| abstract |
A gaseous-fuelled internal combustion engine and a method of operating same are provided for improving 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. The engine comprises a combustion chamber defined by a cylinder, a cylinder head, and a piston movable within the cylinder; and a fuel injection valve operable for introducing the gaseous fuel mixture directly into the combustion chamber, or two separate fuel injection valves for introducing the methane and hydrogen separately. An electronic controller is in communication with actuator(s) for the fuel injection valve(s) for controlling timing for operating the fuel injection valve(s). The engine has a compression ratio of at least 14:1. |