Real Time Detection Of Parameters Of Carbon Dioxide Gas-liquid Two-phase Flow

With the further deepening of energy conservation and emission reduction in the international community,the Carbon Capture and Storage(CCS)technique is getting more and more attention from the world and has enormous development potential.In the transport link of CCS technique,especially transportation by pipeline,the pressure and the temperature will change inevitably after long-distance transportation,which leads to the phase change of carbon dioxide directly.In order to measure flow accurately,it is of great necessity to measure the void fraction of carbon dioxide two-phase flow.This thesis is based on the transportation of carbon dioxide in industry and capacitive sensor is adopted to measure the void fraction of carbon dioxide gas-liquid two-phase flow after the research on the measurement methods of void fraction of the traditional gas-liquid two-phase flow.At the same time three factors affecting the measurement accuracy of capacitive sensors are summarized in this paper,solutions to different factors are given and a coaxial electrode capacitance sensor is manufactured.After that an experimental device is set up and then experiments are carried out respectively at 20 degrees Celsius and 30 degrees Celsius to measure the void fraction of carbon dioxide gas-liquid twophase flow and finally the experimental data are got.At last,the Matlab is used to draw curves between the capacitance value as well as the relative error and the void fraction.The analysis of the curves proves that using the coaxial electrode capacitance sensor to measure the void fraction of carbon dioxide gas-liquid two-phase flow is correct in principle and feasible in reality.By comparing the curves at different temperatures,it is proved that there is necessity of maintaining the temperature constant or taking the temperature compensation measures in the process of experiment.