柴油喷雾燃烧发光机理分析

An Analysis of Combustion Luminous Mechanism of Diesel Spray

为探讨柴油机燃烧光的性质，在容弹上采用光强传感器，并应用双色法在不同温度、压力、氧浓度与二氧化碳浓度的条件下，对柴油喷雾的燃烧光强波进行了测量分析。结果表明：在柴油机燃烧过程中，同时存在碳粒的氧化与还原两种反应，其中以氧化反应占优势，碳粒与其附面层温度基本一致。碳粒的附面层反应与柴油中其它气体成分的氧化反应形成火焰，所以可认为碳粒与火焰处于热平衡状态，碳粒的表面反应热以热辐射的方式向外界传递。表面反应热与辐射传热的平衡确定了碳粒的体积与密度。因此柴油喷雾的燃烧光强反映的是碳粒的辐射热强度，燃烧光强波反映的是碳粒的氧化过程。燃烧光强与火焰内的总碳量、氧的分压力、碳粒温度有关。

In this paper the combustion luminous intensity of diesel spray is measured and analyzed at various temperatures,pressures,oxygen and carbon dioxide concentrations in a combustion bomb by using luminous sensors and the twocolor method.The result shows:in the diesel combustion,the soots have both oxidizing reaction and reducing reaction,and the former is dominative.The soot temperature is equal to the temperature of its attachedlayer on the whole.The reaction in the attachedlayer of the soot and other gas oxidizing reaction of diesel spray form the flame,so there is heat balance of the soot and flame.The heat of surface reaction in the soot is released by heatradiating.And the balance of the surface reaction heat and the radiant heat determines the volume and density of the soot.Therefore,the combustion luminous intensity is a measure of the radiant heat of the soot a