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        검색결과 76

        1.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study intends to use the possibility of an eco-friendly alternative fuel to be applied to ships as a sample manufacturing method for ship MGO and bioethanol mixed fuel oil as basic evidence. The components of the manufactured mixed fuel oil were analyzed using the ISO-8217 standard testing method. As a result of analysis showed that in the lower calorific value decreased to 43030J/g at BE0 fuel and 37010J/g at BE30 fuel. The high calorific value decreased to 46.065MJ/kg at BE0 fuel and 39.460MJ/kg at BE30 fuel. The density decreased to 840.8kg/m3 at BE0 fuel and 837.0kg/m3 at BE30 fuel. In the case of flash point it was 67.5℃ when BE0, and decreased to less than 40.0℃ when BE10 to BE30. Finally the Kinematic Viscosity was 3.011mm2/s at BE0 and decreased to 2.502mm2/s at BE30.
        4,000원
        2.
        2023.05 구독 인증기관·개인회원 무료
        At Nuclear Power Plant (NPP), aging management is performed as part of the Periodic Safety Review (PSR) in accordance with the Nuclear Safety Act. The purpose of the aging management program (AMP) is to manage the integrity of structures, systems and components (SSCs) in NPPs over time and use. Through this, aging deterioration is mitigated to increase equipment life and secure long-term operation safety. Fuel Oil Chemistry is one of the AMPs. Through this program, aging management is performed for storage tanks, piping and other metal components that contact with diesel fuel oil. The program is focused on managing loss of material due to general, pitting, crevice, and microbiologically-influenced corrosion (MIC) and fouling that leads to corrosion of the diesel fuel tank internal surfaces. The fuel oil aging management method currently applied to NPPs in Korea measures the concentration of water and particulate contamination in the oil, analyzed the trend, and periodically cleans and inspect the inside of tanks. Among them, in monitoring MIC, a direct analysis and monitoring of the amount of microorganisms may be more effective. In this study, a method for improving the MIC monitoring system for diesel fuel oil systems was reviewed by reviewing reference documents including NUREG 1801 and examining the methods actually applied in US NPPs.
        3.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The fuel oil used for ships has the viscosity higher than the fuel used for general vehicles and contain impurities, so it’s exhaust gas results in the environment pollution. There have been studies actively conducted to examine alternative fuels for improving the quality of the marine fuel oil. It is, however, necessary to test the quality of fuel for mega ships, by conducting the simulation test using reduced-size models, before the demonstration step, because it takes too much cost and time to directly perform the demonstration of alternative fuels. This study, therefore, developed a 30-liter small-size boiler similar to the ship system and performed an initial fuel test by applying MGO to it. The findings show that the amount of nitrogen oxide to which 4% of the standard oxide level was applied was about 24.69ppm, when the oxide level was 10.02%, with the CO2 of 8.02%, the exhaust gas temperature of 291.15℃ and the combustion efficiency of about 74.53%, indicating that it will be necessary to conduct various studies through the ratio control in the future.
        4,000원
        5.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Silicon oxide (SiOx) has been considered one of the most promising anode materials for lithium-ion batteries due to having a higher capacity than the commercial graphite anodes. However, its practical application is hampered by very large volume variations. In this work, pyrolysis fuel oil is the carbon coating precursor, and physical vapor deposition (PVD) is performed on SiOx at 200 and 400 °C (SiOx@C 200 and SiOx@C 400), followed by carbonization at 950 °C. SiOx@C 200 has a carbon coating layer with a thickness of ~ 20 nm and an amorphous structure, while that of SiOx@C 400 is approximately 10 nm thick and has a more semigraphitic structure. The carbon-coated SiOx anodes display better charge–discharge performance than the pristine SiOx anode. In particular, SiOx@C 200 shows the highest reversible capacity compared with the other samples at high C-rates (2.0 and 5.0 C). Moreover, SiOx@C 200 exhibits excellent cycling stability with a capacity retention of 90.2% after 80 cycles at 1.0 C. This result is ascribed to the suppressed volume expansion by the PFO carbon coating on SiOx after PVD.
        4,000원
        7.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, air pollution from fossil fuels is at a serious level, and the IMO proposes to reduce greenhouse gas emissions by about 70% by 2050, and controls greenhouse gas emissions by applying the energy efficiency disign index(EEDI) to each ship type. In this study, the marine fuel oil viscosity of MGO, MDO, HFO and CGO according to the temperature change was compared and measured and the difference was analyzed. As a result, the viscosity of CGO was 3.32mPa·s, which was almost similar to MGO(3.40mPa·s) and MDO(3.51mPa·s) so it was judged that it could be used as a marine fuel, and it was found that there was a significant difference with HFO at P<0.01 there was.
        4,000원
        9.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        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.
