Development And Calibration Of Two Phase Flow Conductivity Probe

Two-phase flow widely exits in many industries such as chemical industry, petroleum, nuclear energy and so on. The detection of its parameter has important significance. Two-phase flow is extremely complex. At the same time, two-phase flow measurement has not been solved well in the international.So it is called "the fluid difficult to measure". Nowadays, many new technologies have emerged at two-phase flow measurement field. Considering some two-phase flow detection technologies have restrictions in the application, conductivity probe method has great superiority. Although conductivity probe method belongs to the contact measurement, but it is not affected by the operator proficiency, and can directly give the electrical signal which is easy to observe. At the same time, In the aspects such as earthquake resistant, high temperature resistant, resist radiation, conductivity probe method has greater advantages.The thesis researches the conductivity probe method for measuring bubble velocity and void fraction of gas-liquid two phase flow bubble, the main work of the thesis includes:(1)Design and manufacture single sensor conductivity and dual sensor conductivity probe for measuring the void fraction and bubble velocity. Analog circuit of conductivity probe is designed. Completed the compiling and debugging of probe signal collection and processing procedures;(2)Design and set up a calibration bench for the two-phase flow measurement, including hydrostatic test section and L shaped experimental section;(3) Complete the relevant calibration experiments. Single probe to the measurement experiment for the void fraction of gas-liquid two phase flow are carried out based on hydrostatic test section.And the calibration of the probe was made using the height of water level variation method.Make the measurement of bubble velocity of two phase flow with dual sensor conductivity probe.And the calibration of the probe was made using the volume of air flow method. Single probe to the measurement experiment for the void fraction of gas-liquid two phase flow are taking based on L shaped experimental section. And the calibration of the probe will be made by using the quick closing valves method.The experiment result show that the text scetion can generate stable homogeneous bubbly flow. The calibration methods of the void fraction and bubble velocity is practicable.The single sensor conductivity and dual sensor conductivity probe have stable performance, and fast response; Signal analysis program has high precision in void fraction measurement.But there are larger errors in bubble velocity measurement, which needs to be improved.