Abstract
The use of LPG in diesel engines represents an efficient solution to decrease the emissions for the automotive engines in same conditions of the preservation of the high efficiency that characterizes the standard diesel engine. The LPG is an alternative fuel with real future opportunities due to the following aspects: the NOx emission level is lower; the PM emission is indistinguishable; CO2 emission decreases or is maintained to the same level; the engine power is the same or can be increased; the automotive autonomy increases; the HC and CO emissions level decreases; LPG protects the particles filter and environment because don’t contains sulphur; the infrastructure for LPG distribution already exists.
The paper presents some theoretical and experimental results obtained by authors from a research program developed for an automotive diesel engine with 1500 cm3 displacement fuelled with LPG by diesel-gas method. The fuelling system has two separate circuits: one corresponding to diesel fuel and the second to LPG. The LPG is injected in gaseous phase in the front of the inlet valve and the diesel fuel is injected into combustion chamber assuring the ignition of the air-LPG mixture. The engine keeps up its classic diesel fuelling system which is adjusted for dual fuelling. The electronic control unit for the LPG injection system (EU-LPG) is attached by the engine Electronic Control Unit (ECU) and the engine electronic control is provided by the communication between those two electronic control units.
Are shown the influences of LPG dose on energetically and polluting engine performances.
Keywords: alternative fuel, combustion, pollutants, diesel-gas