Influences Of Oxygenate Fuels On Combustion Characteristics Of Diesel

Oxygenated diesel is a blended fuel that ordinary diesel is mixed with oxygenate fuel with a certain proportion, it contains higher oxygen content than ordinary diesel, and can improved combustion efficiency. Effects of diethylene glycol dimethyl ether (DGM)、alkyl ether (WJM)、dimethyl carbonate (DMC)、diethyl carbonate (DEC) and2-methoxy ethyl acetate (MEA) oxygenate fuels on the physicochemical properties of diesel were studied systematically in accordance with the national standard test methods of petroleum and petroleum products, the suitable oxygenate fuel used as a diesel blending component was selected preliminarily; in20L spherical explosive device, deflagration performance of oxygenated diesel and ordinary diesel were tested under negative pressures and positive pressure; the combustion characteristics of oxygenate fuels were studied in limited space. These research could provide a basis for the oxygenated diesel formulation. The main achievements are as follows:(1) The variation of the physical properties of five blended fuels:five selected oxygenate fuels can be readily miscible with diesel; densities of five blended fuels had a linearly growing trend with the ratio of oxygenate fuels, viscosities of five blended fuels varied in a binomial way with proportion of oxygenate fuels, the oxygen contents of five blended fuels varied linearly.(2) The variation of the combustion characteristics of five blended fuels:the net calorific value of the mixed fuels varied binomially with blending ratio, the change of distillation temperature of the mixed fuels had a same trend compared with oridinary diesel, while distillation temperature had reduced by making a comparison with that of ordinary diesel.(3) The variation of the stability and low temperature performance of five blended fuels: the stability of five hybrid fuels was declined; the impact of DGM、WJM、MEA on diesel low temperature performance was little, but DEC and DMC could seriously affect the low temperature property of diesel.(4) In20L spherical explosive device, the best sample storehouse spray pressure was1.717MPa, the appropriate ignition delay time was300ms, the minimum ignition energy was2kJ and the best volume of diesel is50mL.(5) On the basis of the optimum ignition of the spray conditions, at atmospheric conditions, the optimum ratios of WJM and MEA added to diesel were15%in volume, the maximum deflagration pressure of0.625MPa,0.605MPa respectively; at negative conditions, the deflagration performances of15%WJM and15%MEA were investigated and performance of15%WJM was superior to ordinary diesel with range from0.07MPa to0.1MPa, which was suitable to be used under vacuum conditions, the difference between deflagration performances of15%MEA and ordinary diesel was small.(6) In confined spaces, combustion characteristics of three oxygenated fuels by comparing with the flame temperature, and the flame structure under different airflow rates, the results showed that WJM had a relatively stable combustion characteristic.