Korean Journal of Air-Conditioning and Refrigeration Engineering (설비공학논문집)

The Society of Air-Conditioning and Refrigerating Engineers of Korea (대한설비공학회)
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Pool Boiling Heat Transfer Coefficient of R245fa on the Plain Tube and the Low Fin Tube

평활관과 낮은 핀관에서 R245fa의 풀 비등 열전달계수

  • 박기정 (인하대학교 기계공학과 대학원) ;
  • 이요한 (인하대학교 기계공학과 대학원) ;
  • 임병덕 (인하대학교 기계공학과 대학원) ;
  • 정동수 (인하대학교 기계공학과)
  • Received : 2009.12.10
  • Accepted : 2011.01.20
  • Published : 2011.03.10
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Abstract

In this work, pool boiling heat transfer coefficients(HTCs) of R22, R123, R134a, and R245fa are measured on both horizontal plain and 26 fpi low fin tubes. The pool boiling temperature is maintained at $7^{\circ}C$ and heat flux is varied from 80 $kW/m^2$ to 10 $kW/m^2$ with an interval of 10 $kW/m^2$. Wall temperatures are measured directly by thermocouples inserted through holes of 0.5 mm diameter. Test results show that HTCs of high vapor pressure refrigerants are usually higher than those of low pressure fluids in both plain and low fin tubes. On a plain tube, HTCs of R245fa are 23.3% higher than those of R123 while on a 26 fpi low fin tube, HTCs of R245fa are 46.3% higher than those of R123. The fin effect is more prominent with low vapor pressure refrigerants than with high vapor pressure ones due to a sweeping effect.

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References

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