Ventilation controls for dual-fuel engines

Patent metadata

Field	Value
Publication number	US-10677175-B2
Application number	US-201715403895-A
Country	US
Kind code	B2
Filing date	Jan 11, 2017
Priority date	Jan 15, 2016
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

One exemplary embodiment is a system comprising a dual-fuel engine structured to selectably combust a first fuel type and a second fuel type, and an electronic control system in operative communication with the dual-fuel engine. The electronic control system is structured to control a transition of the dual-fuel engine from a dual-fuel mode to a single-fuel mode. After initiating the transition from the dual-fuel mode to the single-fuel mode, the control system stops provision of the second fuel type, requires combustion using control parameters configured for the dual-fuel mode until a transition ventilation condition is satisfied, permits non-emergency commanded engine shutdown only if the transition ventilation condition is satisfied.

First claim

The invention claimed is:

1. A method of controlling a system including an engine and an electronic controller in operative communication with the engine, the method comprising:
operating the system in a dual-fuel combustion mode in which both diesel fuel and gaseous fuel are supplied to and combusted by the engine;
commanding a transition from the dual-fuel mode to a diesel-only mode in which only diesel fuel is supplied to and combusted by the engine; and
in response to the commanding the transition from the dual-fuel mode to the diesel-only mode:
operating an actuator to stop supplying gaseous fuel to the engine,
monitoring a gaseous fuel ventilation condition of the engine after the act of operating the actuator to stop supplying gaseous fuel to the engine,
commanding operation of the engine using first combustion controls configured for the dual-fuel mode if the act of monitoring indicates that the gaseous fuel ventilation condition is not satisfied, and
commanding operation of the engine using second combustion controls configured for the single-fuel mode if the act of monitoring indicates that the gaseous fuel ventilation condition is satisfied.

2. The method of claim 1 wherein the monitoring the gaseous fuel ventilation condition of the engine comprises monitoring whether a predetermined ventilation volume has been displaced by the engine.

3. The method of claim 2 wherein the predetermined ventilation volume is determined based upon an intake system volume, an engine displacement volume and an exhaust system volume.

4. The method of claim 1 comprising:
commanding starting of the engine in the diesel-only mode; and
in response to the act of commanding starting of the engine, monitoring the gaseous fuel ventilation condition of the engine and inhibiting provision of diesel fuel to the engine if the gaseous fuel ventilation condition is not satisfied.

5. The method of claim 4 wherein the monitoring the gaseous fuel ventilation condition of the engine comprises monitoring one of a timer value and a counter value.

6. The method of claim 5 wherein the act of monitoring comprises one of decrementing and incrementing the one of the timer value and the counter value and evaluating the one of the time value and the counter value relative to a predetermined value indicating that the gaseous fuel ventilation condition is satisfied.

7. The method of claim 1 wherein the act of operating the system in a dual-fuel combustion mode comprises supplying gaseous fuel to the engine at an intake system location upstream of an intake manifold.

8. The method of claim 1 wherein the gaseous fuel ventilation condition indicates whether or not removal of unburned gaseous fuel present in the intake system has occurred.

9. The method of claim 1 comprising: inhibiting operation of a non-emergency engine shutdown command if the act of monitoring indicates that the gaseous fuel ventilation condition is not satisfied.

10. A method of controlling a system including a dual-fuel engine with an electronic controller in operative communication with the engine, the method comprising:
after starting the engine, operating the system in a dual-fuel combustion mode in which both diesel fuel and gaseous fuel are supplied to and combusted by the engine;
commanding a transition from the dual-fuel mode to a diesel-only mode in which only diesel fuel is supplied to and combusted by the engine; and
in response to the commanding the transition from the dual-fuel mode to the diesel-only mode:
operating a valve to stop supplying gaseous fuel to the engine,
monitoring a gaseous fuel ventilation condition,
commanding operation of the engine using first combustion controls configured for the dual-fuel mode if the gaseous fuel ventilation condition is not satisfied.

11. The method of claim 10 wherein the gaseous fuel ventilation condition will ensure that a volume has been displaced by the engine to ventilate gaseous fuel from an intake system and an exhaust system.

12. The method of claim 11 wherein the volume is determined based upon a plurality of calibratible values indicating volume information for a plurality of components of an intake system volume, a plurality of components of an exhaust system volume and the engine displacement.

13. The method of claim 10 comprising:
commanding operation of a starter motor to start the dual-fuel engine;
evaluating whether starting ventilation is required to remove unburned gaseous fuel from the system prior to providing diesel fuel to the engine;
if starting ventilation is required, inhibiting provision of diesel fuel to the engine until the gaseous fuel ventilation condition is satisfied; and
once the gaseous fuel ventilation condition is satisfied, allowing provision of diesel fuel to the engine.

14. The method of claim 10 further comprising inhibiting operation of an non-emergency engine shutdown command if the gaseous fuel ventilation condition is not satisfied.

15. The method of claim 10 further comprising commanding operation of the engine using second combustion controls configured for the single-fuel mode if the gaseous fuel ventilation condition is satisfied.

16. The method of claim 10 wherein the gaseous fuel ventilation condition will ensure that a volume has been displaced by the engine to ventilate gaseous fuel from an intake system and an exhaust system.

17. A system comprising:
an engine including an intake system and configured to be selectably operated in a dual-fuel combustion mode in which both diesel fuel and gaseous fuel are supplied to and combusted by the engine and a diesel-only mode in which only diesel fuel is supplied to and combusted by the engine; and
an electronic controller in operative communication with the engine, the electronic controller configured to perform the acts of:
operating the system in the dual-fuel combustion mode;
commanding a transition from the dual-fuel mode to the diesel-only; and
in response to the commanding the transition, operating an actuator to stop supplying gaseous fuel to the engine and, thereafter, evaluating a gaseous fuel ventilation condition of the engine, commanding operation of the engine using first combustion controls configured for the dual-fuel mode if the act of evaluating indicates that unburned gaseous fuel remains in the intake system of the engine, and commanding operation of the engine using second combustion controls configured for the single-fuel mode if the act of evaluating indicates that unburned gaseous fuel does not remain in the intake system of the engine.

18. The method of claim 17 wherein the engine is configured to supply gaseous fuel to the engine at location of the intake system upstream from an intake manifold.

19. The method of claim 18 wherein the engine is configured to supply gaseous fuel to the engine at a location of the intake system upstream from a compressor.

20. The method of claim 17 wherein the electronic controller is configured to perform the act of inhibiting a non-emergency engine shutdown if the act of evaluating indicates that unburned gaseous fuel remains in the intake system of the engine.

Assignees

• Cummins Inc

Inventors

• Thomas Robert J
• Lambert David

Classifications

• F02D41/062

  for starting (F02D41/061 takes precedence) · CPC title

• F02D19/0621

  Purging of the fuel system · 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

• F02D19/105

  operating in a special mode, e.g. in a liquid fuel only mode for starting · CPC title

• F02D41/042

  for stopping the engine · CPC title