• 설비공학논문집
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• 제24권2호
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• pp.190-195
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• 2012

In this study, as a complementary study of the former study on indoor thermal environment in a tower type apartment house at tropical nights, a field measurement was conducted in winter season. Mainly, characteristics of heat storage and heat emission in apartment structures, in this study, were investigated. As results, indoor air temperature was changed in the range of $22.5^{\circ}C{\pm}1.0^{\circ}C$, and followed not the change of outdoor air temperature but the changed pattern of floor surface temperature. Wall surface temperature was unresponsive to the change of floor surface temperature compared with the change of indoor air temperature because wall structure was composed of concrete which has large heat capacity, and was changed in the range of $22.3^{\circ}C{\pm}0.6^{\circ}C$. Heat was stored continuously into the structures of wall and ceiling through the measurement term. and this means that a large heat capacity of the apartment structure acts as a disadvantage in winter season, too. As a total review of the study with the former study, a large heat capacity of the apartment structure acts against indoor thermal comfort in winter season as well as in summer season.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1999년도 춘계학술발표회요약집
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• pp.29-29
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• 1999

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2002년도 춘계공동학술발표회요약집
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• pp.149-149
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• 2002

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1999년도 추계학술발표회요약집
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• pp.123.1-123
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• 1999

• 대한기계학회논문집B
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• 제35권10호
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• pp.989-996
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• 2011

태양의 집광 열유속을 이해하는 것은 태양에너지를 이용하는 시스템의 해석과 설계에 중요하다. 본 연구는 우수한 유연성과 확장성을 가진 몬테카를로 광선추적법에 기반하면서 태양주연감광과 반사판 표면 기울기 에러를 고려하는 알고리듬 개발과 이를 통한 태양 열유속 해석에 초점을 맞추고 있다. 검증을 위해 한국에너지기술연구원 태양로에서 측정된 열유속과 비교했을 때, 모델링 결과가 측정 에러 범위인 10% 이내에서 잘 일치하였다. 개발된 모델을 통해 태양로의 집광 성능을 2 mrad 의 추적 정밀도에 최대로 도달 가능한 집광비가 4400 sun 으로 평가하였다. 열유속의 측정 위치에 따른 변화와 수광각에 따른 분포를 통해 화학반응기나 보조집광기 설계에 필요한 상세한 정보를 제공하였다.

• 한국수소및신에너지학회논문집
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• 제12권4호
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• pp.267-275
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• 2001

To clear the differences of heat transfer coefficient of in-cylinder gas with fuel properties, the transient heat transfer coefficient of hydrogen gas is investigated by using the hydrogen fueled engine. The measured results were also compared with those of gasoline engine and several empirical equations. Transient heat transfer coefficients were determined by measurements of unsteady heat flux and instantaneous wall temperature in the cylinder head. As the main results, it is shown that transient heat transfer coefficients have remarkable differences according to fuel properties, and it's value for hydrogen engine is twice higher than that of gasoline engine. It means that equation of heat transfer coefficient that the effect of fuel properties is considered sufficiently, is needed to analyze or simulate the gas engine performance.

• Journal of Radiation Protection and Research
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• 제32권1호
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• pp.27-34
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• 2007

