【作者】 肖卓楠；

【导师】 李保卫； 赵增武；

【作者基本信息】 内蒙古科技大学 ， 热能工程， 2009， 硕士

【摘要】 循环流化床锅炉(CFB)具有燃烧效率高、煤种适应性广、烟气中有害气体排放浓度低、负荷调节范围大、灰渣可综合利用等优点,是目前煤洁净燃烧的主要应用方向。风帽作为CFB上的关键部件对锅炉的燃烧过程有着重要影响。本文搭建了循环流化床布风板风帽特性研究的多功能试验台,进行了不同形式风帽的阻力实验和风帽小孔的射流实验。针对包头第一热电厂循环流化床锅炉风帽的改造,并自主设计和制造了新型的多角度侧箭头型风帽,用U型压力计测量了各种典型风帽的阻力变化情况,得出了风帽结构的阻力系数,并定性比较了其优缺点。风帽作为循环流化床锅炉燃烧设计中的核心部件,其阻力特性从一个侧面反映了风帽的性能,而风帽在密相区,尤其是其附近气固流动行为可以通过风帽喷出气体射流的流动轨迹和射流穿透床层的距离来宏观地描述。本文对包头第一电厂9#、10#锅炉改造前后的两种风帽射流深度进行了理论分析和研究。根据动量定理和适当的物理简化,建立了风帽斜向下射流的物理模型,根据密度相近的模化条件建立了射流运动的等效水模化试验台,最后,对改造前后两种风帽在循环流化床锅炉密相区的射流深度进行了对比。结果表明:实测的射流穿透深度和理论计算值吻合,并得到改造前后风帽射流深度的变化情况,为工程设计中风帽的选型与优化和改造提供有益参考。更多还原

【Abstract】 Boiler is one of the main steam power plants. Compared by the other boilers, CFB boiler has its own character .Especially as the advanced clean combustion technology, the large CFB boiler has a strong competitive in the market. So it has important theoretical and practical meaning to study the key problems of the large CFB boiler. This dissertation performs research on the nozzle structure, nozzle resistance character, penetrated depth of nozzle jet in the dense etc.Nozzle is the important burner in the CFB boiler, and its resistance coefficient is the base of the nozzle design. The nozzle resistance has great impact on the economy and stability of the running CFB boiler. The second chapter establishes on the nozzle test stand, and study four typical nozzle drag coefficient,Γtype, symmetrical arrow type and side arrow type which are developed independently, which compares qualitatively their own advantage and disadvantage. Thus the research helps to choose the nozzle in the engineering design。Jet’s moving in the dense phase from the nozzle is an important research subject. The third chapter based on the momentum theorem, simplified properly, physical models of the nozzle jet on the depth and the track of the jet in the dense phase which has been developed. Meanwhile, according to the simulated conditions of similar density, an equivalent water model test stand on the jet movement in the CFB dense-phase zone has been established. Compared with the physical model, the experiments agree well. The models can theoretically guide the structural design of the nozzle in the large CFB boiler and be value of engineering practice.更多还原