Multi-fuel engine system

Patent metadata

Field	Value
Publication number	US-10920694-B2
Application number	US-201916292103-A
Country	US
Kind code	B2
Filing date	Mar 4, 2019
Priority date	Dec 16, 2014
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

Various methods and systems are provided for an engine capable of receiving liquid and gaseous fuel. In one example, cylinder misfire may be identified based on a misfire monitor. The misfire monitor may detect misfire based on signals from a crankshaft sensor.

First claim

The invention claimed is:

1. A system, comprising:
an engine having a plurality of cylinders, the engine configured to operate with at least a first fuel and a second fuel;
a plurality of fuel injectors to inject the first fuel to the plurality of cylinders; and
a controller configured to:
when operating under a tuning mode, operate the engine with both the first fuel and the second fuel and determine a minimum open duration for each of the plurality of injectors that sustains combustion; and
when operating under a second fuel mode, open each injector at its determined minimum open duration to initiate combustion,
where the minimum open duration for each of the plurality of injectors is determined based on a misfire monitor that determines cylinder misfire based on signals from a crankshaft speed sensor, wherein each respective minimum open duration comprises the respective minimum open duration that does not cause cylinder misfire, and wherein the controller is configured to determine cylinder misfire with the misfire monitor by determining half-order torsional oscillation of a crankshaft of the engine based on the signals from the crankshaft speed sensor.

2. The system of claim 1 , wherein the first fuel is liquid fuel and the second fuel is gaseous fuel, and where in the controller is configured to supply a gaseous fuel-air mixture to each cylinder during the second fuel mode.

3. The system of claim 2 , wherein the tuning mode is performed at a given engine speed and/or load, and wherein the second fuel mode comprises subsequent engine operation at the given engine speed and/or load.

4. The system of claim 1 , wherein a first injector of the plurality of fuel injectors has a first minimum open duration and a second injector of the plurality of fuel injectors has a second minimum open duration that is different than the first minimum open duration, and wherein a quantity of fuel delivered by the first injector at the first minimum open duration is the same as a quantity of fuel delivered by the second injector at the second minimum open duration.

5. A system comprising:
an engine having a plurality of cylinders, each cylinder including a piston coupled to a crankshaft;
a crankshaft speed sensor configured to measure a speed of the crankshaft; and
a controller configured to:
measure half-order torsional vibration of the engine based on signals from the crankshaft speed sensor;
determine a coefficient of variation (COV) of cycle-to-cycle combustion variation across the plurality of cylinders based on an amplitude of the measured half-order torsional vibration; and
adjust fueling duration to one or more of the plurality of cylinders based on the COV.

6. The system of claim 5 , wherein the COV comprises a standard deviation of a power output of the plurality of cylinders divided by a mean power output and is linearly proportional to the amplitude of the measured half-order torsional variation.

7. The system of claim 6 , wherein the controller is further configured to determine the COV based on peak cylinder pressure for each of the plurality of cylinders.

8. The system of claim 5 , wherein the engine is configured to combust at least a first fuel and a second fuel, and wherein to adjust the fueling duration to one or more of the plurality of cylinders, the controller is configured to adjust fueling duration of the first fuel relative to the second fuel.

9. The system of claim 8 , wherein the first fuel is liquid fuel and wherein the second fuel is gaseous fuel.

Assignees

• Transp Ip Holdings Llc

Inventors

• Flynn Paul Lloyd
• Bhattacharya Aninda
• Murugesan Ganesasubramanian
• Karunaratne Milan Palinda
• Cullen Daniel

Classifications

• F02D2200/101

  Engine speed · CPC title

• F02D2200/1015

  Engines misfires · CPC title

• F02D19/06

  peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed · CPC title

• F02D19/0623

  Failure diagnosis or prevention; Safety measures; Testing · 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