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ISSN Online: 2377-424X

ISBN CD: 1-56700-226-9

ISBN Online: 1-56700-225-0

International Heat Transfer Conference 13
August, 13-18, 2006, Sydney, Australia

TWO-PHASE FLOW BOILING HEAT TRANSFER AND PRESSURE DROP WITH R-407C, R-410A, R-22, AND CO2 IN HORIZONTAL MINICHANNELS

Get access (open in a dialog) DOI: 10.1615/IHTC13.p28.380
12 pages

要約

Convective boiling heat transfer and pressure drop experiments were performed in horizontal minichannels with R-407C, R-410A, R-22, and CO2. The test section is made of stainless steel tubes with inner tube diameters of 1.5 and 3.0 mm and heated lengths of 1.5, 2.0 and 3.0 m, and is uniformly heated by applying electric current directly to the tubes. Local heat transfer coefficients and pressure drop were obtained for heat flux ranges of 5 to 20 kW/m2, mass flux ranges of 200 to 600 kg/m2s, and quality ranges of up to 0.9. The experimental results were mapped on the Wang et al. (1997) and Wojtan et al. (2005) flow pattern maps to observe the flow regimes. Laminar flow appears in flow with minichannels. The experimental heat transfer coefficients were compared against six existing two-phase heat transfer coefficient prediction methods and the experimental pressure drops were compared against six existing pressure drops prediction methods. A new two-phase heat transfer coefficient correlation based on the superposition model for refrigerants in minichannels was developed. The comparison of the two-phase heat transfer between the present study and the prediction of the new correlation shows 18.71% mean deviation.