【作者】 周樟华；

【导师】 周昊； 岑可法；

【作者基本信息】 浙江大学 ， 工程热物理， 2006， 硕士

【摘要】 气固多相流运动的存在范围十分广泛，在电站锅炉系统中，准确地给出流体的流动特性，具有重要的意义。它关系到系统投入运转后的安全性、可靠性，经济性。光学波动法是测量气固多相流浓度和粒度分布的一种有效的手段。本文阐述了光学波动法测量气固多相流颗粒浓度的原理，并在实验条件下，利用此原理对多相射流的浓度和粒度分布进行了测量研究。 实验利用浙江大学多相流试验台，通过冷模试验对不同工况下的水平浓淡燃烧器出口气固两相射流的扩散特性进行了研究。主要涉及了三方面的内容：第一，按照模化比例进行了相关的模化计算，确定了模化工况，本试验中使用粒径为16μm左右的滑石粉对实际煤粉进行模化；第二，进行无粉送风的单相射流试验，得到了不同撞击块高度下，浓淡两侧射流的速度分布，并据此分析不同撞击块高度对射流的刚性影响以及速度差异对浓淡两侧煤粉分离效果保持的影响，认为撞击块分离装置对速度影响在合理范围之内，不会产生实际运行中淡侧喷口被烧坏的后果，对浓淡分离保持的负面影响也由于隔板的作用变得不是很明显，同时不同撞击块高度下的速度分布图为选择合适的撞击块高度提供了依据；第三，基于浓度测量对燃烧器出口的气固两相浓淡射流扩散特性进行研究，通过固定给粉浓度变换撞击块高度以及固定撞击块高度变换给粉浓度来测量设计测点的浓度分布，比较各种不同工况下浓度分布图，讨论撞击块高度及给粉浓度对浓淡分离的影响，认为撞击块高度是影响浓淡分离的主要因素。最后通过实际应用，对上海理工大学提供的用于测量浓度的光线探针给出了客观的评价。 此外，我们还以某电厂的锅炉为例，针对该电厂水冷壁容易结渣的问题，进行了锅炉冷模试验。我们对各燃烧器的一次风、侧边风、二次风、燃尽风进行不同的配风比，观察炉内的空气动力场，所得结果可以对燃烧器设计、现场运行提供有价值的参考。更多还原

【Abstract】 The gas-solid multiphase flow was existed in normal ways, it was important to get the results of the characteristics accurately, which related to the system works safely and ecomically in the power plant. A novel method of investigation the diffusion characteristics of the gas-solid multiphase jet flow was presented based on optics wave theory in this work. The experiments were conducted to determine the particle concentrations distribution and its size in the gas-solid jet flow from the rich/lean fuel burner with collision block.In this work, the author carrys through some research about the particle dispersion in gas-solid two-phase fuel rich/lean burner flow on the multiphase flow test-bed in Zhejiang University. The content of this test mostly touch upon three aspects: first, do some modeling calculation basing on the modeling ratio and define the test conditions.We use talcum powder with the particle diameter of 16μm in cold modeling tosimulation the coal particle in real boil. Second, do single-phase flow test , get different velocity distribution of rich/lean flow both in and out of the ejector nozzle in the condition of different height of collision block. We analysis the influences of the different height of collision block to the difference between the velocity of the rich side and that of lean side , and we believe that the difference in the rational range because of the exist of the curve plate. Third, a novel fiber probe is employed to investigate particle dispersion in gas-solid two-phase fuel rich/lean burner flow. By means of changing the height of the collision block basing on the fixed density of feeding powder and changing the density of feeding powder basing on the fixed height of the collision block , compare the different density distribution of the flow and discuss the influence to density by the height of collision block and density of feeding powder. We consider that the influence of the height of collision block is the most important and we can get different rich/lean ratio by adjusting the height of the collision block. At last we give更多还原