        4,000원
        10.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        국제해사기구(IMO)의 황함유량 규제에 따르는 저유황연료유는 생산 공정에 따라 다양한 물리화학적 특성을 가지게 된다. 본 연구는 저유황연료유 및 저유황-고유황 혼합연료유의 물리화학적 특성연구 결과를 해양오염 방제대응의 기초자료로 활용하고자 한다. 연구에 사용된 혼합연료유는 황함유량이 0.46 mass%인 저유황연료유와 0.36 mass%인 저유황연료유에 고유황연료유를 25, 50, 75 mass% 혼합하여 제조하였다. 이 혼합연료유에 대해 동점도, 유동점 및 Saturates, Aromatics, Resins, Asphaltenes(SARA)분포 등 물리화학적 특성에 대해 실험실 연구를 하였다. 동점도가 높고 유동점이 낮은 특징의 고유황연료유가 75 mass% 혼합함에 따라, 혼합연료유의 동점도는 350.2 %까지 증가 하였으며, 유동점이 23℃와 -11℃의 저유황연료유는 각각 -3℃ 및 -6℃까지 유동점이 내려가거나 올라갔다. Asphaltenes 분포가 적은 저유황연료유에 고유황연료유를 혼합함에 따라, Saturates분포는 68.8 %까지 감소하고, Asphaltenes분포는 1,417 %까지 크게 증가하였다.
        4,000원
        14.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, four types of water-heavy fuel oil hybrid emulsion oil were manufactured depending on the moisture content ratio in order to reduce exhaust emissions of heavy fuel oil(Bunder-C), which is necessarily used in vessels, power plants and boilers. The components of the manufactured emulsion oil were analyzed using the ISO standard testing method. The analysis result showed that in the EM25 fuel with a maximum moisture content ratio of 25.0%, the moisture content was 25.0%, the sulphur content was 0.20%, the kinematic viscosity was 144.8mm2/s, the specific gravity was 0.9382, and the flash point was 100 Celsius degrees or above.
        4,000원
        18.
        2019.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Petroleum-based impregnating pitches were prepared from pyrolysis fuel oil (PFO) using a two-step heat treatment without a separation process. The pressurized heat treatment, the first step, was used to improve the properties of the pitches and enhance the product yield by promoting the cracking and polymerization of the components in the PFO. An atmospheric heat treatment as the second step was used only to synthesize the impregnating pitches from the liquid pitches prepared during the first step. The prepared impregnating pitches had the properties of a commercial petroleum-based impregnating pitch. The impregnation performance was evaluated by HT-XRD and an impregnation test. The HT-XRD results showed changes in the stacked structure of the pitches at the impregnation temperature. The bulk density of the carbon block was increased to 14.3% and the porosity was reduced by 10.3% after the impregnation/recarbonization process. The high reaction temperature during the first step induced the formation of quinoline insoluble (QI) components during the second step of the treatment, and the QI components adversely affected the impregnation process.
        4,000원
        19.
        2019.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The spray characteristics of two working fluids operating with a bi-fuel injector were investigated. A bi-fuel injector simultaneously sprays two working fluids, both of which possess different properties. An effervescent atomizer containing two separated aerator tubes was employed as the bi-fuel injector. Vegetable oil and kerosene were the working fluids. The mixing ratio and ALR were the experimental parameters. The mixing ratio is the mass fraction of vegetable oil in the total amount of working fluids. The ALR represents the ratio of the atomizing gas to the working fluid mass flow ratio. In order to examine spray characteristics, the spray angle, droplet size distribution, cumulative volume fraction, Sauter Mean Diameter and span factor were measured using a high resolution video camera and a Laser Diffraction Particle Analyzer. From the experimental results, spray angle is decreased with as the ratio of kerosene to vegetable oil in working fluid is increased. Regardless of ALR, SMD was the smallest when the only working fluid was kerosene and uniformity was the most stable when the only working fluid was vegetable oil.
        4,000원
        20.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Structural characterization of pyrolysis fuel oil (PFO) was conducted via 1H NMR and 13C NMR to elucidate its molecular structure and evaluate the feasibility of using PFO as a raw material for mesophase pitch synthesis. The average structural parameters were calculated based on the data from elemental analysis and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS), as well as 1H NMR and 13C NMR data. The resultant structural features of PFO were compared with those of fluidized catalytic cracking-decant oil (FCC-DO). Based on the calculated parameters, we proposed average molecular models of PFO and FCC-DO. The molecular model of PFO showed that it had an aromatic structure consisting of three aromatic rings and one naphthenic ring fused with one pericondensed and two catacondensed aromatic carbons, as well as a short alkyl side chain (with only a methyl group). This structural feature of PFO demonstrated that it is highly favorable for use as a raw material for mesophase pitch synthesis. The empirical findings in this study provide an in-depth understanding of the molecular structure of PFO as well as FCC-DO and can offer insights for future research on the utilization of PFO and other petroleum heavy oils.
        4,200원
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