Research on Overreading Model of Vertical Venturi Flowmeter for Forced Annular Flow

To minimize the impact of flow patterns on flow rate measurement, the swirler is employed to regulate wet gas into the swirling annular flow. This study utilizes a single differential pressure wet gas flow measurement device, which is composed of a swirler and a standard Venturi. By referencing the Chisholm model, the differences in the form and parameters of the overreading (OR) model for swirling annular flow in the vertically rising pipeline are analyzed. It is found that the OR model of the swirling flow is mainly reflected in the exponent n, which characterizes the two-phase slip. After comparing the existing model forms, a flow prediction model for swirling annular flow is established according to the Steven model. The experimental results demonstrate that the relative error of the gas phase flow prediction in the newly established model can be stabilized within ±10%, with a mean absolute percentage error (MAPE) of 2.91%. Furthermore, the model can be extended, particularly for high gas flow rates, where the relative error of flow prediction remains within ±5%.