Multi-fuel engine system

Patent metadata

Field	Value
Publication number	US-2016169141-A1
Application number	US-201514967062-A
Country	US
Kind code	A1
Filing date	Dec 11, 2015
Priority date	Dec 16, 2014
Publication date	Jun 16, 2016
Grant date	—

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

1 . A system comprising:
an engine having a plurality of cylinders coupled to a crankshaft; a crankshaft speed sensor; and a controller configured to:
measure one or more torsional vibration orders of the engine based on signals from the crankshaft speed sensor;
determine an amplitude of the one or more torsional vibration orders; and
when the amplitude is greater than a threshold amplitude, indicate misfire in at least one of the plurality of cylinders.

2 . The system of claim 1 , wherein the controller is further configured to, when misfire is indicated, determine which cylinder of the plurality of cylinders is misfiring based on a phase of the one or more torsional vibration orders.

3 . The system of claim 2 , wherein the controller is further configured to, when misfire is indicated, increase a fuel injection amount to the misfiring cylinder.

4 . The system of claim 3 , wherein the engine is configured to operate with at least a first fuel and a second fuel, and wherein to increase the fuel injection amount to the misfiring cylinder, the controller is configured to increase a fuel injection amount of the first fuel relative to the second fuel.

5 . The system of claim 4 , wherein the first fuel is a liquid fuel and the second fuel is a gaseous fuel.

6 . The system of claim 5 , wherein the controller is configured to determine, for each cylinder of the plurality of cylinders, a misfire limit for each operating point of a plurality of operating points based on an amplitude of the one or more torsional vibration orders measured across the plurality of operating points.

7 . The system of claim 6 , wherein the misfire limit for a given cylinder of the plurality of cylinders includes a minimum open duration for a liquid fuel injector coupled to the given cylinder.

8 . The system of claim 7 , wherein the controller is further configured to operate each cylinder of the plurality of cylinders at a respective predetermined ratio of gaseous fuel to liquid fuel, each predetermined ratio including a maximum amount of gaseous fuel to deliver requested engine output while remaining above a respective misfire limit.

9 . The system of claim 1 , wherein the controller is further configured to determine a level of combustion variation among the plurality of cylinders based on the amplitude.

10 . The system of claim 9 , wherein the controller is further configured to, when the level of combustion variation is greater than a threshold variation, adjust a fuel injection amount to one or more cylinders of the engine.

11 . 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.

12 . The system of claim 11 , 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.

13 . The system of claim 12 , 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.

14 . The system of claim 11 , 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.

15 . The system of claim 11 , 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.

16 . A system comprising:
an engine having a plurality of cylinders coupled to a crankshaft; a crankshaft speed sensor; 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 the plurality of cylinders based on the measured half-order torsional vibration; and adjust fueling duration to one or more of the plurality of cylinders based on the COV.

17 . The system of claim 16 , wherein the COV comprises a standard deviation of a power output of the plurality of cylinders divided by a mean power output.

18 . The system of claim 17 , wherein the controller is further configured to determine the COV based on peak cylinder pressure for each of the plurality of cylinders.

19 . The system of claim 16 , 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.

20 . The system of claim 19 , wherein the first fuel is liquid fuel and wherein the second fuel is gaseous fuel.

Assignees

• Gen Electric

Inventors

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

Classifications

• F02D2200/101

  Engine speed · CPC title

• F02D41/1498

  measuring engine roughness · CPC title

• F02D2200/1015

  Engines misfires · CPC title

• F02D41/008 Primary

  Controlling each cylinder individually · CPC title

• F02D2200/02

  the parameters being related to the engine · CPC title