Abstract
Adsorption refrigeration systems are one of the emerging decarbonization technologies that can use eco-friendly heating sources and working fluids. However, the highly porous adsorbent materials used in these systems have a low thermal conductivity that hinders their system performance enhancement. Graphene nanoplatelets are proposed in the literature to improve the conductive heat transfer through the adsorbent field and the resulting composite adsorbents were favorably testified at the material level. In this study, the impact of employing a composite adsorbent that comprises of 50% activated carbon type Maxsorb III, 40% graphene nanoplatelets, and 10% binder was numerically investigated at a system level. The contradictory effects of heat and mass transfer mechanisms within the composite adsorbent on the performance of an adsorption ice production system were explored for three cases of composite layer thicknesses at different cycle times. The results showed that the maximum specific daily ice production and coefficient of performance of 33.27 kg(ice).kg(ads)(-1).day(-1) and 0.3046 were attained at composite thicknesses of 2 and 5 mm and cycle times of 430 and 1230 s, respectively. The higher composite thickness of 10 mm increased the mass transfer resistances, which overlooked the enhancement in the heat transfer and reduced the overall performance.