Multi-fuel engine starting control system and method
AssigneeFord Global Technologies, LLC
InventorsGopichandra Surnilla, Ross Dykstra Pursifull
Life of this patent
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Abstract
Various example approaches are described, one of which includes a method for controlling injection of gaseous and liquid fuel to a cylinder during engine starting. Specifically, gaseous fuel is injected during or before an intake stroke of the cycle to form a well-mixed overall lean air-fuel mixture, and then liquid fuel is directly injected to the cylinder at least during one of a compression and expansion stroke of the engine cycle to form a rich air-fuel cloud near the spark plug, where a spark initiates combustion of the injected fuels. In one example, the rich cloud enables additional spark retard, and thus faster catalyst light-off, while maintain acceptable combustion stability of the gaseous fuel.
Claims21
A system, comprising:
- an engine having at least a first and second cylinder;
- each of the first and second cylinders having a liquid fuel injector and a gaseous fuel injector coupled thereto;
- a turbocharger coupled to the engine;
- and
- a control system coupled to the engine, the control system having a computer storage medium with instructions encoded thereon, the instructions comprising:
- instructions to, during a first combustion event from rest of engine starting, inject gaseous fuel to the first cylinder from the gaseous fuel injector at least during or before an intake stroke of an engine cycle of the first cylinder to form a well-mixed overall lean air-fuel mixture;
- instructions to initiate spark combustion spark combustion of at least the injected gaseous fuel in the first cylinder;
- and
- instructions to, during a second combustion event immediately following the first combustion event in a firing order of the engine, inject gaseous fuel to the second cylinder from the gaseous fuel injector at least during or before an intake stroke of an engine cycle of the second cylinder to form a well-mixed overall lean air-fuel mixture and to directly inject liquid fuel from the liquid fuel injector to the second cylinder at least during one of a compression and expansion stroke of the engine cycle of the second cylinder to at least form a rich air-fuel cloud near the spark plug;
- and
- instruction to initiate spark combustion of the injected fuels in the second cylinder.
A method of controlling an engine having a cylinder with a spark plug, the method comprising:
- during engine starting, injecting gaseous fuel to the cylinder at least during or before an intake stroke of an engine cycle to form a well-mixed overall lean air-fuel mixture, and then directly injecting liquid fuel to the cylinder at least during one of a compression and expansion stroke of the engine cycle to form a rich air-fuel cloud near the spark plug;
- and
- initiating combustion of the injected fuels via spark ignition.
A method of controlling an engine having a cylinder, the method comprising:
- for a first combustion event, injecting gaseous fuel without injecting liquid fuel to the cylinder and delivering a first spark retard amount to initiate combustion of the gaseous fuel;
- and
- for a subsequent combustion event, injecting gaseous fuel and injecting liquid fuel to the cylinder and delivering a second spark retard amount to initiate combustion of the gaseous and liquid fuel, the second spark retard amount greater than the first spark retard amount.
Dependencies are inferred from the claim text.