The Study Of Electronic Control System For The Diesel-ethanol Dual-injection Engine

To relieve worldwide oil source shortage crisis and ensure diesel engine emission cansatisfy stricter emission laws, researchers all over the world are engaged in diesel engineclear alternative fuel research. Ethanol has special physicochemical property, it can notonly improve the engine combustion process effectively and save fuel consumption, butalso can reduce noxious emission (especially NOx and PM). So, Ethanol has been treatedas a kind of ideal diesel engine clean alternative fuel.Based on the research situation of Ethanol fuel application in diesel engine, it has astudy of electronic control system for the diesel-ethanol dual fuel on the single cylinderdiesel engine, and single point inlet electronic control ethanol spray method is selected asscheme in the paper. In this scheme, the diesel supply system is not modified and use theoriginal mechanical fuel supply system, another ethanol fuel supply system needs to beadded to the bench, by means of the self designed ECU to control electric ethanol pump tosupply ethanol into fuel distribution pipes from ethanol fuel box, the ethanol injector thatconnects distribution pipes and inlet pipes can inject ethanol into the inlet according togiven crank angle at a quantity. The ethanol injected will evaporation and mix with air, themixture goes into the engine at the suction stroke and combusts together with diesel in thecylinders.To achieve precise control on ethanol injection at different diesel engine operatingconditions, the author developed an integral own designed ethanol injection electroniccontrol system, including design of the master circuit board and related hardware circuitand software program. besides, operated the bench experiments on the original dieselengine, having a research for the engine fuel economy, NOx, CO and HC emissions underdifferent ethanol injection pulse width and different ethanol injection modes. Theexperimental results shows that compared with original diesel engine, the diesel/ethanoldual-fuel engine with self designed ethanol injection electronic control system has betterperformance on fuel economy and NOxemission characters.