Condensation of Azeotropic and Nonazeotropic Binary Vapor Mixtures

Hijikata, Kunio; Himeno, Nobuhiro

doi:10.1615/annualrevheattransfer.v3.40

Cited by 6 publications

(4 citation statements)

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“…At the very high temperatures near the heater, the unevenness of the wall surface and vapor-liquid interface results in large spatial and temporal perturbations to the film thickness of the kind discussed by Hijikata et al [27,29]. The high temperature gradients near the heater drive the condensed liquid in the interfacial region down the axis of the heat pipe and toward the corners.…”

Section: Resultsmentioning

confidence: 98%

“…The origins of flooding stem from observations of condensation on subcooled surfaces by Hijikata and Himeno [27] and meniscus evaporation on superheated surfaces by Argade et al [28]. The former found that certain binary vapor mixtures would condense in the form of droplets or streaks even though the two liquids are completely miscible and the vapors of the pure fluids should undergo film-wise condensation.…”

Section: Introductionmentioning

confidence: 99%

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Condensation on Highly Superheated Surfaces: Unstable Thin Films in a Wickless Heat Pipe

et al. 2017

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A wickless heat pipe was operated on the International Space Station to provide a better understanding of how the microgravity environment might alter the physical and interfacial forces driving evaporation and condensation. Traditional heat pipes are divided into three zones: evaporation at the heated end, condensation at the cooled end, and intermediate/adiabatic in between. The microgravity experiments reported herein show the situation may be dramatically more complicated. Beyond a threshold heat input, there was a transition from evaporation at the heated end to large-scale condensation, even as surface temperatures exceeded the boiling point by 160 K. The hotter the surface, the more vapor was condensed onto it. The condensation process at the heated end is initiated by thickness and temperature disturbances in the thin liquid film that wet the solid surface. Those disturbances effectively leave the vapor "superheated" in that region. Condensation is amplified and sustained by the high Marangoni stresses that exist near the heater and that drive liquid to cooler regions of the device.

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Section: Resultsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Condensation on Highly Superheated Surfaces: Unstable Thin Films in a Wickless Heat Pipe

et al. 2017

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“…Studies covering the condensation of zeotropic mixtures are essentially confined to flat plates and smooth tubes. Hijikata and Himeno [13] conducted experiments using horizontal finned tubes during condensation of the binary mixture (90% R113+ 10% R114) and they found that the tube with high fins (3 mm) is better than the one with small fins (0.8 mm), contrary to the condensation of pure fluids. Honda et al [14] conducted experiments during condensation of a downward-flowing zeotropic mixture HFC123/HFC134a (about 9% HFC134a at the test section inlet), on a 13 Â 15 (columns Â rows) staggered bundle of horizontal low finned tubes.…”

Section: Fluid Mixture Casementioning

confidence: 99%

Experimental study and modelling of heat transfer during condensation of pure fluid and binary mixture on a bundle of horizontal finned tubes

Belghazi

Bontemps

Marvillet

2003

International Journal of Refrigeration

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An experimental investigation was conducted to measure the local heat transfer coefficient for each row in a trapezoidal finned horizontal tube bundle during condensation of both pure fluid (HFC 134a) and several compositions of the non-azeotropic binary mixture HFC 23/HFC 134a. The test section is a 13Â3 (rows Â columns) tube bundle and the heat transfer coefficient is measured using the modified Wilson plot method. The inlet vapour temperature is fixed at 40 C and the water flow rate in each active row ranges from 170 to 600 l/h. The test series cover five different finned tubes all commercially available, K11 (11 fins/inch), K19 (19 fins/inch), K26 (26 fins/inch), K32 (32 fins/inch), K40 (40 fins/inch) and their performances were compared. The experimental results were checked against available models predicting the heat transfer coefficient during condensation of pure fluids on banks of finned tubes. Modelling of heat exchange during condensation of binary mixtures on bundles of finned tubes based on the curve condensation model is presented.

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“…Studies covering the condensation of zeotropic mixtures are essentially confined to flat plates and smooth tubes. Hijikata and Himemo [7] conducted experiments using horizontal finned tubes during condensation of the binary mixture (90% R113 + 10% R114), and they found that the tube with high fins (3 mm) is better than the one with small fins (0.8 mm). Honda et al [8] conducted experiments during condensation of a downward-flowing zeotropic mixture HFC123/HFC134a (about 9% HFC134a at the test section inlet), on a 13 × 15 (columns × rows) staggered bundle of horizontal low finned tubes.…”

Section: Introductionmentioning

confidence: 99%

Filmwise condensation of a pure fluid and a binary mixture in a bundle of enhanced surface tubes

Belghazi

Bontemps

Marvillet

2002

International Journal of Thermal Sciences

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An experimental study has been carried out to investigate the characteristics of condensation in a bundle of horizontal tubes. These tubes have different types of external surfaces: smooth surface (1D), low trapezoidal fins with several fin pitches (2D) and specific fins (3D, C+ tube). The used fluids are either pure refrigerant (HFC 134a) or binary mixture of refrigerants (HFC 134a/HFC23). For the pure fluid and a single tube, the influence of fin spacing has been studied (11, 19, 26, 32 and 40 fins/inch) and a comparison has been made with the Gewa C+ tube. The results were analysed with the Beatty and Katz theory and compared to a specific model, taking into account both gravity and surface tension effects, developed for the Gewa C+ tube. For the bundle and for a pure fluid, the inundation of the lowest tubes has a strong effect on the Gewa C+ tubes performances contrary to the finned tubes. For the mixture the heat transfer coefficient decreases dramatically especially for Gewa C+ tube.

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Condensation of Azeotropic and Nonazeotropic Binary Vapor Mixtures

Cited by 6 publications

References 0 publications

Condensation on Highly Superheated Surfaces: Unstable Thin Films in a Wickless Heat Pipe

Condensation on Highly Superheated Surfaces: Unstable Thin Films in a Wickless Heat Pipe

Experimental study and modelling of heat transfer during condensation of pure fluid and binary mixture on a bundle of horizontal finned tubes

Filmwise condensation of a pure fluid and a binary mixture in a bundle of enhanced surface tubes

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