Document IIF

Caractéristiques de transfert de chaleur superficiel du refroidissement par pulvérisation pulsée de R404A avec une tuyère d'expansion-chambrée pour la dermatologie au laser.

Surface heat transfer characteristics of R404A pulsed spray cooling with an expansion-chambered nozzle for laser dermatology.

Auteurs : WANG R., ZHOU Z., CHEN B., et al.

Type d'article : Article, Article de la RIF

Résumé

Cryogen spray cooling is applied to protect epidermis from thermal damage in laser dermatology. However, R134a shows insufficient cooling capacity for minimizing the laser energy absorption by melanin in darkly pigmented human skin. By contrast, the cooling capacity of R404A can be improved with a low boiling point. This study examined the temporal and spatial variations in surface heat transfer during R404A spray cooling using a straight-tube nozzle with an expansion chamber. Substitution of R134a with R404A increases the maximum heat flux by 19%, whereas introducing an expansion chamber enhances the maximum heat flux by 18%. Results indicate that surface heat transfer during R404A spraying exhibits intense temporal and spatial non-uniformity. A sub-region of uniform cooling with a radius of 2?mm appears around the spray center with a high transient heat flux above 300?kW/m2. This finding can help physicians precisely control the therapy area with enhanced laser energy.

Documents disponibles

Format PDF

Pages : 206-216

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 : Surface heat transfer characteristics of R404A pulsed spray cooling with an expansion-chambered nozzle for laser dermatology.
  • Identifiant de la fiche : 30016332
  • Langues : Anglais
  • Source : International Journal of Refrigeration - Revue Internationale du Froid - vol. 60
  • Date d'édition : 12/2015

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