Influence of hot fuel injection on air/fuel mixture preparation and effects on Flex Fuel Engines 2006-01-2619
The scope of this study is to demonstrate the effect of hot fuel injection on mixture preparation, showing the benefits of the heating fuel technology. For these evaluations flexible fuel engines were used, taking into consideration mainly two aspects.
First of all, to overcome the challenge to develop a sophisticated system for cold start assistance to be used when the engine is been propelled with ethanol. The successfulness of this investigation can represent that in the near future the outdated secondary system for cold start (which will be described later in this paper) would be removed and the driver will not need to refuel the additional fuel reservoir.
The second aspect of this technology comes with tight emissions standards, which must be achieved for the next emission legislation level nominated PROCONVE PHASE V.
The hot fuel injection will be emphasized as a strategy to reduce raw hydrocarbons emissions during the cold start of port fuel injected engines. The foundation and performance of this concept are discussed, as well as, other relevant aspects such as high fuel pressure, spray geometry to reduce the risk of wall wetting effect and spray droplet sizes.
In the second part of this paper, laboratory experiments are carried out using a 1,61 and 2,01 inline engines, equipped with flexible fuel technology from mass production.
Both vehicles comply with PROCONVE PHASE IV, level which 100% of newest must attend until 2007. The standard cold start device was physically disconnected to avoid any undesirable influence and replaced by our prototype responsible to heat up the fuel under the necessary conditions. For emission analysis the mass production underflow converter was kept to show up the capability and benefits of the new technology.