Two-phase flow heat transfer and friction characteristics of R-22 and R-407C
- Industrial Technology Research Inst., Hsinchu (Taiwan, Province of China). Energy and Research Labs.
- National Chiao Tung Univ., Hsinchu (Taiwan, Province of China). Dept. of Mechanical Engineering
The two-phase heat transfer coefficient and pressure drop characteristics of refrigerants R-22 and R-407C (a mixture of R-32/R-125/R-134a, 23%/25%/52%) within a smooth tube with a nominal diameter of 9.52 mm are presented in this study. The data were taken at two different evaporation pressures (600 kPa and 680 kPa, respectively). The mass flux was between 100 and 300 kg/m{sup 2}{center_dot}s and the heat fluxes were between 6 and 14 kW/m{sup 2}. Experimental data were presented in the form of quasi-local heat transfer coefficients and frictional pressure gradients. The effects of heat flux, mass flux, and evaporation pressure on the heat transfer coefficients are also reported in the present investigation. It was found that the heat transfer coefficients for R-407C are considerably lower than those for R-22 (50% to 70% less), and the pressure drop of R-407C is similar to that of R-22 at low mass flux (G = 100 kg/m{sup 2}{center_dot}s) and 45% lower compared to R-22 at a higher mass flux (G = 300 kg/m{sup 2}{center_dot}s).
- OSTI ID:
- 392512
- Report Number(s):
- CONF-960254--
- Country of Publication:
- United States
- Language:
- English
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