• Journal of Navigation and Port Research
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• v.48 no.2
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• pp.125-136
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• 2024

This research presents an innovative integrated ethanol solid oxide fuel cell (SOFC) system designed for applications in marine vessels. The system incorporates an exhaust gas heat recovery mechanism. The high-temperature exhaust gas produced by the SOFC is efficiently recovered through a sequential process involving a gas turbine (GT), a regenerative system, steam Rankine cycles, and a waste heat boiler (WHB). A comprehensive thermodynamic analysis of this integrated SOFC-GT-SRC-WHB system was performed. A simulation of this proposed system was conducted using Aspen Hysys V12.1, and a genetic algorithm was employed to optimize the system parameters. Thermodynamic equations based on the first and second laws of thermodynamics were utilized to assess the system's performance. Additionally, the exergy destruction within the crucial system components was examined. The system is projected to achieve an energy efficiency of 58.44% and an exergy efficiency of 29.43%. Notably, the integrated high-temperature exhaust gas recovery systems contribute significantly, generating 1129.1 kW, which accounts for 22.9% of the total power generated. Furthermore, the waste heat boiler was designed to produce 900.8 kg/h of superheated vapor at 170 ℃ and 405 kP a, serving various onboard ship purposes, such as heating fuel oil and accommodations for seafarers and equipment.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.22 no.2
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• pp.105-115
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• 2024

In this study, we employed a small-scale experiment to demonstrate the introduction of a thin copper heat dissipation plate into a bentonite buffer layer of an engineered barrier system. This experiment designed for spent nuclear fuel disposal can effectively reduce the maximum temperature of the bentonite buffer layer, and ultimately, make it possible to reduce the area of the disposal site. For the experiment, a small-scale engineered barrier system with a copper heat dissipation plate was designed and manufactured. the thickness of the cylindrical buffer was about 2 cm, which was about 1/20 of KAERI Repository System (KRS). At a power supply of 250 W, the maximum buffer temperature reduced to a mere 1.8℃ when the thin copper plate was introduced. However, the maximum surface temperature reduced to a remarkable 9.1℃, when a U-collar copper plate was introduced, which had a good contact with the other barrier layers. Consequently, we conclude that the introduction of the thin copper plate into the engineered barrier system for spent nuclear fuel disposal can effectively reduce the maximum buffer temperature in high-level radioactive waste disposal repositories.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.38-44
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• 2000

Compared to other waste, waste tire has much discharge quantity and calorie. When we use waste heat from waste tire, it can be definitely better substitute energy than coal and anthracite in high oil price age. To use as a basic data for providing low cost and highly effective heating system, following conclusion was founded. Annual waste tire production was 19,596 million in 1999, Recycling ratio was almost 55% and more than 8.78 million was stored. Waste tire has lower than 1.5% sulfur contain ratio which is resource of an pollution, So it is a waste fuel which can be combustion based on current exhaust standard value without any extra SOx exclusion materials. Waste tire has 9,256Kcal/kg calorific value and it is higher than waste rubber, waste rubber, waste energy as same as B-C oil. When primary and second air quantity was 1.6, 8.0 Nm$^3$/min, dry gas production time was 270min and total combustion time was 360 min. In the SOx, NOx, HC of air pollution material density were lower than exhaust standard value at the back of cyclone and dusty than exhaust standard value without dust collector.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.1
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• pp.39-45
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• 2008

As a waste management tool, the prohibition of landfilling of food waste has enforced since 2005. the composition of municipal solid waste (MSW) has changed dramatically. In this study, MSW generated from a small city collected once a year in 2004, 2005 and 2007, to qualify the characteristics of MSW before and after implementation of the tool. The prohibition of landfilling of food waste dramatically reduces food waste in MSW to 5.5 weight %, and on the other hand results to increase papers to 50.6 % and plastics to 22.6 %, The bulk density lowers to 50 %, which newly propose the necessity of volume reduction and incineration of MSW to ensure efficient transport and disposal. As water content of MSW reduces to 15.9 %, lower heat value of MSW after prohibition of landfilling of food waste increase to 3565.6 kcal/kg. Mitigation of bad smell and waste leachate with lower contaminants are recommendable as a kind of positive effects benefited by the tool.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.2
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• pp.176-183
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• 2022

