Analysis of Heat Loss with Mirror Array and Receiver Shapes on the Dish Solar Collector

반사경 배치 및 흡수기 형상에 따른 접시형 태양열 집열기의 열손실 해석

  • Seo, Joo-Hyun (Dept. of Mechanical Eng., Graduate School, Inha University) ;
  • Ma, Dae-Sung (Dept. of Mechanical Eng., Graduate School, Inha University) ;
  • Kim, Yong (Dept. of Mechanical Eng., Graduate School, Inha University) ;
  • Kang, Yong-Heack (Solar Thermal Research Center, Korea Institute of Energy Research) ;
  • Seo, Tae-Beom (Dept. of Mechanical Eng., Inha University)
  • 서주현 (인하대학교 대학원 기계공학과) ;
  • 마대성 (인하대학교 대학원 기계공학과) ;
  • 김용 (인하대학교 대학원 기계공학과) ;
  • 강용혁 (한국에너지기술연구원 태양열 수력연구센터) ;
  • 서태범 (안하대학교 기계공학부)
  • Published : 2008.01.10

Abstract

The radiative heat loss from a receiver of a dish solar collector is numerically investigated. The dish solar collector considered in this paper consists of a receiver and multi-faceted mirrors. In order to investigate the performance comparison of dish solar collectors, six different mirror arrays and four different receivers are considered. A parabolic- shaped perfect mirror of which diameter is 1.40 m is considered as the reference for the mirror arrays. The other mirror arrays which consist of twelve identical parabolic-shaped mirror facets of which diameter are 0.405 m are suggested for comparison. Their reflecting areas, which are 1.545 $m^{2}$, are the same. Four different receiver shapes are a conical, a dome, a cylindrical, and a unicorn type. The radiative properties of the mirror surfaces and the receiver surfaces may vary the thermal performance of the dish solar collector so that various surface properties are considered. In order to calculate the radiative heat loss in the receiver, two kinds of methods are used. The Net Radiation Method that is based on the radiation heat balance on the surface is used to calculate the radiation heat transfer rate from the inside surface of the receiver to the environment. The Monte-Carlo Method that is the statistical approach is adopted to predict the radiation heat transfer rate from the reflector to the receiver. The collector efficiency is defined as the results of the optical efficiency and the receiver efficiency. Based on the calculation, the unicorn type has the best performance in receiver shapes and the STAR has the best performance in mirror arrays except the perfect mirror.

Keywords

References

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