• 제목/요약/키워드: Radiation heat

검색결과 1,429건 처리시간 0.023초

메쉬 스크린을 적용한 해양구조물용 방풍 및 복사열 차단막 열유동특성에 관한 연구 (A Study on the Thermal and Flow Characteristics of Wind and Radiant Heat Shield for Offshore by using Mesh Screen)

  • 이중섭;진도훈
    • 한국기계가공학회지
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    • 제11권3호
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    • pp.166-173
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    • 2012
  • This study is about comparison of thermal and flow characteristics on the wind & radiant heat shield with STS mesh type screen for offshore. Numerical analysis was conducted to find transmission coefficient in the mesh and then analyse the flow characteristics about wind & radiant heat shield. The experiment method of solar radiation has been used as thermal radiation source to get the performance of radiant heat shield measurement. The sensor radiation device has been used to measure the reduction of solar radiation with various size of cells and at a distance of 0.5m and 1m from the cold face of the wind & radiant heat shield.

산업용 가스화 용융로를 위한 산소 버너의 개발 (Development of Oxygen Combustion Burner for Industrial Gasification and Smelting Furnace)

  • 배수호;이은도;신현동;김성현;구재회;유영돈
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2005년도 제31회 KOSCO SYMPOSIUM 논문집
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    • pp.170-178
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    • 2005
  • Multi-hole type oxygen combustion burner was developed for industrial gasification and smelting furnace. We investigated characteristics of flame, radiation transfer, and soot emission in the convectional oxygen burner with respect to the feeding condition of fuel and oxygen. Regarding the results of the conventional burner, we designed new burners which have larger fuel consumption rate and radiation heat transfer. We changed the size and hole number and shape of the exit plane of the burner. In addition, the performance of the burner was tested with respect to the feeding condition of the fuel and air: Normal Diffusion flame(NDF) and Inverse Diffusion Flame(IDF). We investigated the flame configuration, radiation heat transfer, and soot formation by using a CCD camera, heat flux meter, and Laser Induced Incadescence(LII), respectively. The stable operating condition was obtained by the flame configuration and the flame of the burner which has dented exit plane was more stable in whole operating conditions. The characteristics of radiative heat transfer were sensitive to the feeding condition of reactants and the flame of 75% primary oxygen and 25% secondary oxygen of the IDF case shows maximum radiation heat transfer. The soot volume fraction of the flame was measured in the axial direction of the flame and the amount of soot volume fraction is proportion to the radiation heat transfer. As a result, we can get the optimal operating condition of the newly designed burner which enhances the characteristics of flame stabilization and radiation heat transfer.

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우주비행체 단일추진제 추력기의 복사 열차폐막 개발 (Development of Radiation Heat Shield of Monopropellant Thruster for Spacecraft)

  • 이균호;유명종;최준민;김수겸
    • 한국항공우주학회지
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    • 제34권10호
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    • pp.92-98
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    • 2006
  • 2006년에 발사된 다목적실용위성은 자세제어 등에 필요한 추력과 모멘트를 발생하기 위해 NASA의 1lbf급 단일추진제 표준 추력기인 MRE-1을 사용하고 있다. 단일추진제 추력기는 추진제와 촉매와의 열분해 반응에 의해 추력을 발생시키는데 이때 발생되는 분해열은 상대적으로 온도가 낮은 주변 구조물 및 전자부품으로 과도한 복사열전달을 발생시키는 열원이 된다. 따라서 추력기와 타 부품 사이에 과도한 복사 열전달을 방지하기 위해서는 복사 열차폐막이 필요하다. 본 논문에서는 열차폐막의 설계/해석 및 제작 등 전반적인 개발 과정에 대해 설명하였다.

150W LED등기구 방열을 위한 열 해석에 관한 연구 (A Study on Heat Simulation for Heat Radiation in 150W LED)

  • 소병문
    • 반도체디스플레이기술학회지
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    • 제15권4호
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    • pp.79-85
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    • 2016
  • For long life time and high efficiency, not necessary in improvement of LED chip structure, but also improve heat radiation for decrease heat in LED chip. In this study, efficiency decline factor has been investigated in LED lamp as study heat characteristic, luminance flux and heat resistance. When LED lamp temperature was increased, about 7% loss of luminance flux. In consequence of temperature analysis, width of fin was the most important factor of heat radiation. As a result, secure the enough heat path is very important factor of LED lamp design.

해양플랜트 복사열 차폐막의 차폐성능에 관한 연구 (Study on Performance of Radiant Heat Shields for Offshore Installations)

  • 김봉주
    • 한국해양공학회지
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    • 제33권4호
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    • pp.330-339
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    • 2019
  • Radiant heat shields are normally installed on offshore oil and gas platforms to protect personnel, equipment, and structures from the thermal radiation emitted by a flare system. A heat shield should be individually designed to reduce the thermal radiation to the target level, and then manufactured and installed after the performance verification. However, in general, a heat shield is designed and manufactured by trial and error based on the performance test. For this reason, it is difficult to develop and design radiant heat shields in the Korean shipbuilding and marine equipment industry because of the lack of performance test data and limited experience. In the present study, the results of experiments conducted to verify the performances of radiant heat shields were analyzed, and the thermal radiation characteristics and performance characteristics of the radiant heat shields were investigated. The insights and conclusions developed in the present study will be useful in terms of the design and development of radiant heat shield, as well as in their performance verification tests.

