Journal of Mechanical Science and Technology

The Korean Society of Mechanical Engineers (대한기계학회)
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An Experimental Study on Convective Boiling of R-22 and R-410A in Horizontal Smooth and Micro-fin Tubes

  • Kim, Yongchan (Department of Mechanical Engineering, Korea University) ;
  • Seo, Kook-Jeong (Department of Mechanical Engineering, Korea University) ;
  • Lee, Kyu-Jung (Department of Mechanical Engineering, Korea University) ;
  • Park, Youn cheol (Department of Mechanical Engineering, Korea University)
  • Published : 2001.08.01
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Abstract

Evaporation heat transfer coefficients and pressure drops were measured for smooth and micro-fin tubes with R-22 and R-410A. Heat transfer measurements were performed for 3.0m long horizontal tubes with nominal outside diameters of 9.52 and 7.0mm over an evaporating temperature range of -15 to 5$\^{C}$, a mass flux range of 68 to 211kg/㎡s, and a heat flux range of 5 to 15kW/㎡. It was observed that the heat transfer coefficient increased with mass flux. Evaporation heat transfer coefficients of R-22 and R-410A increased as the evaporating temperature dropped at a lower heat flux. Generally, R-420A showed the higher heat transfer coefficients than R-22 in the range of low mass flux, high heat flux and high evaporating temperature. Pressure drop increased with a decrease of evaporating temperature and a rise of mass flux. Pressure drop of R-22 was higher than that of R-410A at the same mass flux.

Keywords

References

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