Two-phase mass flow coefficient of V-Cone throttle device

Abstract

The V-Cone throttle device has been paid more and more attentions on the measurement of the wet gas flow in recent years. However, it tends to over-read the gas flow rate when directly used to measure the wet gas. How to correct this over-reading and obtain an accurate yet simple wet gas correlation is still one of the challenges in the investigation on the V-Cone throttle device. In this paper, the two-phase mass flow coefficient of the V-Cone throttle device was proposed to correct the deviation of the readings produced by the device. The parameters affecting the coefficient were determined and discussed experimentally. Two V-Cone throttle devices with the respective equivalent diameter ratios of 0.65 and 0.75 were investigated under the condition of the wet gas flow. The test fluid was air and tap water. The gas-to-liquid density ratio ranged from 0.002445 to 0.006083, and the gas densiometric Froude number ranged from 0.3 to 2.0. The influencing parameters including the Lockhart–Martinelli parameter, the gas-to-liquid density ratio, the gas densiometric Froude number and the equivalent diameter ratio were studied. Then the correlations of the two-phase mass flow coefficient and the influencing parameters were proposed for the two V-Cone throttle devices and evaluated experimentally. The results show that the relative deviations of the correlations are less than ±5.0% and the average deviations of the correlations are 2.06% and 2.22% for the V-Cone throttle devices with the equivalent diameter ratio of 0.65 and 0.75, respectively. It can be concluded that the two-phase mass flow coefficient of the V-Cone throttle device is crucial for the development of the wet gas correlation.