Simple heat transfer model for laminar film condensation in a vertical tube

Kim, Dong Eok; Yang, Ki Hoon; Hwang, Kyung Won; Ha, Young Ho; Kim, Moo Hwan

doi:10.1016/j.nucengdes.2011.04.041

Cited by 10 publications

(4 citation statements)

References 8 publications

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“…In most three-fluid models, the effect of liquid film surface ripple waves has been neglected because of its rather small influence on the entrained droplets flow. 3 However, the new modified three-fluid model is a liquid film-entrained droplets coupling model, which means that the film-droplets momentum transfer (the so-called friction stress) is also considered. Previous experimental studies have shown that the droplet diameter is of 10 À4 m order in annular flow.…”

Section: (D) Condensation and Evaporation Ratesmentioning

confidence: 99%

“…droplets entrainment and deposition, are taken into account by source terms of the mass, momentum, and energy balance equations. Wall-liquid film shear stress The momentum transfer at the liquid film inside condensing vertical pipes can occur for both laminar and turbulent liquid and gas flows. 3 Gas core-entrained droplets and liquid film–gas core shear stresses The three-fluid models consider the effects of frictional shear stresses (as a result of friction between the gas core and the entrained droplets and between the gas core and liquid film). Condensation and evaporation rates In order to calculate the condensation and evaporation rates, the non-equilibrium relaxation method 6 is used. Mean droplet diameter and mean liquid film thickness The equations governing the mass, momentum and energy transfer between the gas and liquid phases are simplified by using uniform-sized droplets and thin liquid film approximations. 4 …”

Section: Governing Equations and Closure Relationsmentioning

confidence: 99%

“…Wall-liquid film shear stress The momentum transfer at the liquid film inside condensing vertical pipes can occur for both laminar and turbulent liquid and gas flows. 3…”

Section: Governing Equations and Closure Relationsmentioning

confidence: 99%

“…The liquid film is coated by two types of waves, long-term large-scaled roll waves and temporary small-scaled ripple waves. 3 Being mostly sheared off from the interfacial wave peaks, the liquid droplets entrained from the liquid film are carried by the gas core. This type of flow configuration is found in various industrial procedures, such as the reactor core of a nuclear power plant, U-tubes in steam generators, and gasoil transportation inside long pipes.…”

Section: Introductionmentioning

confidence: 99%

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Influence of variation of pipe diameter on pressure drop predictions of the new modified three-fluid model inside condensing vertical pipes

Dalir

Saffari

2014

Proceedings of the Institution of Mechanical Engineers, Part E:

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When a loss of coolant accident occurs in the primary system of a water-cooled nuclear reactor, a large amount of steam is released into the reactor containment. Therefore, there is the possibility of over-pressurization of the reactor containment. In such a condition, the released steam is often condensed using a passive containment cooling system. This system consists of condensing vertical pipes with diameters of 30-50 mm. Thus, condensation inside vertical pipes with annular flow happens, which is usually analyzed using the three-fluid models. In the present work, the effect of variation of condensing vertical pipe diameter on pressure drop predictions in downward condensing annular flow of steam is studied using the new modified three-fluid model. In a new pipe diameter, D ¼ 0.03 m, the pressure drops are calculated using the new modified three-fluid model and the correlation of Stevanovic et al. for steam-liquid film interfacial friction coefficient and compared.

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Section: (D) Condensation and Evaporation Ratesmentioning

confidence: 99%

Section: Governing Equations and Closure Relationsmentioning

confidence: 99%

“…Wall-liquid film shear stress The momentum transfer at the liquid film inside condensing vertical pipes can occur for both laminar and turbulent liquid and gas flows. 3…”

Section: Governing Equations and Closure Relationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Influence of variation of pipe diameter on pressure drop predictions of the new modified three-fluid model inside condensing vertical pipes

Dalir

Saffari

2014

Proceedings of the Institution of Mechanical Engineers, Part E:

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Semi-mechanistic model for the interfacial velocity of gravity-driven laminar wavy film flow and its validation using infrared particle tracing velocimetry

Amidu

Kim

2018

Heat Mass Transfer

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Heat transfer coefficient: a review of measurement techniques

Moreira

Colmanetti

Tibiriçá

2019

J Braz. Soc. Mech. Sci. Eng.

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Heat transfer coefficient is a basic parameter used in the calculation of convective heat transfer problems. Due to the importance of the experimental measurements for the development of convective heat transfer, this review identifies, classifies and describes the experimental methods used for the measurement of heat transfer coefficient. The methods were classified into five major groups: (1) direct method, (2) transient method, (3) Wilson method, (4) heat/momentum/mass transfer analogy method and (5) boundary layer thickness method. Their applications, limitations and the reported accuracy were evaluated in the context of new developments in temperature and heat flux measurement techniques. Finally, this review provides criteria for the selection of the most suitable technique for measurements of heat transfer coefficient according to the aspects of spatial resolution, geometric scale, intrusiveness, fluid type, response time and accuracy. Keywords Heat transfer coefficient • Temperature • Heat flux • Convection • Experimental measurements List of symbols 1D One-dimensional 2D Two-dimensional A Surface area (m 2) A e Outer tube surface area (m 2) A i Inner tube surface area (m 2) A s Surface area (m 2) C e Thermal resistances outside the tube and the tube wall (K/W) (constant) C i Constant C f Fanning friction factor (-), C f = s V 2 ∕2 c Constant (-) c p Specific heat capacity (J/kg K) c p,i Specific heat capacity at constant pressure (J/ kg K) d Diameter (m) d e Outer tube diameter (m) d i Inner tube diameter (m) D m Mass diffusivity (m 2 /s) f Darcy friction factor (-), f = 4 ⋅ C f * Cristiano Bigonha Tibiriçá

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Simple heat transfer model for laminar film condensation in a vertical tube

Cited by 10 publications

References 8 publications

Influence of variation of pipe diameter on pressure drop predictions of the new modified three-fluid model inside condensing vertical pipes

Influence of variation of pipe diameter on pressure drop predictions of the new modified three-fluid model inside condensing vertical pipes

Semi-mechanistic model for the interfacial velocity of gravity-driven laminar wavy film flow and its validation using infrared particle tracing velocimetry

Heat transfer coefficient: a review of measurement techniques

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