000134119 001__ 134119
000134119 005__ 20180913055112.0
000134119 0247_ $$2doi$$a10.1016/j.ijheatmasstransfer.2008.12.001
000134119 02470 $$2ISI$$a000264350900010
000134119 037__ $$aARTICLE
000134119 245__ $$aAmmonia two-phase flow in a horizontal smooth tube: Flow pattern observations, diabatic and adiabatic frictional pressure drops and assessment of prediction methods
000134119 269__ $$a2009
000134119 260__ $$c2009
000134119 336__ $$aJournal Articles
000134119 520__ $$aThe present study illustrates new experimental two-phase flow pattern observations together with diabatic boiling and adiabatic two-phase frictional pressure drop results for ammonia (R7117) flowing inside a 14-mm internal diameter, smooth horizontal stainless steel tube. The flow pattern observations were made for mass velocities of 50, 100 and 160 kg s(-1) m(-2) and saturation temperatures of -14, -2 and 12 degrees C for vapor qualities ranging from 0.05 to 0.6. The flow patterns observed during the study included: stratified-wavy, slug-stratified-wavy, slug, intermittent and annular. For all the experimental conditions, the flow structure observations were compared against the predictions of the flow pattern map model of Wojtan et al. [L. Wojtan, T. Ursenbacher, J.R. Thome, Investigation of flow boiling in horizontal tubes: part I - a new diabatic two-phase How pattern map, Int. J. Heat Mass Transfer 48 (2005) 2955-2969] and showed very good correspondence. The frictional pressure drop measurements were obtained for vapor qualities from 0.05 to 0.6, saturation temperatures from -14 to 14 degrees C, mass velocities from 50 to 160 kg s(-1) m(-2) and heat fluxes from 12 to 25 kW m(-2). The experimental results show the traditional pressure drop trends: the frictional pressure drop increases with vapor quality and mass velocity. Moreover, the results also show that both diabatic and adiabatic frictional pressure drop values are similar, that is, the boiling process in itself does not affect the frictional pressure drop. The correlations of Friedel [L. Friedel, Improved friction drop correlations for horizontal and vertical two-phase pipe flow, in: European Two-Phase Flow Group Meeting, paper E2, Ispra, Italy, 1979], Lockhart and Martinelli [R.W. Lockhart, R.C. Martinelli, Proposed correlation of data for isothermal two-phase two-component in pipes, Chem. Eng. Process 45 (1949) 39-48] and Muller-Steinhagen and Heck [H. Muller-Steinhagen, K. Heck, A simple friction pressure correlation for two-phase flow in pipes, Chem. Eng. Process 20 (1986) 297-308] predicted only 54%, 52% and 60% of the experimental data within +/- 30%, respectively. The correlation of Gronnerud [R. Gronnerud, Investigation of liquid hold-up, flow-resistance and heat transfer in circulation type of evaporators, part iv: two-phase flow resistance in boiling refrigerans, in: Annexe 1972-1, Bull. de I'Inst. Froid, 1979] predicted 93% of the data and the flow pattern based method of Moreno Quiben and Thome [J. Moreno Quiben, J.R. Thome, Flow pattern based two-phase frictional pressure drop model for horizontal tubes. Part II: new phenomenological model, Int.J. Heat Fluid Flow 28 (2007) 1060-1072] predicted more than 97% of the experimental data within the same error band, while the latter method captures almost 89% of the data within +/- 20%. (C) 2008 Elsevier Ltd. All rights reserved.
000134119 6531_ $$aAmmonia
000134119 6531_ $$aR717
000134119 6531_ $$aExperimental
000134119 6531_ $$aFlow boiling
000134119 6531_ $$aFlow pattern observations
000134119 6531_ $$aDiabatic
000134119 6531_ $$aAdiabatic
000134119 6531_ $$aTwo-phase frictional pressure drop
000134119 6531_ $$aComparisons
000134119 6531_ $$aPrediction methods
000134119 6531_ $$aHeat-Transfer Model
000134119 6531_ $$aPart Ii
000134119 6531_ $$aVoid Fraction
000134119 6531_ $$aInterfacial Measurements
000134119 6531_ $$aPhenomenological Model
000134119 6531_ $$aStratified Types
000134119 6531_ $$aCo2 Evaporation
000134119 6531_ $$aMap
000134119 6531_ $$aPipe
000134119 6531_ $$aCondensation
000134119 700__ $$0243067$$ada Silva Lima, Ricardo J.$$g153015
000134119 700__ $$aQuibén, Jesús Moreno
000134119 700__ $$aKuhn, Cornel
000134119 700__ $$aBoyman, Tahsin
000134119 700__ $$0240577$$aThome, John Richard$$g108776
000134119 773__ $$j52$$q2273-2288$$tInternational Journal of Heat and Mass Transfer
000134119 909C0 $$0252128$$pLTCM$$xU10312
000134119 909CO $$ooai:infoscience.tind.io:134119$$pSTI$$particle
000134119 937__ $$aLTCM-ARTICLE-2009-001
000134119 973__ $$aEPFL$$rREVIEWED$$sPUBLISHED
000134119 980__ $$aARTICLE