GAS-LIQUID FLOW MEASUREMENT BY MEANS OF THE DUAL PRESSURE DROP TECH: VARIANCE ANALYSIS OF OUTPUT PARAMETERS FROM INPUT PARAMETERS.
André Pianissolla Zorzal1; Rogério Ramos1; Márcio Coelho de Mattos1
1 UFES
doi:10.20906/CPS/COB-2015-1246
Resumo
The multiphase flows measurement is a current technological challenge, especially to valuable oil and gas flows. Among diverse technologies which measure the flow of each phase, in a so-called gas-liquid two-phase flow, the dual pressure drop technique has been prominent in the industry, mainly due to its simplicity, robustness, price and for being non-radioactive, unlike some models available on the market. In order to understand the uncertainty of this type of flow measurement, it is important to estimate the sensibility of each variable in the whole measurement process. The evaluation of the variability of the differential pressure taps (basics input parameter on the model) was performed through random disturbances and the consequent variability in the measurement of the void fraction and the total volumetric flow (output parameters) were computed by a meter model found in the open literature. It was found that, using this dual pressure drop model, the variability in the pressure drops with a standard deviation (SD) of 1% returns void fraction SD of 2.69% to 9.33%, and 1.15 to 8.02% for the velocity, depending on the flow condition. It was also observed that larger SD for the void fraction are found when the void fraction is low (<0.5) and larger SD for the velocity when the void fraction is high (> 0.5) comparing to same fluctuations.
Palavras-chave: Flow Measurement; Multiphase Flow; Homogenous Two-phase Flow; Gas-Liquid; Variance Analysis