• 제목/요약/키워드: Semitransparent Radiation

검색결과 4건 처리시간 0.017초

Overall efficiency enhancement and cost optimization of semitransparent photovoltaic thermal air collector

  • Beniwal, Ruby;Tiwari, Gopal Nath;Gupta, Hari Om
    • ETRI Journal
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    • 제42권1호
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    • pp.118-128
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    • 2020
  • A semitransparent photovoltaic-thermal (PV/T) air collector can produce electricity and heat simultaneously. To maximize the thermal and overall efficiency of the semitransparent PV/T air collector, its availability should be maximum; this can be determined through a Markov analysis. In this paper, a Markov model is developed to select an optimized number of semitransparent PV modules in service with five states and two states by considering two parameters, namely failure rate (λ) and repair rate (μ). Three artificial neural network (ANN) models are developed to obtain the minimum cost, minimum temperature, and maximum thermal efficiency of the semitransparent PV/T air collector by setting its type appropriately and optimizing the number of photovoltaic modules and cost. An attempt is also made to achieve maximum thermal and overall efficiency for the semitransparent PV/T air collector by using ANN after obtaining its minimum temperature and available solar radiation.

접촉전도와 반투명 복사가 반도체 웨이퍼의 CVD 공정 중 열전달에 미치는 영향 (Effect of Contact Conductance and Semitransparent Radiation on Heat Transfer During CVD Process of Semiconductor Wafer)

  • 윤용석;홍혜정;송명호
    • 대한기계학회논문집B
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    • 제32권2호
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    • pp.149-157
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    • 2008
  • During CVD process of semiconductor wafer fabrication, maintaining the uniformity of temperature distribution at wafer top surface is one of the key factors affecting the quality of final products. Effect of contact conductance between wafer and hot plate on predicted temperature of wafer was investigated. The validity of opaque wafer assumption was also examined by comparing the predicted results with Discrete Ordinate solutions accounting for semitransparent radiative characteristics of silicon. As the contact conductance increases predicted wafer temperature increases and the differences between maximum and minimum temperatures within wafer and between wafer and hot plate top surface temperatures decrease. The opaque assumption always overpredicted the wafer temperature compared to semitransparent calculation. The influences of surrounding reactor inner wall temperature and hot plate configuration are then discussed.

굴절 현상을 이용한 건조기에서 건조특성 해석 (Analysis of Drying Characteristics in the Dryer Using the Refraction of Radiation)

  • 이공훈;최병일;홍용주
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2006년도 하계학술발표대회 논문집
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    • pp.1191-1196
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    • 2006
  • Analysis of drying characteristics has been carried out with one-dimensional model in the dryer using the principle of the refraction of radiation. The dryer is composed of hot water tank, a plastic film conveyer belt, drying material, etc. The model considers the conduction and radiation within the plastic film and drying material. The film is semitransparent to radiation and the drying material is assumed to be semitransparent or opaque to radiation. The results shows that the effect of radiative transfer on the drying rate is relatively large when the thickness of drying material is small and the water temperature is high. When the material is thin, the drying rate by only conduction is also enhanced so that drying time can considerably be reduced.

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적외선 굴절식 건조기에서 열전달 및 건조 특성 해석 (Analysis of Heat Transfer and Drying Characteristics in the Dryer Using the Refraction of Radiation)

  • 이공훈;홍용주;김욱중
    • 설비공학논문집
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    • 제18권8호
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    • pp.678-685
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    • 2006
  • Analysis of drying characteristics has been carried out with one-dimensional model in the dryer using the principle of the refraction of radiation. The dryer is composed of hot water tank, plastic film conveyer belt, drying material, etc. The model considers the con-duction and radiation within the plastic film and drying material. The film is semitransparent to radiation and the drying material is assumed to be semitransparent or opaque to radiation. The results show that the effect of radiative transfer on the drying rate is relatively large when the thickness of drying material is small and the water temperature is high. When the material is thin, the drying rate due to conduction is also enhanced and the drying time can considerably be reduced.