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

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 air-cooled 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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1. Bohdal T., Charun H., Czapp M.: Condensation of refrigerant in long coil pipes, Chłodnictwo Klimatyzacja, 46 (2011) 52-57.
2. Chung B.J., Kim S., Kim M.C.: Film condensation of flowing mixtures of steam and air on a inclined flat plate, Int. Commun. Heat Mass Transfer, 32 (2005)
   233-239.
3. Daikilic A.S., Wongwises S.: Intensive literature review of condensation inside smooth and enhanced tubes, Int. J. Heat Mass Transfer, 52 (2009) 3409-3426.
4. Fiedler S., Auracher H., Winkelmann D.: Effect of inclination on flooding and heat transfer during reflux condensation in a small diameter tube Int. Commun. Heat Mass Transfer, 29 (2002) 289-302.
5. Fiedler S., Auracher H.: Experimental and theoretical investigation of reflux condensation in an inclined small diameter tube Int. J. Heat Mass Transfer, 47 (2004) 4031-4043.
6. Hu H.P., Chen C.K.: Simplified approach of turbulent film condensation on an inclined elliptical tube, Int. J. Heat Mass Transfer, 49 (2006) 640-648.
7. Klahm T., Auracher H., Ziegler F.: Heat transfer during reflux condensation of an R134a/R123 mixture in vertical and inclined narrow tubular and rectangular channels, Int. J. Refrigeration, 33 (2010) 1319-1326.
8. Wen M. Y., Ho C. Y.: Condensation heat transfer and pressure drop characteristics of refrigerant R-290/R-600a-oil mixtures in serpentine small-diameter
   U-tubes, Applied Thermal Eng., 29 (2009) 2460-2467.
9. Madejski J.: Teoria wymiany ciepła, Wyd. Uczelniane Politechniki Szczecińskiej, Szczecin 1998.
10. Narain A., Guang Yu., Quingyu L.: Interfacial shear models and their required asymptotic form for annular/stratified film condensation flows in inclined channels and vertical pipes, Int. J. Heat Mass Transfer, 40 (1997) 3559-3575.
11. Petrik P.T., Dadonov P.V., Dvorovenko I.V., Bogomołov A.R.: Heat exchange in condensation of R227 coolant in inclined tubes placed in a granular bed, Int.
    J. Eng. Physics Thermophysics, 77 (2004) 758-761.
12. Schoenfeld P. D., Kroger D. G.: Flooding during reflux condensation of steam in an inclined elliptical tube, Proc. Int. Conf. Heat Exchangers for Sustainable
    Development, Lisbon 1998, pp. 107-115.
13. Shah M. M.: An improved and extended general correlation for heat transfer during condensation in plain tubes, HVAC&R Research, 15 (2009) 889-913.
14. Wang B. X., Du X. Z.: Study of laminar film - wise condensation for vapor flow in a inclined small/mini-diameter tube, Int. J. Heat Mass Transfer, 43 (2000) 1859-1868.
15. Wang J.C.Y., Ma Y.: Condensation heat transfer inside vertical and inclined thermosyphons, J. Heat Transfer, 113 (1991) 777-780.
16. Wiśniewski S., Wiśniewski T.S.: Wymiana ciepła, WNT, Warszawa 1997.