Effect Of Coating Thickness, Binder And Cycle Time In Adsorption Cooling Applications

A numerical analysis was conducted to examine the effect of a coating technique on adsorption cooling system (ACS) performance compared to a fully-filled grain configuration. The main interest was the effect of coating thickness, binder and cycle time for adsorption cooling applications. Validation of the numerical model was confirmed by comparison with experiment. The coating configuration resulted in a larger interfacial area to open space and also a shorter length of vapor flow path compared to the fully-filled configuration, which enhanced the vapor flow and resulted in higher performance. The optimal coating thickness was found to be 0.2-0.5 mm. A short cycle time was enough for the coating configuration, which improved system performance. For example, at coating thickness t = 0.2 mm, a 34.17% enhancement in specific cooling power (SCP) was achieved with a shorter cycle time of 480 s rather than 840 s, with the penalty of 9.87% decrease in coefficient of performance (COP). The coating technique with reduced cycle time is a good design approach for adsorption cooling systems. The binder had a negative effect on system performance, but the coating technique had clear advantages compared to the fully-filled configuration, and there was no other way of binding the adsorbent particles together. Thus, it is recommended that the binder content be kept as small as it can be.