高温容器缺陷的红外三维诊断技术

发布时间：2018-07-27 11:12

【摘要】：许多工业容器由于长期运行在高温、高压及化学侵蚀的恶劣环境下,设备的内壁容易产生应力和腐蚀,进而会导致设备内部出现缺陷或故障,给生产安全带来隐患,因此对工业容器进行高效的在线检测就显得十分重要。红外热像检测技术是一种新的无损检测方法,通过对获得的红外热图像进行分析,来判断容器内部缺陷的情况。它适合外场、在线、在役检测,在电力、冶金、石油化工等众多领域得到了广泛的应用。红外热像检测技术也存在一些不足,目前在对设备状况进行诊断分析时主要依据的是获取的红外图像,但是红外图像空间层次感较差,依据二维红外图像难以准确判定缺陷几何特征,也难以准确确定缺陷位置,这会导致诊断的精度和实用性不足。针对这一问题,本文以高温容器缺陷诊断为目标,开展了红外三维诊断技术研究。采用三维激光扫描仪获取容器的三维点云数据,建立容器的精准几何场,同时热红外相机获取容器的温度场;将三维几何场和温度场叠加形成三维多源场,并结合数值模拟技术,在三维多源场上对缺陷进行三维诊断分析,最终实现了容器缺陷的三维诊断分析技术在实际工程中的应用。本文研究的主要内容如下:首先,通过实验验证了利用红外三维诊断技术对容器缺陷进行诊断的可靠性,并与传统红外检测技术进行了对比分析。结果表明,在得到的三维点云上可以实现缺陷诊断的三维可视化,可以准确定位缺陷位置,与传统方法相比可以比较简便的测出缺陷尺寸。在此基础上进行了一系列实验,研究了内外温差、检测距离、缺陷参数对红外三维诊断技术检测效果的影响规律,得到了以下结论:(1)提高内外温差的数值可以提高该技术的检测能力;(2)检测距离对该技术的检测效果有很大影响,减小检测距离可以提高该技术的检测效果;(3)该技术对缺陷的最大检测距离随缺陷的尺寸、深度的增大而增大,随缺陷尺寸、深度的减小而减小;(4)该技术对缺陷的检测能力受到缺陷本身属性的限制,对大尺寸、大深度的缺陷检测能力较强。在利用红外三维诊断技术对容器进行诊断时,不能仅仅简单判断一下缺陷是否存在,往往还需要依据获取的容器表面温度图谱来分析容器内部缺陷的情况。针对这一问题,本文以高炉炉缸为研究对象,在ANSYS软件中建立了含有不同形状腐蚀孔、裂纹的炉墙三维模型,开展了缺陷温度场数值计算,得到了常见特征缺陷对应的炉墙表面温度图谱,分析总结了不同缺陷对应的炉墙表面温度图谱的特点,从而为实际工程中分析容器内部缺陷情况提供必要的依据。最后,在上述研究的基础上利用红外三维诊断技术对工厂中的容器进行现场检测,建立了高温容器的数字化实景模型,在三维点云上对缺陷进行诊断分析,测出了缺陷尺寸、坐标位置以及缺陷距地面距离等缺陷信息。同时与前面数值模拟得到的温度图谱进行比较分析,推测出容器内部缺陷可能的情况,从而为指导设备维护提供准确依据。
[Abstract]:Many industrial containers are liable to produce stress and corrosion in the harsh environment of high temperature, high pressure and chemical erosion for a long time, which will lead to defects or failures inside the equipment and bring hidden dangers to the safety of production. Therefore, it is very important to carry out efficient line detection for industrial containers. It is a new nondestructive testing method to determine the internal defects in the container by analyzing the infrared thermal image obtained. It is suitable for external field, online, in service, and has been widely used in many fields, such as electric power, metallurgy, petrochemical and other fields. The infrared thermal image testing technology also has some shortcomings, and it is now in the condition of equipment. The infrared image obtained is mainly based on the infrared image obtained in the diagnosis and analysis, but the infrared image has a poor spatial level. It is difficult to accurately determine the geometric characteristics of the defect according to the two-dimensional infrared image, and it is difficult to accurately determine the position of the defect. This will lead to the lack of accuracy and practicability of the diagnosis. The three-dimensional point cloud data of the container is obtained by the three-dimensional laser scanner, the accurate geometric field of the container is established, and the temperature field of the container is obtained by the thermal infrared camera, and the three-dimensional multi-source field is formed by superimposing the three-dimensional geometric field and temperature field, and the defects in the three-dimensional multi source field are combined with the numerical simulation technology. Three dimensional diagnosis analysis is carried out. Finally, the application of three-dimensional diagnosis and analysis technology for container defects in practical engineering is realized. The main contents of this paper are as follows: first, the reliability of the diagnosis of container defects by using infrared 3D diagnosis technology is verified by experiments, and the results are compared with the traditional infrared detection technology. It shows that the 3D visualization of defect diagnosis can be realized on the 3D point cloud, and the defect location can be located accurately. Compared with the traditional method, the defect size can be easily detected. On this basis, a series of experiments are carried out to study the effect of internal and external temperature difference, detection distance and defect parameters on the infrared 3D diagnosis technology. The following conclusions are obtained: (1) increasing the value of the internal and external temperature difference can improve the detection ability of the technology; (2) the detection distance has a great influence on the detection effect of the technology, and the detection distance can be reduced to improve the detection effect of the technology. (3) the maximum detection distance of the technique increases with the size and depth of the defect. Large, decrease with the defect size and depth decrease; (4) the detection ability of the defect is limited by the property of the defect itself, and has a strong ability to detect the defects in large size and deep. In this paper, a three-dimensional model of the furnace wall with different shapes of corrosion holes and cracks is established in the ANSYS software, and the temperature field of the defect is calculated, and the temperature Atlas of the wall surface corresponding to the common characteristic defects is obtained. The characteristics of the temperature map of the furnace wall surface with different defects are analyzed and summarized, which provides the necessary basis for the analysis of the internal defects in the actual engineering. Finally, on the basis of the above research, the infrared three-dimensional diagnosis technology is used to test the container in the factory, and the digital real model of the high temperature container is set up. The defect is diagnosed and analyzed on the three dimensional point cloud. Defect information, such as defect size, coordinate position and distance from the defect to ground, is measured. At the same time, it is compared with the temperature map obtained from the previous numerical simulation, and the possibility of internal defects in the container is speculated, thus providing an accurate basis for the maintenance of the guide equipment.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG115.28;TF57

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