【作者】 惠胜利；

【导师】 金有海； 王建军；

【作者基本信息】 中国石油大学 ， 化工过程机械， 2008， 硕士

【摘要】 结合水煤浆悬浮-流化燃烧的特点,研究了不同操作参数和颗粒物性参数对循环流化床锅炉用直切式旋风分离器分离性能的影响规律。结果表明:随着入口气速和入口颗粒浓度的增加,分离效率会出现一个最大值;对粒度相差较大的物料,分离效率随入口颗粒粒度的增大而增大,而对粒度相差不大的物料,密度对分离效率的影响更为明显。分别采用五孔球探针测试仪及等动采样法对旋风分离器内时均流场和颗粒浓度分布进行了较为全面、详细的测定,分析了流场和颗粒浓度场分布对分离器分离性能的影响。结果表明:环形空间的纵向环流和滞留层会导致“顶灰环”现象;排气芯管下端附近的短路流会把部分未被分离的细小颗粒直接从芯管带出去;锥形空间靠近排尘口处上升气流对小颗粒产生返混夹带作用,以上因素均会导致分离器分离效率的降低。上述测量结果为循环流化床锅炉用直切式旋风分离器分离机理的研究及结构参数的优化设计提供了参考依据。更多还原

【Abstract】 These experiments according to the characteristics of fluidize-suspension burning of coal water mixture in circulating fluidized bed boiler, the effects of operation parameters and physical property of particle on separation performance were studied by measuring separation performance of cut-in style cyclone separator used in the circulating fluidized bed boiler under different operation parameters. Based on the measured results, separate efficiency will appear the biggest value when inlet air velocity and particle concentration increase; separationperformance will increase along with increase of particle size when particle size is more difference, the effect of concentration of inlet particle to separation performance will distinctwhen inlet particle size is similar.The distribution of gas flow field and particle concentration in the cut-in style cyclone were measured with five-orifice pitot tube and by means of isokinetic sampling method,analyze influence of flow field and particle concentration to separation performance of cyclone. Based on the measured results, portrait circumfluence and stagnation velocity layerin annulus space can result in top ash loop; there is a short circuit flow near the bottom of the vortex finder, which can carry the particle out directly; near the dust discharge port, in the section of the cone of the separator there is a re-entrainment of small particle by rise air. Allof them can lower the efficiency of the cyclone separators. All results above provided a base for further research on the cut-in style cyclone separator used in the circulating fluidized bed boiler and design of structural parameter of cyclone separator.更多还原