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ISSN Online: 2377-424X

International Heat Transfer Conference 12
August, 18-23, 2002, Grenoble, France

Experimental Investigation of Heat Transfer and Pressure Drop During Complete Condensation in Miniature Tubes

Get access (open in a dialog) DOI: 10.1615/IHTC12.530
6 pages

Resumo

An experimental study of water undergoing complete condensation in small diameter horizontal tubes at low mass fluxes is reported. Multiple axial temperature measurements were used to determine the condensation length and the average wall temperature. Average heat transfer coefficient and pressure drop in tube diameters of 4.0, 3.2, 2.5, and 1.7 (mm) for condensation lengths between 0.1 and 0.6 (m) have been obtained. The data were collected for mass fluxes between 10 and 25 (kg/m2s) at saturation temperatures of 60, 70, 80, and 90 (°C). It is shown, for complete condensation at a fixed mass flux, that the average heat transfer coefficient decreases and the pressure drop increases as the condensation length increases. Also, the average heat transfer coefficient and pressure drop increase with decreasing tube diameter for the same mass flux. Additionally, a flow visualization experiment of condensation in glass tubes of similar sizes revealed a skewed annular liquid film which was thinnest at the top wall, thickest at the bottom wall, and existed over nearly the entire condensation length.