• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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• pp.145-147
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• 2005

In present, most of metallic structures(gas pipeline, oil pipeline, water pipeline, etc) are running parallel with subway and power line in seoul. Moreover subway system and power line make a stray current due to electrical corrosion on metallic structures. The owner of metallic structures has a burden of responsibility for the protection of corrosion and the prevention against big accident such as gas explosion or soil pollution and so on. So, they have to measure and analyze the data about P/S(Pipe to Soil) potential due to stray current of subway system. So, we have developed the Real-time Wireless Remote Monitoring System for Stray Current of Subway System. In this system, the permanent buried type reference electrode is necessary. In this paper, results of development of buried type reference electrode using porous ceramic$({\alpha}-Al_{2}O_{3})$ are presented.

• 한국가스학회:학술대회논문집
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• 한국가스학회 2001년도 추계학술발표회 논문집
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• pp.45-57
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• 2001

An alternating current (AC) corrosion using coupon has been studied. Coupons were applied in terms of AC voltage from high value to low value through the survey of AC voltages on buried gas transmission pipeline over the country. Parameters such as AC current density of coupon, AC voltage, cathodic protection potential, soil resistivity and frequency were monitored continually. Corrosion induced by AC was observed even under cathodically protected condition that met cathodic protection criterion(: below -850mv vs. CSE). Corrosion rate was affected mainly not by AC voltage but by both of frequency and AC current density. An experimental corrosion rate relationship could be obtained statistically, in which AC corrosion rate increased linearly with effective AC current density and its slope was 0.619.

• Corrosion Science and Technology
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• 제16권5호
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• pp.235-240
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• 2017

Regional cathodic protection has significant impact on pipeline integrity management. After risk analyses of a newly built gas distribution station constructed in an area with large dwelling density, risk score was high because of potential threat caused by galvanic corrosion. Except reinforced steel in concrete, there are four kinds of metal buried under earth: carbon steel, galvanized flat steel, zinc rod and graphite module. To protect buried pipeline from external corrosion, design and construction of regional cathodic protection was proposed. Current density was measured with potential using potential dynamic test and boundary element method (BEM) was used to calculate current requirement and optimize best anode placement during design. From our calculation on the potential, optimized conditions for this area were that an applied current was 3A and anode was placed at 40 meters deep from the soil surface. It results in potential range between $-1.128V_{CSE}$ and $-0.863V_{CSE}$, meeting the $-0.85V_{CSE}$ criterion and the $-1.2V_{CSE}$ criterion that no potential was more negative than $-1.2V_{CSE}$ to cause hydrogen evolution at defects in coating of the pipeline.

• 대한토목학회논문집
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• 제37권1호
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• pp.175-185
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• 2017

가스 사용의 지속적인 증대로 이에 따른 가스의 제조, 취급, 사용이 점점 확대되어 관련 시설이 대형화, 복잡화되어, 이로 인한 크고 작은 사고가 지속적으로 발생하고 있다. 이러한 사고는 인명피해 및 물적 손실 뿐만 아니라 국가의 경제적인 손실의 큰 원인이 된다. 가스시설의 공통적으로 많은 부분을 차지하고 있는 Pipe Line 부분에 외부의 영향에 의한 사고가 가장 큰 위험요소를 가지고 있다. 특히, 도심지역 및 인구밀집지역의 경우의 고압가스배관의 사고 발생은 경제적 손실을 비롯한 보다 많은 손실을 야기시킬 수 있다. 이러한 매설배관의 사고에 대한 예방대책으로 여러 관련 기관에서는 가스배관에 대한 안전성을 확보하기 위해서는 전체 시스템의 파손 및 위험요소를 효과적으로 평가할 필요가 있다. 특히 가스배관이 설치되거나 작동되어 질 때에 이러한 파손(failure)의 가능성을 매우 작게 하더라도 위험요소가 존재하게 된다. 그러나 일단 파손이 발생하면 인명 및 재산상의 피해가 매우 크기 때문에 파손의 원인을 분석하여 파손사고의 비율을 최소한으로 낮추는 것이 필요하다. 그러므로 본 논문에서는 Scoring Model의 정성적 위험성 분석기법을 이용하여 매설배관의 위험성을 점수로 표현하여 정량적인 숫자로 표현하였다. 이러한 가시적인 평가의 결과는 매설배관의 안전을 확보하여 실질적인 매설배관의 유지관리를 하는데 있어서 매우 효율적으로 적용될 수 있을 것이다.

