【摘要】 以250～300μm稻壳、麦秸和玉米秸为对象,研究了生物质粉在燃烧过程中颗粒尺寸和形态的变化,以及热解、燃烧条件的影响。结果表明:生物质粉颗粒形态差异显著,热解和燃烧后颗粒形貌均发生了不同程度的变化;热解过程中颗粒的收缩和破碎导致焦颗粒等效直径减小了9%～59%,燃烧后灰颗粒等效直径的变化取决于生物质种类和燃烧条件;而描述颗粒形态的参数(如横纵比、圆形度和圆度)的变化相对较小(2%～28%),受生物质种类及颗粒破碎、熔融聚集(简称融聚)作用的共同影响;热解温度主要影响颗粒尺寸参数的变化,而对形态参数的影响较小;燃烧温度、气氛则通过影响颗粒破碎、融聚等影响各参数变化。更多还原

【Abstract】 Size and morphology evolution during combustion of pulverized rice husk, wheat straw and corn stalk of 250-300 μm were studied, while the influences of pyrolysis and combustion conditions were investigated. Results show that the morphology of pulverized biomass particles is significantly different even for the same kind of biomass, and the morphology changes at different degrees after pyrolysis and combustion. Shrinkage and fragmentation of the pulverized biomass particles during pyrolysis lead to the reduction of the equivalent diameter by 9%-59%, depending on the biomass category and combustion conditions. The variations of the parameters describing the particle morphology, such as the aspect ratio, circularity and roundness, are relatively small by only 2%-28%, which are affected by the biomass species as well as the particle fragmentation, melting and conglomeration during pyrolysis and combustion. The influence of pyrolysis temperature on the variation of particle size is greater than that on the variation of morphology, and the influence of combustion temperature and environment on the variation of each parameter is realized through their actions on the particle fragmentation, melting and conglomeration.更多还原