• 공업화학
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• 제20권6호
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• pp.675-680
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• 2009

SM탄(인도네시아산)을 이용하여 NOx 배출 특성을 조사하였다. 실험은 석탄 거치 후 승온하며 연소하는 방법과 승온 후 석탄을 주입하는 방법을 이용하였다. 산소희박 분위기에서는 배출 NOx가 연소온도와 반비례의 관계를 나타내었으며 이는 fuel N이 강한 환원 분위기에서 $N_{2}$로 전화되기 때문인 것으로 나타났다. 또한 주입 가스량 증가 시에는 산화 분위기에 의해 fuel N이 NO로 산화되어 total fuel NO가 증가하는 경향을 나타내었다. 제조 온도에 따른 char의 연소시 발생되는 NO의 분석으로 total fuel N, volatile-N, char-N이 각각 NO로 전화되는 부분으로 구분될 수 있었으며 실험결과 본 연구에 사용된 SM탄은 total NOx의 대부분이 volatile-N에 기인하는 것으로 나타났다.

• 항공우주시스템공학회지
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• 제11권4호
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• pp.8-14
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• 2017

본 연구에서는 n-데칸과 물을 혼합한 에멀젼 연료를 제조하고, 연료의 유변학적 안정성을 측정하였다. 에멀젼 연료는 n-데칸과 순수, 유화제로 Span 80을 혼합하여 제조되었다. 연료 내부 물 부피비 및 연료온도 증가는 연료의 상분리를 촉진시키는 요소로 확인되었다. 연료의 물 부피비, 온도 및 제조시간 경과에 따른 유변학적 변화를 관찰하였을 때, 물 부피비가 증가할수록 연료의 비뉴턴 유체거동이 확인되었으며, 온도가 높아질수록 연료 내부 물액적 응집으로 인한 점도감소가 관찰되었다. 낮은 물 부피비에서는 연료 제조시간에 따른 점도변화가 크지 않았으나, 혼합비가 3:7 인 경우 3시간 이후부터 점도의 점진적인 감소가 관찰되었다.

• 한국연소학회지
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• 제20권3호
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• pp.21-26
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• 2015

This study was performed to provide the information of the combustion characteristics of n-butanol fuel in accordance with the n-heptane fuel mixing ratio. The closed homogeneous reactor model was used for the analysis. The analysis conditions were set to 800 K of the initial temperature, 20 atm of initial pressure and 1.0 of equivalence ratio. The results of analysis were compared in terms of combustion temperature, combustion pressure, CO, Soot and $NO_X$ emissions. The results of combustion and exhaust emission characteristics showed that ignition delay was decreased and the combustion temperature was increased as the n-heptane mixing ratio was increased. Also, the carbon monoxide(CO) was slightly decreased however, the soot and nitrogen oxides($NO_X$) increased a little in accordance with the n-heptane fuel mixing ratio. In addition, the pressure difference was almost the same in any conditions.

• 한국자동차공학회논문집
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• 제17권1호
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• pp.35-42
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• 2009

In this study, a spark ignition engine operated with LPG and DME blended fuel was studied experimentally. The effect of n-butane and propane on performance and emissions of a SI engine fuelled by LPG/DME blended fuel were examined. Stable engine operation was achieved for a wide range of engine loads with propane containing LPG/DME blended fuel compare to butane containing LPG/DME blended fuel since octane number of propane was much higher than that of butane. Also, engine output operated with propane containing blended fuel was comparable to pure LPG fuel operation. Engine output power was decreased and break specific fuel consumption (BSFC) was increased with the blended fuel since the energy content of DME was much lower than that of LPG. Considering the results of engine output power, bsfc, and exhaust emissions, the propane containing LPG/DME blended fuel could be used as an alternative fuel for LPG.

• 동력기계공학회지
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• 제9권3호
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• pp.15-20
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• 2005

In this paper, the effect of oxygen component in fuel on the exhaust emissions has been investigated for an indirect injection diesel engine. It was tested to estimate change of engine performance and exhaust emission characteristics for the commercial diesel fuel and oxygenated blended fuel which has four kinds of mixed ratio. And, the effects of exhaust gas recirculation(EGR) on the characteristics of NOx emission have been investigated. Ethylene glycol mono-n-butyl ether(EGBE) contains oxygen component 27% in itself, and it is a kind of effective oxygenated fuel of mono-ether group that the smoke emission of EGBE is reduced remarkably compared with commercial diesel fuel, that is, it can supply oxygen component sufficiently at higher loads and speeds in diesel engine. It was found that simultaneous reduction of smoke and NOx was achieved with oxygenated fuel(10vol-%) and cooled EGR method(10%).

