Experimental Study On Improving The Combustion Process Of Diesohol With Cetane Improvers

Because energy is the problem that the every country of the world is facing, most countries have been researching alternative energy sources. Ethanol, one of the most potential alternative fuels, has become investigators'emphasis.Ethanol's solution with diesel is very poor. The mixture of ethanol and diesel easily brings delamination and the steady emulsion can't come true. So we add a solublizer to the mixture of ethanol and diesel and solve the problem. That ethanol has more vaporization heat, lower density, lower cetane number, lower heat value and lower flash point than diesel, influence the performances of engine fueled with diesohol.Without any configuration modification to a turbocharged intercooled CI engine, and keeping same volume supply delivery of different fuels at the same mode, engine performance and combustion experiments were carried out on a engine fueled with diesel(E0) and seven kinds of diesohol fuels (E10, E10-1,E10-2,E10-3,E10-4,E10-5 and E10-6). From the engine performance, comparing with E10's, 2-EHN(2-Ethylhexyl Nitrate) and DTBP(Ditert-butyl) has little influence on power, economic and PM emission; 2-EHN and DTBP make the diesohol's CO emission decrease; 2-EHN reduces diesohol's HC emission, but DTBP increases its HC emission; 2-EHN makes diesohol's NOx down and when the proportion is up to 0.5%, NOx of the engine goes down most. Adding DTBP to diesohol, NOx goes down greatly, especially at the mode of 1700r/min, the decreasing range of NOx is more, but at the mode of 2800r/min, it is not so large. Whatever it is 2-EHN or DTBP; there is an optimal proportion in the diesohol. More or less than this proportion, the effect to diesohol's performance is not good. From the result of these experiments, it is very good to add 0.5% of 2-EHN and DTBP into diesohol. When the adding proportions are all 0.5%, at 10% load, To CO emission, DTBP is better; To HC emission, 2-EHN is better than DTBP wholely. The all and the one, at the middle and small load mode, 2-EHN is better than DTBP at reducing NOx, but at high load mode, it is inverse.From the characteristics of combustion, adding 2-EHN and DTBP into diesohol makes the cylinder pressure decrease greatly at smaller mode. DTBP and 2-EHN make diesohol's ratio of pressure and combustion down, and with the load it is variable: at little load, the reduction of the peak about the ratio of combustion is large, and at higher load, it is small. Comparing the effect of the two additive...