【摘要】 在中试试验台上研究了水煤浆流经直管、渐缩管、突缩管以及90°水平弯管的阻力特性,分析了渐缩角、管径比以及弯径比对上述局部管件阻力损失和均配的影响.结果表明,渐缩角的增加使得渐缩管的局部阻力损失减少;水煤浆流经突缩管的局部阻力损失先下降然后迅速地增加,同时存在一个最佳弯径比,使得水平弯管的局部阻力损失最小.随着雷诺数的增加,渐缩管当量长度与管径比值(Le/D)逐渐下降然后趋于稳定;突缩管则先下降再增加,而对于弯管成线性增加.弯管的摩擦阻力损失之比随着De的增加而迅速增加.更多还原

【Abstract】 The resistance characteristics of coal-water slurry fluid flowing through a straight pipe and three types of local fittings,which were gradual contraction,sudden contraction and 90° horizontal bend,were investigated at a pilot test-bed.The influences of gradual angle,contraction ratio and bend diameter ratio on resistance loss and equal allocation of local fittings were measured.The results show that,as contraction angle increases,local resistance loss of gradual contraction decreases,that of sudden contraction reduces first and then increases quickly,and there exists an optimal value of bend diameter ratio,at which resistance loss of horizontal bend is the least.With the increase of Reynolds number,the ratio of equivalent length to pipe diameter Le/D of gradual contraction diminishes first and then gets steady,that of sudden contraction decreases first and then increases,and that of 90° horizonal bend increases linearly.The ratios of friction loss of different bends increase as Dean number(De) increases.更多还原