Experimental investigation of a solid adsorption chiller based on a heat exchanger coated with hydrophobic zeolite

In this paper, the experimental results of a lab scale adsorption chiller working with hydrophobic Y zeolite–methanol are presented and discussed. The main feature of this chiller is the innovative adsorbent bed consisting of a shell and tube heat exchanger in which the finned tubes are coated with a zeolite layer. In this way, the interesting sorption properties of the Y type zeolite and the good heat transfer quality of the coated heat exchanger are joined in an advanced sorption machine, driven by a low temperature heat source. The experimental results on the device show a specific power of 30–60 W/kg of adsorbent (binder included) and a cycle time of 15–20 min depending on the working conditions. These values are sensibly better than those measured with a same zeolite pelletised bed. This latter bed was realized starting from the same zeolite powder that was extruded using the same amount and type of binder. The good results obtained, evidently due to the improved heat transfer properties of the advanced bed, sound attractive for those applications in which a quick dynamic cycle is important.