• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.2553-2558
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• 2014

Military rotorcraft should be designed taking into account the condition of the fuel cell bullet impact. The internal fluid pressure, stress of metal fitting and fuel cell, bullet kinetic energy can be included as the design factor for the fuel cell. The best way to obtain the important design data is to conduct the verification test with actual product. But, the verification test requires huge cost and long-term effort. Moreover, there is high risk to fail because of the sever test condition. Thus, the numerical simulation is required to reduce the risk of trial-and-error together with prediction of the design data. In the present study, the bullet impact simulation based on SPH(smoothed particle hydrodynamics) is conducted with the commercial package, LS-DYNA. As the result of the numerical simulation, the internal pressure of fuel cell is calculated as 350~360MPa and the equivalent stress caused by hydro-ram effect is predicted as 260~350MPa on metal fittings.

• Journal of Energy Engineering
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• v.17 no.1
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• pp.38-45
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• 2008

In this work, we investigated the variation of physical and chemical characteristics of solvent-insolubles and solvent-solubles in Canada's Athabasca oil sands by solvent-insolubles experiments. N-Heptane, n-Hexane, and n-Pentane were tested for solvents and asphaltenes were separated from maltenes by using a modified ASTM D 3279 method. Elemental analysis, boiling point distribution (SIMDIS), molecular weight distribution, heavy metal contents, API gravity, viscosity and SARA fractions were measured for thorough samples. The asphaltenes-removed maltenes contained less sulfur and heavy metal amounts and had lower molecular weight than the original bitumen. N-Pentane solvent could lower sulfur and heavy metal amounts, molecular weight, and viscosity of maltenes compared to the other solvents. Eventually, we confirmed that the obtained experimental data could be used as basic informations of bitumen upgrading processes for the production of SCO (synthetic crude oil).

• Nuclear Engineering and Technology
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• v.53 no.10
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• pp.3367-3378
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• 2021

The design phase and safety assessment of Generation IV liquid metal-cooled fast reactors calls for the improvement of fuel pin performance codes, in particular the enhancement of their predictive capabilities towards uranium-plutonium mixed oxide fuels and stainless-steel cladding under irradiation in fast reactor environments. To this end, the current capabilities of fuel performance codes must be critically assessed against experimental data from available irradiation experiments. This work is devoted to the assessment of three European fuel performance codes, namely GERMINAL, MACROS and TRANSURANUS, against the irradiation of two fuel pins selected from the SUPERFACT-1 experimental campaign. The pins are characterized by a low enrichment (~ 2 wt.%) of minor actinides (neptunium and americium) in the fuel, and by plutonium content and cladding material in line with design choices envisaged for liquid metal-cooled Generation IV reactor fuels. The predictions of the codes are compared to several experimental measurements, allowing the identification of the current code capabilities in predicting fuel restructuring, cladding deformation, redistribution of actinides and volatile fission products. The integral assessment against experimental data is complemented by a code-to-code benchmark focused on the evolution of quantities of engineering interest over time. The benchmark analysis points out the differences in the code predictions of fuel central temperature, fuel-cladding gap width, cladding outer radius, pin internal pressure and fission gas release and suggests potential modelling development paths towards an improved description of the fuel pin behaviour in fast reactor irradiation conditions.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.6
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• pp.106-114
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• 1999

Today, one of the most important objective in automobile development is to reduce the weight of automobile . The eventual depletion of petroleum and environmental regulations brought considerable emphasis to this area on increasing fuel efficiency. Conventional intake air-fuel system is very heavy because it is composed of numerous parts. The bulky size caused increase in the amount of metal being used to build automobile chassis and this became a serious weight problem. The size also caused difficulties in optimization of fuel supply system which in turn decreased engine efficiency. Currently , there are efforts to integrate several intake system modules into one. The purpose of this paper is to evaluate the directions of such development.

• Nuclear Engineering and Technology
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• v.52 no.4
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• pp.689-699
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• 2020

In this work, new multi-recycling options of TRU nuclides using PWR fuel assemblies comprised of MOX and FCM (Fully Ceramic Micro Encapsulated) fuels are suggested and neutronically analyzed. These options do not use a fully recycling of TRU but a partial recycling where TRUs from MOX fuels are recycled while the ones from FCM fuels are not recycled due to their high consumption rate resulted from high burnup. In particular, additional external TRU feed in MOX fuels for each cycle was considered to significantly increase the TRU consumption rate and the finally selected option is to use external TRU and enriched uranium feed as a makeup for the heavy metal consumption in MOX fuels. This hybrid external feeding of TRU and enriched uranium in MOX fuel was shown to be very effective in significantly increasing TRU consumption rate, maintaining long cycle length, and achieving negative void reactivity worth during recycling.

