Experimental study of an ultrasonic regenerative evaporative cooler for a desiccant cooling system

摘要

This paper presents fabrication of an ultrasonic regenerative evaporative cooler, coupled with a desiccant dehumidifier. Ultrasonic regenerative evaporative cooler consists of several sets of a dry channel and a wet channel. A part of the air from the dry channel is redirected into the wet channel where it is cooled by evaporation of water mist from an ultrasonic atomiser. Air flowing through dry channels is pre-cooled by heat transfer between wet and dry channels, without changing its humidity. In this cooler, the conventional hygroscopic layer for wetting the plate surface is replaced with the water mist. It is observed that the performance of the cooling system significantly depends on the channel spacing, channel length, inlet airflow rate and extraction ratio, and marginally depends upon feed water temperature. The room cooling capacity is eminently responsive to both air mass flow rate and extraction ratio. The maximum available room cooling capacity of 339.8 W is obtained for the optimal values of 0.0488 kg/s mass flow rate of air and 0.37 extraction ratio. The prototype achieved wet-bulb effectiveness values as high as 1.15 and delivered more than 10celcius temperature drop.