残炭颗粒的形态、结构及其在燃烧过程中的分布

MORPHOLOGY AND STRUCTURE OF CHAR PARTICLES AND THEIR DISTRIBUTION DURING COMBUSTION

本文利用光学显微镜和电镜,阐述了不同残炭颗粒的形态和结构以及它们在燃烧过程中的分布特征。这些结果表明,残炭颗粒的形态结构特征不仅依赖于煤的显微组分组成,而且也依赖于煤的变质程度。由镜质组形成的残炭(包括薄壁煤胞、厚壁煤胞和网状炭)在燃烧过程中迅速减少。而来自于惰性组的未熔炭,当它以等密度方式燃烧时,其数量上的减少非常缓慢,所以它们可能导致电厂飞灰中未燃炭含量增高。

The optic microscopy and electron microscopy have been used to observe the morphology and structure of individual char particles, and determine their distribution during combustion. The results indicate that the morphology and structure of char particles are dependent not only on maceral composition but also on coal rank. The vitrinite chars including thin and thick walled cenospheres and network char are generally characterized by developing many opened vesicles with spherical or elliptical contour. They decreased rapidly during combustion. The inertinite chars including micro disrupted,skeleton and unf used chars have an irregular shape and few vesicles. Their distribution is more complex than that of vitrinite chars during combustion. The amount of unfused char decreases very slowly when the combustion conducts in the iso- density way. Therefore, this unfused char may result in the high level of carbon content in fly ash.