• 전기학회논문지
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• 제57권10호
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• pp.1720-1725
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• 2008

Because of the continuous increasing of energy consumption, metallic pipelines are widely used to supply services to customers such as gas, oil, water, etc. Most common metallic pipelines are underground and are now frequently being installed in nearby electric power lines. In recent years, buried gas pipeline close to power lines can be subjected to hazardous induction effects, especially during single line to ground faults. because it can cause corrosion and it poses a threat to the safety of workers responsible for maintenance. Accordingly, it is necessary to take into consideration for analysis of induced voltage on gas pipelines in transmission lines. This paper analyzed the induced voltage on the gas pipelines due to the 154kV transmission lines in normal case and in different faulty case conditions using EMTP (Electro-Magnetic Transients Program).

• 한국가스학회지
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• 제14권6호
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• pp.1-6
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• 2010

하천통과 배관은 부력과 외부 충격을 방지하기 위하여 1.2~4m의 매설 깊이로 설치되어 운영된다. 하천통과 배관은 수압과 토하중에 의한 외압으로부터 소성붕괴에 대한 저항성을 가져야한다. 하천통과 배관에 수압과 토하중으로 발생하는 원주응력을 유한요소해석으로 파악하여 배관의 건전성에 미치는 영향을 평가하였다. 콘크리트 보호공이 없는 경우 동일 수심에서는 매설 깊이 증가에 따라 원주응력은 증가하나, 동일 매설 깊이에서는 수심이 증가함에 따라 배관에서 발생하는 원주응력은 감소하고 있었다.

• Earthquakes and Structures
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• 제20권1호
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• pp.109-122
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• 2021

Significant progress in the oil and gas industry advances the application of pipeline into an intelligent era, which poses rigorous requirements on pipeline safety, reliability, and maintainability, especially when crossing seismic zones. In general, strike-slip faults are prone to induce large deformation leading to local buckling and global rupture eventually. To evaluate the performance and safety of pipelines in this situation, numerical simulations are proved to be a relatively accurate and reliable technique based on the built-in physical models and advanced grid technology. However, the computational cost is prohibitive, so one has to wait for a long time to attain a calculation result for complex large-scale pipelines. In this manuscript, an efficient and accurate surrogate model based on machine learning is proposed for strain demand prediction of buried X80 pipelines subjected to strike-slip faults. Specifically, the support vector regression model serves as a surrogate model to learn the high-dimensional nonlinear relationship which maps multiple input variables, including pipe geometries, internal pressures, and strike-slip displacements, to output variables (namely tensile strains and compressive strains). The effectiveness and efficiency of the proposed method are validated by numerical studies considering different effects caused by structural sizes, internal pressure, and strike-slip movements.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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• pp.2732-2734
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• 2005

In present, most of metallic structures(gas pipeline, oil pipeline, water pipeline, etc) are running parallel with subway and power line in seoul. Moreover subway system and power line make a stray current due to electrical corrosion on metallic structures. The owner of metallic structures has a burden of responsibility for the protection of corrosion and the prevention against big accident such as gas explosion or soil pollution and so on. So, they have to measure and analyze the data about P/S(Pipe to Soil) potential due to stray current of subway system. So, we have developed the Real-time Wireless Remote Monitoring System for Stray Current of Subway System. In this system, the permanent buried type reference electrode is necessary. In this paper, results of development about the permanent buried type reference electrode($Cu/CuSO_4$) are presented.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 A
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• pp.130-132
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• 2002

Because of the continuous growth of energy consumption and also the tendency to site power lines and pipelines along the same route, the close proximity of power lines and buried metallic pipelines has become more and more frequent. Therefore there has been and still is a slowing concern about possible hazards resulting from the influence of power lines on metallic pipelines. Underground pipelines that run parallel to or in close proximity to power lines are subjected to induced voltages caused by the time-varying magnetic fields produced by the power line currents. The induced electro- motive force cause currents circulation in the pipeline and voltages between the pipeline and surrounding earth. This paper analyzes the induced voltage on the gas pipelines buried in parallel with 22.9kV distribution lines. Their magnitude depends on the length of parallelism and on the distance between distribution lines and pipeline.

• 한국가스학회:학술대회논문집
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• 한국가스학회 2003년도 추계학술발표회 논문집
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• pp.43-46
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• 2003