• 에너지공학
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• 제18권4호
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• pp.230-238
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• 2009

우리나라는 에너지 절약 및 온실가스 배출저감 기술 중 하나로써 소형 열병합 발전과 소형 연료전지 열병합 발전을 연구해 왔으며 정책적으로 이를 보급하려고 한다. 기존의 석탄화력발전설비, 복합화력발전설비, 석유 화력발전설비를 열병합 발전설비로 대체하는 시나리오를 작성하여 에너지소비량과 온실가스 배출량의 변화추이를 에너지 경제 모델인 LEAP (Long-range Energy Alternative Planning system)을 이용하여 정량적으로 분석하였다. 2019년을 기준으로 열병합 발전설비를 석탄화력발전설비와 교체하였을 경우, 온실가스 배출량이 약 6.34%가 감소하였고 복합화력발전설비와 교체하였을 경우, 온실가스 배출량이 약 0.8%가 증가하였으나 열병합발전설비의 열생산량을 고려해주면 배출량이 감소하는 경향을 보일 것으로 사료된다. 석유화력발전설비를 열병합발전설비로 대체할 경우, 온실가스 배출량이 약 0.8% 감소할 것으로 예상된다.

• 한국자동차공학회논문집
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• 제15권6호
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• pp.17-22
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• 2007

GTL(Gas-to-Liquids) fuel technology was converted from the natural gas, coal and biomass into the diesel or kerosene by Fisher-Tropsch synthesis. GTL fuel have very good merits on high cetane number, low density, free sulfur, lower aromatics contents and no poly-aromatic hydrocarbons as well as the autoignition characteristics. These physical properties make it valuable as a diesel fuel with lower emissions than the conventional diesel fuel. Furthermore, GTL fuel can be use not to the engine any modification. Therefore, to evaluate emissions of GTL fuel, the tested diesel vehicles were fueled on blends of GTL fuel/ultra low sulfur diesel fuel(ULSD). And then, we found out that GTL fuel reduced regulated emissions(CO, NOx, HC, PM) compare with conventional diesel fuel.

• 한국물환경학회지
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• 제26권5호
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• pp.754-760
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• 2010

This study was carried out not only to evaluate optimal operating condition to increase biogas production, but also to estimate feasibility of renewable energy from anaerobic digester of sewage sludge. Semi- continuous Fed and Mixed Reactors (SCFMRs) were operated in various condition to quantify the reactor variables. The result of SCFMR operation showed that the biogas productivity and total volatile solids (TVS) removal of total solids (TS) 4% reactor at hydraulic retention time (HRT) 20 days with Organic Loading Rate (OLR) of $1.45kg/m^3-d$ were $0.39m^3/m^3-d$ and 26.7%, respectively which was two times higher than that of TS 2.5% reactor. Consequently the daily biogas production of $20,000m^3$ would be possible from the total volume of $52,000m^3$ of anaerobic digesters of the municipal wastewater treatment plant in D city. In feasibility study for the Biogas utilization, combined heat and power system (CHP) and CNG gasification were examined. In case of CHP, the withdrawal period of capital cost for gas-engine (GE) and micro gas-turbine (MGT) were 7.7 years and 9.1 years respectively. biogas utilization as Clean Natural Gas (CNG) shows lower capital cost and higher profit than that of CHP system. CNG gasificaion after biogas purification is likely the best alternative for Biogas utilization which have more economic potential than CHP system. The withdrawal period of capital cost appeared to be 2.3 years.

• Journal of Advanced Marine Engineering and Technology
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• 제39권10호
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• pp.1054-1061
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• 2015

