Predicting heat transfer in long, R-134a filled thermosyphons

M.H.M. Grooten, C.W.M. Geld, van der

    Onderzoeksoutput: Bijdrage aan tijdschriftTijdschriftartikelAcademicpeer review

    11 Citaten (Scopus)


    When traditional air-to-air cooling is too voluminous, heat exchangers with long thermosyphons offer a good alternative. Experiments with a single thermosyphon with a large length-to-diameter ratio (188) and filled with R-134a are presented and analyzed. Saturation temperatures, filling ratios, and angles of inclination have been varied in wide ranges. A higher sensitivity of evaporation heat transfer coefficients on reduced pressure than in previous work has been found. Measurements revealed the effect of pressure or the saturation temperature on condensation heat transfer. The condensate film Reynolds number that marks a transition from one condensation heat transfer regime to another is found to depend on pressure. This effect was not accounted for by correlations from the literature. New correlations are presented to predict condensation and evaporation heat transfer rates.
    Originele taal-2Engels
    Pagina's (van-tot)051501-1/9
    Aantal pagina's9
    TijdschriftJournal of Heat Transfer
    Nummer van het tijdschrift5
    StatusGepubliceerd - 2008


    Duik in de onderzoeksthema's van 'Predicting heat transfer in long, R-134a filled thermosyphons'. Samen vormen ze een unieke vingerafdruk.

    Citeer dit