Search Results

In this study, the novel fuel design concept has been proposed in order to realize the low emission and combustion control in engine systems. In the fuel design concept, the fuel mixed with high volatility fuel (gasoline or gaseous fuel components) and low volatility fuel (gas oil or fuel oil components) are used to improve the spray characteristics using flash boiling effect. The authors has addressed the combustion processes of the mixed fuel with n-pentane and n-tridecane (n-pentane/n-tridecane) using heat release analysis, shadow photography and two-color method in rapid compression and expansion machine (RCEM). It has been reported the spray characteristics of single component fuel, but that of multicomponent fuels is almost unknown. In the present study, it is reported the results of spray experiments for mixed fuels conducted in RCEM. The liquid and vapor distributions of n-pentane/n-tridecane were analyzed by using Mie scattering and planar laser-induced fluorescence (PLIF).

In the present study, we have proposed a novel fuel design concept in order to achieve low emissions and combustion control in engine systems. The fuel design concept is based on the combustion control that could be realized by using a mixed fuel with a lower boiling point fuel, such as gasoline or gaseous fuel components and a higher boiling point fuel, such as gas oil or fuel oil components. According to the fuel design concept proposed in this work, the characteristics of vaporization during mixture formation process as well as of combustion can be reasonably improved due to the formation of two-phase region. The heat release analysis was conducted to compare the temporal history of heat release for both a mixed fuel and a single component fuel that has the same transport properties of mixed fuels. In addition, the two-color method, which simultaneously allows the measurements of temperature distribution and soot concentration, is applied to the combustion field for mixed fuels.

In previous our work, we revealed that the flash boiling process could improve remarkably the spray atomization for the pure substance-single component fuel in relation to the port-injected S.I. engines. Then, we applied this flash boiling spray to the Diesel spray process by the use of the two phase region formed between liquefied CO2 and n-Tridecane as the first step of fuel design concept. And the promoted atomization properties could be obtained in this mixed fuel concept. Further, we could obtain the simultaneous reduction of NO and soot emissions in Diesel engine exhaust due to the spray internal EGR effect and reburning of soot. As the second step, we proposed a novel fuel design concept for low exhaust emission and combustion control, relating to mixed and reformulated fuels with a lower boiling point fuel such as gasoline components or gas fuel and a higher boiling point fuel such as gas oil or heavy oil components to obtain the both advantages of their fuels for combustion.