Combined evaporative air cooler and refrigeration unit for water purification and performance enhancement of air cooling system

Abstract

Experimental and theoretical studies of hybrid system combined an evaporative air cooler and refrigeration unit are presented. The aim of the current study is to enhance performance of the evaporative air cooler and reduce moisture content in the outlet air as well as to produce fresh water. Heat and mass transfer for wetted pad in the air cooler and the evaporator of the refrigeration unit are formulated and simulated under Basra climate conditions in (May, June, July, and August).  Different controlling parameters like (inlet temperature, relative humidity, evaporator coil temperature, frontal air velocity and thickness of the wetted pad are studied). The evaporative air cooler used in the  experimental rig. was of (2061) cfm volumetric flow rate with dimension (0.72m, 0.72m, 0.85m). It has a selector of two air velocities (low and high)  the minimum and maximum frontal air velocities are (0.5 m/s - 4 m/s) respectively. The refrigeration unit consist of a Compressor of 1/3hp capacity (AC 220 volts, R134a refrigerant). The evaporator coil has one row, 18 tube of 24.5 cm length,  and outside diameter of 0.9 cm. The experimental results show a decrease in outlet temperature by (1-3 ) and the fresh water production increases with increasing, humidity ratio, relative humidity, and decreasing of the coil temperature. A comparison between the experimental and theoretical work shows a good  agreement[