A Study on the Causes and the Treatment Measures of Slack Line Flow at the Crossing-over Points of the Oil Pipeline

Abstract

This paper points out the definition of the oil pipeline crossing-over points, and thereby identifies the existence and the position of crossing-over points by applying the graphical method and the analytical method. Besides, this paper analyzes the phenomenon of slack line flow from the perspectives of thermodynamics, structural mechanics and fluid mechanics. In order to analyze the motion characteristics of slack line flow, this study divides the control volume in stratified flow into several sections, and then carries out a mechanical analysis of the accelerating and the uniform flow section. Based on the analysis, the equations of the gas-liquid two-phase volume and other parameters in the pipeline are worked out. What’s more, with the time-averaged continuum equation, momentum equation, energy equation for turbulent flow, and RNG k − ε two-equation turbulence modeling, this paper works out closed-form simultaneous equations for gas-liquid two-phase flow in order to establish the calculation model of slack line flow section. This paper also introduces the calculation methods of fluid motion equations and some common simulation software. Furthermore, taking into account the fast velocity and instability of slack line flow, and its buffering effect, this paper points out its hazards, and puts forward the application of its buffering effect and the energy dissipation measures to prevent and control slack line flow.