细水雾在低浓度瓦斯输送管道中沉降规律的研究

Study on Settling Law of Fine Water Mist in Low Gas Transportation Pipeline

低浓度瓦斯输送细水雾安全保护系统是一项新兴技术。然而,细水雾在低浓度瓦斯输送管道中受到附加质量力、拖拽阻力和热泳力等作用而沉降,使得细水雾的浓度降低而直接影响低浓度瓦斯的安全输送。文章通过对细水雾颗粒沉降运动轨迹的理论分析得到细水雾颗粒在瓦斯流场中的力平衡方程,并从试验中得到在距喷嘴0.25m处细水雾的沉降速率明显大于其他位置,当瓦斯流场速度大于1m/s时,细水雾颗粒沉降速率随着输送距离的增加逐渐降低;对既定测试位置,细水雾沉降速率随着瓦斯流场速度的增大先降低后升高。其研究结果对低浓度瓦斯细水雾安全输送保护系统的设计及工程应用有一定的参考价值。

A fine water mist protection system of the low concentration gas transportation is a new technology. The fine water mist in the low concentration gas transportation pipeline affected by the additional mass force, drag resistance, thermophoresis force and other role would be settled down and thus the concentration of the fine water mist reduced would directly affect to the safety transportation of the low concentration gas. With the theoretical analysis on the particle settling movement trace of the fine water mist, a force equilibrium equation of the fine water mist particle in the gas flow field was obtained. From the experiments, the settling speed of the fine water mist at a 0. 25m distance of the spray nozzle was obviously higher than other locations. When the speed of the gas flow filed was higher than 1 m/s, the particle settling speed rate of the fine water mist would be steadily reduced with the transportation distance increased. At the fixed measuring location, the settling speed rate of the fine water mist would be firstly reduced and then increased with the gas flow field speed increased. The study results would have certain reference value to the design and engineering application of the safety transportation protection system for the low concentration gas with fine water mist.