Closed circuit cooling tower is a type of evaporative cooler who will absorbs the heat of the cooled fluid by evaporation of spray water outside the coil. Closed circuit cooling tower adopts two-stage cooling mode; during the first stage, air cooling occurs when the wind cools the coil of the cooler; Secondary stage take place when the ambient temperature is relatively high. The spray system will water on the surface of the cooler, and the heat of the coil can be washed away when the water evaporates, so as to achieve the cooling effect.