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        검색결과 83

        25.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        우리나라 시설 재배면적은 2015년 기준 52,526ha이고 이 중 난방면적은 15,878ha이다. 이중 석유를 이용하여 난방하는 온실 면적은 13,314ha로서 전체 난방면적의 84%를 차지하고 있다. 고가의 시설비가 투자된 자동화 온실에서 겨울철에 난방기를 사용하여 채소 및 화훼류를 재배할 경우 생산비 중에 난방 비가 차지하는 비중이 40%를 웃돌고 있다. 우리나라의 폐윤활유 발생량은 2015년에는 249,965kL이고 이중 회수량은 197,469kL로서 발생량의 79% 수준이다. 또한 회수한 폐윤활유의 재활용량은 2015년 기 준 195,691kL로서 재활용율이 99%에 달한다. 그러므로 저가의 대체연료 사용에 따른 농가 소득 증대의 관점에서 볼 때 시설난방에 폐윤활유를 사용하는 것은 매우 중요하다고 할 수 있다. 따라서 본 연구는 폐윤활유를 농용 난방기의 연료로서의 사용 가능성을 분석하고자 하였다. 연구결과 농용 난방기의 연소 가스온도는 폐윤활유를 연료로서 사용하였을 때가 중유를 연료로서 사용했을 때에 비해 평균 6.1%, 경 유를 연료로 사용하였을 때보다 평균 3.1% 높게 나타났다.
        4,000원
        26.
        2016.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        선박엔진은 잔사유를 에너지원으로 활용하여 운항할 수 있으며, 이를 활용한 선박에서 환경 규제와 경제성을 모두 만족시키는 다양한 방안들이 모색되고 있다. 그 중에 한 방안으로 연료 첨가제를 활용하는 기술이 있을 수 있다. 분산제와 연소촉진제는 잔사유활용 시 엔진의 연소특성 촉진에 기여할 것이라는 기대를 받고 있다. 따라서, 본 연구에서는 연소성 분석 장비(FIA/FCA)와 열 중량 분석 장비(TGA)를 활용하여 잔사유 연료첨가제가 혼합된 잔사유의 연소성을 분석하였다. 연소성 분석 장비(FIA/FCA)의 결과로는 연소에 의한 일의 총량을 분석하도록 분석법이 개발되었으며, 이 때문에 본 연구를 통하여 동일 장비를 활용하면서도 연소 효율을 간단하게 평가할 수 있는 방안을 제시하였다. 연소성 분석 결과인 ROHR 곡선으로부터, 단순한 삼각함수를 활용하여 연소특성을 예측할 수 있는 방안을 제시하였으며, 이 기법을 활용하여 기존의 압력 곡선과 유사한 결론을 도출할 수 있었다. 열 중량 분석(TGA)의 경우 연료유의 증발 특성에 민감하게 반응함을 확인하였고, 첨가제가 연료유 증발에 효과적으로 작용함을 확인하였다.
        4,000원
        27.
        2016.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Our environment is faced with serious problems related to the air pollution from automobiles in these days. In particular, the exhaust emissions from the diesel engines are recognized main cause which influenced environment strong. In this study, the potential of biodiesel fuel and oxygenated fuel (ethylene glycol mono-n-butyl ether; EGBE) was investigated as an effective method of decreasing the smoke emission. The smoke emission of blending fuel (EGBE 0~20 vol-%) was reduced in comparison with diesel fuel and it was reduced approximately 64% at 2000 rpm, full load in the 20% of blending rate. But torque and brake specific energy consumption (BSEC) didn't have no large differences. But, NOx emissions from biodiesel fuel and EGBE blended fuel were increased compared with diesel fuel.
        4,000원
        30.
        2015.11 구독 인증기관 무료, 개인회원 유료
        In this study, we investigated the effects of EGR rate and engine load on the emission characteristics in a 4-cylinder common rail direct injection diesel engine fueled with canola oil biodiesel (BD) blended fuel. The biodiesel blend fuel, BD20 (20 vol.% biodiesel and 80 vol.% ULSD blend) was used at an engine speed of 1,500rpm. The experimental results showed that with the increasing of EGR rate, the combustion pressure and rate of heat release (ROHR) of three test fuels were decreased, and the ignition delay was extended, the carbon monoxide (CO) and particulate matter (PM) emissions increased slightly, but the nitrogen oxide (NOx) emission decreased clearly. On the other hand, with the increasing of engine load, the combustion pressure and ROHR were increased, and the CO and PM emissions decreased. However, the NOx emission was increased due to the rise of the combustion temperature.
        4,000원
        32.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study describes the effects of canola oil biodiesel (BD) blended fuel on the combustion performance and emission characteristics in a 4-cylinder common-rail direct injection diesel engine. In this study, with the increasing of engine loads, the biodiesel blend fuels(100 vol.% ULSD and 0 vol.% biodiesel blend, BD0; 80 vol.% ULSD and 20 vol.% biodiesel blend, BD20; 0 vol.% ULSD and 100 vol.% biodiesel blend, BD100; ULSD: ultra low sulfur diesel) were used at an engine speed of 1,500rpm. The experimental results showed that with the increasing of biodiesel blend rate, the combustion pressure decreased slightly at engine load of 20~60Nm. However, the rate of heat release (ROHR) increased clearly and ignition delay time was shortened. With the increasing of biodiesel blend rate, the carbon monoxide (CO) and particulate matter (PM) emissions were more decreased at all of the engine loads.
