E. Lépinasse¹, M. Marion¹, V. Goetz^2
1 Laboratoire de Thermodynamique des Procédés, IUT - département GTE,
120 rue de l'exode, 50000 St Là.
² IMP-CNRS, Institut de Science et Génie des Matériaux et Procédés,
Site Carnot, rambla de la thermodynamique, 66100 Perpignan, France

Le procédé à résorption, basé sur l'utilisation de deux réacteurs solide-gaz, répond efficacement à toute application de stockage de production de froid où la présence d'une phase liquide n'est pas souhaitable. A partir des résultats expérimentaux, il est montré que ce système est adapté à une production effective de froid à des températures de l'ordre de 273 K.

Abstract :
The resorption process is based on the use of two solid-gas reactors. It is an efficient system for cold production. in any application where the presence of a liquid phase is not desirable. Experimental results show that this system is adapted to an effective production of cold at a temperature ofthe order of 273 K.

A. Syed¹, G.G. Maidment¹, J.F. Missenden¹, R.M. Tozer^1,2
1 School of Engineering Systems & Design, South Bank University, 103 Borough Road, SE1 OAA, London, United Kingdom,
² Waterman Gore – M&E Consulting Engineers, Versailles Court, 3 Paris Garden, SE1 8ND, London, United Kingdom

This paper provides a review of recent developments and future prospects in the field of solar cooling systems from their applications in air-conditioning and refrigeration. A total of twenty solar-thermal cooling system combinations based on five heat powered cycle technologies have been identified with respect to their generic operating temperature ranges. A comparison of their efficiencies and cost performances shows that the liquid desiccant ‘Spray-LiBr/LiCl/ evacuated tube collectors’ performs most efficiently with an overall cooling COP of 1.05-1.08 in the 12-18° C range for direct cooling of supply air. Whereas the absorption double-effect LiBr/H₂O/ evacuated tube collectors shows the highest known overall cooling COP of 0.630-0.648 in the 4-12° C range for providing chilled water. The solid absorption SrCl₂-NH₃/ evacuated tube collectors has the highest overall cooling COP value range of 0.319-0.168 in the category of 0 to -17° C of ice-making and cold storage. Finally, the absorption single-effect NH₃-H₂O/ concentrating parabolic collectors with an overall efficiency of 0.230-0.146 in the widest known range of operating temperatures (-4 to -40° C) is shown to be the best option for ice-making/ cold storage and deep freezing. The photovoltaic-compression system presently seems to be the most economical option for solar cooling.

S. Riffat, N. Abodahab, P. Doherty and S. Al-Huthaili
School of the Built Environment, University of Nottingham, University Park, Nottingham, NG7 2RD, UK

P. Haberschill¹, B. Horber², M. Lallemand^1
1 CETHIL, UMR 5008, INSA, 20 av. A. Einstein, 69621 Villeurbanne Cedex
² EDF-DER, Centre des Renardières, BP n°1, Ecuelles, 77250 Moret-sur-Loing

Cet article est relatif à une étude expérimentale d’une installation à compression de vapeurs fonctionnant au CO₂ pour laquelle un banc d’essais a été construit. Les performances de l’installation ont été déterminées pour des températures respectives des sources froide et chaude de 27 et 35°C et des vitesses d’air fixées à 2,6 m/s. La puissance frigorifique obtenue est de l’ordre de 4,5 kW avec un coefficient de performance de 1,2. Les conditions optimales de fonctionnement ont été déterminées en fonction de l’ouverture du détendeur manuel et de la charge en CO₂ de l’installation. Le rôle de la présence de bouteilles de stockage de la charge, soit du côté haute pression, soit du côté basse pression a également été analysé.

Abstract :
This paper deals with an experimental study of a vapour compression system using CO₂ as refrigerant. A test bench has been built for performance and operational testing purposes. The CO₂ system performance have been carried out for heat sink and heat source temperatures of 27 and 35°C, respectively and air velocities of 2.6 m/s. A refrigerating capacity of about 4.5 kW with a coefficient of performance of 1.2 are achieved for the prototype. The optimal operating conditions are given according to the hand expansion valve opening and the CO₂ charge. The effect of accumulators, either on the high pressure side or on the low pressure side is also analysed.