Abstract: It is a challenge to reduce unburned hydrocarbon emissions for gaseous fuelled engines, especially at low engine load conditions, to meet demanding emission regulation targets. A method for reducing unburned hydrocarbon emissions in a lean-burn internal combustion engine that is fuelled with a gaseous fuel comprises adjusting the timing for closing of an intake valve as a function of engine operating conditions by one of advancing timing for closing of the intake valve and closing the intake valve earlier during an intake stroke; and retarding timing for closing of the intake valve and closing the intake valve later during a compression stroke. The volumetric efficiency of the internal combustion engine is reduced and unburned hydrocarbon emissions are maintained below a predetermined level.

Abstract: A method for introducing a gaseous fuel into a combustion chamber of an internal combustion engine includes forming a non-ignitable mixture of the gaseous fuel and a gas including oxygen in a predefined mixture mass ratio within a predetermined range of tolerance having a pressure suitable for directly introducing the non-ignitable mixture into the combustion chamber during at least the compression stroke; and introducing the non-ignitable mixture directly into the combustion chamber.

Abstract: A method for operating a gaseous-fuelled internal combustion engine by directly injecting the gaseous fuel into the combustion chamber is disclosed wherein the gaseous fuel is injected at injection pressures higher than 300 bar and the pressure ratio between the gaseous fuel injection pressure and the peak cylinder pressure is between 1.6:1 and 3:1, and preferably between 2.5:1 to 2.8:1. The injection pressure is selected to be between 300 and 540 bar and preferably between 300 bar and 440 bar. The injection pressure can be selected based on a preferred range for the pressure ratio.

Abstract: It is a challenge to reduce unburned hydrocarbon emissions for gaseous fuelled engines, especially at low engine load conditions, to meet demanding emission regulation targets. A method for reducing unburned hydrocarbon emissions in a lean-burn internal combustion engine that is fuelled with a gaseous fuel comprises adjusting the timing for closing of an intake valve as a function of engine operating conditions by one of advancing timing for closing of the intake valve and closing the intake valve earlier during an intake stroke; and retarding timing for closing of the intake valve and closing the intake valve later during a compression stroke. The volumetric efficiency of the internal combustion engine is reduced and unburned hydrocarbon emissions are maintained below a predetermined level.

Abstract: Emission targets, such as NOx levels, for gaseous fuelled internal combustion engines that burn a gaseous fuel in a diffusion combustion mode are increasingly more challenging to achieve. A method of fuel injection for an internal combustion engine fuelled with a gaseous fuel comprises introducing a first amount of pilot fuel in a first stage of fuel injection; introducing a first amount of main fuel (the gaseous fuel) in a second stage of fuel injection; and introducing a second amount of main fuel in a third stage of fuel injection. The first and second amounts of main fuel contribute to load and speed demand of the internal combustion engine. Engine maps calibrated for different engine performance can be employed in different regions of the load and speed range of the engine. The engine maps are blended when the engine transitions between two regions; and momentary excursions into different regions do not change the engine calibration.

Abstract: An apparatus and method for igniting a gaseous fuel directly introduced into a combustion chamber of an internal combustion engine comprises steps of heating a space near a fuel injector nozzle; introducing a pilot amount of the gaseous fuel in the combustion chamber during a first stage injection event; controlling residency of the pilot amount in the space such that a temperature of the pilot amount increases to an auto-ignition temperature of the gaseous fuel whereby ignition occurs; introducing a main amount of the gaseous fuel during a second stage injection event after the first stage injection event; and using heat from combustion of the pilot amount to ignite the main amount.

Abstract: A method for operating a gaseous-fuelled internal combustion engine by directly injecting the gaseous fuel into the combustion chamber is disclosed wherein the gaseous fuel is injected at injection pressures higher than 300 bar and the pressure ratio between the gaseous fuel injection pressure and the peak cylinder pressure is between 1.6:1 and 3:1, and preferably between 2.5:1 to 2.8:1. The injection pressure is selected to be between 300 and 540 bar and preferably between 300 bar and 440 bar. The injection pressure can be selected based on a preferred range for the pressure ratio.

Abstract: Emission targets, such as NOx levels, for gaseous fuelled internal combustion engines that burn a gaseous fuel in a diffusion combustion mode are increasingly more challenging to achieve. A method of fuel injection for an internal combustion engine fuelled with a gaseous fuel comprises introducing a first amount of pilot fuel in a first stage of fuel injection; introducing a first amount of main fuel (the gaseous fuel) in a second stage of fuel injection; and introducing a second amount of main fuel in a third stage of fuel injection. The first and second amounts of main fuel contribute to load and speed demand of the internal combustion engine. Engine maps calibrated for different engine performance can be employed in different regions of the load and speed range of the engine. The engine maps are blended when the engine transitions between two regions; and momentary excursions into different regions do not change the engine calibration.

Abstract: An apparatus and method for igniting a gaseous fuel directly introduced into a combustion chamber of an internal combustion engine comprises steps of heating a space near a fuel injector nozzle; introducing a pilot amount of the gaseous fuel in the combustion chamber during a first stage injection event; controlling residency of the pilot amount in the space such that a temperature of the pilot amount increases to an auto-ignition temperature of the gaseous fuel whereby ignition occurs; introducing a main amount of the gaseous fuel during a second stage injection event after the first stage injection event; and using heat from combustion of the pilot amount to ignite the main amount.

