• Journal of Advanced Marine Engineering and Technology
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• 제34권5호
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• pp.632-637
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• 2010

천연가스는 메탄을 주성분으로 하는 청정한 대체연료로 자동차나 트럭 등에 압축천연가스와 액화천연가스 형태로 사용할 수 있다. 그리고, 천연가스만을 사용하는 전소엔진과 가솔린 및 천연가스를 동시에 사용할 수 있는 겸용엔진이 있으며, 특히, 겸용엔진의 경우 두가지 연료를 동시에 사용할 수 있는 것으로 정의할 수 있다. 본 연구에서는 선박용 가솔린 시스템을 인젝터, 레귤레이터, 연료탱크 및 전자제어장치로 구성된 압축 천연가스 겸용시스템으로 전환시켜 연료시스템과 동력값을 비교하였다. 그 결과, 천연가스엔진의 경우 적은 배출가스를 나타내었으며 최대동력은 가솔린엔진과 비교 약 7%정도 감소함을 확인할 수 있었다.

• 플랜트 저널
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• 제9권3호
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• pp.38-42
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• 2013

지속적인 유가 상승과 환경규약 및 안전성, NIMBY현상 등의 문제로 해상 가스전에 대한 관심이 높아지고 있다. LNG-FPSO는 해양 가스전에서 채취된 천연가스의 불순물을 제거하고, condensate와 LPG를 회수하며, 정제된 가스를 이송 가능한 형태로 액화시키는 최첨단 해양플랜트이다. 반면 작업 시 해상 환경에 많은 영향을 받으므로 선체 운동을 고려한 전처리 공정 효율을 파악하고 설계에 반영해야 한다. 본 연구는 LNG-FPSO의 선체 운동 영향 및 제한된 선상 공간의 최적화를 고려한 해상 전처리 기술을 개발하기 위한 기초 연구이다. 이에 아민 흡수공정과 멤브레인 공정을 혼합한 hybrid 공정을 검토하였으며, 일반 아민흡수공정에 비하여 낮은 용매 순환량, 낮은 열용량, 작은 컬럼 크기가 요구되어 해상용 전처리 공정에 적합함을 확인하였다. 이것은 또한 6자유도 운동 실험 및 CFD 해석을 병행하여 시뮬레이션을 가시화함으로써 다양한 해상상태에 따른 LNG-FPSO의 공정 효율을 검토할 수 있다.

• 대한기계학회논문집B
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• 제20권5호
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• pp.1591-1602
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• 1996

In operating the underwater engines such as encountered in exploring submarines, the dumping of the exhaust gas out of the engine requires a large portion of the total power, frequently amounting to 25-30% of the power generated. This unfavorable circumstance can be cured by liquefying the exhaust gas and storing it. In the present study, two liquefaction systems were simulated to enhance the overall efficiency; one is a closed cycle diesel engine and the other is a closed cycle LNG engine. The liquefied natural gas (LNG) is chosen as a fuel, not only because its use is economical but also because its cold energy can be utilized within the liquefaction system. Since a mixture of oxygen and carbon dioxide is used as an oxidizer, liquefying carbon dioxide is of major concern in this study. For further improving this system, the intercooling of the compressor is devised. The necessary power consumed for the liquefying system is examined in terms of the related properties such as pressure and temperature of the carbon dioxide vessel as a function of the amount of the exhaust gas which enters the compressor. The present study was successful to show that much gain in the power and reduction of the vessel pressure could be achieved in the case of the closed cycle LNG engine. The compression power of exhaust gas were observed remarkably lower, typically only 6.3% for the closed cycle diesel engine and 3.4% for the closed cycle LNG engine respectively, out of net engine power. For practicality, a design -purpose map of the operating parameters of the liquefaction systems was also presented.

• 환경영향평가
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• 제7권2호
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• pp.89-102
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• 1998

The purpose of this study is to seek AEI(Air Environmental Indices), PSI(Pollutant Standard Index) and the urban air quality control goal(the best available alternative energy program) by assessing the best ratio of energy types used in urban enterprises, based on harmful health effect and air quality standard and costs. This study is focused on an urban area(Puchun), where area sourcees are associated with heavy traffic, large population, and its industrial sources with large emissions. In the first step, air modeling, estimation of AEI and PSI, and benefit-cost analysis were carried out. In the second step, we assessed that 660 scenarios about the ratio of B-C oil, light oil and LNG used in urban enterprises with regard to air quality and cost. In the third step, the best available alternative energy program was selected for the ratio of energy species(B-C oil, light oil and LNG) by using the lexicographic method. From the emission analysis, main source of $NO_2$ is identified as industries and air quality is evaluated according to the ratio of B-C oil, light oil and LNG used in urban enterprise. The modeling data of TSP, $SO_2$, $NO_2$, CO, $O_3$, by ISC3 and PBM are respectively $118{\mu}g/m^3$, 0.027ppm, 0.025ppm, 2.0ppm, 0.55ppm in indurstrial area. That data are close to Environmental Air Quality Standard. By means of sensitivity analysis, we obtained the difference in concentration between the areas(Nae-dong, Joong-dong) according to the ratio of B-C oil, light oil and LNG used in the industries. From the result of alternatives assessment the lowest AEI value and cost, the ratio of B-C oil, light oil and LNG are 2.5%, 20%, 77.5%, respectively.

