中文摘要：

使用高速摄影、超细热电偶和纹影技术,对方形开口管道中锆粉尘云火焰传播特性进行了实验研究.锆粉尘通过压缩空气喷散到管道中形成粉尘云,随后,锆粉尘云被电火花点燃.实验结果表明,低质量浓度下,火焰传播速度和温度随质量浓度增加而增加.当粉尘云质量浓度为0.627 kg/m时,火焰传播速度和温度达到最大值,分别为30.41 m/s和1 716 K,其后随着质量浓度的继续增加,火焰传播速度和温度开始略微下降.锆粉尘云中粒子与空气形成气-固表面燃烧体系,一些粒子在燃烧结束前发生微爆.预热区厚度在0.39～2.52 cm,随粉尘云质量浓度的增加先减小后增加.

英文摘要：

The flame propagation characteristic of zirconium particle cloud in square-open tube was investigated. The zirco- nium dust was dispersed into the chamber by pressuring air flow to form a zirconium particle cloud, which was then ignited by an electrode spark. A high-speed video camera was used to record the images of flame propagation. Micro-thermocouples were used to obtain temperature profiles and schlieren optical system was used to detect flame structure. The results demon- strate that flame propagation velocity and temperature increase with the increase of dust cloud concentration at lower concen- tration, which reach the maximum values of 30.41 m/s and 1 716 K respectively at 0.627 kg/m3, and then decrease slightly at higher concentration. Zirconium particles and air form surface combustion system and micro-explosion occurs to some particles before the end of combustion. Preheat zone thickness is between 0.39-2.52 cm, which decreases first and then increases with the increase of dust concentration.