Recently, the International Maritime Organization is strengthening regulations for ships operating in polar regions. Hence, insulated multi-core tubes as components for vessels operating in extreme cold need to be investigated in various aspects. Furthermore, the demand for research on electric propulsion vessels is also increasingly growing. Thus, to utilize a 4-core insulated multi-core tube with glass wool as insulation, which was previously developed for ships operating in polar regions, as a water-cooled electrical cable, this study conducted an experiment on the temperature change when water at normal temperature 25℃ was supplied as a coolant under the overcurrent varied from 10A to 25A. As a result, the temperature increase of the core in 10A condition was 3.3℃, but it increased to 13.05℃ in the 25A condition. This showed that a temperature difference of approximately 9.75℃ occurred according to the overcurrent load. However, the coolant inlet and outlet temperatures were relatively uniform around 1℃ in all conditions. This suggests that increasing the residence time by proper control of the coolant flow in the future could achieve a higher cooling effect.
In this study, the types of thermal breakers applied to structures to prevent thermal bridges were identified. Condensation prevention performance was evaluated for apartment houses with standard floor structures to which a thermal breaker was applied. In addition, the effect of thermal cross-blocking was compared by calculating the total heat and equivalent U-value through the wall. (1) As a result of the evaluation of anti-condensation performance, when “가” grade insulation was applied, the surface temperature increased by about 1K due to the application of the thermal breaker. The TDR value increased by about 0.06 to 0.07. When "나" grade insulation was applied, the minimum surface temperature increased by about 1K, and the TDR value increased by about 0.05~0.06. (2) As a result of the evaluation of total heat and U-equivalent, it was possible to reduce the total heat by 38.5~44.9% and U-equivalent by 38.5~45.0% for the "가" grade insulation to which the thermal breaker was applied. In addition, the "나" grade insulation to which the thermal breaker was applied can reduce total heat by 38.9 to 43.6%, and reduce the Uequivalent by 38.9 to 43.7%.
This study aims to evaluate thermal performance using the ASTR method. Its findings are as follows: 1) The measured U-Values of 49A type and 59A type walls were almost the same as the theoretically calculated values. 2) One notable phenomenon for both walls was that the interior surface temperatures of the channels attached to corners were up to 10.4% lower than that of the cross of the wall, even though they consisted of the same materials. This is due to the surface temperature drop caused by the thermal bridge. 3) The surface temperatures of the thermal bridge were converted into U-Values. The U-Value of the top left corner on the 59A type house was 1.044W/m²K, and of the bottom right corner on the 49A type house was 0.959W/m²K. Therefore, the thermal performance of the thermal bridge area was decreased after construction. 4) Differences were found in the results of comparing heat transfer analysis simulation data and measured data. A maximum difference of 12.4% occurred in the top left corner on 59A type, and of 7.6% occurred in the bottom right corner on 49A type. 5) The results of a heat transfer analysis simulation showed that the temperature of both 49A type and 59A type top right corner were the lowest, but in-situ measurement results were the lowest in the bottom right corner on 49A type and in the top left corner on 59A type. These results are considered to be due to the occurrence of thermal bridges and a deterioration in the construction quality.
본 연구는 공기주입 이중피복온실과 관행 이중피복온실의 생육환경과 단열성능을 비교하기 위하여 수 행하였다. 두 온실의 온도, 상대습도, 포차, 이산화탄소농도, 일사량, 딸기 생산량 및 난방연료소비량을 비교하 였다. 공기주입온실이 관행온실보다 야간에 상대습도가 더 높고 포차는 더 낮게 나타나 딸기의 생육에 좋지 않은 환경을 보여주었다. 이산화탄소농도는 공기주입온실이 관행온실보다 더 높게 나타났으며, 이는 공기주입 온실이 더 밀폐되어 있어 환기량이 적기 때문인 것으로 판단된다. 관행온실의 광투과율이 77%로 공기주입온실 의 72%보다 더 높아 관행온실의 광환경이 더 우수한 것으로 나타났다. 관행온실의 딸기 생산량이 더 높게 나 타났으며, 이는 관행온실의 생육환경이 공기주입온실보다 더 우수한 결과로 판단된다. 난방연료는 공기주입온 실에서 더 적게 소모되어 공기주입온실의 단열성능이 더 우수한 것으로 나타났다.
