Optimized fuel management system for direct injection ethanol enhancement of gasoline engines

Patent metadata

Field	Value
Publication number	US-11067012-B2
Application number	US-202117147905-A
Country	US
Kind code	B2
Filing date	Jan 13, 2021
Priority date	Nov 18, 2004
Publication date	Jul 20, 2021
Grant date	Jul 20, 2021

Abstract

Fuel management system for enhanced operation of a spark ignition gasoline engine. Injectors inject an anti-knock agent such as ethanol directly into a cylinder. It is preferred that the direct injection occur after the inlet valve is closed. It is also preferred that stoichiometric operation with a three way catalyst be used to minimize emissions. In addition, it is also preferred that the anti-knock agents have a heat of vaporization per unit of combustion energy that is at least three times that of gasoline.

First claim

What is claimed is:

1. A fuel management system for a spark ignition engine, comprising:
a first fueling system that uses direct injection;
a second fueling system that uses port fuel injection; and
a three-way catalyst configured to reduce emissions from the spark ignition engine,
wherein the fuel management system is configured to provide fueling in a first torque range, the first torque range being a first range of torque values at which both the first fueling system and the second fueling system are operable throughout the first range of torque values,
wherein the fuel management system is further configured such that a fraction of fueling provided by the first fueling system increases with torque in at least a part of the first range of torque values,
wherein the first fueling system is configured to provide octane enhancement by evaporative cooling,
wherein the fuel management system is further configured such that both the first and second fueling systems are used at a maximum value of torque at which the spark ignition engine is operable at different speeds,
wherein the fuel management system is further configured to provide fueling in a second torque range, the second torque range being a second range of torque values at which the second fueling system is operable throughout the second range of torque values and the first fueling system is not operable throughout the second range of torque values,
wherein the fuel management system is further configured such that when the system provides fueling at a torque value that exceeds the second range of torque values, the spark ignition engine is operated in the first torque range, and
wherein the spark ignition engine is configured to operate at a stoichiometric or substantially stoichiometric air/fuel ratio in at least part of the first torque range and in at least part of the second torque range.

2. The fuel management system of claim 1 , wherein a highest value of torque in the first torque range is the value of torque at which a highest fraction of fueling from the first fueling system is employed.

3. The fuel management system of claim 2 , wherein the fuel management system is further configured such that stoichiometric operation or substantially stoichiometric operation is used throughout the first and second torque ranges.

4. The fuel management system of claim 1 , wherein the fuel management system is further configured to employ open loop control using predetermined information to increase a fraction of direct injection with increasing torque in at least part of the first torque range that begins with a lowest value of torque in the first torque range.

5. The fuel management system of claim 1 , wherein the fuel management system is further configured to employ open loop control using predetermined information to determine a lowest value of torque in the first torque range.

6. The fuel management system of claim 5 , wherein the predetermined information includes information about an occurrence of undesired autoignition in end gas in the spark ignition engine when direct injection is not employed.

7. The fuel management system of claim 1 , wherein each of:
(1) an open loop control of the fuel management system; and
(2) a closed loop control of the fuel management system, in conjunction with a knock detector are configured to be used at the same torque in at least part of the first torque range.

8. The fuel management system of claim 1 , wherein the second torque range extends from a zero value of torque to a highest value of torque in the second torque range.

9. The fuel management system of claim 1 , wherein at least one fuel injector in the first fueling system is configured to provide a uniform fuel distribution in at least one cylinder of the spark ignition engine at all values of torque in the first torque range.

10. The fuel management system of claim 1 , wherein the first fueling system is further configured to introduce gasoline into the spark ignition engine and the second fueling system is configured to introduce gasoline into the spark ignition engine.

11. The fuel management system of claim 1 , wherein the fuel management system is further configured to prevent undesired autoignition of end gas in at least one cylinder in the spark ignition engine.

12. A fuel management system for a spark ignition engine, comprising:
a first fueling system that uses direct injection;
a second fueling system that uses port fuel injection; and
a three-way catalyst configured to reduce emissions from the spark ignition engine,
wherein the fuel management system is configured to provide fueling in a first torque range of a drive cycle, the first torque range being a first range of torque values at which both the first fueling system and the second fueling system are operable throughout the first range of torque values,
wherein a maximum value of torque in the first torque range is a maximum value of torque at which the spark ignition engine is operable at different speeds,
wherein the fuel management system is further configured to provide fueling in a second torque range, the second torque range being a second range of torque values at which the second fueling system is operable throughout the second range of torque values and the first fueling system is not operable throughout the second range of torque values,
wherein the fuel management system is further configured such that when the system provides fueling at a torque value that exceeds the second range of torque values, the spark ignition engine is operated in the first torque range,
wherein during at least a part of the first torque range the fuel management system is further configured to use spark retard to enable an increase in an amount of fueling from the second fueling system, and
wherein the spark ignition engine is configured to operate at a stoichiometric or substantially stoichiometric air/fuel ratio in at least part of the first torque range and in at least part of the second torque range.

13. The fuel management system of claim 12 ,
wherein the first fueling system is configured to use open loop control, and
wherein the open loop control is configured to use predetermined information to increase a fraction of fueling from the first fueling system as torque increases in at least part of the first torque range.

14. The fuel management system of claim 12 , wherein the fuel management system is further configured to employ closed loop control in conjunction with a knock detector to initiate use of the first fueling system as torque increases so as to prevent undesired autoignition from end gas in at least one engine cylinder.

15. The fuel management system of claim 12 , wherein the second torque range extends from a zero value of torque to a highest value of torque in the second torque range.

16. The fuel management system of claim 12 , wherein at least one direct fuel injector from the first fueling system is configured to provide a uniform fuel distribution in at least one cylinder of the spark ignition engine throughout the first torque range.

17. The fuel management system of claim 12 ,
wherein the first fueling system is configured to use open loop control,
wherein the open loop control is configured to use predetermined information to select a lowest value of torque in the first torque range, and
wherein the predetermined information includes information about an occurrence of knock in an absence of use of the first fueling system.

18. The fuel management system of claim 12 , wherein the fuel management syste

Assignees

• Massachusetts Inst Technology

Inventors

• Bromberg Leslie
• Cohn Daniel R
• Heywood John B

Classifications

• Y02T10/30

  Use of alternative fuels, e.g. biofuels · CPC title

• F02D19/0665

  Tanks, e.g. multiple tanks · CPC title

• F02D41/3094

  the fuel injection being effected by at least two different injectors, e.g. one in the intake manifold and one in the cylinder · CPC title

• F02D19/0689

  for in-cylinder direct injection · CPC title

• F02D19/0655

  at least one fuel being an alcohol, e.g. ethanol (F02D19/084 takes precedence) · CPC title