Abstract: Using the three-dimensional numerical simulation method to simulate the flow field characteristics of natural draft counter-flow wet cooling tower,can provide reference for improving the design of the cooling tower.Based on the heat and mass transfer theory and the characteristics of the FLUENT software,applying Euler-Lagrange method and the standard wall function,using the standard k-ε turbulence model for closure, a three-dimensional numerical simulation platform was established. For 9 000 m² natural draft counter-flow wet cooling tower as an example, with no lateral aerodynamic field, the three-dimensional flow field of the tower was simulated. First of all,the cooling towers outlet water temperature was simulated. After validation with measured data, the calculated value is proved correctly. So the model is reasonable. Then using the platform,the cooling water distribution characteristics was simulated. it is concluded the change process curve of droplet temperature and velocity along with the time and location and the Temperature Distribution in fill layer and collecting tank .the results help to the optimization of water distribution system of tower

Key words: natural draft wet cooling tower, cooling water characteristics, Three-dimensional numerical simulation, drop speed, drop temperature