• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.291-295
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• 2009

As a reasonable energy policy has become required because of consuming substantial amounts of oil than others, the studies on energy consumption are in work for energy savings of buildings that spend up to 24% of total energy consumption. However, there aren't basic data on energy consumption and installationregulations for effective equipments in energy guzzled buildings. The best plan to reduce the building energy consumption is that the insulation performance should be improved because the insulation and airtight of building envelopes have an effect on the energy consumption basically. Thus, we should prepare the alternatives to improve insulation performance of envelopes and the efficiency of insulation performance of the window for reducing energy consumption.

• Journal of the Korean housing association
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• v.22 no.1
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• pp.115-122
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• 2011

This study aimed at quantifying the impact of envelope insulation on energy consumption for thermal controls in residential buildings in southern part of Korea. A series of parametric simulations for a range of R-values of walls, roof, floor, and windows were computationally conducted for a prototypical Korean detached house. Analysis revealed that the total amount of heat gain was larger than that of heat loss, while the amount of energy for cooling was smaller than that for heating due to the difference of system efficiency; the envelope heat transfer was more significant for the heat loss, thus, the increase of the envelope insulation was more effective to reduce heating load; and there were certain levels of envelope insulation after which the energy saving effect was not significant. These findings are expected to be a fundamental database for the decision of proper insulation level in Korean residential buildings.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.13 no.4
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• pp.21-30
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• 2017

Recently, It has increased the importance of building energy saving. Pipe insulation as well as building envelope insulation is to improve energy efficiency and reduce the energy loss. However, there continues to use the old standard for pipe insulation that is one of the most important elements in energy savings in buildings. The purpose of this study is to propose suitable pipe insulation thickness for reducing building energy use. The study also reviews pipe insulation thickness standard in accordance to Korea standard, ASHRAE 90.1 and BS5422 and analyzed through thermal simulation. As a result, it is necessary to apply the performance design method of the pipe insulation thickness to reduce the energy loss of the piping.

• Journal of Environmental Science International
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• v.20 no.11
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• pp.1499-1507
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• 2011

Practical disposal of transformer insulation oil laden with PCBs (polychlorinated biphenyls) by a chemical treatment has been studied in field work. The transformer insulation oil containing PCBs was treated by the required amounts of PEG (polyethylene glycol) and KOH, along with different reaction conditions such as temperatures and times. The reaction of PEG with PCBs under basic condition produces arylpolyglycols, the products of nucleophilic aromatic substitution. Removal efficiencies of PCBs in insulation oil before and after chemical treatment were examined. The removal efficiency of PCBs was very low at lower temperatures of 25 and $50^{\circ}C$. Under the reaction condition of PEG 600/KOH/$100^{\circ}C$/2hr, removal efficiency of PCBs was approximately 70%, showing completely removal of PCBs containing 7~9 chlorines on biphenyl frame which appear later than PCB IUPAC Number 183 (2,2',3,4,4',5',6-heptaCB) in retention time of GC/ECD. However, when increasing the reaction temperature and time to $150^{\circ}C$ and 4 hours, removal efficiency of PCBs reached 99.99% without any formation of PCDDS/PCDFs during the process. Such reaction conditions were verified by several official analytical institutions. In studying the reaction of PEG with PCBs, it confirmed that the process of chemical treatment led to less chlorinated PCBs through a stepwise process with the successive elimination of chlorines.

• Journal of Power Electronics
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• v.11 no.6
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• pp.880-889
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• 2011

In this paper, a novel Active Voltage Quality Regulator (AVQR) topology with a thyristor rectifier and an adaptive dclink voltage control strategy are proposed. The proposed AVQR can efficiently mitigate the long duration variations (e.g. undervoltages/overvoltages), voltage imbalances and voltage harmonics. Compared with conventional AVQRs, it can regulate the load voltage very well with a much lower dc-link voltage. This is accomplished by replacing the diode rectifier with a thyristor rectifier. Moreover, its dc-link voltage can vary with the deviations of the supply voltage through the proposed adaptive dc-link voltage control strategy. All of these contribute to its significantly higher efficiency for online operating, which is very important and attractive for many applications. The proposed topology and control strategy are theoretically analyzed in detail. Simulation results are also provided in the paper. Finally, the feasibility and effectiveness of the proposed method are verified by means of experimental results from a 2kVA prototype. Both of the simulation and experimental results show that the proposed AVQR can achieve a much higher efficiency and similar regulation performance when compared with the conventional ones.

