• Title/Summary/Keyword: distribution of temperature

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Mock-up실험에 의한 바닥복사 냉방시스템의 온도특성에 관한 연구 (A Study on the Temperature Characteristics of the Floor Cooling System of Mock-up Experimentent)

  • 유호천;이영아
    • 한국태양에너지학회 논문집
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    • 제28권6호
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    • pp.48-57
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    • 2008
  • The research analyzed the distribution of the indoor temperatures of a radiant floor cooling system through mock-up experiments. It investigated the temperature difference of feed water, the vertical temperature difference of indoor air, the temperature difference of floor surface, and so on. The following is the results of the research. First, the research shows that the difference between indoor temperature and outside temperature was the smallest when the temperature of feed water was set at 16$^{\circ}C$. In addition, the temperature changes according to indoor positions (wall, room, floor, and ceiling) were the most uniform. Thus, the research found that the cold water temperature of 16$^{\circ}C$ is the most proper. In addition, it confirmed that the feed water temperature of 18$^{\circ}C$ is effective because the temperature can lower the temperature of a room to 13.55$^{\circ}C$, which is lower than the temperature of a non-cooling mode. Second, an investigation on the temperature distribution of vertical air in indoor space shows that the temperature distribution had a difference of 0.2 to 1.9$^{\circ}C$ on the average, which satisfies the range of 3.0$^{\circ}C$ in the standard of ISO.

Al6061 열간단조시 계면열전달계수에 관한 연구 (A study on interface heat transfer coefficient in hot forging of Al6061 by experiments and FE analysis)

  • 권진욱;이영선;권용남;이정환
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2005년도 춘계학술대회 논문집
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    • pp.219-222
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    • 2005
  • The temperature difference between die and workpiece has frequently caused various surface defects. The non-homogeneous temperature distribution of forged part should be analyzed to prevent the generation of various defects related with the temperature. The surface temperatures were mainly affected by the coefficient of thermal contact conductance. The precise coefficient is necessary to predict accurately the temperature changes of die and workpiece. The experiment is preformed to measure the temperature distribution of die and workpiece in closed die upsetting. And then, the coefficient is classified into function of pressure and confirmed by the comparison between experiments and FE analyses using the other model. The FE analysis to predict the temperature distribution is performed by commercial software $DEFORM-3D^{TM}$. However, it might be impossible to measure directly the temperature distribution of forged part. Therefore, the comparisons between measured temperature and predicted values are performed with the hardness of Al6061-forged part.

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대공간의 실내온열환경 실측 및 분석 (The Field Measurement and Analysis of Indoor Thermal Environment in Large Enclosures)

  • 채문병;양정훈;최동호;석호태
    • 한국공간구조학회논문집
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    • 제8권1호
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    • pp.77-88
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    • 2008
  • 본 연구에서는 대공간을 동계 및 하계로 구분하여 실내온열환경의 변화를 실측하고 냉 난방조건과 관련하여 대공간에서 형성되는 실내온열환경의 특성을 파악하는 것을 목적으로 하여, 대공간의 수직 및 수평온도분포, 객석온도분포, 실내표면온도분포, 실내온열쾌적성 등의 실내온열환경을 검토하였다.

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웨이퍼 프로버 척의 저온 온도균일도 향상에 관한 연구 (A Study of Improvement of Low Temperature Uniformity of Wafer Prober Chuck)

  • 주영철;신휘철;강명구
    • 한국산학기술학회논문지
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    • 제10권10호
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    • pp.2572-2576
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    • 2009
  • 반도체 양산공정에 사용되는 웨이퍼 프로버의 척은 고온이건 저온이건 항상 일정한 온도균일도가 요구된다. 저온으로 운전 시에 온도분포를 써모커플을 이용하여 측정한 결과 온도균일도를 향상할 필요가 있음을 발견하였다. FLUENT를 이용한 전산해석을 하여 온도분포를 해석하였으며, 이 결과를 이용하여 냉각수 회로 배치의 변경과 국부적인 회로 폭의 확대 등 개선안을 제시하였다. 제시된 개선안과 현재 척의 온도분포를 비교한 결과 온도균일도가 향상되었음을 확인하였다.

