Partager

Document IIF

Modélisation mathématique d'un processus évaporatif minimal pour le refroidissement d'immeubles.

Mathematical modelling of a low approach evaporative cooling process for space cooling in buildings.

Numéro : pap. n. 185

Auteurs : NASRABADI M., FINN D., COSTELLOE B.

Résumé

This paper describes a mathematical model of a low approach open evaporative cooling tower for the production of high temperature indirect cooling water (14-16°C) for use in building radiant cooling and displacement ventilation systems. There are several potential approaches to model evaporative cooling, including: the Poppe method, the Merkel method and the effectiveness-NTU (e-NTU) method. A common assumption, applied to the Merkel and e-NTU methods, is that the effect of change in tower water mass flow rate due to evaporation is ignored, which results in a simpler model with reduced computational requirements, but with somewhat decreased accuracy. In this paper, a new improved method, called the corrected e-NTU approach is proposed, where the water loss due to evaporation is taken into account. It is expected by this correction the results of improved e-NTU in the category of heat transfer will be more close to the results of more rigorous Poppe method. The current mathematical model is evaluated against experimental data reported for a number of open tower configurations, subject to different water temperature and ambient boundary conditions. It is shown that the discrepancies between the calculated and experimental tower outlet temperatures are to within ±0.35°C for a low temperature cooling water process (14-16°C), subject to temperate climate ambient conditions and ±0.85°C for a high temperature cooling water process (29-36°C), subject to continental climate ambient conditions. Considering the associated tower cooling loads, predicted results were found to be within a 6% root-mean-square difference compared to experimental data.

Documents disponibles

Format PDF

Pages : 8 p.

Disponible

  • Prix public

    20 €

  • Prix membre*

    Gratuit

* meilleur tarif applicable selon le type d'adhésion (voir le détail des avantages des adhésions individuelles et collectives)

Détails

  • Titre original : Mathematical modelling of a low approach evaporative cooling process for space cooling in buildings.
  • Identifiant de la fiche : 30004326
  • Langues : Anglais
  • Source : 10th IIR-Gustav Lorentzen Conference on Natural Working Fluids (GL2012). Proceedings. Delft, The Netherlands, June 25-27, 2012.
  • Date d'édition : 25/06/2012

Liens


Voir d'autres communications du même compte rendu (142)
Voir le compte rendu de la conférence

Indexation