• 해양환경안전학회지
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• 제27권1호
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• pp.113-118
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• 2021

The International Maritime Organization(IMO)는 2020년 1월 1일부터 국제항해 선박에 사용되는 모든 연료의 황분을 0.5 % 이하로 제한하고 있다. 연료유 황 함유량 규제 대응을 위해 LNG 선박, SOx scrubbers, 저유황유(Very Low-Sulfur Fuel Oil, VLSFO) 사용 등이 고려되고 있으며, 이 중 투자비용이 상대적으로 적은 저유황유가 선호되고 있다. 따라서 저유황유를 사용하는 선박이 증가함에 따라 오염사고 위험성이 높아질 것으로 예상된다. 특히, 해수 온도가 저유황유의 유동점 이하로 유출될 경우 고형화됨에 따라 방제에 어려움을 겪고 있는 사례도 나타나고 있다. 본 논문에서는 국내서 생산되는 저유황유 6종과 고유황유(MF380) 1종에 대해 해수 온도 조건에 따라 유처리제의 분산 능력을 평가하였다. 연구결과, 저유황유는 국내 기준(0.5 min 정치 60 % 이상, 10 min 정치 20 % 이상)을 만족하지 못했으며, 고유황유에 비해 상대적으로 낮은 유화율을 보였다. 본 연구결과는 저유황유가 해상에 유출될 경우, 방제방향을 설정하는 데 활용될 수 있을 것으로 기대된다.

• 한국안전학회지
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• 제23권3호
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• pp.1-7
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• 2008

As a clean fuel, LNG or LPG is widely used in large restaurants or plants instead of coal. These fuels are easy to use and cheap. However, they are inflammable very much and easily exploded at the worst. So there are many laws and regulations legislated for the handling and usage of the gas facilities. Nevertheless, very harsh explosions occurred in several domestic or foreign places. In this paper a gas detection and alarm system was developed for large facilities. A new concept for connecting many gas detectors was proposed and based upon that a system including hardware and software have been developed and tested. Although up to 16 gas detectors apart 1 km from main controller can be connected currently, this system can be easily expanded for more detectors because each gas detector receiver communicates with main controller using industrial standard RS-485 multi drop technique. Furthermore several additive functions was included for the installation and maintenance convenience.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2002년도 제25회 KOSCI SYMPOSIUM 논문집
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• pp.41-47
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• 2002

Oxygen has been used extensively in various industries for many years. Despite earlier successful attempts to use oxygen in industrial combustion furnaces, its full theoretical researches have only recently begun to be realized. The aim of this study is to investigate the effect of oxygen enriched combustion. This paper analyzes the characteristics of oxygen enriched combustion, and deals with the experimental investigation of the flame temperature and NOx concentration in exhaust gas. The flame temperature, concentration of exhaust gas were measured and flame configurations were photographed according to the variation of oxygen concentrations in oxidizer.

• 대한조선학회 특별논문집
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• 대한조선학회 2008년도 특별논문집
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• pp.76-83
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• 2008

New and more efficient propulsion systems are required for LNG carriers. One of the proposed systems is a combination of a gas turbine with a heat recovery steam generator. This system constitutes a novel approach, which needs to be analyzed by system analysis and risk assessment to compensate for the lack of field experience. Of specific concern is the high pressure fuel supply system. This paper describes the dispersion and fire analysis performed to identify for safety and design improvement of proposed system.

• 한국전자통신학회논문지
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• 제6권3호
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• pp.405-410
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• 2011

단조산업에서의 철강제품의 열처리는 산업의 근간이 되며 제품경쟁력에 아주 중요한 부분을 차지한다. 열처리를 수행하는 열처리로에서의 버너제어는 연료인 LNG가스의 절감뿐만 아니라 균질한 열처리를 요구하는 제품 경쟁력에 막대한 영행을 준다. 본 연구는 열처리로에서의 버너제어를 비례제어를 이용하여 수행하고, 그 결과가 에너지 절감뿐만 아니라 열처리로의 성능을 향상시키는 것을 보여준다.

• 대한조선학회지
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• 제21권4호
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• pp.1-9
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• 1984

This study is concerned with the economic aspects of $125,000m^3$ class LNG carriers with different propulsion plant such as conventional steam turbine and slow speed diesel engine with reliquefaction plant. The ship's speed and L/B ratio were optimized with criterion of required freight rate(RFR) by using the PROCAL computer program package. In order to investigate the effect of fuel oil price, round trip distance and boil-off rate on the RFR and the optimum speed, sensitivity analysis were also performed.