Partager

Performances expérimentales et optimisation d'un procédé thermochimique solide/gazeux pour le refroidissement solaire.

Experimental performances and optimization of a solid/gas thermochemical process for solar cooling.

Numéro : pap. n. 23

Auteurs : STITOU D., MAZET N., MAURAN S.

Résumé

This paper focuses on the analysis of experimental performances and potential optimisations of a solar air-conditioning pilot plant, which is running in PROMES-CNRS laboratory (Perpignan, France) since 2006. This device consists of a solid/gas thermochemical sorption process powered at 60-70°C by 21.6 m² of flat plate solar collectors. The experimental device of a daily cooling capacity of 20 kWh of cold at 4°C, is able to refresh a conference room of 130m² and can provide a cooling power of 5 kW during 4 hours. The thermochemical process is based on the coupling of a liquid/gas phase change of a refrigerant (NH3) and a reversible chemical reaction between a reactive solid (BaCl2) and this refrigerant. It operates discontinuously according two phases : a diurnal period during which the reactor is connected to a condenser and heated by the solar collectors loop, and a nocturnal period where the reactor is connected to the evaporator and cooled down by an in-ground geothermal loop. The cold is produced at the evaporator and is stored into a PCM that solidifies at 5°C for a subsequent utilization during the day. In this paper, the analysis of the experimental results collected over two summer seasons is carried out. It leads to an averaged efficiency of 50% for the solar collectors, a process COP ranging from 30 to 40% and a daily cooling productivity of about 0.8 to 1.2 kWh of cold per m² of solar collector. The mean experimental solar COP is about 18% for the summer period (july-august) and decreases to 11% from april to september. A modelling of the whole process has been carried out in order to analyse the unsteady functioning of this solar cooling process under variable operating conditions and optimize its performances. This analysis allows identifying ways of improvements of the design of the different components, and defining new strategies for the control/command of the whole process. As a result, an improvement of the performances of 10% can be achieved by a better adjustment of the trigger thresholds for the different operating phases. The use of more efficient solar collectors and the change of their tilt angle can provide an improvement of 80% of the yearly performances. The simulations showed also that a better design of the thermochemical reactor and the in-ground cooling loop may provide an improvement of 35% of the yearly produced cold.

Documents disponibles

Format PDF

Pages : 10 p.

Disponible

  • 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 : Experimental performances and optimization of a solid/gas thermochemical process for solar cooling.
  • Identifiant de la fiche : 30013445
  • Langues : Anglais
  • Source : International sorption heat pump conference (ISHPC2014), College Park, United States, March 31-April 2, 2014.
  • Date d'édition : 02/03/2014

Liens


Voir d'autres communications du même compte rendu (125)
Voir le compte rendu de la conférence

Indexation