【作者】 杨志军；

【导师】 戴光；

【作者基本信息】 大庆石油学院 ， 化工过程机械， 2003， 硕士

【摘要】 油田储罐底板由铁磁性材料制成，长年在自然环境和液位变化条件下运行，受到多种不利因素的影响，不可避免地受到各种损伤。特别是环境中的化学腐蚀和电化学腐蚀引发的腐蚀穿孔、裂纹扩展以及破裂等，使介质泄漏，引起严重灾害和环境污染，给国家财产造成巨大损失。所以，每隔几年必须彻底检查储罐，对腐蚀程度做出评估。以往，国内油田多采用手工检测方法，劳动强度大，检测时间长，报废、维修缺乏科学性，尤其对罐底外表面金属腐蚀没有很好的检测方法。近年来，随着计算机软硬件技术和无损检测(NDT)理论的发展，储罐的智能化探伤已经成为可能。 储罐检测目前常用的方法有超声检测(UT)、涡流检测(ET)、磁粉检测(MT)、漏磁检测(MFL)。我们分别对这几种方法在储罐罐底检测时进行比较，尝试找出最适宜的储罐底板检测方法，并研制储罐底板磁检测仪，以便高效地对储罐罐底进行检测和科学管理。 本文针对现场立式储罐底板检测的实际情况，选择以罐底板漏磁检测技术为研究对象，开展立式储罐底板漏磁检测技术研究，以期实现方便快捷的对立式储罐底板进行检测和对其腐蚀状态进行评估。 开展储罐底板漏磁检测技术研究，主要是通过建立储罐底板磁化状态下数学模型，根据底板的厚度、电阻率和磁导率以及缺陷漏磁场的特点，计算出理想状态下所需磁化场的强度和缺陷漏磁场的大小等一系列关键技术参数。根据设计所需磁化场的强度要求，以及从最大程度上减轻仪器体积和重量上考虑，选择铷铁硼材料的永久磁铁作为励磁场。根据漏磁场的大小和特点，选择合适的高灵敏度的磁传感器，并确定相应的数据采集、滤波和放大电路。在这些工作的基础上，在实验室条件下组建一个相对简单(四个通道)的检测系统，然后编制相应的数据采集和分析软件。用这个小型检测仪做大量的实验，来验证所设计的漏磁检测装置的合理性和可行性。在前期研究的基础上，研制24通道储罐底板磁检测仪。编制了其数据采集和分析软件，可以实现数据波形实时显示，检测结果图形可视化，使缺陷的识别和分析更加直观、可靠。在实验室条件下利用人工模拟储罐底板锥型缺陷，做了大量的实验，证明了所研制的储罐底板磁检测仪具有很高的准确性和可靠性。分析了提离值、检测速度、涂层厚度、磁化场强度、储罐底板表面粗糙度以及底板上的铁磁性碎片等各种影响因素对检测灵敏度的影响。并对各种影响因素提出解决方案，对其软、硬件进行不断的改进和完善，使之能够在实际现场中得到应用。这些对指导实际储罐底板的漏磁检测具有重要的意义。更多还原

【Abstract】 Tank floor is made of ferromagnetic material, however, due to their operation in the condition of the change of environment and medium height all the year round, they inevitably suffer from various damnification and other factors. Especially corrosion perforation, crack expanding and rive and so on by chemical corrosion and electrochemistry corrosion make medium leak and cause serious disaster and environment pollution. This is a big economic loss to the state economy. Therefore, it must be inspected at intervals of several years. Anciently, oil field in our country always uses to inspect by hand, it has big labour intensity, long inspection time, and reject servicing is lack of science. Especially there are no good methods to inspect the corrosion of tank floor underside. Recently, with the development of the hard ware technology of computer and theory of non-destructive testing (NDT) methods, it is possibly to intellectualized inspect tank floor.The usual methods to inspect tank floor are ultrasonic testing (UT). eddy current testing (ET). magnetic particle testing (MT) and magnetic flux leakage (MFL). We compare the methods to each other on inspecting tank floor, try to find the optimum method to inspect tank floor, and develop apparatus to inspect tank floor with magnetic flux leakage. So that we can inspect tank floor with high effect and scientific manage tank.This paper aims at the fact to inspect tank floor in the field, chooses magnetic flux leakage technology for the inspection of tank floor as research object. Develop the object in order to inspect tank floor and estimate corrosion expediently and fleetly.Develop magnetic flux leakage technology for the inspection of tank floor, the main work is build mathematical modal of tank floor under magnetization. According to the thickness of tank floor % resistance radio , specific magnetism and characteristic of magnetic field leakage, work out a series of technical key parameters needed at perfect status. Such as the intensity of magnetization size of magnetic field leakage and so on. According to the designed intensity of magnetization, and think about trying to lighten instrument’s volume and weight whole hog, we choose Nd-Fe-B permanent magnet as magnetizer. According to the size and characteristic of magnetic field leakage, select appropriate sensors with high sensitivity radio, and select corresponding circuit for data collection, filter the waves and magnify. On the base of these works, we organize a relatively simple system for inspection (four channels) in lab, and then work out corresponding software for data collection and analysis. To examine the equipment that we designed is reasonable and feasible, we do plentiful experimentation with it. On the base of the first stage of research, we develop magnetic instrument with 24 channels to inspect tank floor. We work out the software of it for data collection and analysis. The software can carry out the wave of data at actual time, and result figure of inspection visible. It makes identify and analyse disfigurement more easy and reliable. In lab We do plentiful experimentation using man-made simulative cone-shaped disfigurement of tank floor. It proves that magnetic instrument with 24 channels to inspect tank floor has veracity and reliability. With it, we analyse the influence to sensitivity radio of inspection with a great variety of effectible factors, such as lift values speed of inspections thickness of coats intensity of magnetizations roughness of tank floor surface and fragments of ferromagnetic material and so on. And we take out the methods to solve the factors. We constantly ameliorate the software and hardware of the instrument to make sure that it can be use in field. These have important meaning to guide tank floor inspection with magnetic flux leakage technology.更多还原