Abstract: A fuel injection valve injects a fuel into the combustion chamber or into the injection port of an internal combustion engine, the valve being actuated by an actuator assembly that includes a small displacement actuator and a large displacement actuator. The method includes commanding the small displacement actuator to move the valve member to a first open position corresponding to a first flow area and commanding the large displacement actuator to move the valve member to a second open position corresponding to a second flow area that is larger than the first flow area such that the ratio between the second flow area and the first flow area is at least 15:1. The fuel injection valve can also be operated to alternatively inject two different fuels, one of the fuels being a gaseous fuel and the other one being a liquid fuel.

Abstract: A method for introducing a gaseous fuel into a combustion chamber of an internal combustion engine includes forming a non-ignitable mixture of the gaseous fuel and a gas including oxygen in a predefined mixture mass ratio within a predetermined range of tolerance having a pressure suitable for directly introducing the non-ignitable mixture into the combustion chamber during at least the compression stroke; and introducing the non-ignitable mixture directly into the combustion chamber.

Abstract: A fuel injection valve injects a fuel into the combustion chamber or into the injection port of an internal combustion engine, the valve being actuated by an actuator assembly that includes a small displacement actuator and a large displacement actuator. The method includes commanding the small displacement actuator to move the valve member to a first open position corresponding to a first flow area and commanding the large displacement actuator to move the valve member to a second open position corresponding to a second flow area that is larger than the first flow area such that the ratio between the second flow area and the first flow area is at least 15:1. The fuel injection valve can also be operated to alternatively inject two different fuels, one of the fuels being a gaseous fuel and the other one being a liquid fuel.

Abstract: An apparatus and method for igniting a gaseous fuel directly introduced into a combustion chamber of an internal combustion engine comprises steps of heating a space near a fuel injector nozzle; introducing a pilot amount of the gaseous fuel in the combustion chamber during a first stage injection event; controlling residency of the pilot amount in the space such that a temperature of the pilot amount increases to an auto-ignition temperature of the gaseous fuel whereby ignition occurs; introducing a main amount of the gaseous fuel during a second stage injection event after the first stage injection event; and using heat from combustion of the pilot amount to ignite the main amount.

Abstract: In a gaseous-fuelled stoichiometric compression ignition internal combustion engine, a pilot fuel is injected directly into the combustion chamber to help initiate a multi-point ignition. The engine provides performance improvements approaching those of high pressure direct injection engines but with less complexity because the gaseous fuel is introduced into the intake air subsystem at relatively low pressure and as a result of the stoichiometric combustion, the low oxygen content in the combustion products exiting the combustion chamber allows the use of a three-way catalyst instead of other after treatment arrangements normally associated with conventional compression ignition engines that require the addition of a reductant.

Abstract: A gaseous-fuelled internal combustion engine and a method of engine operation improve combustion stability and reducing emissions of NOx, PM, and unburned hydrocarbons. The method comprises fuelling an internal combustion engine with hydrogen and natural gas, which can be directly injected into the combustion chamber together or introduced separately. Of the total gaseous fuel delivered to the engine, at least 5% by volume at standard temperature and pressure is hydrogen. For at least one engine operating condition, the ratio of fuel rail pressure to peak in-cylinder pressure is at least 1.5:1. A fuel injection valve introduces the gaseous fuel mixture directly into the combustion chamber. Two separate fuel injection valves could also introduce the methane and hydrogen separately. An electronic controller controls timing for operating the fuel injection valve(s). The engine has a preferred compression ratio of at least 14:1.

Abstract: A gaseous-fuelled internal combustion engine and a method of engine operation improve combustion stability and reducing emissions of NOx, PM, and unburned hydrocarbons. The method comprises fuelling an internal combustion engine with hydrogen and natural gas, which can be directly injected into the combustion chamber together or introduced separately. Of the total gaseous fuel delivered to the engine, at least 5% by volume at standard temperature and pressure is hydrogen. For at least one engine operating condition, the ratio of fuel rail pressure to peak in-cylinder pressure is at least 1.5:1. A fuel injection valve introduces the gaseous fuel mixture directly into the combustion chamber. Two separate fuel injection valves could also introduce the methane and hydrogen separately. An electronic controller controls timing for operating the fuel injection valve(s). The engine has a preferred compression ratio of at least 14:1.

Abstract: A gaseous-fuelled internal combustion engine and a method of engine operation improve combustion stability and reducing emissions of NOx, PM, and unburned hydrocarbons. The method comprises fuelling an internal combustion engine with hydrogen and natural gas, which can be directly injected into the combustion chamber together or introduced separately. Of the total gaseous fuel delivered to the engine, at least 5% by volume at standard temperature and pressure is hydrogen. For at least one engine operating condition, the ratio of fuel rail pressure to peak in-cylinder pressure is at least 1.5:1. A fuel injection valve introduces the gaseous fuel mixture directly into the combustion chamber. Two separate fuel injection valves could also introduce the methane and hydrogen separately. An electronic controller controls timing for operating the fuel injection valve(s). The engine has a preferred compression ratio of at least 14:1.

Abstract: A method and apparatus adjust pilot fuel injection timing in relation to a main fuel injection timing into a piston cylinder of an operating gaseous-fuelled direct injection internal combustion engine using high levels of EGR. A set of engine parameters are monitored which determine engine load and engine speed and an indicator of EGR concentration within the intake charge. Pilot fuel timing relative to main fuel injection timing is then adjusted according to the engine parameters. High levels of EGR are shown to be tolerated with relatively limited penalties in relation to other emissions typically found with high EGR by reducing the relative injection timing the pilot fuel as compared to main fuel injection timing.