• Fire Science and Engineering
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• v.31 no.3
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• pp.63-72
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• 2017

This study fabricated a low-voltage 10 circuit distribution board based on the KEMC (Korea Electrical Manufacturers Cooperative) 2102-610 standard and performed a characteristics assessment of the developed 10 circuit distribution board to secure product stability. The developed 10 circuit distribution board is designed to have the characteristics of insulation materials, as well as resistance to corrosion ultraviolet radiation and mechanical impact. The developed distribution board is fabricated to have an appropriate protection class of enclosure, electric shock prevention and protection circuits, switchgear and its components, internal electrical circuits and connectors, external conduct terminal, insulation characteristics, temperature rise test, heat resistance, etc. The developed 10 circuit distribution board consists of a single phase circuit and 3-phase circuits. It is possible to measure in real time the leakage current generated from the load distribution line by installing a sensor module at the load side of each of the branched switchgears. In addition, it is possible to increase a circuit according to the use and purpose of the load and to also manage and check the load in real time. Temperature rise tests were performed on the developed 10 circuit distribution board at 18 places including the inlet connection, main circuit and distribution circuit bus bars and bus bar supports, etc. The highest temperature of $65.3^{\circ}C$ was measured at the R-Phase of the connection of the MCCB power supply for the branch circuit bus bar and a temperature rise of $61.6^{\circ}C$ was measured at the T-Phase of the load side. When applying thermal stress to an MCCB for 6 hours at $180^{\circ}C$ using a heat resistant experimental device, it was found that the actuator lever was transformed and moved in the tripped state.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.721-724
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• 2008

The present study was to develop a dry PFB method similar to the existing gypsum board construction method in order to apply the existing wet PFB method that uses fire.resistant adhesive. It was found that the existing wet method can produce concrete compressive strength of 80MPa and fire resistance of 3 hours with 30mm PF boards. The goal of development in this study was fire resistance of 3 hours through dry construction of 15mm fire resistant boards. The results of fire resistance test showed an increase in thermal durability and thermal strain. It is believed that inorganic fiber reduces thermal strain, and lowers heat insulation performance by 15% or less. This suggests that heat insulation performance was improved by the change in the inner composition of PF board resulting from the adjustment of Al:Si mol ratio, high temperature molding, and dry curing. According to the results of fire resistance test, when the dry PF method was applied, the temperature of the main reinforcing bar was 116$^\circ$C in 15mm, 103.8$^\circ$C in 20mm, and 94$^\circ$C in 25mm, and these results satisfied the current standards for fire resistance control presented by the Ministry of Land, Transport and Maritime Affairs. When a 3 hour fire resistance test was performed and the external properties of the specimen were examined, the outermost gypsum board hardly remained and internal PF board maintained its form without thermal strain.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.492-500
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• 2018

The performance evaluation of cold weather clothing is mainly carried out with thermal resistance. However, the results of the revised test method regarding the same specimen were decreased compare to previous one. In addition, there were deviations of the results among the authorized testing institutes according to the different interpretation of the KS test method. This makes it a considerable difficulty to the quality assurance of combat supplies. The purpose of this study is to minimize the variation of the results before and after the revision by analyzing the cause of the decrease in the heat insulation rate according to the revised test method. For this purpose, the difference between the test conditions before and after the revision of KS is analyzed and the possible results are reviewed. In addition, we want to minimize the result deviation between testing laboratories by analyzing the cause of the result deviation between test laboratories according to arbitrary interpretation of the standard. Based on this, we propose a standardized test method to prevent the decrease of the heat insulation rate by checking the pre-revision test method and the condition with the least deviation.

• Journal of the Korean Wood Science and Technology
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• v.38 no.6
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• pp.518-525
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• 2010

Infrared (IR) thermography which is the technique for detecting invisible infrared light emitted by objects due to their surface thermal condition and for producing an image of the light has been applied in various field without damaging the objects. It also could be used indirectly to examine the inside of an object. In this study, insulation property of wooden house in Korea Forest Research Institute (KFRI) was evaluated with according to "Thermal performance of building - Quantitative detection of thermal irregularities in building envelopes - infrared method (KS F 2829)". This method uses "Temperature Difference Ratio (TDR)" between outdoor wall surface and indoor wall surface of wooden building for evaluating its thermal performance. The thermal performance of a room on the 2nd floor of the wooden house was focused in this study and IR thermography on the indoor and outdoor surface of the house was captured by IR camera. Heat loss from the corner and the window of the wooden house as well as wall of the house was quantitatively evaluated and the invisible heat loss in the wall was detected. It is expected that the results from this study could contribute to improve the wooden building energy efficiency.