본 논문에서는 일반인과 상대적으로 방사선피폭이 많은 핵의학 종사자들의 생체신호를 측정하여 방사선 피폭에 따른 생체신호 변화 정도를 비교 평가하고자 하였다. 핵의학과 종사자와 타부서 종사자들의 생체신호를 비교평가 하기 위하여 핵의학 종사자는 충북대학교 병원 핵의학과 종사자를 타부서 종사자는 전남대학교 병원 CT설, 일반촬영실, 의무기록실, 접수실 그리고 일반 사무실 종사자들에게 실험을 실시하였다. 실험에 쓰인 계측 장비들은 방사선량 계측을 위하여 Arrow -Tech사(社)의 poket dosimeter를 사용하였고, 생체신호인 심박수, 혈압을 측정하기 위하여 GE Medical Systems사(社)의 TONOPORT V, Heat flux, Skin temperature, Energy expenditure을 측정하기 위하여 Body Media사(社)의 Armband 인 SenseWare 2000을 사용하였다. 실험 결과 다음과 같은 결론을 얻었다. 1) 일일 장소에 따른 개인별 피폭 선량은 핵의학과가 3.05 uSv를 기록하였고, CT실, 일반촬영실, 병원 의무기록실, 병원 접수실, 일반 사무실, 교원 등이 뒤를 이었다. 핵의학과가 다른 장소(핵의학과를 제외한 나머지)에 비해 약1.4배 선량이 많았다. 2) 방사선 누적선량이 Heat flux, Skin temperature, Energy expenditure와는 별다른 관계가 없는 것을 알 수 있었다. 3) Blood pressure 에서는 Systolic blood pressure와 Diastolic blood pressure 이 핵의학과 종사자, 일반사무직 종사자, 일반인이 고르게 나타났다. 방사선선량이 상대적으로 많은 곳에서 근무하는 핵의학 종사자와 다른 직종에 종사하는 사람의 혈압을 비교해 왔을 때 변화가 없었다. 이 같은 결과로 볼 때 방사선 피폭이 상대적으로 많은 핵의학종사자들의 방사선 피폭에 따른 유해는 없다는 것을 알 수 있었다.

• Journal of Advanced Marine Engineering and Technology
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• 제25권3호
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• pp.552-562
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• 2001

Measurement of average of heat transfer and friction coefficients were obtained with air flowing through electrically heated ducts having square, rectangular(aspect ration, 5), and triangular cross section for range of surface temperature from $540^{\circ}$to $1780^{\circ}$ R and Reynolds number from 1000 to 330,000. The results indicates that the effect of heat flux on correlations of the average heat transfer and friction coefficients is similar to that obtained for circular tubes in previous investigation and was nearly eliminated by evaluating the physical properties and density of the air a film temperature halfway between the average surface and fluid bulk temperatures, With the Nusselt and Reynolds numbers on the hydraulic diameter of the ducts, the data for the noncircular ducts could be represented by the same equations obtained in the previous investigation for circular tubes. Correlation of the average difference between the surface corner and midwall temperatures for the square duct was in agreement with predicted values from a previous analysis. However, for the rectangular and triangular ducts, the measured corner temperature was greater by approximately 20 and 35 percent, respectively, than the values predicted by analysis.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 추계학술발표대회 논문집
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• pp.190-195
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• 2008

The objective of this research is to determine overall heat transfer coefficients (K-value) of exterior wall, floor, and roof of Nakseonjae, a Korean traditional residence via field measurement of transient heat flow and temperature difference across each envelope component. Heat flow sensors and T-type thermocouple were attached on the internal and the external surface of each building component, and real-time measurement data were collected for the three consecutive summer days. The K-values determined in this research showed good agreement with other results from open literature. Peak and annual thermal loads of the traditional residence estimated by a commercial energy simulation program were compared with those for a current apartment house. The traditional house showed lower annual cooling load than that of the current building. It may caused by the fact that the traditional building has less air-tight envelopes and no fenestration passing direct solar radiation into the space.

• 열처리공학회지
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• 제5권3호
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• pp.171-178
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• 1992

The effect of nozzle characterristics on the mist-cooling heat transfer was investigated under the various flow conditions. Two different types of twin fluid nozzle were used, one is a $90^{\circ}$ angle tip nozzle with needle and the other is a $90^{\circ}$ angle tip non-needle nozzle. The cooling rate from the heated surface was measured and obtained the boiling curve as a function of surface temperature. An immersion sampling was employed for the measurement of droplet size of the spray. As a result of this experiment, the liquid sheet type nozzle shows better atomization when the mass ratio Mr>2.0, and collects more liquid droplets on the heated surface that results in better cooling effect. It was found that the maximum heat flux and heat transfer coefficient increased with increase in the volumetric flow rate, whereas the maximum heat flux decreased with increase in spray distance. The cooling effect depends upon the amount of collected droplet and droplet size, but it strongly depends upon the amount of collected droplet.