• Korean Institute of Interior Design Journal
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• v.21 no.4
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• pp.114-120
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• 2012

There are lots of buildings which were built before the Legislation on building energy rating system. Remodeling of the buildings would be required for an improvement of the building energy rating system was enforced by the government. In the Passive Building Design, Elements which will be used for the remodeling are Insulation, Window, External venetian blind, Heat exchanger. The Purpose of this study is to indicate a Method for the improvement of Energy saving by an analysis of Construction Cost, Cost Evaluation, Energy performance Efficiency in applied design elements. In this study, the remodeling of existing public buildings to improve energy efficiency rating was applied to extract the elements of design-specific energy performance, efficiency, and the application of the designs that has been analyzed. The results were as follows: applying the design-specific cost-effective investment that represents the economy (investment efficiency/%) surveyed the average insulation(7.0%), triple glazed windows(10.1%), double glazed windows(12.1%), external shading(24.5%), and Heat(77.2%) were analyzed in order to be more efficient. Analysis of the basis of information on the existing public buildings to improve energy efficiency rating for the remodeling depending on driving conditions at a degree of individual difference. The main effect, however, depending on economic investment, design elements, heat exchangers, external awning, double glazed windows, triple glazed windows, insulation, is recommended as review of the order shall be determined.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.4
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• pp.93-100
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• 2014

The packaging with environment-friendly materials become more important issue since the concern for the environment and the disposal of waste such as the packaging materials has increased. Although the paper based packaging such as corrugated box are widely used as a typical environment-friendly packaging stuff, the heat insulation properties of paper packaging did not get many attention. In this study, the heat insulation properties of paper were deeply evaluated to improve the functional properties as packaging material of the cold storage goods. The simple device for evaluating the heat insulation of paper product was developed. Subsequently, the changes in the heat insulation depending on the paper structure and the addition of the inorganic fillers were investigated by using the instrument. The higher basis weight and the less beating time resulted in the bulkier structure and the less efficiency of heat transfer. The addition of the perlite powder as a filler resulted in the great increase in the heat insulation, although the addition of the calcium carbonate decreased the heat insulation potential of paper.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.10
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• pp.1972-1977
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• 2011

The mechanical integrity of generator stator windings is one of the critical point because the electric power is generated and conducted to power system through these windings. To cool down the heat emitted from generator winding during its operation, a majority of generators use de-mineralized water characterized by high cooling efficiency. Contrary to such the excellent cooling efficiency, however, the damaged bar insulations attributed to the absorption of cooling water in the generator stator winding lead to highly time- and cost consuming efforts as well as to service deterioration due to unexpected forced outage of generator. It is described that the new design of water absorption sensor using cross capacitance for generator in power plant in order to increase the reliability of water absorption diagnostics for generator stator bar insulation.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.101-102
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• 2015

This paper is about the suggestion for the development in the commercialization for 3.6kW Class On-Board charger. It is suggesting non-insulation AC-DC Boost Power Factor correction circuit and insulation DC-DC resonant Converter for circuit design. In addition, Input AC voltage in the power supply is DCM control which can be designed to decrease the inductance for the inductor size to be reduced. DCM controls and Interleaved PFC can be designed to decrease the inductor size increasing the power conversions. Also, using the insulation DC-DC resonant converter, the efficiency can be increased. This system is verified using prototype hardware.

• Journal of the Korean Solar Energy Society
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• v.31 no.6
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• pp.95-102
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• 2011

The purpose of study is to estimate heating, cooling load performance and economic efficiency in office building with applied the functional paint. this paint can reduced SHGC(Solar Heat Gain Coefficient) on the glazing surface by coating. In this study, estimated to compared with double glazing, low-e glazing, IP(Insulation Paint) and IPu(Insulation UV-Cut Paint) coating glazing. As a result of this study, 1)heating & cooling load Analysis, SHGC value and U-factor of double glazing is about 0.70 and 3.29($W/m^2K$). low-E glazing is about 0.65 and 2.70($W/m^2K$). Two-side it is about 0.27 and 3.25($W/m^2K$). When compared to double glazing, annual heating & cooling load of low-E glazing, Two-side IPu and IP paint coating glazing is 3,012MWh($124kWh/m^2$), 2,910MWh($120kWh/m^2$), 2,867MWh($118.4kWh/m^2$) and 2,867MWh($118.4kWh/m^2$). It i sreduced to 2.0%, 5.2%, 6.7%, and 6.7% respectively. 2)the estimation of economic efficiency, low-e glazing installed in office building can not recover the investment within a lifetime 40years. but IPu and IP paint, two-side coating in glazing, have a payback period of 13 years respectively.