• Title/Summary/Keyword: thermal distribution

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An Analysis of Indoor Thermal Environment by Macro Model (매크로 모델에 의한 실내온열환경 검토)

  • Jung, Jae-Hoon
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.584-589
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    • 2008
  • It is known that slab thermal storage which uses concrete slab as thermal material is effective in the load leveling and using the nighttime electric power. The temperature distribution is not constant in plenum in thermal storage time by beams, ducts such as several factor. It is considered that this fact will effect on efficiency of thermal storage and indoor thermal environment. The purpose of this paper is to examine the thermal environment inside plenum. A macro model was made for the analysis of indoor thermal environment as the first step. The flow rate distribution and temperature distribution of object room model was examined by use of basic equations such as airflow by the pressure difference between unit cells, heat flow by air and heat transfer.

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Analysis of Thermal Comfort Factor′s Distribution in Convective Heating Space (대류난방공간에서 온열쾌적조건의 분포상태 분석에 관한 연구)

  • 공성훈
    • Journal of the Korean housing association
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    • v.6 no.1
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    • pp.31-37
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    • 1995
  • The purpose of this study is to analyse the distribution of thermal sensation response and thermal environment condition in convective heating space. The contents of this study are as follows: 1)the spatial distributions of thermal conditions are measured 2)the thermal sensation vote of residents is taken in order to investigate the relation between thermal condition and human thermal sensation in sedentary condition 3)to analyse the distribution of subject's thermal sensation vote and thermal environment condition by two methods-regression method and graph method.

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Detection and Diagnosis of Power Distribution Supply Facilities Using Thermal Images (열화상 이미지를 이용한 배전 설비 검출 및 진단)

  • Kim, Joo-Sik;Choi, Kyu-Nam;Lee, Hyung-Geun;Kang, Sung-Woo
    • Journal of the Korea Safety Management & Science
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    • v.22 no.1
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    • pp.1-8
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    • 2020
  • Maintenance of power distribution facilities is a significant subject in the power supplies. Fault caused by deterioration in power distribution facilities may damage the entire power distribution system. However, current methods of diagnosing power distribution facilities have been manually diagnosed by the human inspector, resulting in continuous pole accidents. In order to improve the existing diagnostic methods, a thermal image analysis model is proposed in this work. Using a thermal image technique in diagnosis field is emerging in the various engineering field due to its non-contact, safe, and highly reliable energy detection technology. Deep learning object detection algorithms are trained with thermal images of a power distribution facility in order to automatically analyze its irregular energy status, hereby efficiently preventing fault of the system. The detected object is diagnosed through a thermal intensity area analysis. The proposed model in this work resulted 82% of accuracy of detecting an actual distribution system by analyzing more than 16,000 images of its thermal images.

Research on the relationship between the thermal characteristics and the type of land cover in Beijing urban area by ASTER data

  • Zhu, QiJiang;Zhang, Xin;Bai, Xianghua
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.277-279
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    • 2003
  • The study utilizes remote sensing as the main monitoring means. With different spatial high-resolution, multichannel ASTER remote sensing image as the main information in Beijing city zone; with regional border and statistical data as auxiliary factor a study between the thermal space distribution character and the underground medium is analyzed based on the GIS logical algorithm and synthetic analysis technology. Results show thermal forming mechanism and the rule of distribution is mainly related to the underground medium and the change of the city distribution. Different underground medium has different degree and intensity influence on the thermal space distribution. Furthermore, urban greenbelt and water areas can reduce the thermal effect and large-scale greenbelt creates green island effect. In addition, Road net, residential area, population density, heat resources and so on have some positive effect on the thermal distribution, which increase the local temperature and intensity on the other hand. It is important to study the thermal distribution and its related factors, which contributes to the plan, construction and development of the city.

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The Temperature Distribution and Thermal Stress Analysis of Mold transformer (주상용 몰드변압기의 온도분포와 열응력 해석)

  • 조한구;이운용;한세원
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.387-390
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    • 2000
  • The life of transformer is significantly dependent on the thermal behavior in windings. To analyse winding temperature rise, many transformer designer have calculated temperature distribution and hot spot point by finite element method(FEM). Recently, numerical analyses of transformer are studied for optimum design, that is electric field analysis, magnetic field, potential vibration, thermal distribution and thermal stress. Therefore design time and design cost are decreased by numerical analysis. In this paper, the temperature distribution and thermal stress analysis of 50kVA pole cast resin transformer for power distribution are investigated by FEM program. The temperature change according to load rates of transformer also have been investigated. We have carried out temperature rise test and test results are compared with simulation data.

