Optimisation d'un évaporateur pour une distribution d'air non homogène.

Evaporator optimization for non-uniform air distribution.

Résumé

This study demonstrates the performance improvements that can be achieved by accounting for the air flow distribution during the design phase of a heat exchanger. The heat exchanger used in this study was a two-slab, A-shaped finned-tube evaporator installed in a horizontal duct with a condensate collection pan and condensate droplet collection metal sheet. The installation configuration and attachments resulted in a large degree of air maldistribution, with approximately 20% more air passing through the upper slab than the lower slab. Additionally, the heat exchanger's mounting brackets blocked air flow to the refrigerant tubes closest to the front edge of the slabs resulting in minimal air flow to these tubes. In this analytical effort, we used the NIST heat exchanger model EVAP-COND and intelligent system for heat exchanger design to examine options for improving the evaporator design for its capacity with the actual, measured air velocity profile. Optimization of the refrigerant flow split between the two slabs provided 1.1% capacity improvement, while optimization of refrigerant circuitry for both slabs improved the capacity by 5.6%. Simulations also showed that the tubes with minimal air flow had a very small contribution to the overall capacity, and that eliminating them from the assembly may prove to be an attractive cost saving method. Evaporator designs with optimized refrigerant circuitry and reduced number of tubes had better capacities than the original 120-tube evaporator, showing an improvement of 5.2% for a 108-tube design and 4.0% for a 102-tube design.

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  • Prix public

    20 €

  • Prix membre*

    15 €

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

Détails

  • Titre original : Evaporator optimization for non-uniform air distribution.
  • Identifiant de la fiche : 2011-0293
  • Langues : Anglais
  • Source : IIR/Eurotherm sustainable refrigeration and heat pump technology conference. Proceedings of the Eurotherm Seminar No. 88, Stockholm, Sweden, June 13-16, 2010.
  • Date d'édition : 13/06/2010

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