花瓣燃烧器流场特性分析与研究  

Study on Flow Field Characteristic of Petal Swirl Burner

作　　者：赵伶玲[1] 周强泰[1] 赵长遂[1] 

机构地区：[1]东南大学洁净煤发电及燃烧技术教育部重点实验室,南京210096

出　　处：《燃烧科学与技术》2007年第1期20-24,共5页Journal of Combustion Science and Technology

摘　　要：采用三维贴体坐标结构化网格,对复杂曲面形状的新型旋流燃烧器(花瓣燃烧器)进行了三维的流场数值实验.模拟了旋流的衰减过程,分析了花瓣燃烧器的流场特点;首次给出了旋流燃烧器回流区的立体形状图,直观地反映了回流区的特性;分析了普通旋流燃烧器和花瓣燃烧器的流场参数,并对掺混系数进行了对比;通过花瓣燃烧器流场特性的研究得出,花瓣燃烧器的回流区是由径向回流区和中心回流区融合构成,端部呈花瓣状,所形成的特殊流场能够使煤粉颗粒从燃烧器喷入炉内后,不是首先向外扩散,而是迅速地进入回流区,与高温烟气迅速混合,形成稳定热源,为煤粉着火燃烧提供了前提条件,具有良好的稳燃性能.A three-dimensional body-fitted coordinate mathematics model is set up to simulate the flow field of petal swirl burner（PSB） . The swirl decaying is simulated, and the flow field characteristics of PSB are analyzed. The three-dimensional shape of the recirculation zone of PSB is presented. The parameters and the mixed coefficient of common swirl burner and PSB are analyzed. The results show that the recirculation zone of PSB consists of the radial recirculation zone behind each petal and the center recirculation zone, and the head of the recirculation zone has the petal-like shape. The mixing of the primary air-pulverized coal flow with the recirculation flue gas is taken into consideration for PSB design. The transfer of mass and heat transfer between the pulverized coal and the flue gas depend on not only the fluctuation of microscopic turbulence at the edge of the recireulation zone which is the main driving force in the older swirl burner, but also the highly intensive macroscopic convection transfer. This kind of flow pattern can force part of pulverized coal to move into recirculation zone and is profitable for reliable ignition and burnout of low volatile pulverized coal, excellent turndown feature and lower NOx emission.

关 键 词：花瓣燃烧器 数值模拟 流场特性 径向回流区 

分 类 号：TK223.23[动力工程及工程热物理—动力机械及工程]