EXPERIMENTAL-STUDY OF AIR COOLING BY WATE R SPRAY HEAT-EXCHANGER FOR ADSORPTIVE DESICCANT COOLING SYSTEM

A hot air stream was successfully cooled across the heat transfer surf ace of a cross-flow finned plate heat exchanger with honeycomb structu re of aluminum while fine water droplets accompanied in excess over sa turation were evaporated in a cold air stream. Hot stream temperature efficiency is improved over that without sprayed droplets and attained up to 60% in a typical example, even at high ratio of hot/cold air fl ow rate of 4 and a small fraction of water droplets, as small as 0.3% wt. The effect of flow rate ratio and amount of accompanied droplets o n heat transfer performance is investigated to propose a scheme of so- called self cooling in which a cold air stream was prepared by sprayin g water droplets to a part of process air. Thus cooling under constant humidity reduces enthalpy in contrast to the conventional direct cont act evaporative cooler at constant enthalpy. A high value of Ca is exp ected in an adsorptive desiccant cooling system equiped with the prese nt sprayed heat exchanger.