瞬态工况下柴油机燃烧模型参数变化研究

The Variation of Combustion Model Parameters during Diesel Engine Transient Operation

为了研究零维燃烧模型中特征参数在瞬态工况下的变化规律,对涡轮增压柴油机在转速1500r/m in负载由30%额定功率在5 s内均匀增加到100%的瞬态工况下的缸内压力、进气流量、燃油流量等参数进行了测量,用三次W iebe函数模拟了加载过程中每循环的燃烧放热率,利用非线性回归方程求解出了W iebe函数中的特征参数,并对其在瞬态工况下的变化规律进行了分析,提出了三次W iebe函数特征参数选取的经验公式,可以用来预测瞬态工况下的放热规律。

In order to analyze the character parameters of zero dimensional combustion model under transient conditions, the pressure in cylinder, air mass flow and fuel mass flow of turbocharged diesel engine were measured under the condition of engine speed fixed at 1 500 r/min and load increased from 30% to 100% continuously in 5seconds. The rate of heat release （RoHR） of every cycle during engine transient operation was simulated by thrice Wiebe＇ s function, the character parameters of Wiebe＇ s function were calculated using non-linear regression equation, and the change rule under transient operation is analyzed. The experimental formulas of character parameters were brought out, and the RoHR under transient engine operation can be predicted by using the formulas.