Adsorption performance of round fin and tube type adsorber employing activated carbon fiber/ethanol pair

The severity of the ozone layer destruction problem has been calling for rapid developments in environment friendly adsorption cooling systems. However, the widespread dissemination of adsorption system is hindered due to its poor performance, which mainly results from the inadequate design of adsorber/desorber heat exchanger. The present paper deals with the numerical investigation on the adsorption performance of a round fin-and-tube type adsorber/desorber heat exchanger using activated carbon fiber (ACF)-ethanol as adsorbent-refrigerant pair. The effects of the local heat and mass transfer as well as the fin geometry of the adsorber/desorber are accounted in the present two-dimensional modeling. Adsorption performance have been determined varying five parameters, such as the ACF bed apparent density, fin thickness, fin pitch, fin height and tube diameter along with evaporator and cooling water inlet temperatures. The results show that the adsorption performances increase by optimizing the tube diameter, fin height and fin pitch. It is also found that all parameters have some influence on the optimum adsorption cycle time and the optimum cycle time is found to be around 150 s.