Dual fuel combustion intensity

Patent metadata

Field	Value
Publication number	US-10935449-B2
Application number	US-201815971957-A
Country	US
Kind code	B2
Filing date	May 4, 2018
Priority date	May 5, 2017
Publication date	Mar 2, 2021
Grant date	Mar 2, 2021

Abstract

A method of detecting uncontrolled combustion in an internal combustion engine includes sampling in-cylinder pressure sensor configured to measure pressure in a cylinder of the engine and generate a pressure signal, calculating a combustion intensity metric based on the pressure signal, determining a parameter describing how close the engine is to an uncontrolled combustion condition based on the combustion intensity metric, and controlling a substitution rate of a first fuel and a second fuel based on one or more of the parameter and the combustion intensity metric.

First claim

What is claimed is:

1. A method of detecting uncontrolled combustion in an internal combustion engine, comprising:
sampling a pressure signal from in-cylinder pressure sensor, the pressure signal representative of a measured pressure in a cylinder of the engine;
calculating a combustion intensity metric based on the pressure signal, wherein the combustion intensity metric is an indicator of the engine's proximity to an uncontrolled combustion condition, where the combustion intensity metric is a function of at least a peak cylinder pressure, a rate of cylinder pressure rise, cylinder pressure ripple, burn duration, and a slope of heat release;
determining an engine control parameter as a function of the combustion intensity metric; and
controlling the engine based on the engine control parameter.

2. The method of claim 1 , wherein the internal combustion engine comprises a dual-fuel internal combustion engine and wherein the engine control parameter comprises a substitution rate of a first fuel and a second fuel based on at least one of the engine control parameter or the combustion intensity metric.

3. The method of claim 2 , wherein the first fuel is diesel and wherein the second fuel is natural gas.

4. The method of claim 1 , wherein the combustion intensity metric is calculated within a same combustion cycle as the sampling of the in-cylinder pressure sensor.

5. The method of claim 1 , comprising:
calculating, based on the pressure signal, a pressure metric, a heat release metric, and a knock metric,
wherein the combustion intensity metric is a function of the pressure metric, the heat release metric, and the knock metric.

6. The method of claim 5 , wherein the heat release metric comprises an adiabatic heat release rate of combustion in a cylinder of the engine.

7. The method of claim 1 , comprising calculating at least one of the following combustion metrics based on the pressure signal:
the peak cylinder pressure;
the crank angle of peak cylinder pressure;
the rate of cylinder pressure rise;
the cylinder pressure ripple;
the crank angle of a cylinder pressure ripple;
the burn duration;
the slope of heat release;
the crank angle of centroid of heat release; or
the crank angle of max heat release rate.

8. The method of claim 7 , wherein the combustion intensity metric is further a function of at least one of:
the crank angle of peak cylinder pressure;
the crank angle of cylinder ripple;
the crank angel of centroid of heat release; or
the crank angle of max heat release rate.

9. The method of claim 1 , comprising determining a fuel input signal, a throttle position signal, and an ignition timing signal for the engine based on at least one of the combustion intensity metric or the engine control parameter.

10. A controller for controlling operation of a dual-fuel internal combustion engine of an engine system, the engine system comprising a pressure sensor configured to measure pressure in a cylinder of the engine and generate a corresponding pressure signal and a crank angle sensor configured to measure the crank angle of the engine and generate a corresponding crank angle signal, the controller comprising:
a processor couplable to the in-pressure sensor and the crank angle sensor; and
at least one non-transitory computer readable medium storing instructions operable to cause the processor of the controller to perform operations comprising:
(a) sample the pressure signal;
(b) calculate a combustion intensity metric based on the pressure signal, wherein the combustion intensity metric is an indicator of the engine's proximity to an uncontrolled combustion condition, and the combustion intensity metric is a function of at least a peak cylinder pressure, a rate of cylinder pressure rise, cylinder pressure ripple, burn duration, and a slope of heat release;
(c) determine a substitution rate of a first fuel and a second fuel delivered to the cylinder based on the combustion intensity metric; and
(d) control the dual-fuel internal combustion engine based on the substitution rate.

11. The controller of claim 10 , wherein first fuel is diesel and wherein the second fuel is natural gas.

12. The controller of claim 10 , wherein steps (b) and (c) occur within a next cycle of the cylinder.

13. The controller of claim 10 , wherein the instructions include calculating, based on the pressure signal, a pressure metric, a heat release metric, and a knock metric, and wherein the combustion intensity metric is a function of the pressure metric, the heat release metric, and the knock metric.

14. The controller of claim 13 , wherein calculating the heat release metric comprises calculating an adiabatic heat release rate of combustion in the cylinder of the engine.

15. The controller of claim 10 , wherein the instructions include calculating at least one of the following combustion metrics based on the pressure signal:
the peak cylinder pressure;
the crank angle of peak cylinder pressure;
the rate of cylinder pressure rise;
the cylinder pressure ripple;
a location of cylinder pressure ripple;
the burn duration;
the slope of heat release;
the crank angle of centroid of heat release; or
the crank angle of max heat release rate.

16. The controller of claim 15 , wherein the combustion intensity metric is further a function of at least one of:
the crank angle of peak cylinder pressure;
the crank angle of ripple;
the crank angle of centroid of heat release; or
the crank angle of max heat release rate.

17. The controller of claim 10 , wherein the instructions include:
determine at least one of: a fuel input signal, a throttle position signal, or an ignition timing signal for the dual-fuel internal combustion engine based on at least one of the combustion intensity metric or the substitution rate, and
control the dual-fuel internal combustion engine using at least one of: the fuel input signal, the throttle position signal, or the ignition timing signal.

18. A controller for controlling operation of an internal combustion engine of an engine system, the engine system comprising a pressure sensor configured to measure pressure in a cylinder of the engine and generate a corresponding pressure signal and a crank angle sensor configured to measure the crank angle of the engine and generate a corresponding crank angle signal, the controller comprising:
a processor couplable to the in-pressure sensor and the crank angle sensor; and
at least one non-transitory computer readable medium storing instructions operable to cause the processor of the controller to perform operations comprising:
(a) sample the pressure signal;
(b) calculate a combustion intensity metric based on the pressure signal, wherein the combustion intensity metric is an indicator of the engine's proximity to an uncontrolled combustion condition, and the combustion intensity metric is a function of at least a peak cylinder pressure, a rate of cylinder pressure rise, cylinder pressure ripple, burn duration, and a slope of heat release;
(c) determine an engine control parameter as a function of the combustion intensity metric; and
(d) control the engine based on the engine control parameter.

Assignees

• Woodward Inc

Inventors

• Barta Jason
• Hampson Gregory James
• Nair Suraj
• Carlson Jeffrey

Classifications

• F02D35/028

  by determining the combustion timing or phasing · CPC title

• G01L23/222 Primary

  using piezoelectric devices · CPC title

• F02D2200/0614

  Actual fuel mass or fuel injection amount · CPC title

• F02D2200/0404

  Throttle position · CPC title

• F02D41/3047

  said means being a secondary injection of fuel · CPC title