Experimental testing of a lab-scale adsorption chiller using a novel selective water sorbent silica modified by calcium nitrate

In this paper, a novel composite water sorbent silica modified by calcium nitrate (SWS-8L) has been tested for utilization in adsorption chillers driven by low-temperature heat. The isosteric diagram of the working pair under investigation has been calculated from experimental adsorption data measured at equilibrium. The equivalent specific heat of the sorbent as a function of the water loading was experimentally measured by a calorimetric technique. Thermodynamic cooling COP was estimated to be 0.51-0.71, with desorption temperature lower than 90 degrees C. Real performance was measured by testing a SWS-8L based sorbent bed in a lab-scale adsorption chiller. With this aim, SWS-8L grains were embedded inside a compact aluminium heat exchanger with high thermal efficiency. Experimental cooling COP, mass specific cooling power SCP and volumetric specific cooling power VSCP obtained are 0.18-0.31 (cycle time 10 min), 190-389 W/kg dry sorbent and 104-212 W/dm(3), respectively. (C) 2010 Elsevier Ltd and IIR. All rights reserved.