A comparison of R-22, R-134a, R-410a, and R-407c condensation performance in smooth and enhanced tubes: Part 1, Heat transfer
Local and average heat transfer coefficients during condensation are reported for R-22, R-134a, R-410a, and R-407c in one smooth tube and three enhanced surface tubes. The test tubes included a 3/8 inch outer diameter smooth tube, a 3/8 inch outer diameter microfin tube, a 5/16 inch outer diameter microfin tube, and a 5/8 inch outer diameter microfin tube. The local and average heat transfer coefficients were measured over a mass flux range of 92,100 lb/ft{sup 2}{center_dot}h to 442,200 lb/ft{sup 2}{center_dot}h and at saturation temperatures of 104 F and 122 F. A comparison of the performance of the different refrigerants reveals that R-134a has the highest heat transfer performance followed by R-22 and R-410a, which have similar performances. In general, R-407c had the lowest performance of the refrigerants tested. The microfin tube more than doubles the heat transfer coefficient compared to the smooth tube for all refrigerants at the low mass fluxes, but only increases the heat transfer coefficients by 50% at the highest mass flux tested. The measured heat transfer coefficients are also compared with a number of correlations for condensation.
- Research Organization:
- Kansas State Univ., Manhattan, KS (US)
- Sponsoring Organization:
- American Society of Heating, Refrig. and Air Conditioning Engineers
- OSTI ID:
- 20085634
- Resource Relation:
- Conference: ASHRAE Annual Meeting, Seattle, WA (US), 06/18/1999--06/23/1999; Other Information: PBD: 1999; Related Information: In: ASHRAE Transactions: Technical and symposium papers presented at the 1999 annual meeting in Seattle, Washington of the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.; Volume 105, Part 2, by Geshwiler, M.; Harrell, D.; Roberson, T. [eds.], 1360 pages.
- Country of Publication:
- United States
- Language:
- English
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