본 연구는 NO96 화물창의 BOG(boil off gas), BOR(boil off rate)을 감소시키기 위한 노력으로 단열재료 및 단열층을 변화시켜서 개발된 NO96-GW, NO96-L03의 방열구조에 대해서 BOG, BOR 값을 계산하고 단열성능을 비교․평가하였다. 두 가지의 변형된 NO96 모델을 기존의 NO96 방열과 단열층 및 단열재료의 차이점을 비교하고, 각각의 열저항 및 BOG/BOR 값의 비교 결과를 제시하였다. 열저항 값은 유한요소해석법을 이용하여 계산되었으며, 준정적 열평형 상태를 가정하여 열유속과 온도분포를 통하여 단열성능을 비교하였다. 계산에 사용된 화물창의 모든 재료물성치는 온도 의존값으로서 반영하여 -163oC에서의 극저온 상태에서 특성을 반영되었다. 각 화물창의 BOG, BOR 계산은 국부 열전달 해석을 통해 방열판에서 발생하는 열유속을 계산하고, 등가모델을 적용하여 계산하는 과정으로 수행되었으며, 그 결과를 각 화물창의 단열성능을 비교평가하기 위해서 검토하였다.
Structural insulated panels, structurally performed panels consisting of a plastic insulation bonded between two structural panel facings, are one of emerging products with a viewpoint of its energy and construction efficiencies. These components are applicable to fabricated wood structures. In Korea, there are few technical documents regulated structural performance and engineering criteria in domestic market. This study was conducted to identify fundamental performance of both monotonic load and quasi static cyclic load for SIPs in shear wall application. Static test results showed that maximum load was 44.3kN, allowable shear load was 6.1kN/m, shear stiffness was 1.23 M N/m, and ductility ratio was 3.6. Cyclic test was conducted by two kinds of specimens : single panel and double panels. Cyclic test results, which were equivalent to static test results, showed that maximum load was 45.42kN, allowable shear load was 6.3kN/m. Furthermore the accumulated energy dissipation capability for double panels was as 2.3 times as that for single panel. From performance of structural tests, it was recommended that the allowable shear load for panels was at least 6.1kN/m.
Structure Insulated Panel (SIP) is an wooden structure material with which structure and insulation functions are satisfied. Hence, it would be a cost-effective model to implement low energy house which has higher insulation and structure performance and which the wall thickness is able to be reduced. In this study, performance of thermal insulation and fire resistance were evaluated in order to verify applicability to low energy house. Fire resistance test is performed on vertical load bearing members for partitions, and the test results satisfy one hour of fire resistance condition according to KS F 2257. The members include two layers of fireproof gypsum board with thicknesses of 12.5mm attached to SIP. Thermal insulation performance is satisfied with the 2012 standard (0.225W/㎡·K). As the performance of resistance and thermal insulation are satisfied, SIP is expected to be applied to low energy building materials. In the future, the structural safety will be confirmed by structural performance and seismic performance test and the guidelines for distribution will be drawn up.
Structural insulated panels, which are structurally performed panels consisting of a plastic insulation bonded between two structural panel facings are one of emerging products with a viewpoint of its energy and construction efficiencies. These components are applicable to fabricated wood structures. By now, there are few technical documents regulated structural performance and engineering criteria in domestic market. This study was conducted to suggest fundamental reports such as racking resistance, axial capacity, transverse load capacity, and lintel load capacity for SIPs. Test results showed that maximum load was 44.3kN, allowable load was 14.7kN for racking resistance, and that maximum load was 137.6kN, allowable load was 37.4kN/m for axial compression capacity. For transverse load capacity, test results showed 10.3kN/㎡ of maximum load, 3.4kN/㎡ of allowable load. For lintel load capacity for SIPs dependent to lengths, allowable loads were 20.4kN for 600㎜ long lintel, 23.9kN for 1,200㎜ long lintel, 19.3kN for 1,800㎜ long lintel, and 2,400㎜ long lintel had 14.1kN of allowable load. In the near future, when the allowable load for wall application is established, SIPs is considered to substitute the existent post-and-lintel construction to bearing wall structure.
This study is related to evaluate the performance of structural insulated panels. This panel are composed of exterior structural member with insulated materials simultaneously. The test to evaluate the transverse capacity and lintel capacity was performed according to ASTM E-72 and KS F2273. The test result shows the panels are applicable to the required load sufficiently.
This study is related to evaluate the performance of structural insulated panels. This panel plays a role as structural member and insulation simultaneously. This study is focused to test the racking shear capacity and axial compression capacity based on ASTM E-72 and KS F2273. The test result shows the panels are applicable to the required load sufficiently.
In this study, the heat insulating performance increase the indoor temperature of the building is applied to the concrete was compared with plain concrete. As a result, the indoor surface at the outside temperature of 4.69∼7.32 ℃ temperature conditions showed a difference of up to 1.10 ℃, the lowest 0.54 ℃, indoor temperature is up to 0.95 ℃, 0.63 ℃ lower results showed a minimum.
