title

• F02M26/28

  with liquid-cooled heat exchangers · CPC title

• F02D9/04

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

• F02M26/15

  in relation to engine exhaust purifying apparatus · CPC title