The International Maritime Organization (IMO) has been regulating emissions by making mandatory the compliance with institutions aimed at protecting air quality such as the Energy Efficiency Design Index (EEDI), Ship Energy Efficiency Management Plan (SEEMP) and Tier III. Under the circumstances, one of the response measures considered to be the most feasible is the replacement of existing marine fuel with Liquefied Natural Gas (LNG). The industry has been preemptively building infrastructure and developing and spreading engine technology to enable the use of LNG-fueled ships. The IMO, in turn, recently adopted the International Code of Safety for Ships Using Gases or Other Low-Flash-Point Fuels (IGF Code) as an institutional measure. Thus, it is required to comply with regulations on safety-related design and systems focused on response against potential risk for LNG-fueled ships, in which low-flash-point fuel is handled in the engine room. Especially, the Standards of Training, Certification and Watchkeeping (STCW) Convention was amended accordingly. It has adopted the qualification and training requirements for seafarers who are to provide service aboard ships subject to the IGF Code exemplified by LNG-fueled ships. The expansion in the use of LNG-fueled ships and relevant facilities in fact is expected to increase demand for talents. Thus, the time is ripe to develop methods to set up appropriate STCW training courses for seafarers who board ships subject to the IGF Code. In this study, the STCW Convention and existing STCW training courses applied to seafarers offering service aboard ships subject to the IGF Code are reviewed. The results were reflected to propose ways to design new STCW training courses needed for ships subject to the IGF Code and to identify and improve insufficiencies of the STCW Convention in relation to the IGF Code.

• 한국분무공학회지
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• 제29권2호
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• pp.68-74
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• 2024

As awareness of environmental pollution problems increases worldwide, interest in air pollutants is increasing. In particular, NOx and PM, which are major pollutants in diesel vehicles, are contributing significantly to emissions. As a result, its importance is increasing. In this study, based on research results applied to large diesel vehicles, the problem of natural regeneration caused by low exhaust gas temperature during low speed and low load operation is solved by applying a complex regeneration DPF that is not affected by temperature conditions to small diesel vehicles. The feasibility of application to small diesel vehicles was reviewed by measuring the emission reduction efficiency. As a result of the engine test, the power reduction rate and fuel consumption rate before and after device installation under full load conditions were 2.9% decrease and 3.5% increase, respectively, satisfying the standard for a 5% reduction, and as a result of the regeneration equilibrium temperature (BPT) test, the regeneration temperature was 310℃. appeared at the level. The reduction efficiency test results for the actual vehicle durability test equipment showed 97.3% PM, 51.0% CO, and 31.1% HC, while the city commuter vehicle had PM 97.5%, CO 61.7%, HC 40.0%, and the school bus vehicle had PM 96.8%, CO 44.4%, HC 34.3%, and low-speed logistics vehicles showed a reduction efficiency of 98.2% for PM, 36.0% for CO, and 45.7% for HC. Based on the results of this study, in the future, it is necessary to secure DPF technology suitable for all vehicle types through actual vehicle application research on temperature condition-insensitive composite regenerative DPF for medium-sized vehicles.

• 한국산학기술학회논문지
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• 제19권5호
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• pp.681-688
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• 2018

최근 강화된 환경규제 및 높은 연비에 대한 요구로 인해 천연가스를 연료로 사용하는 선박이 증가하고 있다. 친환경 선박 연료로 대두되고 있는 LPG 혹은 메탄올을 사용한 선박의 요구도 증가하고 있다. 이러한 흐름의 연장선상으로 LPG 혹은 메탄올을 사용하는 ME-LGI 엔진에 대한 연구가 최근 활발히 이루어지고 있다. ME-LGI 엔진을 탑재한 선박은, 선박 항해 중 연료분사밸브의 작동 신뢰도를 지속적인 테스트를 통해 확인해야할 필요가 있다. 따라서 연료분사밸브 테스터의 개발은 ME-LGI 엔진의 상용화를 위해 반드시 필요하다. 이에 본 연구에서는 요구조건 분석, 기능분석, 설계 합성의 순서로 진행되는 시스템 엔지니어링 프로세스를 활용하여 ME-LGI 엔진용 연료분사밸브 테스터의 개념설계를 수행하였다. 요구조건 분석 단계에서 먼저 연료분사밸브의 작동 프로세스를 분석하였고, 밀폐 오일 누유 여부 확인의 필요성을 도출하였다. 그 다음 기능분석 단계에서 연료분사밸브 테스터의 기능 및 기능의 흐름을 수준별로 정의하였다. 이후 설계 합성 단계에서 각 기능에 해당하는 장비들을 설정하였고, 이를 바탕으로 process block diagram을 도출하였다. 또한 시스템 분석 및 조정 단계의 일환으로 초기위험도 분석을 수행하여 안전 방안을 개념설계 안에 추가하였다. 본 연구는 시스템 엔지니어링 프로세스가 개념설계에 적용되는 과정을 상세히 보여줌으로써 향후 타 시스템의 개념 설계 시 좋은 참고자료가 될 수 있을 것으로 기대된다.

