METHOD AND APPARATUS FOR DUAL FUEL INJECTION INTO AN INTERNAL COMBUSTION ENGINE

摘要

Two different fuels are injected into the combustion chamber of an internal combustion engine. A main fuel is ignited by a pilot fuel that is more readily auto-ignitable than the main fuel. According to the method, load conditions on the engine are monitored and sets of conditions are defined to constitute low load conditions and high load conditions. Distinct operating modes are defined for each set of load conditions. Under low load conditions, a homogeneous mixture of main fuel and air is too lean to ensure stable combustion; consequently, the main fuel is injected at high pressure immediately following injection of the pilot fuel. Under high load conditions, fuel is injected in three stages. In the first stage, the main fuel is mixed with intake air prior to introduction into the combustion chamber or the main fuel is injected during the intake stroke or early in the compression stroke.