Condensation heat transfer on single horizontal smooth and finned tubes and tube bundles for R134a and propane

Gebauer, Thomas; Al-Badri, Alaa R.; Gotterbarm, Achim; Hajal, Jean El; Leipertz, Alfred; Fröba, Andreas P.

doi:10.1016/j.ijheatmasstransfer.2012.09.049

Cited by 52 publications

(11 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…They provide a very good prediction only for fluids and fin shapes contained in the data base used. Numerical models using Navier-Stokes equations together with the heat balance equation [6,7], not only predict the heat transfer but also the behavior of condensate film on the finned surface. Unfortunately, they require a very detailed description of the fin profile and time consumption of the calculation is very high.…”

Section: Introductionmentioning

confidence: 99%

Experimental investigation of force balance at vapour condensation on a cylindrical fin

Glushchuk

Minetti

Machrafi

et al. 2017

International Journal of Heat and Mass Transfer

View full text Add to dashboard Cite

Abstract:Experimental investigation of vapour condensation on single cylindrical fin has been carried out under various gravity conditions: 1g0, 1.8g0 and 0.05g0. For the first time, a balance of forces acting on the condensate flow is analyzed. The fin surface is divided in seven areas, each one being characterized by the main force acting on the liquid motion: gravitational vs surfacetension pressure gradient. The magnitude of the areas does not depend on the gravity level. This confirms the correctness of the fin surface segmentation, as used by various authors, to simplify the condensation modelling. It has been shown that the most intensive vapour condensation takes place in the areas, where the surface-tension pressure gradient is higher than the gravity force. Analysis of the heat load shows that each region affected by STPG provides 10-15 % of the total heat load, a contribution that is not negligible and should be taken into account. In case of low gravity, the most intensive condensation takes place at the corner of the fin tip, where the curvature gradient is maximum, and on its cylindrical part. The heat loads in these regions are comparable.

show abstract

Section: Introductionmentioning

confidence: 99%

Experimental investigation of force balance at vapour condensation on a cylindrical fin

Glushchuk

Minetti

Machrafi

et al. 2017

International Journal of Heat and Mass Transfer

View full text Add to dashboard Cite

show abstract

“…Ein Modell, das die Änderung des äußeren Wärmeübergangskoeffizienten bei Rippenrohren in Abhängigkeit der Rohrreihe beschreibt, wurde in der Literatur nicht gefunden. In den Veröffentlichungen zur Kondensation an Rippenrohrbündeln lässt sich aus den Messwerten ablesen, dass die Änderung des äußeren Wärmeübergangskoeffizienten von Kältemitteln mit steigender Rohrreihennummer kleiner ist im Vergleich zu den Änderungen an einem Glattrohrbündel 17, 18.…”

Section: Theoretische Grundlagenunclassified

Untersuchung der Kondensation von Reinstoffen an einem horizontalen berippten Rohrbündel

Büchner

Reif

Rehfeldt

et al. 2014

Chemie Ingenieur Technik

View full text Add to dashboard Cite

Bei der Kondensation an niedrig und eng berippten Rohren ist der äußere Wärmeübergangskoeffizient deutlich höher als bei Glattrohren. Um eine Auslegungsgrundlage für Rohrbündel mit diesen Rohren zu schaffen, wird der globale äußere Wärmeübergangskoeffizient bei der Kondensation von Reinstoffen (iso-Propanol, n-Pentan, iso-Oktan) an einem Rohrbündel aus drei GEWA-K30 Rohren aus Baustahl vermessen. Es zeigt sich, dass die Inundation, im Gegensatz zu Glattrohren, bei Rippenrohren keinen erkennbaren Einfluss auf den äußeren Wärmeübergangskoeffizienten der untersuchten drei Rohrreihen hat. Examination of the Condensation of Pure Substances on a Horizontal Low-Finned Tube BundleThe heat transfer coefficient for condensation on low-finned tubes is significantly higher than for smooth tubes. In order to create a design basis for heat exchangers with a bundle of these tubes, the global outer heat transfer coefficient for condensation of pure substances (iso-propanol, n-pentane, iso-octane) is measured on a tube bundle of three GEWA-K30 tubes made of steel. With these experiments, it is shown that inundation has, contrarily to smooth tubes, no influence on the outer heat transfer coefficient for low finned tubes for the here measured first three rows.

show abstract

“…Gebauer et al studied the condensation heat transfer on single horizontal smooth and finned tubes and tube bundles for R134a and propane. Raja et al conducted an experimental study under varied heat flux test conditions on in‐tube flow boiling heat transfer of a R134a/R290/R600a refrigerant mixture.…”

Section: Introductionmentioning

confidence: 99%

Performance study on the evaporation and pressure drop of low‐temperature refrigerant blends in porous media

Tarawneh

2019

Heat Trans. Asian Res.

View full text Add to dashboard Cite

An experimental investigation on the performance of different low‐temperature refrigerant blends is presented in this work. Five different low‐temperature refrigerant blends are put on display to replace the R22 refrigerant, which has a high ozone depletion potential. These five blends are R404A, R407C, R410A, R417A, and R422A. Different performance studies have been performed on these alternative refrigerants to replace R22. A comparative experimental performance study is performed during the evaporation of these refrigerant blends in porous media. A porous metallic heat transfer medium is used with different porosities (40%, 43%, and 45%) in the evaporator during the test experiments. The evaporator superheat and the condenser subcool are maintained constant throughout the experiments at 8°C (±0.5°C) and 6°C (±0.5°C), respectively. The condensing temperature is kept constant at 38.5°C, and the mean evaporating temperatures were selected to be from −33 to −18°C. The effect of the above‐mentioned given operating conditions on the compressor discharge temperature, evaporation pressure drop, evaporation capacity, and coefficient of performance of these five low‐temperature refrigerant blends has been analyzed for different porosities. This experimental study showed that the refrigerant R422A can give a similar or greater performance to R22 and R404A with a global warming effect and zero ozone depleting potential.

show abstract

Condensation heat transfer on single horizontal smooth and finned tubes and tube bundles for R134a and propane

Cited by 52 publications

References 15 publications

Experimental investigation of force balance at vapour condensation on a cylindrical fin

Experimental investigation of force balance at vapour condensation on a cylindrical fin

Untersuchung der Kondensation von Reinstoffen an einem horizontalen berippten Rohrbündel

Performance study on the evaporation and pressure drop of low‐temperature refrigerant blends in porous media

Contact Info

Product

Resources

About