【作者】 李晓龙；

【导师】 张仕民；

【作者基本信息】 中国石油大学（北京） ， 机械工程， 2017， 博士

【摘要】 目前,刚性摆臂式多通道高精度通径检测器广泛应用于检测管道变径、变形、内表面缺陷以及腐蚀等特征。但相对国外,国内对于刚性摆臂式多通道高精度通径检测器的研究起步较晚,直到2012年才第一次实现了刚性摆臂式多通道通径检测器的自主研发,这就造成了多通道通径检测器方面的理论研究相对较少。本文基于以上背景开展了对刚性摆臂式多通道通径检测器相关关键技术的研究。具体内容包括如下:(1)研制了适用于?355mm天然气管道的刚性摆臂式多通道通径检测器,并开发了通径检测器数据后处理软件,实现了管道内表面不同缺陷特征的检测和识别。进行了各部件性能测试实验,验证了自主研制的通径检测器的性能,使其满足了通径检测器的基本检测要求。在设计过程中总结了关键部件的设计原则及理论,为刚性摆臂式多通道通径检测器的国产化提供一定的理论基础。(2)针对通径检测器检测臂检测精度问题,分析了检测臂划过管道内表面凸起和凹陷特征的运动过程,并基于此提出了检测臂划过凸起缺陷的“弹跳模型”和划过凹陷缺陷的“收缩模型”。从模型中可以看出,检测臂的运行速度、弹簧预紧力、弹簧刚度以及缺陷外型对于检测臂的动力学特性具有重要影响。进一步证明以上因素与检测臂的径向检测精度以及轴向检测精度密切相关。(3)针对检测臂的检测精度问题,搭建了检测臂检测精度实验系统,通过实验的方法分别研究了检测臂运行速度、弹簧预紧力、缺陷外型等因素对于径向和轴向检测精度的影响规律。通过分析得出,检测臂运行速度越大,检测臂划过凸起缺陷的径向弹跳高度越大,划过凹陷缺陷的收缩值越大,因此径向和轴向检测精度都相应的下降。同理,弹簧预紧力或弹簧刚度越小,径向弹跳高度越大,收缩值也越大,径向和轴向检测精度相应的下降。对于凸起缺陷轮廓,检测臂与缺陷外轮廓接触点处切线斜率绝对值越大,检测臂径向弹跳高度越大,检测精度越低。此外,通过实验的方式验证了检测臂的”弹跳模型“和“收缩模型”正确性和准确性,对管道缺陷以及固有特征的准确识别具有重要指导意义。(4)在通径检测器数据处理方面,建立通径检测信号特征识别模型以及管道内表面识别基准,理论上实现了通径检测器中心偏移的误差修正,提高了检测精度。此外,分析了检测臂通过管道内部缺陷、焊缝、三通以及弯道等特征段的特性,并基于此分析基础上提出了相应的识别算法,为通径检测数据处理提供了一定的理论基础。论文的研究成果将为刚性摆臂式多通道高精度通径检测器的国产化提供一定的工程指导,也为后续通径检测相关技术的研究提供了一定的理论基础。更多还原

【Abstract】 At present,multi-channel high-resolution caliper pipe inspection gauge(pig)is widely used to measure pipeline deformation and diameter reductions such as dents and ovalities.CoMParing with the foreign caliper technology,the domestic product is left behind.China has not developed a multi-channel caliper pig independently until 2012.Consequently,it results in the lack of theoretical research on the caliper pig.Based on the above background,this dissertation is mainly to study the key technologies of multi-channel caliper pig,including:(1)A multi-channel caliper pig which is used in 14.7 inches gas pipeline and a data processing software are developed.It can be used to detect pipeline fedect,deformation and so on.Through experiment method,its performances are tested to ensure it meets basic detection requirements.Furthermore,some design principles and theries about caliper pig are proposed in the designing process,which provide theoretical basis for china caliper pig development to some extent.(2)Through analyzing the process of the detection arm of caliper pig sweeping across the convex and concave defect,“bouncing model” and “contraction model” are proposed.Through analyzing the models,it shows that the running speed,spring reload,spring stiffness and the shape of defect have an important influence for the detection precision.(3)An inspection system are built to study the detection precision of detection arm.Through experiment method,it studies the realtion between the running speed,spring reload,spring stiffness and defect shape and the detection precision of the detection arm.Through analyzing the experiment result,the following conclusion can be obtained.With the increasing of the running speed of the detection arm,its bouncing height will increase,so the radial and axial detection precision will decrease.With the increasing of the spring reload or spring stiffness of the detection arm decrease,its bouncing height will increase,so the radial and axial detection precision will decrease.For the defect,the precision decreases as the defect curvature grows.In addition,the experiment result prove the correctness and accuracy of the “bouncing model” and “contraction model”.(4)Through building recognition model of caliper pig detection data,the offset error between caliper pig center line and the center line of the pipeline is corrected and it improves the detection precision of caliper pig.In addition,the characteristics of the decteion arms sweeping across the defect,weld,pipeline tee and pipeline bend are studied and the recognition algorithm of these pipe features are proposed,which provides a theoretical basis for the study of caliper pig data processing.The results of this paper may be helpful for the development and theoretical studies of domestic caliper pig in the future.更多还原