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Thermal Characteristics and Heatsink Modeling. for IGBT (IGBT의 열 특성 및 히트싱크 모델링)

  • Ryu, Se-Hwan;Bea, Kyung-Kuk;Shin, Ho-Chul;Ahn, Hyung-Keun;Han, Deuk-Young
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.172-173
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    • 2007
  • As the power density and switching frequency increase, thermal analysis of power electronics system becomes imperative. The thermal analysis provides valuable information on the semiconductor rating, long-term reliability. In this paper, thermal distribution of the Non Punchthrough(NPT) Insulated Gate Bipolar Transistor has been studied. For analysis of thermal distribution, we obtained experimental and simulation results by using finite element simulator, Ansys and by using photographic infrared thermometer, we compared experimental date with simulation result. and got good agreement. Also this paper provided thermal distribution of IGBT connected to heat sinks. and this results will be good information to design optimal heat sink for IGBT.

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Estimation of Empirical Equation on Thermal Conductivity (열전도계수 경험식의 국내 적용성에 관한 평가)

  • Kim, Hak-Seung;Lee, Jang-Guen;Kim, Young-Seok;Kang, Jae-Mo;Hong, Seung-Seo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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    • pp.1151-1155
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    • 2010
  • Frost depth is one of important factors to design roadway structure, and it can be estimated with numerical simulation on thermal distribution through subgrade soils. Thermal conductivity is a key parameter for accurate prediction on thermal distribution, but there are few studies on thermal conductivity of subgrade soils in Korea. Thermal conductivity can be affected by several factors such as dry density, moisture content, and saturation degree based on previous researches. Two empirical equations to estimate thermal conductivity are applied to access the accuracy of these equations with experimental data. Results indicate that the equation can be used to estimate thermal conductivity with proper quartz fraction.

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

  • Chae, Mun-Byoung;Yang, Jeong-Hoon;Choi, Dong-Ho;Seok, Ho-Tae
    • Journal of Korean Association for Spatial Structures
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    • v.8 no.1
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    • pp.77-88
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    • 2008
  • This research aims to divide the large enclosures according to summer and winter seasons, and to measure changes in the indoor thermal conditions. Also, with regard to air conditioning and exterior environments, it aims to identify the characteristics of indoor thermal environments such as indoor vertical and horizontal temperature distribution in large enclosures, temperature distribution in the audience's seating, indoor surface temperature distribution, wind speed distribution in the audience's seating, and indoor thermal comfort.

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Analysis of Heat of Hydration and Thermal Stresses in Mass Concrete (매스 콘크리트의 수화열과 온도 응력 해석)

  • 박영진;김진근;전상은;방기성
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.04a
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    • pp.281-286
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    • 1999
  • Nonlinear temperature distribution induced by the hydration heat generates thermal stress in mass concrete. At early ages, such thermal stress may induce thermal cracks in the structure which can affect on the durability and safety of the structure. Up to now, a lot of works have focused on the prediction of temperature distribution and thermal stress in the structure. In most of such works, however, the inside of structure was considered as adiabatic state to predict temperature distribution and the thermal stress. And due to the lacks of appropriate analysis models after crack, there was little research on the crack occurrence. This paper deals with the prediction of the temperature distribution in the structure using the rate of hydration heat generation and also estimates the behavior of structure before and after cracking due to hydration heat using crack band model.

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An Experimental Study on Thermal Stratification of Pressurized Plenum Underfloor Air Distribution System during Cooling (가압식 바닥급기 시스템의 여름철 성층화 경향에 관한 실험적 연구)

  • Kim, Dong-Hee;Yu, Ki-Hyung;Cho, Dong-Woo;Seo, Jung-Seok;Han, Sung-Phil
    • Proceedings of the SAREK Conference
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    • 2007.11a
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    • pp.340-345
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    • 2007
  • The underfloor air distribution system has been attracting to architects and building owners as one of valuable system for the renovated and newly office building. In this paper, we discussed the thermal stratification profile of pressurized plenum underfloor air distribution(UFAD) according to indoor setting temperature, diffuser number, diffuser type. For this, the space of office building(H corp.) is selected for measuring the air volume of underfloor diffuser and vertical temperature profile. As a result, the thermal stratification profile is influenced by the number and type of the underfloor diffuser and thermal storage character of the underfloor. Whereas indoor setting temperature have a lower significant impact on thermal stratification.

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