利用双差压式节流装置测量湿气

Wet gas metering using double differential pressure device

为实现湿气气液两相的在线不分离测量,提出一种由内锥和文丘里组合构成的新型双差压式湿气测量装置,并进行了实验研究。针对内锥及文丘里湿气虚高值的特点,建立了基于Lockhart-Martinelli参数、Froude数、气液密度比的内锥高精度虚高模型;建立了文丘里Deleeuw修正模型,实现了对n值的高精度拟合。通过对内锥和文丘里管在湿气测量中气液两相精度的对比分析,建立了湿气气液两相测量的迭代修正算法。实验结果表明,对于压力P为0.1～0.2MPa,气相弗劳德数0.6～1.5,L-M参数0.002～0.12,质量含气率在30%～99%范围内,气相流量测量的平均相对误差优于±1%,液相流量测量的满度误差小于±10%。

In order to measure the gas and liquid flow rates of wet gas flow without separation on line,a novel double differential pressure device composed of one cone device and one Venturi tube for metering wet gas is presented here,and experimental research was carried out.Considering the overreading performance of Wafer-cone and Venturi,an overreading model for high accuracy cone differential pressure device based on Lockhart-Martinelli parameter,Froude number,density ratio of gas and liquid is put forward.A modified Deleeuw overreading model for Venturi differential pressure device was built,in which the polynomial representation of ＂n＂ value is given.Through comparing the metering accuracies of gas flow rates and liquid flow rates of cone flow meter and Venturi flow meter,respectively,a wet gas metering iteration algorithm for gas and liquid flow rates is obtained.Experiment results show that the mean relative error of gas flow rates is less than ±1% and full scale error of liquid flow rates is less than ±10% under the condition that the test pressure range is 0.1 MPa to 0.2 MPa,Froude number range is 0.6 to 1.5,L-M number range is 0.002 to 0.12,and gas mass rate range is 30% to 99%.