University of Science and Technology of China, Hefei 230026, People's Republic of China; City University of Hong Kong, Hong Kong, People's Republic of China.
University of Science and Technology of China, Hefei 230026, People's Republic of China.
J Hazard Mater. 2017 Apr 5;327:116-126. doi: 10.1016/j.jhazmat.2016.12.050. Epub 2016 Dec 26.
Research surrounding premixed flame propagation in ducts has a history of more than one hundred years. Most previous studies focus on the tulip flame formation and flame acceleration in pure gas fuel-air flame. However, the premixed natural gas-air flame may show different behaviors and pressure dynamics due to its unique composition. Natural gas, methane and acetylene are chosen here to conduct a comparison study on different flame behaviors and pressure dynamics, and to explore the influence of different compositions on premixed flame dynamics. The characteristics of flame front and pressure dynamics are recorded using high-speed schlieren photography and a pressure transducer, respectively. The results indicate that the compositions of the gas mixture greatly influence flame behaviors and pressure. Acetylene has the fastest flame tip speed and the highest pressure, while natural gas has a faster flame tip speed and higher pressure than methane. The Bychkov theory for predicting the flame skirt motion is verified, and the results indicate that the experimental data coincide well with theory in the case of equivalence ratios close to 1.00. Moreover, the Bychkov theory is able to predict flame skirt motion for acetylene, even outside of the best suitable expansion ratio range of 6<E<8.
管道中预混火焰传播的研究已有一百多年的历史。大多数先前的研究都集中在纯气体燃料-空气火焰中的郁金香火焰形成和火焰加速上。然而，由于其独特的组成，预混天然气-空气火焰可能表现出不同的行为和压力动态。本文选择天然气、甲烷和乙炔来进行不同火焰行为和压力动态的对比研究，探索不同成分对预混火焰动力学的影响。使用高速纹影摄影和压力传感器分别记录火焰前缘和压力动态的特征。结果表明，气体混合物的成分对火焰行为和压力有很大的影响。乙炔具有最快的火焰尖端速度和最高的压力，而天然气的火焰尖端速度和压力都高于甲烷。验证了用于预测火焰裙运动的 Bychkov 理论，并且在当量比接近 1.00 的情况下，实验数据与理论非常吻合。此外，即使在最佳膨胀比范围 6<E<8 之外，Bychkov 理论也能够预测乙炔的火焰裙运动。