• 한국연소학회:학술대회논문집
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• 한국연소학회 2002년도 제24회 KOSCO SYMPOSIUM 논문집
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• pp.185-191
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• 2002

The influence of N2 addition on soot formation, flame temperature and NOx emissions is investigated experimentally with methane fuel co-flow diffusion flames. The motivation of the present investigation is the differences in NOx reduction reported between fuel-side and oxidizer-side introduction of N2. To determine the influence of dilution alone, fuel was diluted with nitrogen while keeping the adiabatic flame temperature fixed by changing the temperature of the reactants. And to see the thermal effect only, air was supplied at different temperature without N2 addition. N2 addition into fuel side suppressed the soot formation than the case of oxidizer-side, while flame temperature enhanced the soot formation almost linearly. These results reveals the relative influences of the thermal, concentration effects of N2 additives on soot formation In accordance with experimental study, numerical simulation using CHEMKIN code was carried out to compare the temperature results with those acquired by CARS measurement, and we could find that there is good agreement between those results. Emission test revealed that NOx emissions were affected by not only flame temperature but also N2 addition.

• 한국분무공학회지
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• 제21권1호
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• pp.29-36
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• 2016

The effect of high ambient temperature and pressure conditions on the combustion performance of n-butanol, n-heptane and its mixing fuel (BH 20) were studied in this work. To reveal this, the closed homogeneous reactor model applied and 1000-1200 K of the initial temperature, 20-30 atm of initial pressure and 1.0 of equivalence ratio were set to numerical analysis. It was found that the results of combustion temperature was increased and the ignition delay was decreased when the ambient conditions were elevated since the combustion reactivity increased at the high ambient conditions. On the contrary, under the low combustion temperature condition, the combustion pressure was more influenced by the ambient temperature in the same ambient conditions. In addition, the total mass and the mass density of tested fuels were influenced by the ambient pressure and temperature. Also, soot generation of mixing fuel was decreased than n-heptane fuel due to the oxygen content of n-butanol fuel.

• Korean Chemical Engineering Research
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• 제50권1호
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• pp.118-127
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• 2012

고분자전해질 연료전지용 분리판 소재로 스텐레스 강의 내식성과 전기전도성을 향상시키기 위해 표면을 TiN(titanium nitride) 또는 Ti/TiN(titanium/titanium nitride)으로 코팅하여 연료전지 운전환경에서 표면 코팅층의 물성 변화를 조사하였다. 200시간의 연료전지 운전에서 표면 코팅층의 부식, 균열(crack), 박리, 표면 화학조성 변화 등을 분석하여 코팅된 TiN 또는 Ti/TiN 박막의 역할을 규명하고자 하였다. 스텐레스 강 분리판의 전기전도도와 부식저항성은 소재 표면에 질화층 박막을 코팅함으로써 증가하였으나 연료전지 환경하에서 운전시 코팅된 박막의 부식과 박리현상이 SUS316L-Ti/TiN을 제외하고 현저히 발생하였다. TiN 코팅층과 하부 기재 사이에 Ti 중간층을 도입함으로써 TiN 박막의 밀착성이 향상되고 또한 코팅층의 두께 증가로 부식 위험성이 감소하는 것을 관찰하였다.

• 한국환경농학회지
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• 제18권1호
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• pp.83-85
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• 1999

관개수중에 함유된 경유정량을 위한 간이법을 개발하기 위하여 수행한 본 시험의 결과, n-Pentane를 이용하여 경유를 정량하기 위한 최적 파장은 257nm, 정량범위는 $100{\sim}800mg/l$이었으며, 시료에 함유된 경유의 회수율은 $102{\sim}121%$이었다. 실험 온도를 $20^{\circ}C$ 전후로 유지시킬 경우, 침출후 1시간까지 농도변화가 5% 이내로 휘발에 의한 실험 오차가 적었다.

• Nuclear Engineering and Technology
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• 제53권11호
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• pp.3704-3710
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• 2021

The characteristics of the external radiation on the surface of the casks for spent nuclear fuel (SNF) storage by dry method are investigated for the case when the spatial distribution of SNF in the basket changes due to the destruction of the fuel rod claddings. The surface areas are determined, where the changes in fluxes of neutrons, produced by ²⁴⁴Cm actinide, and γ-quanta, produced by long-lived isotopes, are maximum in the result of the decrease in the height of the SNF area. Concrete (VSC-24) and metal (SC-21) casks are considered as examples. The procedure of periodic measurement of the dose rate of neutrons or γ-quanta at the specified points of the cask surface is proposed for identifying the fuel rod cladding destruction. Under normal operation, the decrease in the dose rate produced by neutrons as the function of SNF storage duration is determined by the half-life of ²⁴⁴Cm, and for γ-quanta - by the half-lives of long-lived SNF isotopes. Consequently, a stepwise change in the dose rate of neutrons or γ-quanta, detected by the measurements, as compared to the previous one, would indicate the destruction of the fuel rod claddings.