Theoretical comparison of the refrigerating performances of a CaCl2 impregnated composite adsorbent to those of the host silica gel

In this paper, the coefficient of performance (COP), and the specific cooling power SCP) are theoretically evaluated for each of the two adsorbents S40 (microporous silica gel impregnated through immersion in 40% concentrated aqueous solution of calcium chloride), and SO (the host microporous silica gel), and compared one to another. The validating data are measured on a purposely constructed single-bed basic cycle lab-scale adsorption chiller. The measured values of SCP and COP have been found far lower than those computed with the purposely developed simulation software. Those theoretical values correspond to the highest attainable ones, subject to the conditions of their evaluation. The mass ratio (MR), calculated as the ratio of SCP of S40 to that of SO, has been found to be independent of the system performance and has therefore been used to validate the model, with a rather acceptable agreement. A maximum COP value of 0.62 is predicted in the case where the composite adsorbent is used in a single-bed system with a half cycle time of 50 mm. (C) 2007 Elsevier Masson SAS. All rights reserved.