Energy, Vol.106, 13-22, 2016
Dynamic optimization of adsorptive chillers: The "AQSOA(TM)-FAM-Z02-Water" working pair
Despite significant progress in commercial ACs (adsorption chillers) achieved for the last thirty years, still there is a much room for their further improvement. This paper addresses the optimization of dynamic performance of ACs utilizing loose grains of a novel adsorbent AQSOA(TM)-FAM-Z02. The dynamic data were measured by a Volumetric Large Temperature Jump method under typical conditions of isobaric ad/ desorption stages of real AC cycle. For the first time, the effects of number of the adsorbent layers (N = 2, 4, and 8), grain size (0.2-0.9 mm) and cycle boundary conditions were comprehensively studied. The most notable findings revealed for the water ad/desorption dynamics are: 1) the initial part of all kinetic curves is exponential and can be described by a single characteristic time tau; 2) at equal values of the ratio (S/m) (heat transfer surface)/(adsorbent mass), the dynamic curves are very close regardless the adsorbent grain size R (the "grain size insensitive" regime is observed at 0.44 m(2)/kg <= (S/m) < 1.75 m(2)/ kg); 3) the maximal specific cooling power is a linear function of the (S/m)-ratio. Appropriate recommendations on improving the AC cycle dynamics which concern the optimal conversion degree, grain size and (S/m)-ratio are made. (C) 2016 Elsevier Ltd. All rights reserved.
Keywords:Adsorption chillers;Heat&mass transfer;Adsorption dynamics;Dynamic optimization;Specific cooling power