基于红外热像的气液两相分层流液膜厚度非介入测量

Gas-liquid two phase stratified flow liquid film height non-invasive measurement based on infrared imaging technique

对于输送高压、易燃易爆、强腐蚀性介质的气液两相流管道,电导探针等传统的介入式液膜厚度测量方法不适用.针对这种情况,提出了通过红外热像测量气液两相分层流液膜厚度的新方法:在管道外壁敷设加热带,通过施加恒定热流密度来增加气液相温差,通过采集红外图像识别气液界面获得液膜高度.在建立VOF多相流模型模拟恒定热流密度条件下管截面上温度分布特征基础上,实验在气液两相流环道上进行,采用热像仪采集管壁红外图像,真实液膜厚度由介入式电容探针测量,在试验范围内红外方法液膜厚度测量最大误差8.2%.

Traditional invasive liquid film measurement method such as conductance probe technique is not suitable for the gas-liquid two-phase flow system with high pressure,flammable,combustible and corrosity medium.A novel method was proposed based on infrared imaging for gas-liquid two phase stratified flow liquid film height measurement.In order to improve the measurement accuracy,a heating belt was applied to improve the temperature difference between the gas and liquid,the film height was obtained using infrared imaging to distinguish gas-liquid interface.A VOF multiphase flow model was used to simulate the temperature distribution of the pipe section under constant heat flux,based on this,the experiments were carried out at an air-water two-phase flow loop and the infrared image were obtained using an infrared camera.The gas-liquid interface position was determined according to the temperature gradient characteristics.The measurement results were compared with capacitance probe method.It showed during the experimental range,the maximum measurement error was 8.2%.