Abstract: A method and apparatus for controlling to a target heat release rate (HRR) uses an HRR control lever, namely, pilot fuel timing and/or pilot fuel quantity, used in a gaseous-fuelled compression ignition internal combustion engine. The mechanism to control HRR to a target HRR improves engine performance and emissions. A target HRR is determined for a cycle of an engine. An HRR control lever is then used to adjust to the target HRR in consideration of combustion conditions in the engine and the difference between the target HRR and cycle HRR predicted for the cycle by reference to, by way of example, a derived HRR trace from a previous cycle, a pressure trace, a measured property of the exhaust gas directly determined or mapped values provided during calibration allowing for adjustment to a target HRR for the engine. The mapped values can be cross-referenced to engine combustion conditions.

Abstract: A method and apparatus for controlling to a target heat release rate (HRR) uses an HRR control lever, namely, pilot fuel timing and/or pilot fuel quantity, used in a gaseous-fuelled compression ignition internal combustion engine. The mechanism to control HRR to a target HRR improves engine performance and emissions. A target HRR is determined for a cycle of an engine. An HRR control lever is then used to adjust to the target HRR in consideration of combustion conditions in the engine and the difference between the target HRR and cycle HRR predicted for the cycle by reference to, by way of example, a derived HRR trace from a previous cycle, a pressure trace, a measured property of the exhaust gas directly determined or mapped values provided during calibration allowing for adjustment to a target HRR for the engine. The mapped values can be cross-referenced to engine combustion conditions.

Abstract: A method and apparatus for injecting a gaseous fuel into a combustion chamber of an internal combustion engine (ICE) cylinder employs a combination of operating modes. First, one of a low load and a high load mode of operation is selected during the operation of the ICE. Low load and high load modes are distinguished by the combustion characteristics of an amount of fumigated fuel added to the combustion chamber. Fumigated fuel that supports combustion will cause high load to be selected. Fumigated fuel that does not support combustion will cause low load to be selected. A directly injected amount of fuel is provided under low load. Under high load, a directly injected quantity of fuel is added when the piston is near top dead center to allow the engine to meet load requirement above that provided by the fumigated fuel.

Abstract: A method and apparatus for introducing gaseous fuel into a piston cylinder of an operating internal combustion engine in two separate stages involves monitoring a set of engine parameters, determining engine load and engine speed from the set of engine parameters, in a first stage, introducing a first portion of the gaseous fuel into the cylinder where the first portion of gaseous fuel forms a substantially homogeneous mixture comprising gaseous fuel and air prior to combustion, and in a second stage, occurring sequentially after the first stage, introducing a second portion of the gaseous fuel into the cylinder. The gaseous fuel quantity is variable in response to at least one of engine load and engine speed. Initiation and duration for at least one of the first and second stages is also variable in response to at least one of engine load and engine speed.

Abstract: A method and apparatus for injecting a gaseous fuel into a combustion chamber of an internal combustion engine (ICE) cylinder employs a combination of operating modes. First, one of a low load and a high load mode of operation is selected during the operation of the ICE. Low load and high load modes are distinguished by the combustion characteristics of an amount of fumigated fuel added to the combustion chamber. Fumigated fuel that supports combustion will cause high load to be selected. Fumigated fuel that does not support combustion will cause low load to be selected. A directly injected amount of fuel is provided under low load. Under high load, a directly injected quantity of fuel is added when the piston is near top dead center to allow the engine to meet load requirement above that provided by the fumigated fuel.

Abstract: A method and apparatus for introducing gaseous fuel into a piston cylinder of an operating internal combustion engine in two separate stages involves monitoring a set of engine parameters, determining engine load and engine speed from the set of engine parameters, in a first stage, introducing a first portion of the gaseous fuel into the cylinder where the first portion of gaseous fuel forms a substantially homogeneous mixture comprising gaseous fuel and air prior to combustion, and in a second stage, occurring sequentially after the first stage, introducing a second portion of the gaseous fuel into the cylinder. The gaseous fuel quantity is variable in response to at least one of engine load and engine speed. Initiation and duration for at least one of the first and second stages is also variable in response to at least one of engine load and engine speed.