An optimal plate fin heat exchanger for adsorption chilling: Theoretical consideration

•The criteria for optimal AdHex for air conditioning cycle were formulated.•AdHex should provide the maximal power per unit of its volume.•Heat removal should be balanced with heat generation due to adsorption.•Mathematical model of AdHex performance was proposed and experimentally verified.•The optimal geometry of AdHex for considered air conditioning cycle was suggested. Adsorption heat transformation (AHT) makes it possible to accumulate and use renewable energy and waste heat. This emerging technology is based on the reversible adsorption-desorption of vapour by an adsorbent. One of the most crucial factors affecting the AHT efficiency is heat transfer in the system "adsorbent-heat exchanger"(AdHex), which depends on the AdHex geometrical parameters. For designing compact and efficient units, it is necessary to maximize the AHT useful power per AdHex unit volume. Therefore, the optimization of AdHex geometry is an essential and urgent task. In this purpose the intensity of heat transfer and heat generation inside the restricted volume of AdHex have to be properly balanced. The aim of this work is to find out the optimal geometry of AdHex for adsorption chilling application with use of “methanol-LiCl/SiO2” working pair. The procedure for defining the optimal AdHex geometry is based on finding the compromise between the volume of the adsorbent granules placed inside the AdHex and number of plate channels and fins. The results of calculations were experimentally verified.