Flow Boiling Heat Transfer in Vertical Tubes Correlated by an Asymptotic Model
TL;DR: In this article, a new model, based on asymptotic addition of the two boiling components, is introduced It follows the established principles of flow boiling and converges correctly to the extremes of all parameters Tested on the University of Karlsruhe data bank containing over 13,000 data points in vertical flow boiling, results superior to previous correlations are demonstrated
Abstract: In flow boiling, the nucleate and convective components are superimposed by a very complex mechanism, which so far is not well understood Two models exist in present literature, one by Chen [3] (1963), using addition of the two components with a suppression factor; and one by Shah [8] (1976), using the “greater of” the two components with a Bo-number simplified correlation Neither model presents a satisfactory solution, as attested by the numerous methods published since then, mostly based only on regression analysis-derived correction factors In this article a new model, based on asymptotic addition of the two boiling components, is introduced It follows the established principles of flow boiling and converges correctly to the extremes of all parameters Tested on the University of Karlsruhe data bank containing over 13,000 data points in vertical flow boiling, results superior to previous correlations are demonstrated
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TL;DR: In this paper, a review examines recent advances made in predicting boiling heat fluxes, including some key results from the past, including nucleate boiling, maximum heat flux, transition boiling, and film boiling.
Abstract: ▪ Abstract This review examines recent advances made in predicting boiling heat fluxes, including some key results from the past. The topics covered are nucleate boiling, maximum heat flux, transition boiling, and film boiling. The review focuses on pool boiling of pure liquids, but flow boiling is also discussed briefly.
575 citations
TL;DR: In this paper, the authors measured and predicted saturated flow boiling heat transfer in a water-cooled micro-channel heat sink and found that the dominant heat transfer mechanism is forced convective boiling corresponding to annular flow.
556 citations
Cites background from "Flow Boiling Heat Transfer in Verti..."
...6 Steiner and Taborek [34] (1992) htp 1⁄4 Nu3 Nu4 1⁄2ðEhspÞ 3 þ ðShnbÞ3 1=3 46....
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...[8,30]; (b) Shah [9,31]; (c) Gungor and Winterton [32]; (d) Kandlikar [15]; (e) Liu and Winterton [33] and (f) Steiner and Taborek [34]....
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TL;DR: In this paper, a review of recent research on boiling in micro-channels is presented, which addresses the topics of macroscale versus micro-scale heat transfer, two-phase flow regimes, flow boiling heat transfer results for micro-channel, heat transfer mechanisms in microchannels and flow boiling models for micro channels.
553 citations
TL;DR: In this paper, a heat transfer model for intube flow boiling in horizontal plain tubes is proposed that incorporates the effects of local two-phase flow patterns, flow stratification and partial dryout in annular flow.
Abstract: A new heat transfer model for intube flow boiling in horizontal plain tubes is proposed that incorporates the effects of local two-phase flow patterns, flow stratification and partial dryout in annular flow. Significantly, the local peak in the heat transfer coefficient versus vapor quality can now be determined from the prediction of the location of onset of partial dryout in annular flow. The new method accurately predicts a large, new database of flow boiling data, and is perticularly better than existing mehods at high vapor qualities (x > 85%) and for stratified types of flows.
376 citations
TL;DR: In this article, the authors investigated the heat transfer coefficients for Freon R11 and HCFC123 in a smooth copper tube with an inner diameter of 1.95 mm and found that the coefficients are a strong function of the heat flux and the system pressure, while the effects of mass flux and vapour quality are very small in the range examined.
304 citations
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TL;DR: In this article, a new general correlation for forced convection boiling has been developed with the aid of a large data bank consisting of over 4300 data points for water, refrigerants and ethylene glycol, covering seven fluids and 28 authors.
1,050 citations
TL;DR: In this article, a simple correlation was developed earlier by Kandlikar (1983) for predicting saturated flow boiling heat transfer coefficients inside horizontal and vertical tubes, which was further refined by expanding the data base to 5,246 data points from 24 experimental investigations with ten fluids.
Abstract: A simple correlation was developed earlier by Kandlikar (1983) for predicting saturated flow boiling heat transfer coefficients inside horizontal and vertical tubes. It was based on a model utilizing the contributions due to nucleate boiling and convective mechanisms. It incorporated a fluid-dependent parameter F{sub fl} in the nucleate boiling term. The predictive ability of the correlation for different refrigerants was confirmed by comparing it with the recent data on R-113 by Jensen and Bensler (1986) and Khanpara et al. (1986). In the present work, the earlier correlation is further refined by expanding the data base to 5,246 data points from 24 experimental investigations with ten fluids. The proposed correlation gives a mean deviation of 15.9 percent with water data, and 18.8 percent with all refrigerant data, and it also predicts the correct h{sub TP} versus x trend as verified with water and R-113 data yielded the lowest mean deviations among correlations tested. The proposed correlation can be extended to other fluids by evaluating the fluid-dependent parameter F{sub fl} for that fluid from its flow boiling or pool boiling data.
1,003 citations