• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.414-421
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• 2022

Subsea oil and gas exploration is increasingly moving into deeper water depths, and typically, subsea pipelines operate under high pressure and temperature conditions. Owing to the difference in these components, the axial force in the pipe is accumulated. When a pipeline is operated at a high internal pressure and temperature, it will attempt to expand and contract for differential temperature changes. Typically, the line is not free to move because of the plane strain constraints in the longitudinal direction and soil friction effects. For a positive differential temperature, it will be subjected to an axial compressive load, and when this load reaches a certain critical value, the pipe may experience vertical (upheaval buckling) or lateral (snaking buckling) movements that can jeopardize the structural integrity of the pipeline. In these circumstances, the pipeline behavior should be evaluated to ensure the pipeline structural integrity during operation in those demanding loading conditions. Performing this analysis, the correct mitigation measures for thermal buckling can be considered either by accepting bar buckling but preventing the development of excessive bending moment or by preventing any occurrence of bending.

• 한국가스학회:학술대회논문집
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• 1998.09a
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• pp.127-138
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• 1998

• 월간 기계설비
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• no.9 s.194
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• pp.87-88
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• 2006

최근 삶의 질이 향상됨에 따라 쾌적한 환경 추구와 WellBeing 문제가 사회 이슈로 부각되면서 생산라인 및 위생배관에 대한 관심이 높아지고 있다. 그 중에서도 특히 우리가 먹고 마시는 공기와 물은 물론 냉난방과 각종 액체, 가스 통신선 등이 전달되는 통로인 Pipeline 속의 청결은 인체의 건강에 직접적인 영향을 미치므로 더욱 세심한 주의가 요구되고 있다. 조은 시스템은 최근 생산라인 및 건축물 배관 등의 파이프라인을 신개념으로 클리닝하는 시스템을 한국에 도입시켜 파이프클리닝에 새로운 바람이 불 것으로 예상 된다.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.218.1-218.1
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• 2010

천연가스를 대체하며 21세기 신 에너지원으로 기대되고 있는 메탄 하이드레이트가 주목을 받게된 것은 1930년대 시베리아의 화학 플랜트에서 고압의 천연가스 수송용 파이프라인이 막히는 사고가 빈번하게 발생하여 그 원인을 조사한 결과, 파이프 내에서 가스와 물이 결합하여 하이드레이트를 형성하고, 그것이 파이프의 내벽에 부착되어 파이프를 막고 있다는 것으로 밝혀지면서 천연가스 하이드레이트가 주목을 받게 되었다. 또한 메탄 하이드레이트의 경우 46개의 물분자에 8개의 메탄가스 분자가 포획된 구조로, 그 분자식은 $CH_4{\cdot}5.75H_2O$이다. 따라서 메탄가스와 물의 이론적 용량비가 216:1로써, 표준상태에서 $1m^3$의 메탄 하이드레이트는 $172m^3$의 메탄가스와 $0.8m^3$의 물로 분해된다. 만약 이와 같은 특징을 역으로 이용할 경우 메탄을 주성분으로 하는 천연가스를 물에 포집시켜 인공적으로 하이드레이트를 제조할 수 있기 때문에 천연가스 수송 및 저장의 수단으로써 그 중요성이 커지고 있으며, 액화수송보다 18-24%의 비용절감이 이루어진다고 보고하였다. 그러나 인공적으로 메탄 하이드레이트를 제조할 경우 가스 포집율의 예측이 매우 어려운 것으로 알려져 있다. 따라서 본 연구에서는 동일한 조건에서 메탄 하이드레이트 형성의 반복성 실험을 10회 수행한 결과 과냉도가 클수록 최대최소차이가 줄었고 또한 교반을 시킬 경우도 최대최소차이가 줄어 들었다.

• JOURNAL OF ELECTRICAL WORLD
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• s.264
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• pp.18-26
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• 1998

• Journal of the Korean Institute of Gas
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• v.2 no.2
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• pp.61-69
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• 1998

The risk assessments for gas leak in underground pipeline are conducted about the explosion accident of AHYUN-DONG underground service-base on December, 1994(Gaussian gas, LNG) and the accident of TAEGU subway on April 1995(Heavy gas LPG). We have calculated the total mass of gas release and have respected the efficient of explosions with report of the spot. The dispersion zones of LNG were calculated as large as fifteen times to those of LPG by ALOHA. The effects of thermal radiation from LNG explosion were assumed less than that from LPG by PHAST.

• Journal of the Korean Institute of Gas
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• v.18 no.5
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• pp.26-32
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• 2014

CCS(Carbon Capture and Storage) which is technic to capture and storage the carbon-dioxide is the method that reduces the carbon-dioxide from the industries to prevent earth from the global warming. In order to apply to the practical site, it is inevitable to investigate the possibility of damage in the pipe or components by carbon-dioxide. In this paper, the immersion test is performed to estimate the suitability of the rubber which is used to seal or connect the pipelines because the rubber has not been validated. Also, the immersion test is carried out in a certain condition(pre- and supercritical state).

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.1
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• pp.40-49
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• 2004

In this paper, vibration response of aerial gas pipeline due to vehicle loads was quantitatively estimated through experiment and analysis in open cut construction site. The vehicle vibration of various construction machines causes serious effect to the aerial gas pipeline. The new vibration prediction equations presented in this study can estimate the vibration velocity response of the aerial gas pipeline. In the nitration prediction equations, the vehicle′s weight and traveling velocity, which are the sources of vibration, are combined into the term called, "scaled weight" Methods to reduce vibration were proposed in case the vibration velocity response of the gas pipeline exceeded the vibration criterion, using the vibration prediction equations presented in this study. One was to limit the vehicle′s traveling velocity and the other to install the isolation equipment. Both methods can be estimated quantitatively.

• 한국가스학회:학술대회논문집
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• 1999.09a
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• pp.250-255
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• 1999

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.406-413
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• 2022

The subsea pipeline pre-commissioning stage consists of the following processes: Flooding, Venting, Hydrotesting, Dewatering, Drying, and N2 Purging. Among these processes, drying and nitrogen purging processes are stipulated to reduce and maintain the relative humidity below dew point to prevent the generation of hydrate and the risk of gas explosion in the pipeline during operation. The purpose of this study is to develop an analysis method for the air drying and nitrogen purging process during pre-commissioning of the subsea pipeline, and to evaluate the applicability of the analysis method through comparison with on-site measurement results. An analysis method using Computational Fluid Dynamics (CFD) was introduced and applied as a method for evaluating the relative humidity inside a subsea pipeline, and it was confirmed that analysis results were in good agreement with the on-site measurement results for the air drying and nitrogen purging process of the offshore pipeline. If the developed air drying and nitrogen purging analysis method are used as pre-engineering tools for pre-commissioning of subsea pipelines in the future, it is expected to have a significant impact on the improvement of work productivity.