高速大负荷下EGR阀开度对柴油机热量分布的影响

Effect of EGR Valve Opening on Heat Distribution of Diesel Engine at High Speed And High Load

为研究采用EGR路线排放控制技术的柴油机热量分布特点,以某增压中冷直喷柴油机为对象,研究高速大负荷下改变EGR阀开度对柴油机热量分布的影响。在柴油机上通过改变EGR阀开度,分析其热量分布随EGR阀开度变化而变化的特点。结果表明:当转速一定,增大EGR阀开度,柴油机中有用功热量、废气带走热量、中冷器带走热量百分比总体呈下降趋势,冷却液带走热量、余项损失总体呈上升趋势;并且相较于更低转速,高转速时冷却液带走热量百分比在整个过程中变化率更大。

In order to study the characteristics of heat distribution of diesel engine with EGR route emission control technology,a supercharged intercooled direct-injection diesel engine is taken as an object to study the effect of changing the EGR valve opening on the heat distribution of the diesel engine under high speed and large load.The characteristics of heat distribution with the change of EGR valve opening are analyzed in the diesel engine by changing the EGR valve opening.The results show that:when the rotational speed is certain,increasing the EGR valve opening,the percentage of heat taken away by useful work,heat taken away by exhaust gas,and heat taken away by the intercooler in the diesel engine shows a decreasing trend in general,and the percentage of heat taken away by the coolant and the residual loss shows an increasing trend in general;and the percentage of heat taken away by the coolant at high rotational speed shows a larger rate of change in the whole process compared to lower rotational speeds.