Fuel management system for very high efficiency flex fuel engines powered by methanol and gasoline

• US 8,677,949 B2
• Filed: 12/28/2009
• Issued: 03/25/2014
• Est. Priority Date: 11/12/2007
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Bromberg, Leslie, Cohn, Daniel R.
• Primary Examiner(s): Nguyen, Hung Q
• Application Number:
  US12/648,082
• Publication Number:
  US 20100174470A1
• Time in Patent Office: 1,548 Days
• Field of Search: 123/1.A, 123/299, 123/304, 123/198.A, 123/525, 123/527, 123/528, 123/564, 123/568.11
• US Class Current: 123/3
• CPC Class Codes: F02B 1/12 with compression ignition with fuel-air charge ignited by compression ignition of an additional fuel F02B7/00
• CPC Class Codes: F02B 17/00 Engines characterised by means for effecting stratification of charge in cylinders
• CPC Class Codes: F02D 13/0257 Independent control of two or more intake or exhaust valves respectively, i.e. one of two intake valves remains closed or is opened partially while the other is fully opened
• CPC Class Codes: F02D 19/0644 the gaseous fuel being hydrogen, ammonia or carbon monoxide
• CPC Class Codes: F02D 19/0655 at least one fuel being an alcohol, e.g. ethanol F02D19/084 takes precedence
• CPC Class Codes: F02D 19/0665 Tanks, e.g. multiple tanks
• CPC Class Codes: F02D 19/0671 Means to generate or modify a fuel, e.g. reformers, electrolytic cells or membranes
• CPC Class Codes: F02D 19/0689 for in-cylinder direct injection
• CPC Class Codes: F02D 19/081 Adjusting the fuel composition or mixing ratio; Transitioning from one fuel to the other
• CPC Class Codes: F02M 25/10 adding acetylene, non-waterborne hydrogen, non-airborne oxygen, or ozone
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

Turbocharged or supercharged spark ignition engine. The engine includes a source of methanol for direct injection of methanol into the engine and for delivering a portion of the methanol to a reformer for generating a hydrogen-rich gas.

Claims

1. A fuel management engine system for a turbo-charged or supercharged spark engine comprising:

an engine;

a source of alcohol;

manifold structure for direct injection of the alcohol into the engine;

a reformer;

valve structure for delivering a portion of the alcohol to the reformer for generating a hydrogen-rich gas at lower engine torque values wherein the hydrogen-rich gas is introduced into the engine to extend limit of lean operation; and

a fuel management control unit operating the engine at a substantially stoichiometric fuel/air ratio during part of a drive cycle and at a lean fuel/air ratio during other parts of the drive cycle.

2. The engine system of claim 1 where at some time in the drive cycle the fuel management control unit establishes an equivalence ratio less than or equal to 0.5.

3. The engine system of claim 1 where at some time in the drive cycle the fuel management control unit controls the reformer to reform more than 30% of the alcohol into the hydrogen-rich gas.

4. The engine system of claim 1 where the reformer uses pyrolytic reforming using heat from exhaust.

5. The engine system of claim 1 including manifold structure for introducing hot reformate into the engine.

6. The engine system of claim 5 where a temperature of the reformate that is introduced into the engine is between 300°

and 700°

C.

7. The engine system of claim 5 where the hot reformate is only used below a certain level of torque.

8. The engine system of claim 1 where the reformer is a hybrid plasmatron/thermal reformer used during cold start.

9. The engine system of claim 8 where plasma heating in the fuel reformer is reduced or eliminated during only part of reformer operating time.

10. The engine system of claim 1 where the reformer uses pyrolytic reforming.

11. The engine system of claim 1 wherein the reformer is controlled by the fuel management unit to provide the hydrogen-rich gas to assist in engine cold start.

12. The engine system of claim 1 where the compression ratio of the engine is at least 11.

13. The engine system of claim 1 where a three-way catalytic converter is used.

14. The engine system of claim 1 where the engine is fueled with the hydrogen-rich gas using port fuel injection.

15. A fuel management engine system for a turbo-charged or supercharged spark ignition engine comprising:

an engine;

a source of ethanol;

manifold structure for direct injection of the ethanol into the engine;

a reformer;

valve structure for delivering a portion of the ethanol to the reformer for generating a hydrogen-rich gas at lower engine torque values wherein the hydrogen-rich gas is introduced into the engine to extend limit of lean operations; and

a fuel management control unit operating the engine at a substantially stoichiometric fuel/air ratio during part of a drive cycle and at a lean fuel/air ratio during other parts of the drive cycle.

16. The engine system of claim 15, where at some time in the drive cycle the fuel management control unit establishes an equivalence ratio less than or equal to 0.5.

17. The engine system of claim 15 where at some time in the drive cycle the fuel management control unit controls the reformer to reform more than 30% of the ethanol into the hydrogen-rich gas.

18. The engine system of claim 15 where the reformer uses pyrolytic reforming using heat from the exhaust.

19. The engine system of claim 15, including means for introducing hot reformate into the engine.

20. The engine system of claim 19, where a temperature of the reformate that is introduced into the engine is between 300 and 700°

C.

21. The engine system of claim 19, wherein the hot reformate is only used below a certain level of torque.

22. The engine system of claim 15, where the reformer is a hybrid plasmatron/thermal reformer used during cold start.

23. The engine system of claim 22, wherein the plasma heating in the fuel reformer is reduced or eliminated during only part of a reformer operating time.

24. The engine system of claim 15 where the reformer uses pyrolytic reforming.

25. The engine system of claim 15 wherein the compression ratio is at least 11.

26. The engine system of claim 15 where a three-way catalytic converter is used.

27. The engine system of claim 15 wherein the engine is fueled with the hydrogen-rich gas using port fuel injection.