Dynamic optimization of adsorptive chillers: The “AQSOA™-FAM-Z02 – Water” working pair

•Dynamic optimization of adsorptive chillers with loose FAM-Z02 grains is addressed.•Water sorption dynamics is studied by a Volumetric Large Temperature Jump method.•Effects of adsorbent bed thickness, grain size and cycle boundaries are analyzed.•Recommendations on improving the dynamics of real adsorptive chillers are made.•Their implementation can lead to more compact chillers utilizing the loose grains.

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™-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 τ; 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 m2/kg ≤ (S/m) ≤ 1.75 m2/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.