本文選題：非接觸　切入點：埋地管道　出處：《東北石油大學》2017年碩士論文　論文類型：學位論文

【摘要】：埋地管道在國家經(jīng)濟運行和人們?nèi)粘Ｉ钪邪l(fā)揮著極其重要的作用,但卻面臨著十分突出的老化問題,加上運行環(huán)境復雜,一旦發(fā)生泄漏、爆炸,往往造成巨大的人員傷亡和經(jīng)濟損失,同時帶來嚴重的環(huán)境污染,已經(jīng)成為危害公共安全的重大隱患。對在役運行的埋地管道安全狀況進行評價,實行全面開挖檢測是不現(xiàn)實的,往往需要在非開挖的情況下非接觸式檢測。非接觸磁記憶檢測技術(shù)它能確定應力集中區(qū)-設備損傷發(fā)展的主要根源,為埋地管道在線非接觸式磁記憶檢測提供了理論基礎(chǔ)。本文在現(xiàn)場試驗檢測的基礎(chǔ)上,對不同埋深、內(nèi)壓和材質(zhì)的埋地管道進行了檢測分析和評估。在有缺陷的位置處,磁記憶信號表現(xiàn)為:切向分量和法向分量出現(xiàn)大幅度的下降或上升,梯度出現(xiàn)明顯的往復性波動。對其有異常磁記憶信號的管道部位進行開挖,檢測得知:在異常位置會出現(xiàn)泄漏、外腐蝕、內(nèi)腐蝕。通過仿真軟件對不同埋深、壓力的埋地管道進行了有限元模擬和分析,得到了不同深度和不同壓力下磁記憶信號的變換規(guī)律,不考慮焊接殘余應力時,隨內(nèi)壓增大,切向磁場強度峰值和法向磁場強度峰峰值均略有減小;隨著埋深增大,切向磁場強度峰值和法向磁場強度峰峰值均不斷減小;埋地管道內(nèi)壓對地面上非接觸磁記憶信號影響遠遠小于埋深。在考慮了焊接殘余應力時,進一步進行焊縫缺陷的多場耦合仿真,結(jié)果可以看出,相比于無缺陷時,無論是埋地部分的管頂、管中、管底,有缺陷管道的切向磁場強度峰峰值和法向磁場強度峰峰值均有所增大,且管上和管下的法向磁場強度信號發(fā)生反轉(zhuǎn)。最后將有限元仿真結(jié)果與磁記憶檢測試驗結(jié)果進行對比,在有缺陷的位置,切向磁場強度和法向磁場強度的峰峰值均在不斷增加,梯度由大幅度的變化,仿真的磁記憶信號與實際相符合,為埋地管道非接觸式磁記憶檢測與評價的實際工程應用提供基礎(chǔ)性理論研究和方法依據(jù)。
[Abstract]:Buried pipelines play an extremely important role in the national economic operation and people's daily life, but they are faced with a very prominent aging problem, coupled with the complexity of the operating environment. Once leakage occurs, it explodes. It often causes huge casualties and economic losses, and at the same time brings serious environmental pollution, which has become a major hidden danger to public safety. The safety situation of buried pipelines in service is evaluated. It is not realistic to carry out full-scale excavation detection, which often requires non-contact detection under the condition of non-excavation. Non-contact magnetic memory detection technology can determine the stress concentration zone-the main source of equipment damage development. This paper provides a theoretical basis for on-line non-contact magnetic memory detection of buried pipelines. On the basis of field test, this paper analyzes and evaluates buried pipelines with different buried depths, internal pressure and materials. The magnetic memory signal shows that the tangential component and the normal component decrease or rise by a large margin, the gradient shows obvious reciprocating fluctuation, and the pipeline with abnormal magnetic memory signal is excavated. The detection results show that leakage, external corrosion and internal corrosion will occur in abnormal locations. Finite element simulation and analysis of buried pipelines with different buried depths and pressures are carried out by simulation software. The transformation law of magnetic memory signal at different depth and pressure is obtained. When welding residual stress is not considered, the peak value of tangential magnetic field intensity and the peak value of normal magnetic field intensity decrease slightly with the increase of internal pressure, and with the increase of buried depth, The peak value of tangential magnetic field intensity and the peak value of normal magnetic field intensity decrease continuously, and the influence of buried pipeline pressure on the non-contact magnetic memory signal on the ground is much smaller than that of buried depth. When welding residual stress is considered, The results show that, compared with those without defects, the pipe top, tube bottom and tube bottom of the buried part are different from those without defects. The peak value of tangential magnetic field intensity and the peak of normal magnetic field intensity are increased, and the normal magnetic field intensity signals on and under the tube are reversed. Finally, the finite element simulation results are compared with the results of magnetic memory test. In the defective position, the peak value of tangential magnetic field intensity and normal magnetic field intensity is increasing, the gradient varies greatly, and the simulated magnetic memory signal is in accordance with the actual situation. It provides the basic theoretical research and method basis for the practical engineering application of non-contact magnetic memory detection and evaluation of buried pipeline.
【學位授予單位】：東北石油大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TE973.6
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本文編號：1558849