Cost Effectiveness Analysis for an Air-Conditioning System with Water Spray Cooling

In this study, a cost effectiveness analysis is conducted for an air-conditioning system equipped with a water mist generating device. System simulations coupled with computational fluid dynamics are utilized to study air conditioner power-saving benefits versus water cost. A k-epsilon turbulence model, species transport equations, and a discrete phase model are solved simultaneously to capture heat and mass transfer effects in CFD. A parametric study is carried out by varying the spray water droplet diameter, the ambient dry bulb temperature, the ambient relative humidity, the spraying water amount, the water temperature, and the spray system's location. After calculating air temperature drop and humidity ratio increase by the water spray, a system simulation is conducted to estimate the power consumption reduction and the capacity enhancement for each condition. This study deduces the operating condition should be carefully selected to save the total cost of air-conditioning equipment operation.