柴油机燃用液化石油气两种方式的燃烧特性  

Combustion characteristics of two modes of diesel engine fueled with LPG

作　　者：祁东辉[1] 边耀璋[1] 刘卷苍[1] 

机构地区：[1]长安大学汽车学院

出　　处：《长安大学学报（自然科学版）》2006年第6期90-93,共4页Journal of Chang’an University(Natural Science Edition)

基　　金：陕西省自然科学基金项目(99C07)

摘　　要：根据实测示功图,计算了发动机的燃烧放热率,分析了一台小型直喷柴油机燃用液化石油气(LPG)两种方式的燃烧特性。研究表明:在小负荷运行时,预混进气方式的最高爆发压力随LPG替代率的升高逐渐降低,在大负荷运行时随替代率的升高先增后减;混合喷射方式的最高爆发压力在整个负荷范围内随替代率的升高逐渐降低。LPG替代率较小时,预混进气方式与混合喷射方式相比滞燃期较长,最高爆发压力和最大燃烧放热率较低,对应的曲轴转角滞后;LPG替代率较大时,预混进气方式的滞燃期较短,在小负荷时,最高爆发压力和最大燃烧放热率较低,但在大负荷时,最高爆发压力和最大燃烧放热率较高,对应的曲轴转角提前。Based on the cylinder pressure diagram, this paper calculated the heat release rate, analyzed the combustion characteristics of light duty DI diesel engine fueled with LPG in two different modes. The results indicate that at light loads the peak cylinder pressure of pre-mixing model decreases with the increase of LPG alternating ratios, but at high loads the peak cylinder pressure firstly increases and then decreases. The peak cylinder pressure of mixing injection model decreases with the increase of LPG alternating ratios at all range of loads. When the LPG alternating ratio is smaller, the ignition delay of pre-mixing model is longer, and the peak cylinder pressure and heat release rate are higher than those of mixing injection model, and their corresponding crank angles retard. When the LPG alternating ratio is larger, the ignition delay of pre-mixing model is shorter, and at light loads the peak cylinder pressure and heat release rate are lower, but at high loads, the peak cylinder pressure and heat release rate are higher, their corresponding crank angles move forward. 1 tab, 5 figs, 6 refs.

关 键 词：汽车工程 柴油机 LPG 燃烧特性 替代率 

分 类 号：U464.172[机械工程—车辆工程]