Method of controlling a dual fuel engine

Patent metadata

Field	Value
Publication number	US-10018129-B2
Application number	US-201514876040-A
Country	US
Kind code	B2
Filing date	Oct 6, 2015
Priority date	Oct 28, 2014
Publication date	Jul 10, 2018
Grant date	Jul 10, 2018

Abstract

In a method of controlling a dual fuel engine in which power in the form of a first gaseous fuel and in the form of a self-igniting second fuel is fed to at least one combustion chamber, a knock signal representative of the combustion chamber is detected. When a knock signal indicating a knock of at least a first intensity is detected, the amount of first fuel fed to the combustion chamber of the engine is increased, the increased introduction of power into the combustion chamber caused by the increase in the amount of first fuel being compensated by a corresponding reduction in the power contribution of the second fuel. When a knock signal indicating a knock of at least a second intensity greater than the first intensity is detected, the amount of first fuel is reduced.

First claim

The invention claimed is:

1. A method of controlling a dual fuel engine in which power in form of a gaseous first fuel and in form of a self-igniting second fuel is fed to a combustion chamber of the dual fuel engine, the method comprising:
detecting a knock signal representative of the combustion chamber;
upon occurrence of a knock signal, indicating a knock of at least a first intensity, increasing an amount of the gaseous first fuel fed to the combustion chamber of the engine, and compensating for an increased introduction of power into the combustion chamber caused by the increase in the amount of the gaseous first fuel by providing a corresponding reduction in power contribution of the self-igniting second fuel; and
upon occurrence of a knock signal, indicating a knock of at least a second intensity, the second intensity being greater than the first intensity, reducing the amount of the gaseous first fuel fed to the combustion chamber.

2. The method as set forth in claim 1 , wherein the corresponding reduction in the power contribution of the self-igniting second fuel is effected by at least one of (i) reducing the amount of the self-igniting second fuel introduced to the combustion chamber, (ii) delaying a moment in time for introduction of the self-igniting second fuel, and (iii) changing an injection characteristic of the self-igniting second fuel.

3. The method as set forth in claim 2 , wherein the reduction in the power contribution of the self-igniting second fuel is effected at least in part by changing an injection characteristic of the self-igniting second fuel, the injection characteristic being changed so that a larger portion of an injected amount of the self-igniting second fuel is fed to the combustion chamber at a later moment in time within an injection event.

4. The method as set forth in claim 2 , wherein the reduction in the power contribution of the self-igniting second fuel is effected at least in part by changing an injection characteristic of the self-igniting second fuel, the injection characteristic being changed so that a commencement of injection occurs at a later moment in time within an injection event.

5. The method as set forth in claim 4 , wherein the commencement of injection occurs without a change in a shape of a profile of a mass flow of the injected second fuel over time.

6. The method as set forth in claim 1 , wherein the gaseous first fuel is admixed with air to produce a mixture, and temperature of the mixture of the air and the gaseous first fuel is reduced to increase the amount of the gaseous first fuel.

7. The method as set forth in claim 1 , wherein a charge pressure of the gaseous first fuel is increased to increase the amount of the gaseous first fuel.

8. The method as set forth in claim 1 , wherein the gaseous first fuel is admixed with air, and a ratio of the gaseous first fuel and the air is increased to increase the amount of the gaseous first fuel.

9. The method as set forth in claim 1 , wherein an extent of the increase in the amount of the gaseous first fuel is based on an intensity of the knock signal.

10. The method as set forth in claim 9 , wherein the extent of the increase in the amount of the gaseous first fuel is proportional to the intensity of the knock signal.

11. The method as set forth in claim 1 , wherein the self-igniting second fuel is injected in a plurality of intervals.

12. The method as set forth in claim 1 , wherein the self-igniting second fuel is a liquid.

13. A dual fuel engine comprising:
a combustion chamber to which power is supplied in a form of a gaseous first fuel and in a form of a self-igniting second fuel;
a control device for controlling the dual fuel engine, the control device being one of an open-loop control device or a closed-loop control device; and
a knock sensor arranged on the combustion chamber for providing a knock signal, representative of the combustion chamber, to the control device of the engine;
wherein the control device is configured to:
upon occurrence of a knock signal, indicating a knock of at least a first intensity, increase an amount of the gaseous first fuel fed to the combustion chamber of the engine, and compensate for the increased introduction of power into the combustion chamber caused by the increase in the amount of gaseous first fuel by providing a corresponding reduction in power contribution of the self-igniting second fuel, and
upon occurrence of a knock signal, indicating a knock of at least a second intensity, the second intensity being greater than the first intensity, reduce the amount of the gaseous first fuel fed to the combustion chamber.

14. The engine as set forth in claim 13 , wherein the self-igniting second fuel is a liquid.

Assignees

• Ge Jenbacher Gmbh & Co Og

Inventors

• Imhof Dino
• Schaumberger Herbert
• Lemke Mark James

Classifications

• F02D19/0647

  the gaseous fuel being liquefied petroleum gas [LPG], liquefied natural gas [LNG], compressed natural gas [CNG] or dimethyl ether [DME] · CPC title

• F02D35/027

  using knock sensors · CPC title

• F02D41/0025

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

• F02D41/3047

  said means being a secondary injection of fuel · CPC title

• F02D19/10 Primary

  peculiar to compression-ignition engines in which the main fuel is gaseous · CPC title