Study On Fuel Evaporative Emission Property Of Motor Vehicles

The fuel evaporative emission of motor vehicles is one of the sources of HC pollutants in the atmosphere. By studying fuel evaporative rules and influence factors, in-depth understanding of the mechanism of fuel evaporation and the factors affecting the mass of fuel evaporation, we can effectively control the fuel evaporation, thus reducing vehicle fuel evaporative emissions.In order to study the fuel evaporative rules, the TGA (Thermo Gravimetric Analyzer) is used to investigate the evaporative rules under diverse conditions, such as different types of fuel, different heating rates, different temperature conditions, different film thickness and different flow rate conditions. The results show that fuel temperature, fuel film thickness and air flow rate affect the fuel evaporation greater. In addition, the evaporative rules of different proportions of ethanol and gasoline vary, which is related with the mixed effect of different proportions of ethanol and gasoline.Static fuel evaporation is simulated by the software of FLUENT, and the fuel evaporation process, the control equations and calculation methods are explained. The processes of static fuel evaporation and fuel temperature changes are simulated. The results show that gasoline evaporates rapidly in the beginning, until after the evaporation of light components, the trend of evaporation starts slowing down. The simulation is studied under different heating rates, different wall temperatures, different film thickness and different fuels. The results find that temperature, film thickness and different fuels have different extent effect on evaporation. Finally, the reason of error between simulation results and experimental results is analyzed.Using motorcycle as a study object, different factors on vehicle evaporation are studied in experiment. Study finds that fuel tank is the major source of motorcycle evaporative emission and the key factor which affects fuel tank HC evaporation is heating rate, heating range, ambient temperature, fuel surface area and volume of fuel. In addition, using compared method study evaporative emission between E10 and 93#gasoline and find that E10 slightly larger than 93#gasoline in evaporation, but the present evaporative emission control system on E10 is still effective.