구명 조끼는 익수자의 부력을 유지시키는 기능을 가지며, 낮은 해수 온도에서 저체온증에 빠지는 시간을 단축 시킬 수 있는 역 할을 할 수 있다. 본 논문은 서멀 마네킹 실험과 수치적 방법을 적용하여 단열성능을 향상 시키기 위해서 개발된 팽창형 구명 조끼와 폼형 구명 조끼의 단열성능 및 저체온증 방지 효과를 평가하였다. 단열성능 평가를 위해서 서멀마네킨을 이용하여 열유속 및 열저항을 계측하였으 며, 본 연구에서 제시된 구명 조끼의 단열성능을 기존의 제품과 비교하여 검토하였다. 또한 저체온증에 빠지는 정도를 상대적으로 파악하기 위해서 유한요소해석을 이용하여 구명 조끼의 종류에 따른 체온 저감 시간을 예측하고 이를 비교 평가하였다. 저체온증 예측모델은 Pennes의 신체 열전달 해석 모델을 기반으로 작성되었으며, 실험으로부터 계측한 열저항 값을 이용하여 대류 열전달 조건을 환산하여 계산되었다. 그 결과 본 연구에서 단열성능을 향상시키기 위해서 제시된 하는 구명 조끼가 기존 제품에 비해 단열성능이 우수하게 평가됨을 확인하였다.
구명정의 열전달 특성 및 해상상태에 따른 조난자의 저체온증 발생 가능성에 대한 기술적 검토는 선박의 좌초 및 침몰 사고에 대 응하기 위해 활용될 수 있다. 본 연구는 해상용 구명정(또는 구명벌)의 설계에 필요한 열전달 특성 및 단열 성능을 분석 및 평가방법에 대해 서 연구하였다. 또한, 해상 저체온증 발생 가능성을 파악하기 위한 연구로써 Thermal manikin과 인체를 대상으로 체온 저하의 예측을 판단하 기 위한 단열성능 실험 및 인체 온도 특성 해석 결과를 제시하였다. 열전달 해석은 구명 뗏목의 열전도 특성, 해수의 대류 효과 및 단열 재료 의 특성에 따른 성능 변화를 파악하도록 유한요소해석 방법을 적용하였다. 인체 시험에서 입수 시 신체 온도 변화를 파악하기 위해서 각 부 위에 열전대를 부착한 상태로 구명정에 탑승하여 온도 변화 및 열유속 변화를 계측하였다. 실험으로부터 계측한 체온 변화와 유한요소해석 모델의 체온 변화를 비교함으로써 결과의 타당성을 제시하였다. 나아가 유한요소해석을 통해 저체온증 발생 가능성을 검토하였다.
In this study, the heat insulating performance increase the indoor temperature of the building is applied to the concrete was compared with plain concrete. As a result, the indoor surface at the outside temperature of 10.4 ~ 22.4 ℃ temperature conditions showed a difference of up to 0.6 ℃, the lowest 0.6 ℃, indoor temperature is up to 0.2 ℃, 0.2 ℃ lower results showed a minimum.
본 연구에서는 압축강도 24MPa 이상 열전도율이 기존 콘크리트보다 2배 감소된 구조용 단열성능 향상 콘크리트를 개발하고 현장적용 하기 위한 실험을 진행하였다. 슬럼프 및 공기량 시험결과 Plain과 규조토 미분말을 사용한 배합은 경과시간에 따라 슬럼프와 공기량 저하 가 나타났으며, 마이크로기포제를 사용한 배합은 슬럼프와 공기량 저하가 나타나지 않았다. 또한 단열성능 향상 재료를 사용한 배합의 단위 용적질량은 Plain 대비 감소하였다. 압축강도는 단열성능 향상 콘크리트가 Plain보다 감소한 결과를 나타내었으나 목표강도 24MPa를 만족 하였으며, 열전도율은 Plain보다 감소하는 경향을 보였다. 단열성능 향상 콘크리트의 동결융해 저항성은 Plain과 유사하였고, 중성화 저항 성은 규조토 미분말을 사용한 배합이 재령 4주에 Plain과 유사했으며, 마이크로기포제를 사용한 배합은 Plain보다 중성화 저항성이 저하되 었고, 길이변화율은 Plain보다 전체적으로 증가되었다.
In this study, improving insulation of concrete, we developed insulated concrete and applied it in the field to reduce amount of energy. As a result, we could get the physical and performance similar to normal concrete's performance and the amount of energy is expected to decrease for improving insulation performance.
Recently climate change have increased consumption of building heating and cooling energy. Furthermore, the study on energy reduction is important. Especially the outer covering of the building has been made of concrete more than 70%. The study is to evaluate durability of concrete using insulation performance improvement materials.