High-purity waste CNTs were mixed into cement mortar to manufacture heat-generating concrete that can use low voltage power, and carbon fiber and waste cathode materials were also used improve the conductivity of the mortar. The waste CNTs were analyzed to have a high concentration of multi-walled CNTs, and substituted liquid type waste CNTs were used during mortar mixing in order to increase dispersibility. The temperature change of the mortar with CNT was evaluated when using electric power below DC 24 V in order to utilize a small self-generation facility such as small solar power module when the mortar heats up and to minimize electromagnetic waves. When liquid-type waste CNTs were applied and a voltage of DC 24 V was introduced, it rose to 60 ℃ in a 200 × 100 × 50 mm mortar block specimen. The field applicability of self heating mortar with waste CNT was sufficient and also the amount of change in heat energy in mortar with liquid type waste CNT, carbon fiber and waste cathode materials is more effective compared to it of other variables.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.634-637
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• 2008

Ground source heat pumps are clean, energy-efficient and environment-friendly systems cooling and heating. Although the initial cost of ground source heat pump system is higher than that of air source heat pump, it is now widely accepted as an economical system since the installation cost can be returned within an short period of time due to its high efficiency. In the present study, performances of ground source compound hybrid heat pump system applied to a large community building are simulated. The system design and operation process appropriate for the surrounding circumstance guarantee the high benefit of the heat pump system applied to a large community building. If among several renewable energy sources, ground, river, sea, waste water source are chosen as available alternative energies are combined, COP of the system can be increased largely and hybrid heat pump system can reduced the fuel cost.

• Resources Recycling
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• v.15 no.3 s.71
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• pp.30-37
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• 2006

For keeping the indoor air quality, we develop the pulsating heat pipe(PHP) type heat recovery ventilator using an used radiator for vehicles. We compare the PHP type with existing model. There are some merits that are able to change the unit number according to heat load and show us the similar performance to existing models.

• Journal of Energy Engineering
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• v.21 no.4
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• pp.393-397
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• 2012

In this study, an organic Rankine cycle(ORC) for gas engine waste heat recovery for industry has been constructed and a performance analysis test has been carried out. Shell & tube style heat exchanger has been equipped on an engine exhaust manifold in order to absorb heat of engine exhaust gas into the working fluid(refrigerant R134a). Under 60 kW of engine power output, about 63 kW of engine exhaust gas heat was discharged and the proportion of heat recovered was 68~73% while 43~46 kW of heat was absorbed into working fluid. Consequently rated power output of ORC was 4.6 kW while the ratio of rated power output to engine exhaust gas heat was 7.3%.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.776-779
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• 2003

To reduce the storage space of spent fuel used at the atomic power plants in the over the world, the uranium elements contained in the spent fuel is being extracted and effectively stored. For this, the spent fuel are oxidized and deoxidized. In this study, it is produced the heat-resisting methods about the spent fuel management technology research and test facility for the spent fuel waste for spent fuel minimized. The first considered processes in the facility are the electrolytic metal reduction reactor process. Since the electrolytic metal reduction reactor is operated at the high temperature range, we have to consider the heat-resisting methods for the devices. For the heat-resisting methods, we have searched and analyzed technical reference for the heat-resisting methods. We have calculated thermal stress and strain of each devices by the commercial analysis software, ANSYS. D.S. It is experimented for inspecting confidence rate of analysis results. By using the results, we have analyzed the problems of parts and determined the heat-resisting material, commercial parts, and the size of parts and O-ring. Based on these results, it is produced the heat-resisting methods of magnesia filter, cathode, and reactor for the electrolytic metal reduction reactor.

• Journal of Korea Soil Environment Society
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• v.2 no.2
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• pp.61-72
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• 1997

This research aims to remove the heavy metals, nonbiodegradable COD(NBDCOD), and color using the coal waste. The experimental by heat treatment was performed to advance the adsorption capacity. The results are as follows ; i) The coal waste had the adsorption capacity of heavy metals and the rates were in the range of 20 to 30 percents. ii) The heat treatment was the optimum condition that the reaction time was 6 hours at $500^{\circ}C$, , iii) In the column experimen, non-treated coal waste removed the COD and color in the range of 20 to 60 percents. iv) Heat-treated coal waste showed higher removal rate of the color in biological effluent, and heavy metal and COD removal rates were changed by the filteration rates.