• Transactions of the Korean hydrogen and new energy society
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• v.22 no.4
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• pp.546-551
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• 2011

The corrosion on steam generator tubes of the secondary side of pressurized water reactor inhibits heat transfer. One of the most efficient techniques improving the heat transfer performance of a nuclear electric generation is a corrosion control. The environmental parameters mostly affecting corrosion are materials and chemical additives. It seems that no further corrosion occurs in steels with Polyacrylic acid polymer dispersant treatment. Polyacrylic acid forms a protective coating with uniform thickness on metal surface. Polyacrylic treatment appears to be the most convenient way to enhance the thermal performance by the thermal conductivity improvement in steam generators.

• Journal of the Korean Society of Industry Convergence
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• v.20 no.2
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• pp.187-194
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• 2017

This study examined the validity and reliability of the thermal safety design, in order to maintain the heat generated from integrated circuit (IC) chips in the converter, condenser, resistor, and transistor (which are considered as heat sources for thermoelectric devices with a printed circuit board) below target levels during the process of developing a control board and a main power board. The study analyzed the heat generation and dissipation characteristics of the entire printed circuit board (PCB) model to examine its thermal safety.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05c
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• pp.265-270
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• 1996

The temperature distribution in the pellet was obtained from beginning the general heat conduction equation. The thermal conductivity of pellet used the SIMFUEL data that made clear the effect of burnup on the thermal conductivity degradation. Since the pellet rim acts as the thermal barrier to heat flow. the pellet was subdivided into several rings in which the outer ring was adjusted to play almost the same role as the rim. The local burup in each ring except the outer ring was calculated from the power depression factor based on FASER results. whereas the rim burnup at the outer ring was achieved by the pellet averaged burnup based on the empirical relation. The rim changed to the equivalent Xe film so the predicted temperature shooed the thermal jump across the rim. The observed temperature profiles depended on linear heat generation rate. fuel burnup. and power depression factor. The thermal conductivity degradation modelling can be applied to the fuel performance code to high burnup fuel,

• KEPCO Journal on Electric Power and Energy
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• v.8 no.2
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• pp.119-126
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• 2022

A growing number of gas-insulated transformers in underground power substations in urban areas are approaching 20 years of operation, the time when failures begin to occur. It is thus essential to prevent failure through accurate condition diagnosis of the given facility. Various solid insulation materials exist inside of the transformers, and the generated decomposition gas may differ for each gas-insulated equipment. In this study, a simulation system was designed to analyze the deterioration characteristics of SF₆ decomposition gas and insulation materials under the conditions of partial discharge and thermal fault for diagnosis of gas-insulated transformers. Degradation characteristics of the insulation materials was determined using an automatic viscometer and FT-IR. The analysis results showed that the pattern of decomposition gas generation under partial discharge and thermal fault was different. In particular, acetaldehyde was detected under a thermal fault in all types of insulation, but not under partial discharge or an arc condition. In addition, in the case of insulation materials, deterioration of the insulation itself rapidly progressed as the experimental temperature increased. It was confirmed that it was possible to diagnose the internal discharge or thermal fault occurrence of the transformer through the ratio and type of decomposition gas generated in the gas-insulated transformer.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.4
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• pp.531-536
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• 2016

The worldwide research and development for high-efficiency power generation system is progressing steadily because of the growing demand for reducing greenhouse gas emissions. Many countries have spurred the research and development of supercritical $CO_2$ power generation technology since 2000 because it has the advantage of compactness, efficiency, and diversity. Supercritical $CO_2$ power generation system can be classified into an indirect heating type and a direct heating type. As of now, most studies have concentrated on the development of indirect type supercritical $CO_2$ power generation system. In the United States, NREL(National Renewable Energy Lab.) is developing supercritical $CO_2$ power generation system for Concentrating Solar Power. In addition, U.S. DOE(Department of Energy) also plans to start investing in the development of the supercritical $CO_2$ power generation system for coal-fired thermal power plant this year. GE is developing not only 10MW supercritical $CO_2$ power generation turbomachinery but also the conceptual design of 50MW and 450MW supercritical $CO_2$ power generation turbomachinery. In Korea, the Korean Atomic Energy Research Institute has constructed the supercritical $CO_2$ power generation test facility. Moreover, KEPRI(Korea Electric Power Research Institute) is developing a 2MW-class supercritical $CO_2$ power generation system using diesel and gas engine waste heat with Hyundai Heavy Industries.

• The Transactions of the Korean Institute of Power Electronics
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• v.23 no.6
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• pp.408-414
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• 2018

Given that lithium-ion batteries are expected to be used as power sources for electric and hybrid vehicles, thermodynamics experimentation and prediction based on experimental data were performed. Thermal, electrochemical, and electrochemical/electrical-thermal models were used for accurate battery modeling. Various applications of different battery packs were demonstrated, and thermal analysis was performed using the same experimental conditions for square and rectangular battery packs. Accurate thermal analysis for a single cell should be prioritized to determine the thermal behavior of the battery pack. The energy balance equation, which contains heat generation and heat transfer factors, defines the thermal behavior of the battery pack. By comparing battery packs of different shapes tested under the same condition, this study revealed that the rectangular battery pack is superior to the square battery pack in terms of the maximum temperature of inner cells and temperature variation between cells.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.89-94
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• 2006

For a development of the software which estimates the economics of a combined heat and power generation system in apartment estates, the thermal consumption and electric power consumption data were investigated in about 115 apartment estates. And the algorithm was developed, then the software was made by the macro function of the Excel spread sheets.

• 전기의세계
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• v.26 no.2
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• pp.95-98
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• 1977

Commercially available fuel oil for power plant contains relatively much sulphur, which means accordingly high content sulphur deoxide in exhaust gas. Sulphur deoxide has been identified as the worst-pollutant caused by thermal power generation. This paper primarily deals with the stack gas diffusion effects of various parameters, namely vertical stability, wind velocity, exhaust gas velocity, stack height, etc., on the ground concentration. thereof the relation between stack height and maximum plant capacity is analyzed from the standpoint of air pollution prevention. The limit capacity is calculated by means of mean concentration introducing Mead and Lowry coefficient respectively.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.6
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• pp.667-672
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• 2023

This study proposes polymer electrolyte membrane fuel cell (PEMFC) based cogeneration system for greenhouse heating and cooling. The main scope of this study is to examine the proposed cogeneration system's suitability for the 660 m²-class greenhouse. A 25 kW PEMFC system generates electricity for two identical air-cooled heat pumps, each with a nominal heating capacity of 70 kW and a cooling capacity of 65 kW. Heat recovered from the fuel cell supports the heat pump, supplying hot water to the greenhouse. In cooling mode, the adsorption system provides cold water to the greenhouse using recovered heat from the fuel cell. As a result, the cogeneration system satisfies both heating and cooling capability, performing 175 and 145 kW, respectively.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.197.1-197.1
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• 2011

Target generation capacity of geothermal power generation pilot plant project through the Enhanced Geothermal Systems (EGS) with a doublet system down to 5 km depth was estimated. Production and re-injection temperatures of geothermal fluid were assumed $160^{\circ}C$ and $60^{\circ}C$, respectively, based on reservoir temperature of $180^{\circ}C$ calculated from the geothermal gradient of $33^{\circ}C$ in Pohang area. In this temperature range, 0.11 of thermal efficiency of the binary generation cycle is a practical choice. Assuming flow rates of 40 kg/sec, which is possible in current EGS technology, gross power generation capacity is estimated to reach 1.848 MW. Net generation considering auxiliary power including pumping power for geothermal fluid and condensing (cooling) energy of working fluid can be 1.5 MW.