• Fire Science and Engineering
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• v.24 no.4
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• pp.12-17
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• 2010

The purpose of this study is to determine how effectively waste tire recycled material mixed with flame retardant work in combating fire. As discovered in the previous study, waste tire mixed with cement mortar has more insulation capacity. However, this mortar is weak against fire. Therefore flame retardant, with a specific proportional mix, will be added to increase its fire prevention capacity. Tests will be made in accordance with ISO 5657 procedures for measuring fire ignition time, flame and shape variation of test pieces at the Building Material Test Institute. The test piece will be set up with horizontal levels having a constant radiation heat of $1{\sim}5W/cm^2$. Temperature transfers and increases from the surface into the interior. Combustible gases result due to pyrolysis, and regular contact is maintained between the fire source and the center of the test piece for assessment purposes. Ignition has not been occurred without adding retardant meaning that there is almost no possibility of ignition of waste tire particle. This fact can be considered as fire load to appreciate a volume of combustion materials. Flame is not occurred due to heat-absorbing effect by adding non-organic series retardant into waste tire particle. Conclusions have been summarized as follows; 1) Combustion of building material can be decreased by adding retardant to waste tire-mixing mortar. But compressive strength and insulation capacity of the material should be measured later. 2) Firing prevention and ignition are main points of building fire. Reasonable fire engineering assessment of interior material should be made for establishing effective disaster prevention system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.625-632
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• 2018

This study was done to reduce total energy demand based on resource shortage problems and to provide improvement points for more efficient adjustment of the high insulation standards for saving energy in Korea. The demand sensitivity was fully considered by varying the slope of each building. The energy performance of the building was maximized by the introduction of outdoor air at night. A final low-energy building model was developed with the two measures combined, and the short-term operation of the night-fuzzy ventilation system was simulated. The result showed a reduction of about 6 to 7 percent compared to the base model. The results could have many implications in terms of the need to conduct demand sensitivity analyses in architectural design.

• Journal of the Korean Wood Science and Technology
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• v.45 no.3
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• pp.343-359
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• 2017

Many researches and policies have been carried out for saving energy in buildings. However, there are a few studies of thermal characteristics of wood-based materials that have been widely used as structural materials and finishing materials in buildings. In this study, thermal bridging areas were found to investigate thermal performance of residential building using non wood-based materials and wood-based materials. And heat transfer analysis of 16 case studies according to composition of structural materials and finishing materials was conducted. Also in this experiment, Physibel Trisco was used as the heat transfer analysis simulation tool, which conforms to the calculation method of ISO 10211. Analytical modeling was also carried out according to the ISO 10211, and the boundary temperature conditions were set at room temperature $20^{\circ}C$ and outdoor temperature $-11.3^{\circ}C$ (Seoul standard) according to the energy saving design standard in South Korea. Applied structures are classified according to the cases of concrete structure with non wood-based finishing materials, concrete structure with wood-based finishing materials and wood structure. Analyzed building elements were divided into a wall, a roof, an interlayer floor and a bottom floor. As a result, it can be confirmed that the thermal bridge of the concrete structure and wood structure were caused by the geometrical and material causes. In addition, the structural thermal bridge was caused in the discontinuity of the insulation in the concrete structure. Also it was confirmed that the linear heat transfer coefficient of the wall decreases when the wood-based materials are applied to the concrete structure.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.683-688
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• 2018

In this study, we analyzed the heat generation state of a flat heating element by using image processing technology in conjunction with carbon fiber. The flat heating element is manufactured by chopping the carbon fiber to a small size and bonding it again using a dispersing agent. The solution of carbon fiber, bound together using the dispersant, is then filtered onto the nonwoven fabric. The last step is to obtain flat carbon fibers in the form of nonwoven fabrics for the purpose of drying the filtered carbon fibers. In the flat heating element, electricity may be applied to the carbon fiber on the surface produced in this manner. In this study, the flat heating element was analyzed by four methods. The analysis of the heat generation characteristics and heating rate of the flat heating element confirmed that the fabricated sheet heating element corresponds to a normal army. The analysis of the insulation coating and flat heating element module, which can be used for actual product manufacturing, involves two dimensional image analysis using image processing technology. The thermal image analysis of the flat heating element is a programming technique that not only analyzes the heat generation state in both two and three dimensions, but also displays the upper and lower 15 to 20% ranges of temperature corresponding to the heat generation in the image. In the final analysis, it is possible to easily find the erroneous part in the manufacturing process by directly showing the state of the fabricated flat heating element on the screen. By combining this image analysis method of the flat heating element with the existing method, we were able to more accurately analyze the heat generation state.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.1819-1824
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• 2014

The vacuum-glazing panel is a panel that keeps two glasses completely sealed in a vacuum condition. It is the high function insulation material of having the wall level minimizing the heat loss by the conduction and convection heat transmission coefficient. The edge sealing is a very important process of vacuum glass on the strength, thickness and air tightness. In this study, by using the hydrogen mixture gas torch, two sheets of glass was sealing in the furnace. The thickness and strength of the glass according to the process parameters is measurement and analysis, and predicting the edge sealing strength of glass by using taguchi method of experiment. We verified the validity of the experiment by checking the error rate through additional experiment.

• Fire Science and Engineering
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• v.34 no.2
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• pp.7-13
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• 2020

In this study, water glass was applied as a coating material to a rigid polyurethane foam to improve the flame-retardant properties of the foam. The heat release rate of the cone calorimeter of the urethane foam, in which the inorganic water-glass coating layer was applied, decreased rapidly. The water glass coated on the polyurethane surface formed a glassy foam by foaming with water, which did not escape during the vitrification reaction when the foam or glass was heated. The glassy foam formed on the polyurethane foam became a fire-resistant insulation layer that inhibited the combustion of the polyurethane foam for more than 10 min. Water glass was found to improve the flame-retardant properties of the rigid polyurethane foam.