Effect Of Fuel Additive On Unregulated Emissions From A Direct Injection Methanol Engine

Application of alternative fuel oil is suit for China's basic energy situation, can reduce dependence on a single fuel, ensure energy diversity, and thus the oil shortage problem which is solved or not is more and more attentioned. In China, the methanol production technology is mature, the scale of production has been industrialized, and methanol prices become relatively lower. Meanwhile, the theoretical methanol mixture slightly lower calorific value than gasoline, or octane number is very high. Therefore, methanol fuel could be directly used in gasoline which does not need major improvements, and as alternative fuels to oil, methanol has a good economy.Physicochemical properties of methanol and gasoline are similar, methanol can be directly used in the traditional gasoline engine and needs no major improvements. Also, which is more stable than gasoline, methanol combustion has high thermal efficiency and anti deflagration performance is very good, regular emission much lower than gasoline. However, due to latent heat of vaporization of methanol is 3.6 times that of gasoline and boiling point higher than gasoline, Methanol has worse volatility than gasoline. Use in direct injection methanol engine, both to ensure quick start the engine, but also ensures the reduction of regulated emissions.Regulated emissions include: hydrocarbons (HC), nitrogen oxides (NOX), carbon monoxide (CO) and particulate matter and so on. The data show that regulated emissions from combustion of methanol is decreased obviously. Therefore, methanol as a gasoline alternative fuel, has good environmental characteristics. Meanwhile, the methanol production has been industrialized, the price has obvious advantages. Methanol fuel engine is the new car power, with extensive prospect, can alleviate environmental protection and energy dual pressures.Methanol engine exhaust are mainly formaldehyde (HCHO) and unburned methanol (CH3OH), these two types of emissions is much higher gasoline engines. Methanol is typical of nerve poison, formaldehyde with genetic toxicity and carcinogenic activity. So in methanol engine applications, we must pay more attention to the combustion process of formaldehyde and unburned methanol discharge of pollutants generation rule, emission characteristics and control method, etc. The necessity of special research of methanol must be attentioned.Chromatography of organic matter for most of the HC can have a good separation and analysis capabilities to a number of quantitative analysis HC composition. By using chromatography method for analyzing, we couid need to select the different analysis conditions for the properties of the sample. Directly by gas chromatography, unburned methanol and formaldehyde wave followed overlap, cannot be completely separated. This paper uses a combination of gas and liquid chromatography analysis method, and the calibration standard solution proved the feasibility of the method.This paper mainly studies on effect of unregulated emissions from a direct injection methanol engine in the stable state with adding ratio of aniline to methanol. The results show that:(1)After adding aniline, the emissions of unburned methanol and formaldehyde are both reduced , engine power (torque) and combustion (maximum combustion pressure) is not much affected. Of these, 0.75% aniline methanol fuel produced lower emissions of unburned methanol and formaldehyde. Aniline methanol fuel shorted the ignition delay period, no effect on the acute burn period, so that shorted the combustion duration of methanol. Aniline also reduced engine exhaust temperature.(2)After preheating the intake,unburned methanol emissions are reduced and formaldehyde emissions are increased, and the engine power(torque) is not much affected. Preheat the intake can promote complete combustion of methanol, slightly increase the exhaust temperature of the cylinder and maximum cylinder combustion pressure, but the effect is not obvious.Through the research found that there is a certain relationship between emissions of unburned methanol and formaldehyde in a methanol engine, however, the transforming relationship between unburned methanol and formaldehyde Is an urgent problem need to be resolved.