煤与瓦斯突出两相流传播特性实验研究*

Experimental study on propagation characteristics of two-phase flow in coal and gas outburst

摘要:

为了探究煤与瓦斯突出后煤粉-瓦斯两相流传播规律，利用自主搭建的煤与瓦斯突出管网实验系统，研究突出后冲击气流压力衰减规律、煤粉运移分布特征。结果表明:在初始压力为0.4 MPa时共突出煤粉3.12 kg，管道内煤粉质量呈正态分布，管道前部煤粉分布较少，占突出煤粉质量33.7%，多为小粒径煤粉；管道中部煤粉分布最多，占突出煤粉质量61%，粒径分布范围广；后部煤粉分布质量最小，仅占突出煤粉质量的5.3%，但多为大颗粒粒径煤粉。煤粉在管道内测点处依次为分层流、均匀流、大颗粒流3种流态，每种流动形态所对应的运移速度与煤粉打击压力均呈现逐渐衰减的规律。突出后冲击气流压力沿管道呈现衰减趋势，冲击气流对管道内所造成的压力扰动可持续 4 s左右。

Abstract:

In order to explore the propagation laws of two-phase flow including the pulverized coal and gas after the coal and gas outburst,a self-built pipe network experimental system of coal and gas outburst was used to study the attenuation laws of impact gas pressure and the characteristics of migration and distribution of the pulverized coal after coal and gas outburst.The results showed that when the initial pressure was 0.4 MPa,the total outburst amount of coal was 3.12 kg,and the mass of pulverized coal in the pipe presented the normal distribution.The pulverized coal at the front of the pipeline was less distributed,accounting for 33.7% of the outburst mass of pulverized coal,with mostly the small particle size pulverized coal.The central part of pipe had the largest distribution of pulverized coal,accounting for 61% of the outburst mass of pulverized coal,with a wide range of particle size distribution.The rear part of pipe had the smallest mass distribution of pulverized coal,accounting for only 5.3% of the outburst mass of pulverized coal,but with mostly the large particle size pulverized coal.The pulverized coal at the measurement points in the pipe presented three flow patterns of stratified flow,uniform flow and large particle flow in the order,and both the migration speed and the impact pressure of pulverized coal corresponding to each flow pattern presented the law of gradual attenuation.After the outburst,the pressure of impact airflow decreased along the pipe,and the pressure disturbance caused by the impact airflow to the pipe could last about 4 s.