Investigation of Hybrid Evaporative Cooling consist of Direct and Indirect Evaporative Cooling

In the present study, the results of performance analysis of a direct-indirect hybrid evaporative cooling system have been discussed. A cooling tower and Cooling Coil Unit (CCU) provide the necessary pre-cooling effects, enabling a Direct Evaporative Cooler (DEC) that cools the air even below its wet-bulb temperature. The hybrid cooling system includes a counter-flow wet cooling tower, a cooling coil unit and a direct evaporative cooler. In the present paper, the amount of saturation effectiveness in different weather conditions and also different cooling tower ranges is investigated. Simulation results revealed that the combination of CCU and DEC system could provide comfort condition whereas DEC alone did not. Based on the simulation results the cooling effectiveness of a hybrid system is more than 100%. Thus, the investigated hybrid system could decrease the air temperature below the ambient wet-bulb temperature. Moreover, a case study for Iran is done to check out the feasibility usage of the hybrid cooling system in selected cities. All the studies aspects of the investigated hybrid system are compared to a stand-alone DEC. This environmentally clean and energy efficient system can be considered as an alternative to the mechanical vapor compression systems.

Keywords:

Direct-indirect evaporative cooling , hybrid cooling , comfort condition , effectiveness