Numerical Simulation of Natural Draft Dry Cooling Tower of Yazd Combined Cycle Power Plant: Evaluation of the Louvre Angle Effect

The main disadvantage of natural draft dry cooling towers is the influence of atmospheric conditions such as ambient temperature and wind speed on the thermal performance. Wind disrupts the natural flow of air inside the tower creating vortices at the back and inside the tower that disrupts the air flow structure. When the wind blows, increasing the velocity of inlet air through the front louvers causes the air to pass through the behind louvers rather than outlet opening. The negative effect of this phenomenon reduces the cooling performance and consequently reduces the turbine production power in power plants. A good solution to this problem is to adjust the Louvers angle correctly. Therefore, in the present study, the thermal performance of the dry cooling tower was evaluated under the conditions of opening and closing the front louvers and changing their angle. In this regard, a natural draft dry cooling tower unit with the dimensions of the cooling tower located in combined cycle power plant was simulated using 3D model in fluent software and the numerical results have been validated by experimental data. The Realizable k-ε turbulent model is used to model the turbulent flow. The performance of the tower has been studied in three modes, including no wind, with the wind and fully open louvers and with the wind and semi-open louvers. According to the results, by partially removing the louvers to 60°, heat transfer and mass flow rate can be increased to 16% and 15% respectively.