论文部分内容阅读
针对一种可降低天然气高温燃烧过程中NOx生成量的脉动供燃料燃烧技术,研究了一个采用燃气流量脉动燃烧方式的射流扩散火焰。采用纹影和直接摄像手段观察了在燃气流量低频率(10Hz以下)脉动工况下的火焰特征及其变化,分析了火焰长度脉动特征和火焰内部结构的周期发展过程。研究发现:火焰内部结构的周期发展过程包括高速(波峰流量)燃气脉冲冲出、增长、燃气惯性冲出、回吸、低速(波谷流量)和高速燃气脉冲的分离、低速脉冲的增长等阶段。其中低速和高速燃气脉冲的分离是单火焰燃烧不稳定的原因。
In view of a pulsating fuel combustion technology that can reduce the amount of NOx generated during high-temperature combustion of natural gas, a jet diffusion flame with pulsating combustion of gas flow is studied. The flame characteristics and changes under low frequency (less than 10Hz) gas flow were observed by using the smear and direct imaging methods. The pulsation characteristics of the flame length and the periodic development of the internal structure of the flame were analyzed. The results show that the periodic structure of the internal structure of the flame includes the stages of high-speed (peak-flow) gas pulse outgrowth, gas inertial outflow, suction back, low speed (trough flow) and high speed gas pulse separation and low speed pulse growth. One of the low-speed and high-speed gas pulse separation is the single flame combustion instability.