Analysis of Characteristics of Spent Fuels on Long-Term Dry Storage Condition

  • Yoon, Suji;Park, Kwangheon;Yun, Hyungju
    • 방사성폐기물학회지
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    • 제19권2호
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    • pp.205-214
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    • 2021
  • Currently, the interim storage pools of spent fuels in South Korea are expected to become saturated from 2024. It is required to prepare an operation plan of a domestic dry storage facility during a long-term period, with the researches on safety evaluation methods. This study modified the FRAPCON code to predict the spent fuel integrity evaluation such as the axial cladding temperature, the hoop stress and hydrogen distribution in dry storage. The cladding temperature in dry storage was calculated using the COBRA-SFS code with the burnup information which was calculated using the FRAPCON code. The hoop stress was calculated using the ideal gas equation with spent fuel information such as rod internal pressure. Numerical analysis method was used to calculate the degree of hydrogen diffusion according to the hydrogen concentration and temperature distribution during a dry storage period. Before 50 years of dry storage, the cladding temperature and hoop stress decreased rapidly. However, after 50 years, they decreased gradually and the cladding temperature was below 400 K. The initial temperature distribution and hydrogen concentration showed a parabolic line, but hydrogen was transferred by the hydrogen concentration and temperature gradient over time.

저온가스 저장공동 주위암반의 온도분포 예측에 관한 연구 (The Estimation of Temperature distribution around Gas Storage Cavern)

  • 이양;이승도;문현구
    • 터널과지하공간
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    • 제14권1호
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    • pp.16-25
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    • 2004
  • 저온가스를 지하공동에 저장하는 것은 안전과 운영 측면에서 많은 장점이 있다. 그러나 저장된 극저온가스는 주변암반의 온도변화를 야기하여 공동의 안정성에 영향을 줄 수 있다. 따라서 성공적인 저장공동의 건설을 위해서는 건설 초기에 공동 주위암반의 온도분포를 정확히 예측하는 것이 필수적이다. 본 연구의 목적은 저장공동 주변의 온도분포를 예측할 수 있는 이론해의 개발과 평가이다. 이를 위해, 공동의 형상을 단순화하고 비정상 열전도 이론을 적용하여 이론해를 도출하였다. 이론해의 적용성을 평가하기 위해서 이론해와 유한 차분 해석프로그램인 FLAC을 이용한 수치해석을 이용해 저장공동 주변의 2차원$.$3차원 온도분포를 추정하여 그 결과를 비교하였다. 또한, 공동의 크기에 대한 영향도 조사되었다.

대기온도에 따른 휘발유 자동차의 배출가스 특성에 관한 연구 (A Study on the exhaust gas characteristics of the vehicle gasoline according to the ambient temperature)

  • 임재혁;김기호;김성우;이민호;오상기
    • 동력기계공학회지
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    • 제19권6호
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    • pp.47-53
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    • 2015
  • Korea is the geographic location during the summer, the temperature rising to $35^{\circ}C$ and winter temperature is $-15^{\circ}C$ to reduce the air temperature changes, such as relatively large compared to other countries. This increase or decrease of the harmful exhaust gas discharged from automobile substantially inconvenience a significant impact on the active side of the car engine temperature and exhaust gas reducing device receives a large impact on the atmospheric temperature is regulation to be different. However, domestic vehicle emissions test temperature of $20{\sim}30^{\circ}C$ is it does not reflect this situation the actual test temperature to accurately measure the exhaust gas volume of the vehicle is difficult. In this study, domestic automobile exhaust gas test conditions of a test temperature $20{\sim}30^{\circ}C$ various temperatures, including (35, 25, 0, -7, -15, $-25^{\circ}C$) under the two vehicles (2.0L MPI, 2.4 L GDI) as was discussed with respect to the exhaust gas characteristics of the vehicle according to the ambient temperature gas. As a result, domestic emissions test temperature of $25^{\circ}C$ than average conditions were temperature decreases greenhouse gas emissions and increase overall increased by up to 15 times higher. Air temperature and the engine exhaust gas inconvenience a direct effect on the activation temperature required in the reduction unit is determined to be an increase of emissions and greenhouse gases, and also an increase in the variety of lubricants based lubricating and viscosity reduction, such as the engine oil due to the low temperature of these result It is considered that shows the.

