单相水流阶段煤层裂缝中沉积煤粉的起动

Motion of incipient sedimental coal fines in coal seam fractures at single phase water flow stage

煤粉属于黏性颗粒,颗粒间的黏结力是影响煤粉起动的一个重要作用力,尤其在微小颗粒中黏结力的作用表现得更加明显。然而,目前学者们在研究煤粉受力时,却忽视了黏结力的影响。在考虑煤粉颗粒黏结力影响的基础上,运用水动力学理论,建立了单相水流阶段煤层裂缝中沉积煤粉起动的力学模型,得到了起动速度随着粒径的变大,表现出先减小后增大的结论。实例分析表明,当流速控制在某个合理范围内时,可以使一定粒径的沉积煤粉起动,并能顺畅通过渗流通道。

Coal fines belong to viscous particles,cohesive force between particles is an important force which affects coal fines incipient,especially in tiny particles. However,in the past studies,the cohesive force wasn＇t under consideration. In this paper,on the basis of considering the effects of cohesive force between coal fines particles,by using the water dynamics theory,the authors have established the mechanical model of sedimental coal fines motion in coal seam fractures at single phase water flow stage. The model show that the incipient velocity decreases first and then increases as coal fines size increase. The example has shown when the velocity is in an appropriate range,corresponding coal fines can start and go through pores smoothly.