热膜流速仪在浮阀塔板局部流动特性研究中的应用

在对热膜流速仪的探头标定及两相信号分离的方法等特性进行研究的基础上，测定了Ｖ－Ｖ浮阀塔板的流动特性。对于水，提出标定数据的两段线性拟合法，能够准确、快捷地用于流速测量。对气液两相信号分离的两类方法进行比较发现，概率法用于测定两相中每一相的时均速度，阈值法用于确定各相所占的比率都能取得比较准确的结果．测定了以Ｖ－Ｖ浮阀塔板几个阀片所形成的局部区域的气含率及流速分布特点，得出对实际应用具有指导意义的结果。

APPLICATION OF HOT-FILM ANEMOMETER IN THE STUDY ON FLOW CHARACTERISTICS OF VALVE TRAY

The characteristics of hot-film anemometer are studied on the aspects of calibration and gas-liquid two phase signal discramination. A new method of two segment linearization according fluid velocity for calibrating hot-film probe in water of uniform temprature developed here has proved to be superior to conventional methods presently in use. Two digits processing methods are analysed and compared on the basis of a large quantity of experimental data. Probability method is found superior to threshold method in case of measuring the mean velocity of either phase. Threshold method can reflect the practical interaction between fluids and probe. It's more favorable to investigate the void fraction of the two phase flow.For the characteristics of its structure,the liquid flow velocity and bubble properties on valve trays is very special. The void fraction above the valves is lower than that over the gaps of several valves apparently. As has proved to effect the mass transfer severly.Liquid flow velocity and void fraction distribution in the local area formed by the adjacent four valves are investigated. It's of great significance for the study of seperation efficiency of the whole tray.