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空气往火焰中的卷吸率和放热率是在一台直喷式柴油机中用热力学方法计算的:推荐了一种双区模型,使用气缸压力、火焰温度和喷油率三个测得的数值作输入数据。由各种条件下的卷吸率和放热率间的相互关系,就可知道,扩散燃烧的初期和主要阶段的燃烧主要受空气往火焰中卷吸的控制。我们也研究了喷射压力、活塞形状和涡流强度对空气卷吸的影响。火焰中的混合程度是用火焰中的当量比评定的,后者也是用同一模型得到的。排气中氧化氮和炭烟浓度趋势是与火焰中的当量比和在所有各种条件下测得的火焰温度密切相关的。
The entrainment rate and heat release rate of air into the flame are calculated thermodynamically in a direct injection diesel engine: a two-zone model is recommended using three measured cylinder pressures, flame temperatures and fuel injection rates Value as input data. From the relationship between the entrainment rate and the heat release rate under various conditions, it can be seen that the combustion in the initial and main stages of the diffusion combustion is mainly controlled by the entrainment of air into the flame. We also studied the influence of injection pressure, piston shape and swirling intensity on air entrainment. The degree of mixing in the flame is assessed by the equivalence ratio in the flame, which is also obtained using the same model. The trends in the concentration of nitrogen oxides and soot in the exhaust gas are closely related to the equivalence ratio in the flame and the flame temperature measured under all conditions.