湍流射流火焰中煤粉颗粒尺寸和结构的变化

采用湍流煤粉射流火焰模拟实际工业煤粉燃烧中的迅速热解，取样分析实验研究煤粉热解过程中颗粒尺寸和内部结构的变化。结果表明：在热解过程中煤粉颗粒体积发生了明显的膨胀，膨胀程度强烈地依赖于颗粒的初始尺寸和加热速率；热解时挥发份的迅速释放及煤的热塑性导致了颗粒内部的空心结构，这种结构有效地提高炭粒的燃烧速率。

A Study of Variation of Size and Structure of Pulverized Coal Particles in a Turbulent Jet Flame

A turbulent coal jet flame is employed to simulate the rapid devolatilization of pulverized coal in practical coal combustion. The variation of the size and internal structure of coal particle during devolatilization were investigated through a sampling analysis technique. It is found that the volume of coal particles obviously expands during the devolatilization and the extent of the expansion heavily depends on the particle size and heating rate. During the devolatilization, the hollow structure of coal particles is formed due to the rapid release of volatile, which can result in more rapid combustion of char particles.