Classification of Biological Effect of 1,763 MHz Radiofrequency Radiation Based on Gene Expression Profiles

  • Im, Chang-Nim;Kim, Eun-Hye;Park, Ae-Kyung;Park, Woong-Yang
    • Genomics & Informatics
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    • 제8권1호
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    • pp.34-40
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    • 2010
  • Radiofrequency (RF) radiation might induce the transcription of a certain set of genes as other physical stresses like ionizing radiation and UV. To observe transcriptional changes upon RF radiation, we exposed WI-38, human lung fibroblast cell to 1763 MHz of mobile phone RF radiation at 60 W/kg of specific absorption rate (SAR) for 24h with or without heat control. There were no significant changes in cell numbers and morphology after exposure to RF radiation. Using quantitative RT-PCR, we checked the expression of three heat shock protein (HSP) (HSPA1A, HSPA6 and HSP105) and seven stress-related genes (TNFRSF11B, FGF2, TGFB2, ITGA2, BRIP1, EXO1, and MCM10) in RF only and RF/HS groups of RF-exposed cells. The expressions of three heat shock proteins and seven stress-related genes were selectively changed only in RF/HS groups. Based on the expression of ten genes, we could classify thermal and non-thermal effect of RF-exposure, which genes can be used as biomarkers for RF radiation exposure.

복사 차폐막이 극저온 용기의 부하에 미치는 영향에 관한 실험적 연극 (An Experimental Study on the Effects of a Radiation Shield on the Thermal Load of a Cryochamber)

  • 김영민;박성제;강병하
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2005년도 동계학술발표대회 논문집
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    • pp.365-370
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    • 2005
  • Infrared (lR) detectors are widely used for such applications as thermoelstic stress analysis, medical diagnostics and temperature measurement. Infrared detectors commonly need to be refrigerated below 80 K, and thus a cooling system should be equipped together with the detector system. The cooling load, which should be removed by the cooling system to maintain the nominal operating temperature of the detector, critically depends on the insulation efficiency of the cryochamber housing the detector. Cryochamber considers the conduction heat transfer through a cold finger, the gases conduction and radiation heat transfer. The thermal loads of an infrared detector Cryochamber with radiation shield are investigated experimentally in present study. Since the effect of radiation heat transfer on thermal loads is significant, radiation shields is installed in the cold finger part to protect heat input through radiation. It is found that the thermal load can be substantially reduced by increasing the number of radiation shield.

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전산유동가시화를 활용한 웨이퍼 이송장치의 복사열전달에 관한 연구 (A Study on Radiation Heat Transfer of Wafer Transfer Module Using Computational Flow Visualization)

  • 추민기;정지홍;손동기;고한서
    • 한국가시화정보학회지
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    • 제20권3호
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    • pp.58-66
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    • 2022
  • The high heat emitted from the process module and heat jacket may cause errors in semiconductor process equipment. Barriers were designed to reduce the temperature of surface on transfer module. A designed barrier was compared and analyzed by numerical analysis using ANSYS Fluent. The average temperature of barrier and effect of radiation heat transfer were also compared through absorbed radiative heat flux of the barrier. The adoption of the barrier had an effect on the radiative heat transfer reduction of the transfer module rod. The effect of the angles of barrier from 50° to 90° on the heat transfer was investigated using the absorbed radiative heat flux with the average temperature. The angle of barrier of 50° reduced the temperature up to 9.6 %.

Introduction of Japanese Ocean Flux data sets with Use of Remote sensing Observations (J-OFURO)

  • Kubota, Masahisa
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
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    • pp.231-236
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    • 1999
  • Accurate ocean surface fluxes with high resolution are critical for understanding a mechanism of global climate. However, it is difficult to derive those fluxes by using ocean observation data because the number of ocean observation data is extremely small and the distribution is inhomogeneous. On the other hand. satellite data are characterized by the high density, the high resolution and the homogeneity. Therefore, it can be considered that we obtain accurate ocean surface by using satellite data. Recently we constructed ocean surface data sets mainly using satellite data. The data set is named by Japanese Ocean Flux data sets with Use of Remote sensing Observations (J-OFURO). Here, we introduce J-OFURO. The data set includes shortwave radiation, longwave radiation, latent heat flux, sensible heat flux, and momentum flux etc. Moreover, sea surface dynamic topography data are included in the data set. Radiation data sets covers western Pacific and eastern Indian Ocean because we use a Japanese geostationally satellite (GMS) to estimate radiation fluxes. On the other hand, turbulent heat fluxes are globally estimated. The constructed data sets are used and shows the effectiveness for many scientific studies.

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