저온 주사 레이저 및 홀소자 현미경을 이용한 YBCO 초전도 선재의 국소적 임계 온도 및 전류 밀도 분포 분석 (Distribution Analysis of the Local Critical Temperature and Current Density in YBCO Coated Conductors using Low-temperature Scanning Laser and Hall Probe Microscopy)

  • 박상국;조보람;박희연;이형철
    • Progress in Superconductivity
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    • 제13권1호
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    • pp.28-33
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    • 2011
  • Distribution of the local critical temperature and current density in YBCO coated conductors were analyzed using Low-temperature Scanning Laser and Hall Probe Microscopy (LTSLHPM). We prepared YBCO coated conductors of various bridge types to study the spatial distribution of the critical temperature and the current density in single and multi bridges. LTSLHPM system was modified for detailed linescan or two-dimensional scan both scanning laser and scanning Hall probe method simultaneously. We analyzed the local critical temperature of single and multi bridges from series of several linescans of scanning laser microscopy. We also investigated local current density and hysteresis curve of single bridge from experimental results of scanning Hall probe microscopy.

높은 미끄럼 비의 점 접촉 EHL 하에서 발생하는 딤플 영역의 온도 분포와 유막 두께 분포의 측정 (Measurements of Film Thickness and Temperature Distribution in Dimple Zone Developed in EHL Point Contact at High Slip Ratios)

  • 김성기;;;;김경웅
    • 대한기계학회논문집A
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    • 제27권4호
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    • pp.479-484
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    • 2003
  • In this paper, film thickness and temperature distribution are measured in EHL point contact at high slip ratios. Infrared temperature mapping with two band pass fillers. proposed by Ausherman (1976). is used to measure temperature distribution. And the optical interferornetric method with two filters (red and green filters) is used to measure film thickness. Result of experiment showed that temperature rising at film and ball surface occurred very dramatically in Dimple zone. As slip velocity, slip ratio and load increased, size of Dimple and temperature rising became more large In addition, Position and shape of Dimple we changed by slip ratios, and increasing of Dimple size decreased traction coefficient. In short, it is appointed that the Dimple phenomenon be developed by the effect of viscosity wedge.

공동주택 바닥용 시멘트 모르타르의 복합강화법 변화에 따른 열전도 특성 (Properties of Thermal Conductivity of Cement Mortar for Apartment Housing Floor Using Combined Strengthening Method)

  • 윤길봉;전충근;정성철;윤기원;한천구
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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    • pp.243-248
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    • 2001
  • The objective of this study is to investigate the thermal conductivity of cement mortar for apartment housing floor using expansive admixture, copper fiber, cower lathe, hollowed aluminum plate. According to test results, temperature at point (a) located above heating pipe does not show significant variation with age, and temperature at (b), which is located at the finishing surface above heating pipe, and temperature at (c), which is located at center surface between heating pipe has remarkable change. Temperature distribution sat (b) are in order for, structure containing copper fiber>plain structure>structure containing hollowed aluminum plate>structure containing expansive admixture. Temperature distribution, shows high tendency in order for, structure containing copper fiber>structure containing copper lathe>structure containing hollowed aluminum plate>plain structure>structure containing expansive admixture. (a) estimation of temperature distribution is determined with the variation of temperature between (b) point and (c) point during 60 minutes heating.

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