• Title/Summary/Keyword: 복사열

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Infrared Radiative Heat Transfer Characteristics of Fiber Mat Catalytic Burners (매트촉매 버너의 적외선 복사열전달 특성)

  • Song, Kwang Sup;Choi, Jung In
    • Korean Chemical Engineering Research
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    • v.50 no.6
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    • pp.1049-1055
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    • 2012
  • The fiber mat catalytic burner that uses infrared radiative heat obtained by flameless catalytic combustion was manufactured and tested to investigate its combustion characteristics. About 9 to 17% of combustion heat was released by sensible heat during the premixed catalytic combustion depend on combustion condition. To find out radiation intensity with distance between catalytic burner and sample, the equation that calculate the receiving surface of radiative energy under the fiber mat catalytic burner was driven. This equation was well correlated with the drying rate of melamine. The drying experiments were carried out to the melamine, wood chip and agricultural pallet by using the fiber mat catalytic burner and the energy efficiency was calculated from drying rate of them. The energy efficiency of the fiber mat catalytic burner reaches to 79% in maximum for drying of the wood chip.

A Numerical Study of Smoke Movement with Radiation in Atrium Fires (아트리움에서 화재 발생시 복사가 고려된 연기거동에 대한 수치해석 연구)

  • 정진용;유홍선;홍기배
    • Fire Science and Engineering
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    • v.15 no.1
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    • pp.7-15
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    • 2001
  • This paper describes the smoke filling process of a fire field model based on a self-developed SMEP (Smoke Movement Estimating Program) codo to the simulation of fire induced flows in the atrium space (SIVANS atrium at Japan) containing smoke radiation effect. The SMEP using PISO algorithm solves conservation equations for mass, momentum, energy and species, together with those for the modified k-$\varepsilon$ turbulence model with buoyancy term. Also it solves the radiation equation using the discrete ordinates method. The result of the calculated smoke temperature containing radiation effect has shown a better prediction than the result calculated by only convection effect in comparison with the experimental data. This seems to come from the radiation effect of $H_2$O and $CO_2$ gas under smoke productions. Thus, the consideration of the radiation effect under smoke in fire should be necessary in order to get more realistic result. Also the numerical results indicated that the smoke layer is developing at a rate of about 0.1 m/s. It would take about 450 seconds after starting the ultra fast fire of 560 kW that the smoke layer move down to 1.5m above the escape level.

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THERMAL DESIGN OF A PROTOMODEL SPACE INFRARED CRYOGENIC SYSTEM (적외선 우주망원경 냉각시스템 시험모델 열설계)

  • Yang Hyung-Suk;Kim Dong-Lak;Lee Byoung-Seob;Kim Geon-Hee;Lee Dae-Hee;Pak Soo-Jong;Nam Uk-Won
    • Journal of Astronomy and Space Sciences
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    • v.23 no.2
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    • pp.153-160
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    • 2006
  • A Protomodel Space Infrared Cryogenic System (PSICS) cooled by a stirling cry-ocooler has been designed. The PSICS has an IR sensor inside the cold box which is cooled by a stirling cryocooler with refrigeration capacity of 500mW at 80K in a vacuum vessel. It is important to minimize the heat load so that the background thermal noise can be reduced. In order to design the cryogenic system with low heat load and to reduce the remained heat load, we have performed numerical analyses. In this paper, we present the design factors and the results obtained by the thermal analysis of the PSICS.

The Characteristics of Comfortable Indoor-Temperature Distribution according to Summer Clo-Unit in South Korea (남한의 하계 인체보온치수에 따른 쾌적 실내온도 분포의 특성)

  • Kang, Chul-Sung
    • Journal of the Korean association of regional geographers
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    • v.11 no.5
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    • pp.383-390
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    • 2005
  • The purpose of this study is to show distribution pattern of comfortable Indoor-Temperature in South Korea based on 10-days normal data(June 3rd, July 2nd, August 1st). Comfortable Indoor-Temperature values and Heat flow equation values for the 68 stations are constructed to show how man tend to feel in various areas. In the early summer, comfortable Indoor-Temperature is very low in Taegwallong regions and the Southern interior regions due to the influence of the orographic effects or the altitude. In the hot summer, All regions except Taegwallong and Central interior regions have been the high value. These are largely derived from the low Clo-values due to the stable weather with the highest insolation, humidity and strong radiation heat by the North Pacific Anticyclone appears in Eastern Asia.

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Numerical Analysis of Arcs in SF6 Gas Circuit Breaker ($SF_6$ 차단기의 열가스 수치해석)

  • Bae, Chae-Yoon;Kim, Hong-Kyu;Jung, Hyn-Kyo
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.816-818
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    • 2000
  • 본 논문에서는 $SF_6$ 차단기 내의 대전류 아크에 대한 수치적인 해석을 모의하는 도구를 제시한다. 대전류의 차단을 위해서 해석을 통해 열적 파괴를 예측하는 것이 필수적이다. 본 논문에서 사용한 방법은 FVFLIC(finite volume fluid in cells)이며 지배방정식은 압축성 오일러 방정식으로 아크와 유동의 상호 작용을 해석한다. 아크는 기본적으로 에너지 보존식에서 열소스항으로 나타나며 주울열과 복사항으로 표현된다. 주울열은 플라즈마 영역내의 전계해석을 통해 계산되며 복사항은 방출과 흡수항의 합으로 나타내어지고 이것은 국소적인 온도와 압력의 함수이다. 본 논문에서는 수정된 방출과 흡수 모델로 복사 열전달을 계산하였다.

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