EXPERIMENTAL TESTING OF AN INNOVATIVE GRAPHITE EXCHANGER FOR ADSORPTION HEAT PUMPS AND CHILLERS

In this work, the realization and experimental testing of an innovative graphite exchanger for adsorption heat pumps and chillers is reported. Graphite plates have been used as supports for zeolite deposition by dip coating method. Basically, the realized adsorbent exchanger consists of several assembled graphite plates and the flow path of heat transfer fluid. Each plate consists of a process side (where zeolite is deposited onto) and a heat transfer fluid (HTF) side where liquid water flows to remove heat during adsorption and provide thermal energy for desorption. The external shapes have been designed on the basis of specific characterizations performed on small-scale samples, whereas inner fluid paths (heat transfer fluid side) have been developed by using Computational Fluid Dynamics in order to enhance heat transfer rate, volumetric specific power and reduce pressure drop. The resulting adsorbent heat exchanger is expected to deliver about 0.5-1 kW cooling power and possesses attractive thermo physical properties, especially in term of low weight, volume and thermal capacity. The metal to adsorbent mass ratio is conveniently lower than one, which is a noticeable advancement in the current state of art. Experimental testing of the full-scale adsorber by a testing station available at CNR ITAE is currently ongoing.