• Journal of the Korean Ceramic Society
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• v.42 no.12 s.283
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• pp.865-871
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• 2005

Submicron thick solid electrolyte membrane is essential to the implementation of low temperature solid oxide fuel cell, and, therefore, development of new electrode structures is necessary for the submicron thick solid electrolyte deposition while providing functions as current collector and fuel transport channel. In this research, a nickel membrane with multi-stage nano hole array has been produced via modified two step replication process. The obtained membrane has practical size of 12mm diameter and $50{\mu}m$ thickness. The multi-stage nature provides 20nm pores on one side and 200nm on the other side. The 20nm side provides catalyst layer and $30\~40\%$ planar porosity was measured. The successful deposition of submicron thick yttria stabilized zirconia membrane on the substrate shows the possibility of achieving a low temperature solid oxide fuel cell.

• Journal of the Korean Electrochemical Society
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• v.16 no.1
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• pp.52-58
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• 2013

In order to overcome the cost issue for commercialization of polymer electrolyte membrane fuel cell (PEMFC), this research was conducted for replacing platinum cathode catalyst with non-precious metal catalyst. The non-precious metal catalyst (Co-PANI-C) was synthesized by the simple reduction method with polyaniline (PANI), carbon black, and cobalt precursor without any heat treatment. Characterization of new Co-PANI-C composite catalysts was done by the measurement of X-ray diffraction (XRD) and thermogravimetric analysis (TGA) for structure analysis and performed by rotating disk electrode (RDE) and rotating ring disk electrode (RRDE) for electrochemical analysis. As a result, Co-PANI-C catalyst showed 60 mV lower on-set potential for oxygen reduction reaction (ORR) than Pt/C catalyst, but the overall reduction current of Co-PANI-C catalysts by ORR was still smaller than that of Pt/C. In addition, the ORR behavior of Co-PANI-C catalysts depending on the rotation speed of electrode and the stability of Co-PANI-C catalyst under potential cycling and the performance of fuel cell conditions are also discussed.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.5
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• pp.421-430
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• 2023

Fe-Ni-Pt nanocatalysts were loaded on carbon black powders which were synthesized by a spontaneous reduction reaction of iron (II) acetylacetonate, nickel (II) acetylacetonate and platinum (II) acetylacetonate. The morphology and the loading weight of Fe-Ni-Pt nanoparticles were characterized by transmission electron microscopy and thermogravimetric analyzer. The amount of Fe-Ni-Pt catalyst supported on the carbon black surface was about 6.42-9.28 wt%, and the higher the Fe content and the lower the Pt content, the higher the total amount of the metal catalyst supported. The Brunauer-Emmett-Teller Analysis (BET) specific surface area of carbon black itself without metal nanoparticles supported was 233.9 m²/g, and when metal nanoparticles were introduced, the specific surface area value was greatly reduced. This is because the metal nanocatalyst particles block the pore entrance of the carbon black, and thereby the catalytic activity of the metal catalysts generated inside the pores is reduced. From the I-V curves, as the content of the Pt nanocatalyst increased, the electrolytic properties of water increased, and the activity of the metal nanocatalyst was in the order of Pt > Ni > Fe.

• 한국연소학회:학술대회논문집
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• 2004.11a
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• pp.175-180
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• 2004

Improving furnace efficiency is a high priority need for aluminum, glass, steel and other metal casting industries. Oxy-fuel combustion is considered to be one of the most effective method to improve thermal efficiency and reduce $NO_x$, SOx and $CO_2$ emissions for high temperature furnaces. The characteristics of an oxy-fuel flame, in particular its shape, radiation profile and exhaust gas composition are considerably different to those of an air-fuel burner. For this reason, a new approach is needed regarding factors such as burner design, power input levels, number and positioning strategies of burners and also control philosophies. In this paper will discuss the latest developments of high performance oxy-fuel combustion reheating furnace system. This high performance oxy-fuel combustion system will be shown to be technologically superior to other types of combustion systems in the areas of fuel efficiency, emissions and productivity.

• Journal of Korea Society of Waste Management
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• v.35 no.7
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• pp.616-626
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• 2018

The quality standards of solid refuse fuel (SRF) define the values for 12 physico-chemical properties, including moisture, lower heating value, and metal compounds, according to Article 20 of the Enforcement Rules of the Act on Resource Saving and Recycling Promotion. These parameters are evaluated via various SRF Quality Test Methods, but problems related to the heavy metal content have been observed in the microwave acid digestion method. Therefore, these methods and their applicability need improvement. In this study, the appropriate testing conditions were derived by varying the parameters of microwave acid digestion, such as microwave power and pre-treatment time. The pre-treatment of SRF as a function of the microwave power revealed an incomplete decomposition of the sample at 600 W, and the heavy metal content analysis was difficult to perform under 9 mL of nitric acid and 3 mL of hydrochloric acid. The experiments with the reference materials under nitric acid at 600 W lasted 30 minutes, and 1,000 W for 20 or 30 minutes were considered optimal conditions. The results confirmed that a mixture of SRF and an acid would take about 20 minutes to reach $180^{\circ}C$, requiring at least 30 minutes of pre-treatment. The accuracy was within 30% of the standard deviation, with a precision of 70 ~ 130% of the heavy metal recovery rate. By applying these conditions to SRF, the results for each condition were not significantly different and the heavy metal standards for As, Pb, Cd, and Cr were satisfied.