Proceedings of the SAREK Conference (대한설비공학회:학술대회논문집)

The Society of Air-Conditioning and Refrigerating Engineers of Korea (대한설비공학회)
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Condensation Heat Transfer Characteristics of Tube-in-Tube Heat Exchanger using Small Diameter Tubes with R-22, R-407C and R-410A

세관을 이용한 Tube-in-Tube 열교환기내 R-22, R-407C 및 R-410A 응축열전달 특성

  • Park, Woo-Jong (Graduate School, Chonnam National University) ;
  • Choi, Kwang-Il (Graduate School, Chonnam National University) ;
  • Park, Ki-Won (Department of Refrigeration Eng. Chonnam National University) ;
  • Oh, Jong-Taek (Department of Refrigeration Eng. Chonnam National University)
  • 박우종 (전남대학교 대학원 냉동공학과) ;
  • 최광일 (전남대학교 대학원 냉동공학과) ;
  • 박기원 (전남대학교 냉동공학과) ;
  • 오종택 (전남대학교 냉동공학과)
  • Published : 2006.06.21
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Abstract

The present paper dealt with an experimental study of condensation heat transfer coefficients with refrigerant R-22, R-407C and R-410A, and was focused on pressure gradient and heat transfer coefficient in horizontal tube-in-tube heat exchangers using inner diameter of 4 mm, 3 mm and 2 mm in a 16.91 mm tube and length of 3,000 mm. Experiments were performed at inlet saturation temperature of 35 to $45^{\circ}C$ and mass flux ranges from 200 to $600 kg/m^2s$. The pressure gradient with inner tube diameter of 4.0 mm is higher 2.5 times than that of 8.0 mm. In tube-in-tube HEX, the pressure gradient of R-410A were lower than those of R-22 and R-407C. The condensation heat transfer coefficients increased with mass flux increase, but they decreased with saturation temperature increased. Condensation heat transfer coefficients of R-410A were a little higher than those of R-22 and R-407C. The condensation heat transfer coefficients of tube-in-tube HEX were about 40% higher than those of double tube HEX.

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