管壁减薄的红外检测方法研究

对红外检测管壁减薄建立了物理和数学模型,提出了通过测量外壁面温度计算管壁厚度的计算方法。通过红外热像仪的测温误差计算公式,引进了安全系数,提高了检测管壁减薄的可靠性。分析发现:通过测量管道外壁面的温度变化,可以判断细微的管壁厚度变化。在相同的外壁面温度和相同流体温度条件下,管壁当量导热系数越低或管内流体的导热系数越低,管道减薄越严重。

Study on Detection of Pipeline Wall Thinning by Infrared NDT

A physical and mathematical model is presented on detection of pipeline wall thinning by infrared NDT,and a cal-culation method is given about how to compute the inner diameter of the pipeline wall through detection of the temperature distribution of pipeline surface. In order to improve the reliability of detection ,a safety coefficient is employed which is deduced from analyzing the error of temperature measurement of infrared imager. The conclusion can be drawn that the temperature difference on the outer surface of the pipeline can reflect the nice thinning of pipeline wall. The lower the thermal conductance or effective thermal conductance of pipeline wall and fluid in the pipeline ,the more seriously the pipeline wall is thinned when both the temperature of fluid and that of the wall are same.