滞止流场非均相燃烧系统及颗粒流着火特性研究

燃料颗粒特别是煤粉的实际反应大都发生在有拉伸流场中，探索均匀单分散颗粒流在有拉伸流场中的着火特性和机理，对推动工业燃烧和污染物减排研究、发展推进技术乃至国防科技均有重要作用。本课题基于对冲射流纯一维特性及拉伸率可控的优点，通过研制均匀单分散颗粒流的产生及输运方法和装置、建立新型对冲颗粒流非均相反应可视化平台，能够精确测量和控制流场拉伸率、颗粒数浓度及质量流率，并以准稳态的来流加热条件测量颗粒着火温度，基于高速摄像技术获得颗粒着火的瞬态特性，基于像增强技术和图像统计算法获得颗粒着火的平均特性。进而以煤粉为研究对象，分别考察拉伸率对单颗粒煤及煤粉云着火特性的影响，建立拉伸流场中颗粒着火特性评价指标和方法、分析影响机理并开展模型预报。从而为改良煤粉燃烧器、提高颗粒流的稳燃性和燃烧效率提供新的视角和理论支持。

Fuel particles, especially pulverized coal, usually react in a strained flow circumstances. Exploring the ignition characteristics of uniform mono-dispersed particle-laden flow in a strained flow is highly useful to the developing of industrial combustion process, as well as the research of aerospace propulsion. This work is aimed at the experimental solution and a theoretical model which can give the detailed mechanism of this question. Based on the one-dimensional counterflow jet system, a new-style mono-dispersed particle generator will be developed, and a high-speed camera together with an ICCD camera will be used to capture and characterize the ignition process of the particle-laden flow. Then a series of experiments focused on ignition of pulverized coal will be carried out to find the regular pattern. Based on the data, a new transient ignition model considering the modification of diffusion term caused by strain rate will be developed to explain and forecast the ignition characteristics of particle-laden flows in stagnation flow.