Enhancement of heat and mass transfer in silica-expanded graphite composite blocks for adsorption heat pumps: Part II. cooling system using the composite blocks

摘要

Cooling systems using graphite/silica-gel composite blocks were built and their performances were compared with that of the silica gel packed bed. Spatial and temporal profiles of temperature in the composite blocks were obtained in axial and radial directions. The amount of adsorption and specific cooling powers for each composite block were also measured. It was shown that the axial profile of temperature was affected mainly by mass transfer while the radial distribution of temperature was largely due to poor heat transfer. When compared with a pure silica gel packed bed, both heat transfer and mass transfer were enhanced by using the composite blocks. As a result, the good mass and heat transfer of the composite blocks led to enhancement of performances of the cooling systems.