槽式孔板低压湿气计量修正模型

Metering Correlation of Slotted Orifice for Low-pressure Wet Gas Flow

槽式孔板用于湿气计量时，由于气相中夹杂少量液体，差压值会发生显著偏高（即“虚高”），需要建立修正模型对“虚高”进行修正。该文对孔径比为0．5的槽式孔板进行了以空气一水为介质的湿气实验研究，分析了“虚高”与Lockhart—Martinelli参数、气体富劳德数、气液密度比之间的关系，提出了一个新的槽式孔板低压湿气计量修正模型。结果表明，在表压为0．25～0．35MPa、Lockhart—Martinelli参数为0．02～0．6、气体富劳德数为0．5—2．7的测试范围内，该修正模型能够很好地预测实际“虚高”，对由于液相存在而引入的气相流量误差进行修正后，气相流量相对误差在97％的置信度下小于±4％，明显优于其他槽式孔板湿气计量修正模型，可以满足生产计量的精度要求。

A slotted orifice in wet gas metering is required to find out a correlation to correct the liquid-induced over-reading. The wet gas response of the horizontally installed slotted orifice with 0.50 beta ratio is experimentally studied. After studying the relationship between the over-reading and Lockhart-Martinelli parameter, gas Froude number, the gas to liquid density ratio, a novel metering correlation for low-pressure wet gas flow is given. The results show that the new correlation corrects the liquid induced gas flow rate prediction error of the wet gas flow to ±4% at a 97% confidence level, with the conditions of pressure from 0.25 MPa to 0.35 MPa, Lockhart-Martinelli parameter from 0.02 to 0.6, and the gas Froude number from 0.5 to 2.7, which is distinctly more precise than other correlations of the slotted orifice.