Partager

Document IIF

Étude expérimentale sur les performances de transfert de vapeur avec diffusion thermique améliorée par membranes à revêtement en silice dérivée du perhydropolysilazane (PDS) lors du processus de déshumidification de l’air.

Experimental study of thermal diffusion enhanced vapor transfer performance with perhydropolysilazane-derived silica (PDS) coating membranes in air dehumidification process.

Auteurs : CHEN Q., ZHANG X., WANG F.

Type d'article : Article de la RIF

Résumé

In membrane-based air dehumidification process, the membrane acts as an intermediate medium separating the humid air and the desiccant solution and be used to simultaneously transfer sensible heat and moisture. However, it produces additional mass transfer resistance reducing the performance of dehumidifier. In order to relieve the additional resistance, breakthroughs need to be found in membrane material and driving force. In this investigation, three different membranes, namely, AAc-modified PTFE with silicon oxynitride coating, neat PTFE with amorphous silica coating and neat PTFE are selected. Large temperature gradient coupled with vapor pressure difference forms the enhancement in driving force and faster desorption rate in the membrane. The composite membrane acts as a temporary solid desiccant rather than a barrier between humid air and desiccant solution. Results show that the water vapor adsorption/desorption performance of neat PTFE has been significantly improved with a thin layer of amorphous silica coating added on. Its permeation activation energy is greatly reduced from 54.8 KJmol−1 to 27.2 KJmol−1 and intrinsic resistance from 225 sm−1 to 180 sm−1. The thermal diffusion enhanced effect improves the latent effectiveness of AAc-modified PTFE membrane from 0.38 to 0.5 and neat PTFE membrane with amorphous silica coating from 0.3 to 0.41. These are mainly due to the decrease of sorption curve constant C and increase of water uptake at lower relative humidity. It can be regarded as the temperature gradient across the membrane applying additional driving force to the water vapor diffusion process. Then better dehumidification performance which originally require larger vapor pressure difference can be achieved, reducing energy consumption in the regeneration process.

Documents disponibles

Format PDF

Pages : 21-32

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 : Experimental study of thermal diffusion enhanced vapor transfer performance with perhydropolysilazane-derived silica (PDS) coating membranes in air dehumidification process.
  • Identifiant de la fiche : 30028105
  • Langues : Anglais
  • Sujet : Technologie
  • Source : International Journal of Refrigeration - Revue Internationale du Froid - vol. 122
  • Date d'édition : 02/2021
  • DOI : http://dx.doi.org/10.1016/j.ijrefrig.2020.11.003
  • Document disponible en consultation à la bibliothèque du siège de l'IIF uniquement.

Liens


Voir d'autres articles du même numéro (22)
Voir la source

Indexation