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气液两相流管道流动参数复杂,一旦发生泄漏,管道内的工艺运行参数会发生改变,从而极大地增加泄漏检测难度。以流体力学基本守恒方程为基础,利用双流体模型建立气液两相流泄漏系统数学模型,并以5 km混输管道为模型,模拟分析分层流和段塞流流型下气液两相流管道的泄漏规律,探究流型、泄漏点尺寸及位置等因素对流动参数的影响。结果表明:管道发生泄漏后,管道沿线压力均降低;泄漏点上游流速略有上升,下游流速明显降低;泄漏点下游持液率降低,上游持液率几乎不变;当流型为分层流时,泄漏不会导致流型改变;当流型为段塞流时,较大尺寸的泄漏会使流型由段塞流变为分层流,较小尺寸的泄漏不会改变流型;泄漏点越靠近管道出口,泄漏点上游压力降低幅度越小。
Gas-liquid two-phase flow pipe flow parameters are complex, in the event of leakage, the process parameters within the pipe will change, thus greatly increasing the leak detection difficulty. Based on the basic conservation equations of hydrodynamics, a mathematical model of gas-liquid two-phase flow leakage system was established by using two-fluid model. The model of 5 km mixed pipeline was used to simulate the gas- Flow pipe leakage law, to explore the flow pattern, the size and location of leaks and other factors on the flow parameters. The results show that the pressure drop along the pipeline after the pipeline leaks; the flow velocity upstream of the leakage point slightly increases and the downstream velocity decreases obviously; the liquid holdup in the downstream of the leakage point decreases and the liquid holdup in the upstream reaches almost unchanged; When the flow pattern is slug flow, larger size leaks cause the flow pattern to flow from slug to stratified flow, and smaller size leaks do not change the flow pattern; leaks The closer the point is to the outlet of the pipeline, the lower the pressure drop in the upstream of the leak point is.