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Photographic Study of Nucleate Pool Boiling on a Horizontal Surface

An experimental study and comparitive validation of macrolayer thickness in nucleate pool boiling for horizontal copper tube heater

A model of a boiling crisis of a liquid on the surface of a horizontal cylinder is proposed for the limiting case of high subcooling to the saturation temperature. For arbitrary subcooling, an interpolation equation is constructed, in which the relations for critical heat fluxes (CHFs) under boiling of saturated and highly subcooled liquids serve as asymptotics.

Subcooled-liquid boiling crisis on horizontal cylindrical heaters

A review of numerical investigation on pool boiling

This experimental project aims to describe the influencing factors in the vacuum boiling o f water in water vapour refrigeration systems Testing was conducted using a 2 kW three-stage steam je t ejector system, w ith barom etric condensers, as the compression device. Three direct-contact evaporators were used to investigate the boiling phenomena. These were : a through-flow evaporator where heal and mass transfer rates were established for boiling mechanisms at various positions within the evaporator; a vertical cylinder where small quantities o f water were subjected to rapid decompression and the effects measured, and a sim ple channel for photographic studies o f the process. Boiling in direct-contact water vapour systems is described herein The vacuum boiling proo ss was found to be controlled by a com bination o f the water surface temperature and the hydrostatic pressure gradient, these being governed by the water vapour flow geometry between the w ater surface and ejector suction and convective heat transfer below the boiling region. The contributions o f the various boiling regimes to the total heat transfer are discussed. Heat and mass transfer coefficients and their applicability to evaporator design are presented

Vacuum boiling of water in a steam jet refrigeration system

Introductory Remarks In Chapter 4 the basic gas–liquid two-phase flow regimes along with flow regime maps were reviewed. The discussion of flow regimes was limited to empirical methods applicable to commonly applied pipes and rod bundles. In this chapter mechanistic two-phase flow regime models will be discussed. Empirical flow regime models suffer from the lack of sound theoretical or phenomenological bases. Mechanistic methods, in contrast, rely on physically based models for each major regime transition process. These models are often simple and rather idealized. However, since they take into account the crucial phenomenological characteristics of each transition process, they can be applied to new parameter ranges with better confidence than purely empirical methods. Some important investigations where regime transition models for the entire flow regime map were considered include the works of Taitel and Dukler (1976), Taitel, Bornea, and Dukler (1980), Weisman and co-workers (1979, 1981), Mishima and Ishii (1984), and Barnea and co-workers (1986, 1987). The derivation of simple mechanistic regime transition models often involves insightful approximations and phenomenological interpretations. The review of the major elements of the successful models can thus be a useful learning experience. In this chapter only conventional flow passages (i.e., flow passages with) will be considered. There are important differences between commonly applied channels and mini- or microchannels with respect to the gas–liquid two-phase flow hydrodynamics. Two-phase flow regimes and conditions leading to regime transitions in mini- and microchannels will be discussed in Chapter 10.

Photographic Study of Nucleate Pool Boiling on a Horizontal Surface

Citations

An experimental study and comparitive validation of macrolayer thickness in nucleate pool boiling for horizontal copper tube heater

Subcooled-liquid boiling crisis on horizontal cylindrical heaters

A review of numerical investigation on pool boiling

Vacuum boiling of water in a steam jet refrigeration system

Two-Phase Flow Regimes – II

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