Heat Transfer in Flow Boiling Over a Bundle of Horizontal Tubes

• Published in: Chemical engineering research & design Vol. 83; no. 5; pp. 527 - 538
• Main Authors: Burnside, B.M., Shire, N.F.
• Format: Journal Article
• Language: English
• Published: Rugby Elsevier B.V 01.05.2005; Institution of Chemical Engineers
• Subjects: 2-phase flow; Applied sciences; boiling models; Chemical engineering; cross-flow heat transfer; Exact sciences and technology; Heat and mass transfer. Packings, plates; Hydrodynamics of contact apparatus; 2-phase flow; cross-flow heat transfer; boiling models; Sensitivity analysis; Two phase flow; Atmospheric pressure; Reynolds number; Upward flow; Heat flow; Crossflow; Heat transfer coefficient; Modeling; Trend analysis; Nucleate boiling; Horizontal tube; Heat transfer
• ISSN: 0263-8762; 1744-3563
• DOI: 10.1205/cherd.04313

The paper describes tests boiling R 113 at atmospheric pressure in upward flow over a 17 row column of square pitched electrically heated tubes. Uniform heat fluxes of 10–65 kW m –2 and maximum Reynolds numbers, Re max, between 7800 and 27 000 were used. The data at the lower heat fluxes of 10 and 20 kW m –2 consistently exhibited a linear increase of heat transfer coefficient, h, with quality, the slope lower at 20 kW m –2, so that h at 10 kW m –2 exceeded that at 20 kW m –2 and both reached h at 40 kW m –2 for the maximum quality tested. At the higher heat fluxes a nucleate boiling controlled region was observed at low quality, with h equal to the value at the same heat flux as observed with an isolated tube in a pool, followed by a rise in h at higher quality. The results were compared with the work of other researchers. Heat transfer coefficients for q ≥ 40 kW m –2 were predicted to an average r.m.s. deviation of 7%, using the asymptotic flow boiling model. However, the sensitivity of h to change of quality and flow rate predicted was much lower than measured and in some cases exhibited opposite trends.