Impact de la morphologie du givre sur la performance thermohydraulique d’évaporateurs tubulaires à ailettes alimentés par ventilateur.

Effect of frost morphology on the thermal-hydraulic performance of fan-supplied tube-fin evaporators.

Auteurs : DA SILVA D. L., MELO C., HERMES C. J. L.

Type d'article : Article

Résumé

In refrigeration applications, frost build-up on the evaporator surfaces depletes the thermal-hydraulic performance due to an increase in the thermal resistance and the blockage of the air flow. These negative effects depend not only on the total amount of frost, but also on the frost morphology that affects the density and, therefore, the thermal conductivity of the frost layer. In this paper, the studies of frost accretion on fan-supplied tube-fin evaporators carried out in previous works are advanced to investigate the effects of the frost morphology on the thermal-hydraulic performance of fan-supplied evaporators. A visual inspection of the frost deposition was carried out to characterize the frost morphologies under different operating conditions. Moreover, a mathematical model was used to figure out how the operating conditions and the geometric parameters affect the cooling capacity and the pressure drop. The visualization confirmed that the operating conditions have a strong effect on the in-situ frost morphology. In addition, the numerical results not only illustrate the impact of the frost morphology on the evaporator performance, but also point out that the number of defrost operations may be reduced if a proper heat exchanger design is adopted.

Détails

  • Titre original : Effect of frost morphology on the thermal-hydraulic performance of fan-supplied tube-fin evaporators.
  • Identifiant de la fiche : 30020939
  • Langues : Anglais
  • Source : Applied Thermal Engineering - vol. 111
  • Date d'édition : 25/01/2017
  • DOI : http://dx.doi.org/10.1016/j.applthermaleng.2016.09.165

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