        4,000원
        33.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study is to investigate the effect of operating conditions on the performance of small HSDI compression ignition engine. Combustion and exhaust emission characteristics of engine were studied by using CFD simulation with ECFM-3Z combustion model. The conditions of simulation were varied with injection timing, injection pressure, and operating speed, and the results were compared in terms of combustion pressure, rate of heat release, NOx and soot. It was found that as injection timing was advanced and injection pressure is increased, combustion pressure and rate of heat release were increased. As a result, NOx generation is increased. Soot generation is also increased due to the wall film caused by the increase of the injection pressure and locally the rich mixture caused by the effect of the advancing of injection timing.
        4,000원
        34.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed to investigate the effect of fuel combustion enhancing apparatus(FCEA) for ionization of intaking air into cylinder combustion chamber on the combustion performance and emissions characteristics in a 4-cylinder common-rail direct injection diesel engine. The experiments were applied to the engine at an engine speed of 1,500rpm under 20Nm, 40Nm, 60Nm and 80Nm conditions. The test results were compared to each other with or without the FCEA. In the case of the FCEA, the combustion pressure, peak combustion pressure and rate of heat release were increased slightly and the brake specific fuel consumption(BSFC) was decreased slightly when compared to that without the FCEA under all loads at an engine speed of 1,500rpm. However, in the case of the FCEA, the nitrogen oxide(NOx) were increased slightly, the carbon monoxide(CO) and particulate matter(PM) were decreased slightly when compared to that without the FCEA under all loads at an engine speed of 1,500rpm.
        4,000원
        35.
        2015.03 구독 인증기관 무료, 개인회원 유료
        The numerical study of laminar syngas-fuel/air mixture with 10% hydrogen content impinging plate was conducted. Effects of impinging distance, Reynolds number and equivalence ratio were major parameters on combustion and emission for stagnation point. The numerical result calculated by SPIN application of the CHEMKIN software. There result showed the following : The Peak point of the axial velocity, the flame temperature and CH reaction were appeared in tip of the inner reaction zone. The emission results in impinging flame of syngas fuel show that the characteristics of NOx emission traced well with adiabatic temperature trend and CO emission due to fuel rich condition increased continuously with respect to the equivalence ratio.
        4,000원
        37.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objectives of this study was to examine experimentally the microexplosion phenomena of single droplet W/O(water-in-oil) type emulsified fuel. Also, measured the combustion characteristics of single droplet emulsified fuel for microexplosion phenomena in atmospheric pressure condition. The larger quantity of adding water makes microexplosion phenomenon with higher intensity of sound level, because larger water droplet has better coalescence for emulsified fuel. The small quantity of adding water makes puffing with lower sound level intensity. In latter period of extinction, large size droplet of the emulsified fuel breaks down rapidly to small size droplet, and microexplosion phenomenon occurs with multi step combustion.
        4,000원
        39.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In case of domestic pyrolysis dry distillation gassification technology, it stays at the stage of its early introduction and development. Moreover, the companies possessed of this technology are limited to Japan and some countries in Europe, and domestic operative performance of this system is nominal, so there exist a lot of difficulties in securing its basic data. In addition, considering its operation and management, there happens a corrosion of metals by the production of corrosive gases in time of combustion of waste, and there arise a problem of occurrence of low temperature corrosion on exterior casing or gas ducts of a combustion chamber due to the high temperature corrosion around the burner of an incinerator, lowering the durability of an incinerator. Therefore, this study looked at the problems arising in time of incineration by understanding the characteristics of the pyrolysis dry distillation gassification incinerating facility, and did research on the improvement plan for durability of an incinerator for more economic, efficient waste incineration.
        4,000원
        40.
        2010.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A SrAl2O4:Eu2+,Dy3+ phosphor powder with stuffed tridymite structure was synthesized by glycine-nitratecombustion method. The luminescence, formation process and microstructure of the phosphor powder were investigated bymeans of X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence spectroscopy (PL). The XRDpatterns show that the as-synthesized SrAl2O4:Eu2+,Dy3+ phosphor was an amorphous phase. However, a crystalline SrAl2O4phase was formed by calcining at 1200oC for 4h. From the SEM analysis, also, it was found that the as-synthesizedSrAl2O4:Eu2+,Dy3+ phosphor was in irregular porous particles of about 50µm, while the calcined phosphor was aggregated inspherical particles with radius of about 0.5µm. The emission spectrum of as-synthesized SrAl2O4:Eu2+,Dy3+ phosphor did notappear, due to the amorphous phase. However, the emission spectrum of the calcined phosphor was observed at 520nm(2.384eV); it showed green emission peaking, in the range of 450~650nm. The excitation spectrum of the SrAl2O4:Eu2+,Dy3+phosphor exhibits a maximum peak intensity at 360nm (3.44eV) in the range of 250~480nm. After the removal of the pulseXe-lamp excitation (360nm), also, the decay time for the emission spectrum was very slow, which shows the excellent long-phosphorescent property of the phosphor, although the decay time decreased exponentially.
        4,000원
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