• Journal of the Korea Institute of Building Construction
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• v.14 no.6
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• pp.583-590
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• 2014

The purpose of this study is to analyze and compare the life cycle cost of window glass with insulation film and regular glass, to verify an economical window construction method. As an approach method, the thermal performance data of each type of glass was measured using Window 6.3 and ECO2-OD Simulation Program, applied it to the case building to calculate the air conditioning and heating maintenance costs and LCC, and compared the economic feasibility. As a result, installing an additional insulation film prevents the solar heat penetration in the summer, so it reduces the cooling cost, on the other hand, it increased heating cost in winter. From the life cycle cost perspective, the effect of cooling cost reduction does not counterbalance the increase in heating cost and the additional cost from film installation and repair; therefore, the installation of insulation film may not be a proper method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.1
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• pp.171-175
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• 2015

In this paper, because of global environmental problems such as energy shortage and abnormal climate, green energy development and energy saving technology development is being magnified. Heat insulation, the most basic and traditional energy saving method, is highly expected. Especially, simple and advanced heat insulation technique based on Nano material is promising future technology. The railway system also requires heat insulation. Especially, traditional heat insulator such as glass wool has been adopted frequently to rolling stock. The heat insulator is also adopted in general railway service buildings. Take account of cost-effective heat blocking performance, the heat insulator shall be adopted in diverse fields such as electric power, railroad, signal and communication. The only and direct solution for this problem is installing heat insulator with outstanding endurance, corrosion resistance and heat resistance to block outer heat Upgrading heat specification of equipment can be a solution, but since price and maintenance cost rise severely, this plan might be incongruous. In this research, energy saving effect of ultrathin heat insulator film was demonstrated by installing the film on roof of electrical room.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.4
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• pp.264-269
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• 2016

This paper reports a fundamental study of temperature characteristics of a solar pond with an insulation layer. Further, these characteristics were compared with those of a solar pond without the insulation layer. The governing equation was discretized via finite difference method. The governing equations are two-dimensional unsteady-state second-order partial differential equations. The conclusions of the study are as follows: 1) If the depth of the solar pond was increased, the desired effect of increase in temperature was not produced because the amount of solar insolation received by the bottom of the solar pond decreased. 2) As the temperature of the soil during winter is higher than the temperature of the water in a solar pond, heat was transferred from the soil to the solar pond. 3) For the case of the solar pond with insulation layer, it was estimated that the dependence rate of solar energy was 83.3% and that of the boiler was 16.7%.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.5
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• pp.567-574
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• 2011

Aluminum extruded panels are widely used instead of corrugated steel panels for weight reduction in high-speed trains. Of the layers in the train body, it makes the largest contribution to the sound insulation. However, compared with that of a flat panel with the same weight, the TL of the aluminum extruded panel is remarkably lower in the local resonance frequency band. We study aluminum extruded panels for next-generation 400-km/h trains. We investigate the problem of sound insulation and propose a practical method to improve the sound-insulation performance. The local resonance frequency region is increased by a modification of the core structure, and urethane foam is placed in the core. The effect on the sound insulation is verified by experiments. Finally, the improvement for the entire sound-transmission loss is estimated for the layered floor panels of express trains.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.179-184
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• 2016

The usual way used by electric power stations to deliver high levels of generated power is via 6.6kV XLPE (or CV) cables. Depending on the manufacturing technique, installation environment, and usage conditions, the deterioration processes of the power cables start from the instant of operation. Cable junctions may break down in three years from the start of operation due to the manufacturing or construction defects. Otherwise they should be in good working order for 20-30 years. When the cable system (the cable itself and cable junctions combined) deteriorates, fire accidents happen due to the dielectric breakdowns. We have invented a device to monitor the deteriorating status of cables at Korean Western Power Co. Ltd. located in Taean, Chungcheongnam-do province. In this paper, we introduce the device hardware. Using the device, we have measured the insulation resistance and humidity in the sheath of the cables. We present, in analysed results, the effect of humidity on insulation resistance in cable sheaths.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.5
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• pp.403-409
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• 2008

Polymer electrolyte membrane fuel cell (PEMFC) is very interesting power source due to high power density, simple construction and operation at low temperature. But it has problems such as high cost, improvement of performance, effect of temperature and initial start at low temperature. These problems can be approached to be solved by using experiment and mathematical method which are general principles for analysis and optimization of control system for heat and hydrogen detecting management. In this paper, insulation vessel and control system for stable operation of fuel cell at low temperature were developed for experiment. The constant temperature capability and the heating time at sub-zero temperatures with insulation control system were studied by using a heating bar of 60W class. PEMFC stack which was made by 4 cells with $50\;mc^2$ active area in each cell is a thermal source. Times which take to reach constant temperature by the state of insulation vacuum were measured at variable environment temperatures. The test was performed at two conditions: heating mode and cooling mode. Constant temperature capability was better at lower environment temperature and vacuum pressure. The results of this experiment could be used as basis data about stable operation of fuel cell stack in low temperature zone.

