凝析天然气管道分层流动相间水力摩阻系数计算式评价

前人已经得出了许多计算分层流动相间水力摩阻系数的经验、半经验半理论的公式.然而,由于它们多是以室内小型实验架上得到的数据为基础,虽然与各自的实验结果符合较好,但是普遍存在适用范围窄、精度低的缺陷.获得了大型多相流环道上的实验数据,并利用这些数据对部分常用的经验公式进行了评价.依据评价结果认为,当气相速度低于15m/s时,依据Chen等人的关联式的计算值与实验结果比较接近,误差不超过13.2%;当气相速度大于15m/s时,Hart等人的模型预测值与实验结果符合较好,误差普遍介于0~15.94%之间.因此,在凝析气管道的分层流动计算中,当气速较低时,推荐使用Chen等人的计算模型;而当气速较高时,则推荐采用Hart等人的模型来计算相间水力摩阻系数.

Evaluation of the formulas for calculating the interfacial friction factor of the two-phase stratified flow in horizontal condensate natural gas pipeline

Predecessors had obtained many empirical and semi-empirical formulas for calculating the interfacial friction factor of stratified flow. But the formulas are all based on the experimental data obtained on small-scale experimental models. They have generally the shortcomings of narrow applicable range and low accuracy although they accord well with the experimental results themselves. Here, the experimental data are obtained from large-scale multiphase experimental circular pipe, and the data are used for evaluating the empirical and semi-empirical formulas. According to the evaluating results, it is held that, the calculated results using the formula presented by Chen, et al are close to the experimental data when the flow speed of gas phase is lower than 15 m/s, the errors between them is less than 13.296 ; whereas the results calculated using the formula presented by Hart, et al are close to the experimental data when the flow speed of gas phase is higher than 15 m/s, the errors between them is in the range of 0- 15. 94% . Therefore, it is suggested that, the formula presented by Chen, et al should be used for calculating the interfacial friction factor when the flow speed of gas phase is lower, whereas the formula presented by Hart, et al should be used when the flow speed of gas phase is higher.