Sensitivity Analysis of Evaporative Condensers Performance Using an Experimental Approach

The evaporative condensers operate at lower condensing temperatures with respect to dry condensing units and involve reduced water consumption if compared with water cooled condensers. A test rig to investigate the evaporative condenser at small scale has been designed and built up. The condensing refrigerant has been simulated by electrical heaters and an air handling unit provides air with dry bulb temperature and relative humidity set by the user. All the c affecting the evaporative condenser performance can be monitored and adjusted, in order to carry out either an extensive experimental campaign or a sensitivity analysis. The results, as expected, clearly show that the heat released to air increases with the outer surface temperature of electrical heaters and decreases with relative humidity. An increase of 37.5% of the air flow rate (at constant sprayed water) leads to a maximum reduction of the heat transfer rate of 50%. Different tubes arrangements have been compared, showing as a decrease of the transversal pitch involves worse performance.