气体—幂律液体两相水平管流的压降计算

在气体—幂律液体两相水平管流实验研究的基础上,按两相介质分布外形,将气液两相流动的流动型态划分为泡状流、层状流、波状流、团状流、冲击流及环状流,并指出流动型态是决定两相管流压降规律的重要因素,对不同流动型态的流动机理和特点进行了探讨,给出了不同流动型态计算压降的方法,对于层状流与波状流,气液间具有明显的界面,可采用分流模型;对于泡状流,两相间无滑动,可采用均流模型;对于团状流与冲击流,由于流动机理十分复杂,故采用定义无因次压力梯度的方法;对于环状流,通过联立分气相折算系数与洛克哈特—马蒂内利参数求得压降。本方法不仅为油气不加热集输工艺的系统设计提供了可靠的水力计算方法,而且也可以应用于石油、化工等领域。通过与其它计算压降的方法对比,说明本计算方法平均绝对百分误差小、准确度较高。

Pressure Drop Calculation of Two Phase Horizontal Flow of Gas-Power Law Liquid.

On the basis of experiment and research on the tow-phase horizontal flow of Gas-Power Law Liquid, classification is done according to two phase medium, the flow state of gas and liquid two phase flow is classified as: bubble flow,stratified flow,wavy flow,slug flow,impacted flow and annular flow. The flow state is the main factor for defining pressure drop rule of two phase flow. The writers went further into the problem of the mechanism of different flow states giving the method of calculating the pressure drop of cliffereat flow states. There is obvious interface between gas and liquid for stratified and wavy flows. Flow separating models can be adopted. As for bubble flow, monophasic flow models can be used for there is no sliding between the two phases. Reguarding slug flow and impact flow, definition but dimensionless pressure gradient method can be chosen because the flow mechanism is rather complicated. And for annular flow, pressure drop value can be available by correlating the simultaneous coefficient of split gas phase and Lockhart and Martineli parameters. The said method provides a reliable hydraulic calculation not only for the design of unheated oil and gas transportation but also for petroleum and chemistry industry. The average absolute error of this method, compared with other methods is very small and high in accuracy.