Fuel management system for variable ethanol octane enhancement of gasoline engines

Patent metadata

Field	Value
Publication number	US-9255519-B2
Application number	US-201414478069-A
Country	US
Kind code	B2
Filing date	Sep 5, 2014
Priority date	Nov 18, 2004
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

Fuel management system for efficient operation of a spark ignition gasoline engine. Injectors inject an anti-knock agent such as ethanol directly into a cylinder of the engine. A fuel management microprocessor system controls injection of the anti-knock agent so as to control knock and minimize that amount of the anti-knock agent that is used in a drive cycle. It is preferred that the anti-knock agent is ethanol. The use of ethanol can be further minimized by injection in a non-uniform manner within a cylinder. The ethanol injection suppresses knock so that higher compression ratio and/or engine downsizing from increased turbocharging or supercharging can be used to increase the efficiency or the engine.

First claim

The invention claimed is:

1. A fuel management system for a turbocharged or supercharged spark ignition engine where the fuel management system controls fueling from a first fueling system that directly injects fuel into at least one cylinder as a liquid and increases knock suppression by vaporization cooling and from a second fueling system that injects fuel into a region outside of the cylinder;
and where there is a range of torque where both fueling systems are used at the same value of torque;
and where the fraction of fuel in the cylinder that is introduced by the first fueling system decreases with decreasing torque and the fuel management system controls the change in the fraction of fuel introduced by the first fueling system using closed loop control that utilizes a sensor that detects knock;
and where the fuel management system also employs spark retard so as to reduce the amount of fuel that is introduced into the cylinder by the first fueling system.

2. The fuel management system of claim 1 where the spark retard is employed to as to reduce the amount of fuel that is provided by the first fueling system to zero.

3. The fuel management system of claim 1 where when the torque is increased the increase in the fraction of fuel that is introduced by the first fueling system is minimized while still preventing knock.

4. The fuel management system of claim 1 where without employing the spark retard there is a range of torque in which only the second fueling system is used.

5. The fuel management system of claim 1 where the fuel management system employs the spark retard in response to sensed information and both the sensed information and information about knock are used to control the fuel that is introduced by the first fueling system.

6. The fuel management system of claim 1 where the maximum torque that the engine provides occurs when both the first and second fueling systems are used at the same value of torque.

7. The fuel management system of claim 1 where the only the first fueling system is used at the maximum torque that the engine provides.

8. The fuel management system of claim 1 where only the first fueling system is used when the highest knock resistance is required.

9. The fuel management system of claim 1 where both the first and second fueling system are used when the highest knock resistance is required.

10. The fuel management system of claim 1 where as the torque is increased the increase in the fraction of fuel in the cylinder that is provided by the first fueling system is substantially equal to that needed to prevent knock.

11. The fuel management system of claims 1 or 3 where the fuel management system minimizes the increase in the fraction of fuel in the cylinder that is provided by the first fueling system as torque is increased.

12. The fuel management system of claim 1 where the second fueling system uses port fuel injection.

13. A fuel management system for a spark ignition engine that controls fueling from a first fueling system that directly injects fuel into at least one cylinder as a liquid and increases knock suppression by vaporization cooling and from a second fueling system that provides fuel to the cylinder using port fuel injection;
and where the fuel management system uses information from a sensed parameter to control spark retard so as to decrease the amount of fuel that would otherwise be provided by the first fueling system;
and where the fuel management system uses input that includes input from the sensed parameter and input from knock sensor.

14. The fuel management system of claim 13 where input from the knock sensor is utilized in a closed loop control system that controls the fraction of fuel that is introduced into the first fueling system.

15. The fuel management system of claim 13 where both the first and second fueling systems are used at the same value of torque.

16. The fuel management system of claim 13 where spark retard is employed so as to reduce the use of the first fueling system to zero.

17. The fuel management system of claim 13 where the engine is turbocharged or supercharged and the level of turbocharging or supercharging is reduced so as to decrease the amount of fuel from the first fueling system.

18. The fuel management system of claim 13 where closed loop control with a knock detector is used to increase the relative amount of fuel from the first fueling system as torque is increased.

19. A fuel management system for a turbocharged or supercharged spark ignition engine where the fuel management system controls fueling from a first fueling system that directly injects fuel into at least one cylinder as a liquid and increases knock suppression by vaporization cooling and from a second fueling system that introduces fuel into the cylinder by port fuel injection;
and where during a driving cycle there is a first torque range where both fueling systems are used at the same torque and where the fraction of fuel in the cylinder that is introduced by the first fueling system is increased so as to prevent knock as torque increases;
and where the fuel management system matches the fraction of fuel that is provided by first fueling system with the amount needed to prevent knock at a given value of torque; and

where the fuel management system uses closed loop control that employs a knock detector.

20. The fuel management system of claim 19 where there is a second torque range where only the second fueling system is used and the highest value of torque in the second torque range is lower than at least one value of torque in the first torque range.

21. The fuel management system of claim 19 where the fuel management system minimizes the amount of fuel from the first fueling system while still preventing knock.

22. The fuel management system of claim 19 where the maximum knock resistance required by the engine is in the first torque range.

23. The fuel management system of claim 19 where for the maximum knock resistance required by the engine only the first fueling system is used.

24. A fuel management system for a spark ignition engine that controls fueling from a first fueling system that introduces fuel into at least one cylinder as a liquid and increases knock resistance by vaporization cooling and from a second fueling system;
and where the knock resistance of fuel introduced by the first fueling system is greater than the knock resistance of fuel introduced by the second fueling system;
and where the fuel management system uses information from a sensed parameter to control spark retard so as to decrease the amount of fuel that would otherwise be provided by the first fueling system;
and where the fuel management system uses input that includes input from the sensed parameter and input from knock sensor.

25. The fuel management system of claim 24 where input from the knock sensor is utilized in a closed loop control system that controls the fraction of fuel that is introduced into the first fueling system.

26. The fuel management system of claim 24 where both the first and second fueling systems are used at the same value of torque.

27. The fuel management system of claim 24 where spark retard is employed so as to reduce the use of the first fueling system to zero.

28. The fuel management system of claim 24 where turbocharging or supercharging is used and the

Assignees

• Massachusetts Inst Technology

Inventors

• Cohn Daniel R
• Heywood John B
• Bromberg Leslie

Classifications

• F02B47/00

  Methods of operating engines involving adding non-fuel substances or anti-knock agents to combustion air, fuel, or fuel-air mixtures of engines · 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

• F02B7/00

  Engines characterised by the fuel-air charge being ignited by compression ignition of an additional fuel (characterised by both fuel-air mixture compression and air compression, or characterised by both positive ignition and compression ignition F02B11/00) · CPC title

• F02M25/00

  Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture (adding secondary air to fuel-air mixture F02M23/00; adding exhaust gases F02M26/00; fuel-injection apparatus operating simultaneously on two or more fuels or on a liquid fuel and another liquid F02M43/00) · CPC title

• F02P5/045

  combined with electronic control of other engine functions, e.g. fuel injection (in general F02D37/02) · CPC title