瓦斯抽采钻孔受限空间内钻屑运移特征

发布时间：2019-08-12 08:51

【摘要】：应用气力输送理论,建立钻屑颗粒群孔内悬浮模型,推导钻屑颗粒群启动最小气流速度求解方程,结合案例分析钻屑颗粒直径、摩擦系数及钻孔倾角对钻屑颗粒群启动速度的影响规律。结果表明,施工俯孔时,最小启动风速存在极值θD,θDθ0时,伴随钻孔倾角θ绝对值增大,所需最小启动风速va逐渐增大,在θD~-π/2范围,伴随钻孔倾角绝对值的增大,所需最小启动风速va呈现小幅度减小趋势;施工仰孔时,存在角度θU,当0θθU时,伴随仰孔倾角逐渐增大,所需最小启动风速逐渐降低,当θθU时,钻屑在自重作用下自行滑落;摩擦系数对最小启动风速的影响规律与钻孔倾角类似,当俯孔倾角θ=-π/2时,不同摩擦系数曲线交于同一点,表明当θ=-π/2时,最小启动风速与摩擦系数无关。
[Abstract]:Based on the pneumatic conveying theory, the suspension model in the hole of drill chip particle group is established, and the equation for solving the minimum airflow velocity of drill chip particle group is derived. the influence of drill chip particle diameter, friction coefficient and drilling inclination angle on the starting speed of drill chip particle group is analyzed with a case study. The results show that the minimum starting wind speed va increases gradually with the increase of the absolute value of drilling inclination angle, and the minimum starting wind speed va decreases slightly with the increase of the absolute value of drilling inclination angle when the minimum starting wind speed exists extreme value theta D, and the minimum starting wind speed va increases gradually with the increase of the absolute value of drilling inclination angle in the range of thd 鈮，

本文编号：2525612