气液混输管道段塞流泄漏声波产生机理研究

Leak-acoustics generation mechanism for gas-liquid pipeline slug flow

气液混输管道的泄漏检测问题是油气混输管道安全运行的重要保障,段塞流是常见流型,同时也是研究难度最大的流型。为研究气液混输管道段塞流型下泄漏声波信号产生的机理,基于Fluent动网格以及UDF模拟泄漏发生的全过程,从气动声学与涡声理论出发分析泄漏全过程的流场、涡量以及声压变化,并与试验采集的声波信号与模拟信号进行类比,得到泄漏过程声波产生的机理。研究结果表明,气液混输管道段塞流泄漏后声波幅值增大,泄漏声源以偶极子声源为主;管道持续泄漏时,声源声压幅值随气塞与液塞交替到达泄漏口而呈周期性脉动;气液混输管道泄漏声压与总压波动趋势一致,可通过测量流体压力波动的方式获得泄漏声源产生的声波波动。泄漏孔径、气液流量是段塞流型下气液混输管道声波波动的主要影响因素。动网格仿真模拟与试验结合的方法可用于研究气液混输管道段塞流泄漏声波产生的机理。

The leakage detection of gas-liquid transportation pipeline is an important guarantee for the safety of oil and gas transportation pipelines.In order to study the leak-acoustics generation mechanism for gas-liquid pipeline slug flow,leakage process was simulated based on Fluent dynamic mesh and UDF.Flow field,vorticity,and sound pressure were analyzed based on aeroacoustics and vortex sound theory.Tests were carried out to evaluate the acoustic signal and analog signal,then mechanism of leak-acoustic generation was obtained.Results show that the amplitude of leak-acoustic of gas-liquid pipeline slug flow increases during leakage,and the leakage source is mainly a dipole source.The amplitude of acoustic pressure fluctuates periodically as the gas plug and liquid plug arrive alternately at the leakage point.The fluctuation trend of the leak-acoustic in the gas-liquid mixed transportation pipeline is consistent with that of the total pressure.The leak-acoustic can be obtained by measuring the fluctuation of the fluid pressure.Aperture and gas/liquid flow rate are the main factors of leak-acoustic wave fluctuation in gas-liquid pipeline slug flow.