Method for operating a spark ignited engine
First Claim
1. A method for operating a spark ignited engine, the spark ignited engine having at least one cylinder, a piston movable in the at least one cylinder, and at least one pre-chamber connected to the at least one cylinder, the method comprising the steps of:
- forming a combustible mixture by mixing generally homogeneously a first fuel and air;
introducing the combustible mixture into the at least one cylinder during an intake stroke;
compressing the combustible mixture with the piston during a compression stroke thereby introducing a part of the combustible mixture into the at least one pre-chamber;
introducing during the intake stroke and/or the compression stroke a second fuel comprising natural gas into the at least one pre-chamber at an introduction-time before start of combustion, with the second fuel being of a different chemical composition and/or concentration with respect to the first fuel;
igniting by spark the combustible mixture and the second fuel in the at least one pre-chamber;
selecting an amount of the second fuel, a chemical composition of the second fuel introduced into the at least one pre-chamber, a timing of igniting by spark in the at least one pre-chamber, and an in-cylinder charge temperature based on a duration of combustion desired;
measuring engine efficiency, amount of emissions, center of gravity and duration of combustion; and
increasing the in-cylinder charge temperature to within a range of 50 to 130°
C. in response to a combustion duration longer than 40 degrees crank angle independent of an rpm of the engine ordecreasing the in-cylinder charge temperature to within the range of 50 to 130°
C. in response to the combustion duration being less than a desired combustion duration.
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Accused Products
Abstract
A method for operating a spark ignited engine, including forming a combustible mixture by mixing generally homogeneously a first fuel and air and introducing this mixture into the at least one cylinder in an intake stroke, and compressing the combustible mixture with a piston in a compression stroke thereby introducing a part of the combustible mixture into a pre-chamber. During the intake and/or the compression stroke, a second fuel is introduced into the pre-chamber at an introduction-time before start of combustion, and the second fuel is of the same or different chemical composition and/or concentration with respect to the first fuel, and a spark ignites in the prechamber. An amount of second fuel and/or the chemical composition of second fuel introduced to the pre-chamber and/or spark timing of the pre-chamber and/or an in-cylinder charge temperature is chosen such that a desired duration of combustion can be achieved.
42 Citations
16 Claims
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1. A method for operating a spark ignited engine, the spark ignited engine having at least one cylinder, a piston movable in the at least one cylinder, and at least one pre-chamber connected to the at least one cylinder, the method comprising the steps of:
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forming a combustible mixture by mixing generally homogeneously a first fuel and air; introducing the combustible mixture into the at least one cylinder during an intake stroke; compressing the combustible mixture with the piston during a compression stroke thereby introducing a part of the combustible mixture into the at least one pre-chamber; introducing during the intake stroke and/or the compression stroke a second fuel comprising natural gas into the at least one pre-chamber at an introduction-time before start of combustion, with the second fuel being of a different chemical composition and/or concentration with respect to the first fuel; igniting by spark the combustible mixture and the second fuel in the at least one pre-chamber; selecting an amount of the second fuel, a chemical composition of the second fuel introduced into the at least one pre-chamber, a timing of igniting by spark in the at least one pre-chamber, and an in-cylinder charge temperature based on a duration of combustion desired; measuring engine efficiency, amount of emissions, center of gravity and duration of combustion; and increasing the in-cylinder charge temperature to within a range of 50 to 130°
C. in response to a combustion duration longer than 40 degrees crank angle independent of an rpm of the engine ordecreasing the in-cylinder charge temperature to within the range of 50 to 130°
C. in response to the combustion duration being less than a desired combustion duration. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method for operating a spark ignited engine, the spark ignited engine having at least one cylinder, a piston movable in the at least one cylinder, and at least one pre-chamber connected to the at least one cylinder, the method comprising the steps of:
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forming a combustible mixture by mixing generally homogeneously a first fuel and air; introducing the combustible mixture into the at least one cylinder during an intake stroke; compressing the combustible mixture with the piston during a compression stroke thereby introducing a part of the combustible mixture into the at least one pre-chamber; introducing during the intake stroke and/or the compression stroke a second fuel comprising natural gas into the at least one pre-chamber at an introduction-time before start of combustion, with the second fuel being of a different chemical composition and/or concentration with respect to the first fuel; igniting by spark the combustible mixture and the second fuel in the at least one pre-chamber; selecting an amount of the second fuel, a chemical composition of the second fuel introduced into the at least one pre-chamber, a timing of igniting by spark in the at least one pre-chamber, and an in-cylinder charge temperature based on a duration of combustion desired; measuring engine efficiency, amount of emissions, center of gravity and duration of combustion; and adjusting the amount of the second fuel in response to a combustion duration longer than 40 degrees crank angle independent of an rpm of the engine;
oradjusting the amount of the second fuel in response to the combustion duration being less than a desired combustion duration.
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Specification