Intensive literature review of condensation inside smooth and enhanced tubes

Dalkılıç, Ahmet Selim; Wongwises, Somchai

doi:10.1016/j.ijheatmasstransfer.2009.01.011

Cited by 149 publications

(49 citation statements)

References 109 publications

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“…Convective condensation in horizontal smooth and enhanced tubes [1][2][3][4] has been widely studied and reviewed in the past. However, Lips and Meyer [5] showed in a previous paper that only a few studies deal with condensation in inclined tubes.…”

Section: Introductionmentioning

confidence: 99%

Experimental study of convective condensation in an inclined smooth tube. Part I: Inclination effect on flow pattern and heat transfer coefficient

Lips

Meyer

2012

International Journal of Heat and Mass Transfer

112

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An experimental study of convective condensation of R134a in an 8.38 mm inner diameter smooth tube in inclined orientations is presented. This article, being the first of a two-part paper (the second part concentrates on the pressure drops and void fractions), presents flow patterns and heat transfer coefficients during condensation for different mass fluxes and vapour qualities for the whole range of inclination angles (from vertical downwards to vertical upwards). The results were compared with three flow pattern maps available in literature. It was found that for low mass fluxes and/or low vapour qualities, the flow pattern is strongly dependent on the inclination angle whereas it remains annular for high mass fluxes and high vapour qualities, whatever the tube orientation. The models of flow pattern maps available in the literature did not predict the experimental data well. In the inclination-dependent zone, experiments showed that there is an optimum inclination angle that leads to the highest heat transfer coefficient for downward flow. The heat transfer coefficient is strongly affected by the liquid and vapour distributions and especially by the liquid thickness at the bottom of the tube for stratified flows. Thus developing a mechanistic model of flow pattern maps is the first step in achieving a predictive tool for the heat transfer coefficient in convective condensation in inclined tubes.

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Section: Introductionmentioning

confidence: 99%

Experimental study of convective condensation in an inclined smooth tube. Part I: Inclination effect on flow pattern and heat transfer coefficient

Lips

Meyer

2012

International Journal of Heat and Mass Transfer

112

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“…Over the years, many studies have been conducted on the modeling of void fractions, and can be divided into several groups Dalkilic and Wongwises [24]: slip ratio void fraction models [2,[25][26][27][28][29][30][31][32][33][34][35], Lockhart and Martinelli parameter based void fraction models [36][37][38][39][40][41][42][43][44], flow regime based void fraction models [45][46][47], ka H parameter based void fractions [48][49][50], and general void fraction models [51][52][53][54][55][56][57].…”

Section: Void Fractionmentioning

confidence: 99%

Condensation pressure drop of R22, R134a and R410A in a single circular microtube

Son

2012

Heat Mass Transfer

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The condensation pressure drop characteristics for pure refrigerants R22, R134a, and a binary refrigerant mixture R410A without lubricating oil in a single circular microtube were investigated experimentally. The test section consists of 1,220 mm length with horizontal copper tube of 3.38 mm outer diameter and 1.77 mm inner diameter. The experiments were conducted at refrigerant mass flux of 450-1,050 kg/m 2 s, and saturation temperature of 40°C. The main experimental results showed that the condensation pressure drop of R134a is higher than that of R22 and R410A for the same mass flux. The experimental data were compared against 14 two-phase pressure drop correlations. A new pressure drop model that is based on a superposition model for refrigerants condensing in the single circular tube is presented.

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“…The phenomenon of condensation in heat exchangers can occur on a flat surface (in plate condensers), on the external surface of the channels (e.g., in shell and tube condensers) or during the flow of the refrigerant inside the channels (e.g., in air-cooled condensers with external enhancement) [1,9,16]. When refining the problem to the condensation of the refrige-rant in a flow inside channels, one needs to pay attention to the shape of the cross-section [3,6,7] (in the majority of cases, pipe channels with a circular cross-section are used), the hydraulic diameter [5,8,14] and the channel length (i.e. a straight segment or a coil pipe), and the orientation of the channel axis in space (horizontal, vertical, inclined) [7,8,10,13].…”

Section: Introductionmentioning

confidence: 99%

Effect of the inclination angle of the condenser on the heat transfer coefficient value – experimental study

Charun¹,

Czapp²,

Czapp³

et al. 2016

ZN PRz Mechanika

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Considering problem of the condensation of the refrigerant in a flow inside channel, the attention should be paid to the shape of its cross-section, the hydraulic diameter, the channel length as well as the orientation of the channel axis in space (horizontal, vertical, inclined). This paper presents an experimental study concerning the effect of the inclination angle of the condenser with a single coil pipe on the heat transfer coefficient value. In the laboratory test the aircooled condenser with R410A refrigerant has been investigated. The results of test have proved that during the condensation in a single inclined pipe channel there is a specific value of the inclination angle at which the highest value of the heat transfer coefficient is obtained.

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Intensive literature review of condensation inside smooth and enhanced tubes

Cited by 149 publications

References 109 publications

Experimental study of convective condensation in an inclined smooth tube. Part I: Inclination effect on flow pattern and heat transfer coefficient

Experimental study of convective condensation in an inclined smooth tube. Part I: Inclination effect on flow pattern and heat transfer coefficient

Condensation pressure drop of R22, R134a and R410A in a single circular microtube

Effect of the inclination angle of the condenser on the heat transfer coefficient value – experimental study

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