Abstract The online measurement of wet gas with extremely-low liquid loading (Lockhart-Martinelli parameter lower than 0.02) remains a challenge. In this study, three types of throttle devices, Venturi, orifice plate and cone, are compared experimentally with air-water two-phase flow in a horizontal pipe of inner diameter of 50 mm. And high-precision correlations are established to measure the gas and liquid flowrates via a single throttle device. Results show that the two-phase mass flow coefficient (K) of the three throttle devices are all increase linearly with the liquid densiometric Froude number and the K correlations are established respectively to correct the gas mass flowrate deviation. The pressure loss ratio (δ) for Venturi is sensitive and monotonous to the liquid loading, which contributes to the high accuracy of liquid flowrate measurement. By incorporating the K correlations, both the gas and liquid mass flowrates can be predicted precisely. The relative error of the gas mass flowrate predicted by the Venturi is within ±2.0% at 95% confidence level, and that of the liquid mass flowrate is within ±15% at 90% confidence level.

中文翻译：

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测量极低液体负载湿气两相流量的节流装置比较

摘要 极低液体负荷（Lockhart-Martinelli 参数低于0.02）的湿气在线测量仍然是一个挑战。本研究对文丘里管、孔板和锥体三种节流装置在内径为50 mm的水平管中与气水两相流进行了实验比较。并建立了高精度相关性，以通过单个节流装置测量气体和液体的流量。结果表明，三种节流装置的两相质量流量系数（K）均随液体密度弗劳德数线性增加，并分别建立K相关性来修正气体质量流量偏差。文丘里管的压力损失比 (δ) 对液体负载敏感且单调，这有助于液体流量测量的高精度。通过结合 K 相关性，可以精确预测气体和液体质量流量。文丘里管预测的气体质量流量相对误差在 95% 置信水平时在 ±2.0% 以内，液体质量流量在 90% 置信水平下的相对误差在 ±15% 以内。