• Magazine of the Korean Society of Agricultural Engineers
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• v.29 no.4
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• pp.117-123
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• 1987

This study was conducted to develop an automatic insulation system to reduce the heat loss through the wall of greenhouses during the nighttime in winter. A double covered model vinyl house was constructed, and blowers were used to fill or remove styrene pellets automatically the inside of the double-wall of the double covered vinyl house. The effects of insulation of the double covered vinyl house insulated with the styrene pellets were analyzed by comparing with the single covered vinyl house. The results obtained from this study can be summarized as follows : 1. The optimum thickness of the double-wall of the double covered vinyl house was found to be 5 to 10 cm. 2.When the outside temperature varied in the range of -8.3 to -1.5$^{\circ}C$ during the nighttime, the inside temperature of the double covered vinyl house insulated with the styrene pellets showed 7.7 to 11.7$^{\circ}C$ and the inside temperature of the single covered vinyl house showed -5.8 to 2.3$^{\circ}C$. Therefore, the effects of insulation of the double covered vinyl house insulated with the styrene pellets were confirmed to be excellent. 3. Also, the excessive increase of the inside temperature in the vinyl house was prevented by the shading effect of the double covered vinyl house insulated with the styrene pellets during the daytime. 4. When the outside temperature varied in the range of 17.7 to 30.0$^{\circ}C$ during the daytime, it was possible to keep the inside temperature at 30${\pm}$4$^{\circ}C$ in the double covered vinyl house by operating the insulation system. 5. The transmissivity of the double covered vinyl house with the styrene pellets removed was 52.4 % on the average.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.6
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• pp.515-522
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• 2019

Since Liquefied Natural Gas (LNG) is normally carried at 1.1 bar pressure and at -163℃, special Cargo Containment System (CCS) are used. As LNG carrier is becoming larger, typical LNG insulation systems adopt a method to increase the thickness of insulation panel to reduce sloshing load and Boil-off Rate (BOR). However, this will decrease LNG cargo volume and increase insulation material costs. In this paper, silica aerogel, glass bubble were synthesized in polyurethane foam to increase volumetric efficiency by improving mechanical and thermal performance of insulation. In order to increase dispersibility of particles, ultrasonic dispersion was used. Dynamic impact test, quasi-static compression test at room temperature (20℃) and cryogenic temperature (-163℃) was evaluated. To evaluate the thermal performance, the thermal conductivity at room temperature (20℃) was measured. As a result, specimens without ultrasonic dispersion have a little effect on strength under the compressive load, although they show high mechanical performance under the impact load. In contrast, specimens with ultrasonic dispersion have significantly increased impact strength and compressive strength. Recently, as the density of Polyurethane foam (PUF) has been increasing, these results can be a method for improving the mechanical and thermal performance of insulation panel.

• Journal of the Society of Disaster Information
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• v.12 no.3
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• pp.286-291
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• 2016

In this study, we conducted about the manufacture of a non-combustible inorganic insulation by replacing the binder type for satisfaction of thermal conductivity for developing a lightweight inorganic insulation. Thermal conductivity was measured using a machine of HFM-436. We made samples are inorganic insulation by using SH-1(liquid) of S company and SH-2(solids). By Mixing Pearlite and SH-4(Liquid) was produced as insulation sample 2. Each was shaped into a binder and pearlite in the frame. After complete drying, thermal conductivity was measured by using HFM-435. The thermal conductivity was determined using two different binder. We analyzed the effect on thermal conductivity in binder.

• Journal of Korean Living Environment System
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• v.21 no.6
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• pp.959-964
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• 2014

Energy performance of building envelope components, including external walls, floors, roofs, windows and doors, is crutial for determining how much energy is required for heating and cooling in a building. Among various building technologies, a green roof system can be a good option for reducing heat gain and loss in new buildings as well as existing buildings for green remodeling. This paper evaluates the performance of green roof systems according to soil depth and Leaf Area Index (LAI) for existing buildings. It also attempts to quantify the energy saving effects on new and existing buildings with different insulation levels. Thermal performance of green roofs is mainly dependent on soil thickness and LAI. Installation of green roofs in deteriorated existing buildings can lead to improvements in roof insulation, due to the soil layer. An increase in soil depth leads to a decrease in heating load, regardless of conditions of vegetation on the green roof. Larger LAI values may reduce cooling loads in the cooling season. Installation of green roof in deteriorated existing buildings showed bigger energy saving effect in comparison to a case in new buildings. A simulation study showed that the installation of green roof systems in deteriorated existing buildings with low insulation levels, due to low thermal performance requirements when constructed, could improve the energy performance of the buildings similar or better to the peformance on new buildings with the most updated insulation standard. Thus, when remodeling a deteriorated building, green roofs could be a good option to meet the most recent energy requirements.