天然气炭黑燃烧特性的热天平研究

Thermogravimetric Study of the Combustion Characteristics of Natural-gas Soot

利用热重分析天平对天然气扩散火炬中直接取样得到的炭黑的燃烧性能进行了研究,并选用了蜡烛炭黑、4种商业炭黑以及一种无烟煤焦炭作为对比。基于试验结果确定了燃烧动力学特性参数,并分析了它的燃烧特性。天然气扩散火焰中生成的炭黑具有着火相对容易、着火温度较低(与煤焦或挥发份较低的煤比)、前期燃烧较弱、后期燃烧较缓慢、燃尽时间较长等燃烧特性。这些结果为利用天然气燃烧过程的炭黑生成强化火焰辐射特性并进行有效控制提供了依据。

By using a thermogravimetric analytical balance a study was conducted of the combustion performance of the soot obtained by a direct sampling in a natural gas diffusion flame. Furthermore, candle soot, four kinds of commercial soot and a kind of anthracite coke were selected for comparison study purposes. On the basis of test results the parameters of combustion kinetics characteristics were determined along with an analysis of their combustion features. The soot obtained in a natural gas diffusion flame possesses the following combustion features: a relative ease of ignition, a comparatively low ignition temperature (compared with coke or coal with a relatively low volatile content), a relatively weak combustion during an earlier period, a relatively slow combustion at a later period, a fairly long time needed for burn-out, etc. These results and findings can provide a basis for utilizing the soot-generated intensified flame radiation characteristics and for their effective control in the natural gas combustion process.