• 대한기계학회논문집B
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• 제34권8호
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• pp.755-760
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• 2010

본 연구는 승용 디젤엔진의 입자상 물질 배출특성에 관한 것으로써, 엔진에서 배출된 입자상 물질이 배기관 및 후처리장치인 디젤산화촉매와 매연여과장치를 통과할 때의 특성 변화를 파악하기 위하여 후처리장치 각각 전 후단 및 배기관에서 직접 측정하였다. 또한 다양한 엔진회전속도 및 부하조건에서 측정함으로써 입자상 물질 배출 맵을 구축하였으며, 디젤산화촉매 및 매연여과장치의 입자상 물질 저감효과에 대해 평가하였다. 뿐만 아니라 배기재순환율과 연료분사시기를 변경시켜 입자상 물질의 배출특성 변화를 파악하였다. 모든 시험에서 입자상 물질을 5~1000nm 크기까지 측정할 수 있는 DMS500을 이용하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제25권3호
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• pp.563-572
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• 2001

With the results of calculation for natural frequencies the reponses of forced coupled vibration of propulsion shafting system were investigated by the modal analysis method. For the forced vibration response analysis, the axial exciting forces, the axial damper/detuner, propeller exciting forces and damping coefficients were extensively considered. As the conclusion of this study, some items are cleared as follows.-The torsional vibration amplitudes are not influenced by the radial excitation forces of the crank shaft. -The axial vibration amplitudes are influenced by the tangential exciting forces as well as the radial exciting forces of the crank shaft. The increase of the amplitudes is observed in the speed range at the neighbourhood of any torsional critical speed. 1The closer the torsional and axial critical speed. the larger coupling effect becomes. -The axial exciting force of propeller is relatively strong comparing with axial exciting forces of cylinder gas pressure and oscillating inertia of reciprocating mechanism. Therefore, the following conclusions are obtained. -Torsional vibration calculation with the classical one dimensional model is still valid. -The influence of torsional excitation at each crank upon the axial vibration is improtant. especially in the neighbourhood of a torsional critical speed. That means that the calculation of axial vibration with the classical one dimensional model is inaccurate in most of cases.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.172-176
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• 2009

We developed a program, "CogenSim-$\mu$," to simulate the operation of micro-combined heat and power (${\mu}CHP$) system. The CogenSim-$\mu$ can reflect the variation of energy efficiency by handling the real-time loads (heat and power) fluctuation. The result obtained using this program was compared with the real operation of 30 kWe gas engine driven ${\mu}CHP$. It was found that the CogenSim-$\mu$ could predict the amount of generated-power, recovered-heat and consumed-fuel with the error less than 3%, and heat and power efficiency with the error less than 4%. The CogenSim-$\mu$ reconstructed the profile of on-off cycle, which represented the operation of a facility, with more than 93% accuracy. The CogenSim-$\mu$ can reflect the effects of various factors such as size of thermal storage tank, desired temperature of reservoir water, natural frequency of generator, etc. As a result, the CogenSim-$\mu$ can be used to optimize the ${\mu}CHP$ operation.

• 한국소음진동공학회논문집
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• 제25권9호
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• pp.606-613
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• 2015

In this study, the torsional vibration analysis for a marine propulsion system is carried out by using the transfer matrix method(TMM). The torsional moment produced by gas pressure and reciprocating inertia force may yield severe torsional vibration problem in the shaft system which results in a damage of engine system. There are several ways to control the torsional vibration problem at hand, firstly natural frequencies can be changed by adjusting shaft dimensions and/or inertia quantities, secondly firing order and crank arrangement are modified to reduce excitation force, and finally lower the vibration energy by adopting torsional vibration damper. In this paper, the viscous torsional vibration damper is used for reducing the torsional vibration stresses of shaft system and it is conformed that optimum model of the viscous damper can be determined by selecting the geometric design parameters of damper and silicon oil viscosity.