小麦淀粉粉尘云火焰传播特性研究

Study on propagation characteristics of wheat starch dust cloud flame

为探究受限空间内小麦淀粉粉尘爆炸燃烧特性,利用自行设计的小尺度粉尘爆燃试验平台、高速摄影系统、微细热电偶等对管道内小麦淀粉粉尘爆燃过程进行试验研究,分析粉尘云质量浓度对火焰传播特性影响。试验结果表明,小麦淀粉粉尘爆燃火焰表现出明显非均相燃烧特性;随粉尘云质量浓度增加,管道内火焰传播速度和火焰峰值温度均表现出先增大后减小的特征,该试验条件下,在粉尘云质量浓度为520 g/m^3时达到最大值;当粉尘云质量浓度低于520 g/m^3时,粉尘火焰的最大火焰传播速度与火焰峰值温度线性相关。

In order to explore the explosion and combustion characteristics of wheat starch dust in confined space,experiments were carried out by using a small scale dust deflagration experimental platform,a high speed photographic system and fine thermocouples among others. The influence of dust cloud mass concentration on flame propagation characteristics was analyzed. The results show that wheat starch dust deflagration has obvious heterogeneous combustion characteristics,that both the flame propagation velocity and the maximum temperature of the flame are a function of dust cloud mass concentration,and under the experimental conditions, the maximum values appear at the concentration of 520g/m^3,and that there is a linear correlation between the maximum flame propagation velocity and the peak temperature of the flame, when the dust concentration is less than 520 g/m^3.