煤燃烧过程中的热应力破碎的研究

从理论上分析了煤燃烧过程中热应力破碎的特性．结果表明煤颗粒的抗压强度越小、煤的热传导系数越小、颗粒越大、炉膛内的温度越高、烟气对颗粒的传热性能越好，煤颗粒越容易或越早破碎．对于小颗粒的情况，尽管颗粒内部的温度梯度很小，但是由于温度的瞬时巨大的变化，在极短的时间内颗粒内部还是产生很大的应力，使得颗粒可能发生破碎。

Fragmentation of coal particles by thermal stresses during combustion

The characteristics of thermal fragmentation were analyzed. The result indicated that the possibility of fragmentation would increase with furnace temperature, particle size and the ability of heat transfer between the combustion gases and coal particles, but would decrease with the compressive strength of coal particle and the thermal conductivity of coal. To the fine coal particle, the internal temperature gradient was small, but the change of temperature was big in a short time, so the internal thermal stresses were big to make the particle fragmentation.