The Study On GVF Influence Regularity And Correction Method Of Gas-Liquid Two Phase Flow Measurement Using Coriolis Flowmeter

In the petroleum industry, the phase interface and the relative speed of gas-liquid flow restrict Coriolis flowmeter's application in the case that the liquid often contains a small part of gas. Traditional Coriolis flowmeter can measure the mass flow of single phase flow accurately, but it results in unusual work conditions and large errors while measuring gas-liquid two-phase flow.According to the above problems, the flowrate and density two parametric measurement of gas-liquid two-phase flow based on Coriolis mass flowmeter was studied by a mass of experiments. In these experiments, liquid flow was maintained at a fixed value, experimental data were collected under different gas void fraction. The relationship among gas void fraction, flow pattern and Coriolis flowmeter measurement accuracy is summed up, the main influence factor on the Coriolis flowmeter measurement accuracy due to the presence of aeration and its influence rules are summarized. When the gas void fraction increases, the small bubbles are coalescent to become bigger, which leads to greater influence on the Coriolis flowmeter performance.To improve the measurement accuracy of gas-liquid two phase flow using Coriolis flowmeter, the correction method based on bubble model and the correction method based on the drift model were proposed, these two correction methods were both applied on experimental data. The simulation results showed that the modified model achieved good effects, when gas fraction is not more than 8%, these two correction modal both play good performance, corrected mass flow measurement error is within 2%A data collection platform based on Visual Basic 6.0 serial interface communication was developed, it contained data acquisition module, modified module, display module and serial interface communication module. The correction model based on drift flux model was implanted to the data collection program, in order to compare the real-time data with standard measurement data. The data collection system can accurately collect data and keep stable operation by laboratory commissioning.