Apparatus for controlling dual fuel supply to a fuel injected engine having an electronic engine management system (1) that supplies a primary injector control signal (8) to each of primary fuel injectors (2), the apparatus comprising an emulator (11) that emulates the electrical characteristics of a primary injector, a fuel control switch (10) that switches the primary injector control signal (8) from the primary injector (2) to the emulator (11) when an alternative mode is selected, a monitor (16) that monitors the primary injector control signal (8) to produce a monitor signal, and a controller (4) that processes the monitor signal to derive an alternative control signal which is used to control the primary fuel supply or a mixture of the primary fuel and a secondary fuel such as LPG, to the engine. Preferably the primary fuel supply is modulated by controlling injector control pulses. A secondary fuel may also be injected (3) and controlled by the controller (4).
F02B 3/00 - Engines characterised by air compression and subsequent fuel addition
F02B 43/00 - Engines characterised by operating on gaseous fuelsPlants including such engines
F02B 47/00 - Methods of operating engines involving adding non-fuel substances or anti-knock agents to combustion air, fuel, or fuel-air mixtures of engines
F02B 13/00 - Engines characterised by the introduction of liquid fuel into cylinders by use of auxiliary fluid
F02M 25/00 - Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
A compression ignition engine is supplied with afirst fuelin a flow of air and a second fuel is injectedinto the combustion chamber. The first fuel comprises a more volatile fuel than dieselsuch as ethanol, LPG or other combustible gas; the second fuel comprises diesel or biodiesel; and the second fuel is injected in multiple pulses in each ignition cycle with the first pulse acting as a pilot pulse to trigger ignition, and the timing of the second pulse being such as to modify the temperature through evaporation of the second fuel and thereby reduce the combustion temperature and mitigate knock susceptibility. Preferably the pilot pulse is followed by a single further pulse of the second fuel in the ignition cycle. The engine may be controlled to operate in two different modes, one mode for light and medium load conditions when there is only a pilot pulse injection of the second fuel which reduces NOx and soot emissions, and the other mode for higher load conditions when there is a pilot pulse injection followed by a main pulse injection of the second fuel. The first fuel may comprise bioethanol and or one or more ofthe following: ethanol, butanol, propanol, lpg, natural gas, hydrogen.
F02D 19/10 - Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed simultaneously using pluralities of fuels peculiar to compression-ignition engines in which the main fuel is gaseous
F02D 19/08 - Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with pluralities of fuels, e.g. alternatively with light and heavy fuel oil, other than engines indifferent to the fuel consumed simultaneously using pluralities of fuels
F02D 41/40 - Controlling fuel injection of the high pressure type with means for controlling injection timing or duration
F02D 41/00 - Electrical control of supply of combustible mixture or its constituents
patents
