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

Patent metadata

Field	Value
Publication number	US-11053870-B2
Application number	US-202017024236-A
Country	US
Kind code	B2
Filing date	Sep 17, 2020
Priority date	Nov 18, 2004
Publication date	Jul 6, 2021
Grant date	Jul 6, 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 is higher at a highest value of torque in the first torque range than in a lowest value of torque in the first torque range,
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 the fuel management system is further configured to increase the fraction of fueling provided by the first fueling system in the first torque range as torque increases in at least a part of the first torque range,
wherein the spark ignition engine is configured to operate at a stoichiometric air/fuel ratio in at least part of the first torque range and in at least part of the second torque range,
wherein fuel introduced by the first fueling system has increased knock resistance due to vaporization cooling as compared to fuel introduced by the second fueling system, and
wherein the fuel management system is configured to use at least one of open loop control or a knock detector in conjunction with closed loop control when varying the fraction of fueling that is provided by the first fueling system as torque varies.

2. The fuel management system of claim 1 , wherein the first fueling system is configured to provide at a substantially stoichiometric air/fuel ratio or a stoichiometric air/fuel ratio at all values of torque in the first torque range.

3. The fuel management system of claim 1 , wherein the spark ignition engine is configured to provide a substantially stoichiometric air/fuel ratio or a stoichiometric air/fuel ratio at all values of torque in the second torque range.

4. The fuel management system of claim 1 , wherein the fuel management system is further configured such that the lowest value of torque in the first torque range is determined by open loop control.

5. The fuel management system of claim 1 , wherein the fuel management system is further configured such that the lowest value of torque in the first torque range is determined by closed loop control using a knock detector.

6. 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.

7. The fuel management system of claim 1 ,
wherein the fuel management system is further configured to increase the fraction of fueling provided by the first fueling system as torque increases in at least a part of the first torque range, and
wherein the fuel management system is further configured to minimize the fraction of fueling provided by the first fueling system.

8. The fuel management system of claim 1 ,
wherein the fuel management system is further configured to increase the fraction of fueling provided by the first fueling system as torque increases in at least a part of the first torque range,
wherein the fuel management system is further configured to minimize the fraction of fueling provided by the first fueling system, and
wherein as torque increases the fraction of fueling provided by the first fueling system is increased to be substantially equal to the fraction of fueling that is sufficient to prevent knock.

9. The fuel management system of claim 1 , wherein the fuel management system is configured such that the fraction of fueling provided by the first fueling system increases with torque in at least a part of the first torque range that begins with the lowest value of torque in the first torque range.

10. The fuel management system of claim 1 , where the first fueling system is configured to provide a uniform fuel distribution in at least one cylinder of the spark ignition engine.

11. The fuel management system of claim 1 ,
wherein the first fueling system is configured to introduce gasoline into the spark ignition engine and the second fueling system is configured to introduce gasoline into the spark ignition engine, and
wherein the gasoline introduced by the first fueling system has a higher knock resistance due to vaporization cooling than the gasoline introduced by the second fueling system.

12. The fuel management system of claim 1 , wherein the fuel management system is configured to use at least one of open loop control or a knock detector in conjunction with closed loop control to avoid undesired self ignition in end gas near a cylinder wall in at least one cylinder of the spark ignition engine.

13. 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 is higher at a highest value of torque in the first torque range than in a lowest value of torque in the first torque range,
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 fueling 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 the fuel management system is further configured to use spark retard to reduce the fraction of fueling provided by the first fueling system,
wherein the spark ignition engine is configured to operate at a stoichiometric air/fuel ratio in at least part of the first torque range and in at least part of the second torque range, and
wherein fuel introduced by the first fueling system has increased knock resistance due to vaporization cooling as compared to fuel introduced by the second fueling system.

14. The fuel management system of claim 13 , wherein the fuel management system is further configured to use a knock detector and spark retard to enable reduction of the fraction of fueling provided by the first fueling system.

15. The fuel management system of claim 13 , wherein the fuel m

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

• F02D41/047

  Taking into account fuel evaporation or wall wetting; (special correction after fuel cut-off F02D41/126) · CPC title

• F02D41/0025 Primary

  Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures · CPC title

• F02D19/0665

  Tanks, e.g. multiple tanks · CPC title

• F02D2200/0406

  Intake manifold pressure · CPC title