管内相分隔双压差在多相流双参数测量中的应用

Dual differential pressure used in multiphase flow double-parameter metering based on phase-isolation

应用管内相分隔技术可以产生沿管道横截面的径向压差和沿管壁变化的轴向压差,研究表明,径向压差与两相流的总流量和相含率呈一定函数关系,若轴向压差与两相流的总流量和相含率也呈一定的函数关系,那么就可以通过双压差(轴向压差和径向压差)的联立实现多相流双参数的测量。以油水两相流为例,系统研究了基于管内相分隔产生的轴向压差在多相流测量的理论机理,并结合径向压差进行了实验验证。结果表明,在管内相分隔状态下,旋流器下游某两截面之间的轴向压差与油水两相流的总流量和体积含油率呈一定的函数关系,两者的实验值和理论值之间的相对误差分别在±1.05%和±9.84%以内;通过双压差的联立,可以求出某一状态下两相流的总流量和相含率,两者的实验值和理论值之间的相对误差分别在±1.13%和±6.89%以内,验证了基于管内相分隔双压差在多相流双参数测量应用的可行性。

The axial differential pressure and radial differential pressure can be generated by phase-isolation method.Once measuring the radial differential pressure between the pipe wall and pipe center of a cross section downstream of the swirler,the mass flowrate and phase holdup can be determined if either of the two parameters was known.If axial differential pressure also has a certain relationship with the mass flowrate and phase holdup,then multiphase flow double-parameter metering can be realized by dual differential pressure(the axial differential pressure and the radial differential pressure).Taking oil-water two-phase flow as an example,the mechanism of axial differential pressure used in multiphase flow measurement was studied and the experimental verification was carried out.The results show that the axial pressure difference between certain two sections downstream of the cyclone is a certain function of the total flow rate and volume oil content of the oil-water two-phase flow under the state of phase separation in the pipe.The relative error between the experimental value and the theoretical value of the two is within±1.05%and±9.84%respectively.Besides,the mass flowrate and oil cut can be determined by dual differential pressure with the relative errors are within±1.13%and±6.89%respectively,which verified the application feasibility of dual differential pressure used in multiphase flow double-parameter metering based on phase-isolation.