• Journal of Advanced Marine Engineering and Technology
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• 제22권3호
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• pp.275-284
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• 1998

Standard on the carbon dioxide extinguishing system was prepared by the committed of the national fire protection assocition(NFPA)in USA on 1980. And this code is also applied to the design of a marine fire extinguishing system The most important problem in design is the uniform discharge of $CO_2$ through each nozzle from the high pressure $CO_2$ storage facility. The purpose of this paper is to develop the computer software to design the marine fire protection piping system. By solving the continuity equation energy equation and Bernoulli's equation simulataneously the flowrate in branch pipelines and discharge nozzles can be calculated.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1702-1707
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• 2007

The reduction of pipe-thickness induced by flow accelerated corrosion (FAC) is one of the most serious problems on the maintenance of piping system in nuclear power plants (NNP). If the thickness of a pipe component is reduced below the critical level, it cannot sustain pressure and consequently results in leakage or rupture. For this reason, wall thinning by FAC has been inspected in secondary side piping systems in NPPs. In this research Round Robin Test (RRT) was conducted to verify confidence of wall thinning measurement system in NPP. 12 inspectors from 3 companies participated and 23 specimens were used according to standard practice in RRT. The gage R&R analysis was introduced in regard to repeatability and reproducibility that are affected to measurement system errors. Confidence intervals of thickness measurement system were obtained.

• 비파괴검사학회지
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• 제30권6호
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• pp.521-526
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• 2010

Gas transmission pipelines are often inspected and monitored using the magnetic flux leakage method. An inspection vehicle known as a "pig" is launched into the pipeline and conveyed along the pipe by the pressure of natural gas. The pig contains a magnetizer, an array of sensors and a microprocessor-based data acquisition system for logging data. This paper describes magnetic flux leakage (MFL) signal processing used for detecting mechanical damages during an in-line inspection. The overall approach employs noise removal and clustering technique. The proposed method is computationally efficient and can easily be implemented. Results are presented and verified by field tests from an application of the signal processing.

• 전기학회논문지
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• 제56권5호
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• pp.876-883
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• 2007

The magnetic flux leakage(MFL) type nondestructive testing(NDT) method is widely used to detect corrosion, defects and mechanical deformation of the underground gas pipelines. The object pipeline is magnetically saturated by the magnetic system with permanent magnet and yokes. Hall sensors detect the leakage fields in the region of the defect. The defects are sometimes occurred in group. The accuracy of the detecting signals in this defect cluster become lowered because of the complexity of the defect cluster. In this paper, the effects of the multi -defects are analyzed. The detecting signals are computed by 3-dimensional finite element method and compared with real measurement. The results say that, rather than the size of the defects, the effects of the relative position of the multi-defects are very important on the detecting signals.

• 한국안전학회지
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• 제12권3호
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• pp.192-199
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• 1997

우리나라의 가스소비량은 매년 크게 증가하고 있다. 본고에서는 국내에서 발생한 가스사고를 분석하고 배관건전성 평가방안 및 안전성 확보방안에 대하여 국내외 분석자료들을 정리하고 그 내용을 검토하였다. 국내 가스사고 자료는 배관손상뿐 아니라 각종가스 사고가 포함된 광범위한 데이터 자료이다. 국내 가스배관이 대부분 매설된 지 얼마안된 상태로서 손상사례가 드물어 매설배관에 대한 손상사례 자료의 체계적인 수집 및 분석이 아직 이루어지지 못하고 있다. 본 보에서 제시하는 데이터는 천연가스뿐 아니라 LPG나 일반가스까지 포함된 자료들로서 앞서 제시한 외국의 데이터와 직접적인 비교는 어려운 상황이다. 또한 가스배관 건전성 확보는 매우 중요한 사항이지만 이에 대한 체계적인 연구가 국내에선 상당히 미흡한 실정이다. 본보에서는 미국의 사례를 중심으로 배관 손상시 원인규명 방법과 손상 억제방안 및 배관손상 조기감지 체계 등에 관하여 설명하도록 한다.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2009년도 춘계학술발표회
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• pp.177-178
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• 2009

관로내의 유속이 급격히 변하면 압력도 크게 상승하거나 강하하게 되어 유체 과도현상을 일으키게 된다. 이러한 수격현상에 대한 연구는 펌프스테이션이 커지고 유체를 이송하는 시스템이 대형화되어 그 중요성이 더욱 증가하였다. 이것은 파이프라인이 길어지고 복잡해지기 때문이다. 이 연구에서는 특성법을 이용하여 대형펌프 시스템의 밸브 개폐로 발생하는 수격현상을 평가하였다.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.80-83
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• 2001

In this study, we investigated irrigation effect for the paddy plot irrigated by pipeline with two types of hydrants: automatic and manual. The automatic hydrant have been introduced to the paddy field to save water and reduce the labor for water management. The automatic hydrant is automatically opened and closed according to the water depth of a paddy plot. The water management labor to close manual hydrant in the afternoon of every three days can be eliminated when we use the automatic hydrant. The water requirements for the automatic hydrant plot 3.26mm/d are much less than those for manual hydrant plot 9.99mm/d.

• 한국안전학회지
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• 제33권3호
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• pp.33-38
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• 2018

Defects in piping caused by corrosion or external impact of underground piping can lead to high risk of rupture of the piping due to high pressure. Flammable gas can be immediately ignited when discharged from piping, causing a jetfire. The damage of the radiant heat not only threatens the health of the workers who work in the industry but also the health of the people living in the neighboring residential areas. It is important to prevent and prepare before an accident occurs. In this study, three types of flammable gas underground piping accident scenarios were investigated, and the ranges of influence were determined using Phast ver7.2. and finally regression models were formulated to predict the ranges using excel and Matlab.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 D
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• pp.657-659
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• 2000

The importance of total management for maritime structures (Ports, Piers, docks. marine bridges, marine roads, submarine pipelines, etc.) is more and more increasing in these days. Especially, in spite of the marine structures are exposed at the various corrosion circumstances, there are not only a standard of Cathodic Protection System but also knowledge of importance for necessity of corrosion monitoring. Therefore, this paper presents the results of development for the Remote Real-Time Corrosion Monitoring and Control System Using by TRS on Maritime Metallic Structures which can be prevents a big accident by corrosion.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(II)
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• pp.170-175
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• 2003

The ASCE formula of pipeline' soil interaction force is the basis of semi-analytical relationship for buried pipelines subjected to longitudinal permanent ground deformation due to seismic induced liquefaction. However, since the ASCE formula has been developed based on the stiffness of non-liquefied region, it is needed to modify for the varied stiffness of liquefied region. With this object, the consideration of decreasing effect of soil stiffness in liquefied region is made: i.e. the spatial distributions of pipeline. soil interaction force in liquefied region. It means that the improved formula can reflect various patterns of permanent ground deformation more realistically. Through the comparative analyses using both the improved and ASCE formula, the applicability of the improved, the limitation of the existing formula and semi-analytical relationship are discussed.