In-tube condensation heat transfer of refrigerant mixtures
- Iowa State Univ., Ames, IA (United States). Dept. of Mechanical Engineering
- Kansas State Univ., Manhattan, KS (United States). Mechanical Engineering Dept.
Heat transfer coefficient and pressure-drop data were taken during in-tube condensation of refrigerant mixtures in a smooth copper tube with an outer diameter (O.D.) of 3/8 in. The data were taken at temperatures of 30 C and 40 C. Five nonazeotropic refrigerant mixtures and pure R-125 were tested and compared against baseline data for R-22. Four different mass fluxes ranging from 125 to 375 kg/s{center_dot}m{sup 2} were tested. The mixtures tested, on a mass basis, were: R-125 (40%)/R-32 (60%), R-134a (90%)/R-32 (10%), R-134a (75%)/R-32 (25%), R-32 (30%)/R-125 (10%)/R-134a (60%), and R-125 (44%)/R-143a (53%)/R-134a (4%). When compared on an equal mass flux basis, only the R-125 (40%)/R-32 (60%) mixture had a heat transfer coefficient higher than that of R-22. All the refrigerants tested had lower heat transfer coefficients than R-22 when compared on an equal heating capacity basis. The equal heating capacity is computed by multiplying the mass flux by the corresponding refrigerant`s enthalpy of vaporization. This makes it easier to compare refrigerants with greatly different enthalpies of vaporization. Also, the heat transfer coefficients of all the refrigerants decreased with increasing temperature.
- OSTI ID:
- 33274
- Report Number(s):
- CONF-9406105-; TRN: IM9518%%95
- Resource Relation:
- Conference: 1994 American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) annual meeting, Orlando, FL (United States), 25-29 Jun 1994; Other Information: PBD: 1994; Related Information: Is Part Of ASHRAE transactions 1994: Technical and symposium papers. Volume 100, Part 2; PB: 1372 p.
- Country of Publication:
- United States
- Language:
- English
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