Condensation heat transfer in smooth inclined tubes for R134a at different saturation temperatures

Meyer, Josua P.; Dirker, Jaco; Adelaja, Adekunle O.

doi:10.1016/j.ijheatmasstransfer.2013.11.038

Cited by 80 publications

(58 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The experimental system (Figure 1) was inherited from past research work in which detailed descriptions and explanations have been provided (Adelaja et al, 2014a(Adelaja et al, , 2014bCanière et al, 2007;Lips and Meyer, 2012a, 2012b, 2012cMeyer et al, 2014;Suliman et al, 2009;Van Rooyen et al, 2010). Therefore, only a brief overview will be provided in this section.…”

Section: Experimental Set-upmentioning

confidence: 99%

“…The inner tube was constructed from an 8.38 mm inner diameter (0.6 ± 0.002 mm wall thickness) smooth, hard-drawn copper tube inside an outer tube from 15.9 mm inner diameter smooth, hard-drawn copper tube. This tube diameter was selected for this study as it was used in several previous studies (Adelaja et al, 2014a(Adelaja et al, , 2014bMeyer, 2012b, 2012c;Meyer et al, 2014) and therefore better comparisons are possible.…”

Section: Experimental Set-upmentioning

confidence: 99%

“…This length was selected to ensure that the results can be compared to previous studies (Adelaja et al, 2014a(Adelaja et al, , 2014bMeyer, 2012b, 2012c;Meyer et al, 2014) and to ensure that experiments could be conducted at a full range of inclination angles from vertical downward to vertical upward in a laboratory with physical height limitations. The entire test section was insulated with 60 mm of insulation with a thermal conductivity of 0.041 W/m.K to minimise heat losses to the ambient air.…”

Section: Experimental Set-upmentioning

confidence: 99%

“…100-200 kg/m 2 .s), the heat transfer coefficients were observed to exhibit a maximum in the region of -30ᵒ to -15ᵒ (downward flow) due to gravity thinning of the stratified liquid layer (Meyer et al, 2014), which led to less thermal resistance. The heat transfer coefficients were observed to reduce with increased saturation temperature for all inclination angles and mass fluxes.…”

Section: Introductionmentioning

confidence: 99%

“…These phases are directly related to the void fraction and a considerable number of measurements have been taken to relate the void fraction to heat transfer and pressure drop equations during condensation (Adelaja et al, 2014a(Adelaja et al, , 2014bMeyer et al, 2014). However, no work has been done to determine the void fraction and its influence on heat transfer coefficients during condensation in inclined tubes.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

The influence of inclination angle on void fraction and heat transfer during condensation inside a smooth tube

Olivier

Meyer

Paepe

et al. 2016

International Journal of Multiphase Flow

Self Cite

View full text Add to dashboard Cite

Most work in literature on condensation in tubes has been done for smooth tubes in the horizontal and vertical configurations. Recent experimental works with condensation at different inclination angles showed that the heat transfer characteristics were a function of inclination angle. These works were limited to heat transfer and pressure drop measurements with visual observations. However, no work has been done on measuring the void fractions during condensation at different inclination angles. The purpose of this study was to measure void fractions and heat transfer coefficients during condensation for tube inclinations ranging from vertical downwards (-90ᵒ) to vertical upwards (90ᵒ) at a saturation temperature of 40 ᵒC. Measurements were taken in an experimental set-up in which condensation occurred on the inside of a test section. The test section was a circular tube with an inner diameter of 8.38 mm and a heat transfer length of 1.488. The refrigerant used was R134a, and the void fractions were measured using two capacitive void fraction sensors. Mass fluxes ranging from 100 -400 kg/m 2 .s and vapour qualities ranging from 10 -90% were considered. Heat transfer coefficients were also compared with void fractions. It was found that at combinations of low mass fluxes and vapour qualities, void fraction and heat transfer were significantly affected by changes in inclination angle. Generally, void fractions and heat transfer coefficients increased with downward inclination angles with an optimum angle between -10ᵒ and -30ᵒ (downward flow). At some intermediate mass flux and vapour quality conditions, the void fraction and heat transfer coefficients were observed to be independent of the inclination angle despite changes in the prevailing flow patterns.2

show abstract

Section: Experimental Set-upmentioning

confidence: 99%

Section: Experimental Set-upmentioning

confidence: 99%

Section: Experimental Set-upmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

The influence of inclination angle on void fraction and heat transfer during condensation inside a smooth tube

Olivier

Meyer

Paepe

et al. 2016

International Journal of Multiphase Flow

Self Cite

View full text Add to dashboard Cite

show abstract

Heat Transfer During Condensation

2021

Two‐Phase Heat Transfer

View full text Add to dashboard Cite

Numerical investigation on entropy generation in the dropwise condensation inside an inclined pipe

2021

View full text Add to dashboard Cite

In this paper, the entropy generation analysis in dropwise condensation in an inclined pipe is carried out. As the vapor passes through the inclined pipe, the flow of the droplets occurs due to the interfacial shear and gravity. Three distinct zones considered in the numerical study include the saturated vapor flowing in the axial direction, saturated liquid traveling through the bottom of the pipe, and the condensate droplet flowing on the inner side of the pipe wall. With the aim of achieving optimal geometrical conditions of the pipe and flow, the entropy generation was calculated for various cases. The results show that the minimum entropy generation of 0.0754 W•K −1 occurs in a configuration with a diameter of 9.5 mm and an inclination angle of 1°. Finally, the Bejan number, irreversibility distribution ratio, and variation according to the flow conditions were presented.

show abstract

Condensation heat transfer in smooth inclined tubes for R134a at different saturation temperatures

Abstract: This paper presents the effects of saturation temperature and inclination angle on convective heat transfer during condensation of R134a in an inclined smooth tube of inner diameter of 8.38 mm.Experiments were conducted for inclination angles ranging from -90° (vertical downwards) to

Cited by 80 publications

References 29 publications

The influence of inclination angle on void fraction and heat transfer during condensation inside a smooth tube

The influence of inclination angle on void fraction and heat transfer during condensation inside a smooth tube

Heat Transfer During Condensation

Numerical investigation on entropy generation in the dropwise condensation inside an inclined pipe

Contact Info

Product

Resources

About