【摘要】 基于炉膛中煤粉空气射流的流场特征，提出了以高温回流区内煤粉挥发分燃烧释热来加热和点燃煤粉气流从而实现火焰稳定的集总分析模型，并以回流区温度的变化率为判据找到了稳定煤粉气流的回流区特征尺度，据此就能近似判定各种煤粉气流流场的火焰稳定性能。更多还原

【Abstract】 Based on the fact that the temperature of the recirculating region formed by the pulver-ized-coal-airstream in the furnace is uniformly distributed in the burning state,a lumped ana-lytical model for explaining the flame stability of the pulverized coal combustion is presented. In the model,it is assumed that onlv the combustion of the volatile matter emitted from thepulverized coal exists in the recirculating region and is controlled by the emission law of thematter. It is also assumed that the preheating and ignition of the pulverized- coal-airstreamresult from the heat and mass transfer between the recirculating region and the mainairstream. Several typical recirculating regions are analyzed with the model and the minimumcharacteristic size of the recirculating region for flame stabilization is found from the fact thatthe rate of ten1perature variation is equal to zero in the recirculating region.更多还原