金属磁记忆检测系统的研究与设计

发布时间：2018-04-13 19:10

本文选题：金属磁记忆 + 管道无损检测　；参考：《哈尔滨理工大学》2015年硕士论文

【摘要】：管道如今被应用在广泛的领域当中，，无论在建筑工程中还是工业工程中，管道都是其中非常重要的一个组成部分，尤其对于石油天然气来说，是最重要的运输手段。也被誉为国家的生命线。据统计全球有8.2×104km的石油天然气运输管道，并且还将以每天7%的增量递增。然而长距离的运输对管道的消耗磨损也是巨大的，在大庆油田，随着时间的推进，埋设10年以上的管道占据了很大一部分，这使得管道发生穿孔断裂经常发生，对管道的检测维护是对石油安全运输的重要保障之一。而传统的检测方法，如超声波检测、漏磁检测等等都有其局限性，而长距离埋设的管道往往处于环境较为恶劣的地区，这使得这些检测设备不能正常使用。本文研究设计的金属磁记忆法弥补了上述不足，它利用处于地磁场中的铁磁性金属，受到外应力的作用产生自有漏磁场的特性，检测到铁磁金属的应力集中区域，从而判断损伤或缺陷的位置，从而达到检测管道的目的。金属磁记忆检测是由俄罗斯专家杜波夫提出的，同时也做出了比较成熟的产品，目前国内在这方面尚处于研究阶段。本文分析研究了金属磁记忆产生的原理，根据大庆炼油五厂的实际情况，设计了金属磁记忆检测系统，以实现贴壁管道检测与埋地管道检测两部分内容。文章选用霍尼韦尔的三轴磁阻传感器作为探头采集信号的部分，并通过单片机控制，实现A/D转换、信号放大等功能。由于地磁场强度及其微弱，采集到的磁信号往往伴随着大量的噪声，本文通过硬件滤波，以及根据滤波后的信号特征，采用了小波变换降噪法进行再次滤波。又经过对比分析，最终选用了dbN小波阈值降噪的方法，使得信号最大程度的去伪存真。本文通过仿真与实际的实验对比，说明了缺陷与应力集中区域的关系，以及影响信号特征的因素等等。最后通过现场实地实验，对管道进行了损伤评估，与实际情况基本一致，基本实现了金属磁记忆检测系统预期实现的功能。
[Abstract]:Pipeline is now used in a wide range of fields, both in construction and industrial engineering, pipeline is a very important part of the pipeline, especially for oil and gas, is the most important means of transportation.Also known as the lifeline of the country.According to statistics, the world has 8.2 脳 104km oil and gas pipeline, and will increase by 7% per day.However, long distance transportation is also a huge wear and tear to the pipeline. In Daqing Oilfield, over 10 years of buried pipelines have occupied a large part with the development of time, which makes pipeline perforation often occur.The inspection and maintenance of pipeline is one of the most important guarantee for the safe transportation of oil.But the traditional detection methods, such as ultrasonic detection, magnetic flux leakage detection and so on, have their limitations, while long-distance buried pipelines are often located in areas where the environment is relatively bad, which makes the detection equipment can not be used normally.In this paper, the metal magnetic memory method is designed to make up for the above deficiency. It uses ferromagnetic metal in the geomagnetic field to produce its own leakage magnetic field under the action of external stress, and detects the stress concentration area of ferromagnetic metal.In order to determine the location of damage or defect, so as to achieve the purpose of pipeline detection.Metal magnetic memory detection was put forward by Russian expert Dubov, and also made more mature products. At present, this aspect is still in the research stage in our country.In this paper, the principle of metal magnetic memory generation is analyzed and studied. According to the actual situation of Daqing No. 5 Refinery Plant, a metal magnetic memory detection system is designed to realize the detection of adherent pipeline and buried pipeline.In this paper, Honeywell's three-axis magnetoresistive sensor is selected as the signal acquisition part of the probe, and the functions of A / D conversion and signal amplification are realized by single-chip microcomputer control.Because of the weak intensity of geomagnetic field, the collected magnetic signal is usually accompanied by a large amount of noise. In this paper, the wavelet transform de-noising method is used to filter again by hardware filtering and according to the characteristics of the filtered signal.After comparison and analysis, the method of dbN wavelet threshold denoising is used finally, so that the signal can distinguish the false things to the greatest extent and retain the real things.In this paper, the relationship between the defect and the stress concentration region, and the factors influencing the signal characteristics are illustrated by comparing the simulation results with the actual experiments.Finally, through field experiments, the pipeline damage assessment is carried out, which is basically consistent with the actual situation, and basically realizes the expected function of the metal magnetic memory detection system.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE973.6;TP274

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