Comparaison de modèles numériques unidimensionnels et bidimensionnels pour identifier les performances du côté air d'un évaporateur à mini-canaux sous déshumidification.

Comparison of one-dimensional and two-dimensional numerical models for air-side performance of a minichannel evaporator under dehumidification.

Résumé

This paper presents a comparative study between two different numerical models to predict the air-side performance of minichannel evaporators under different dehumidifying conditions, and at presence of a temperature difference between tubes (superheating).The first model, referred to as Fin2D-W, discretizes the evaporator fins, tubes, and air flow into a two-dimensional scheme. This scheme takes into account the partial dehumidification scenarios, tube-to-tube heat conduction, and non-uniform air properties in both longitudinal and transverse directions. The second one, Fin1D-MB, is based on the Fin2D-W model; however, the fundamental one-dimensional fin theory is adopted to reduce the complexity of fin/air discretization. This, in turn, substantially saves the computational cost. But to precisely capture the actual fin condition, the fin theory is coupled with the technique of movable boundaries between wet and dry portions along the fin height. The results showed a good agreement between the two models in predicting the actual dehumidifying condition of the fin. Despite this agreement, notable deviations in the heat transfer results were encountered, especially in the region of partially wet fin. The main source of these deviations is the implicit assumption of uniform air temperature and humidity ratio along the fin height, which is usually used by the fin theory. This assumption makes the Fin1D-MB model not able to capture the air temperature and humidity ratio gradients near the evaporator tubes, unlike the Fin2D-W model.

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Pages : 7

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  • Prix public

    20 €

  • Prix membre*

    15 €

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Détails

  • Titre original : Comparison of one-dimensional and two-dimensional numerical models for air-side performance of a minichannel evaporator under dehumidification.
  • Identifiant de la fiche : 30018020
  • Langues : Anglais
  • Source : CYTEF 2016. VIII Congreso Ibérico y VI Congreso Iberoamericano de las Ciencias y Técnicas del Frío, Coimbra-Portugal, 3-6 mayo, 2016.
  • Date d'édition : 03/05/2016

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