The effect of crosswind and installation of wind-break deflector on the performance of natural draft dry cooling tower (NDDCT)

Natural draft dry cooling tower (NDDCT) is one of the most important components of combined power plant cycles in arid regions. Studies illustrate that being subjected to the wind blowing has negative effects on NDDCT's thermal performance. These adverse effects mostly inflict on the outlet port of the tower and the installation platform of the radiators at the bottom of the tower. In this study, the influence of installing wind-break deflectors at the outlet port of the tower and addressing the negative impacts of the wind is investigated. Considering the buoyancy effect for a 3-D incompressible flow, the flow field inside and outside the tower as well as the heat transfer from the radiators is modeled through simultaneously solving the Navier-Stokes and energy equations via computational fluid dynamics method (CFD). The performance of NDDCT is compared with and without the presence of deflectors where considered variables are height of the deflector and wind velocity. The improvement in the rate of the heat released to the atmosphere from the radiators will be estimated. Generally, in the presence of deflector walls the thermal performance of the tower enhances. With the increase in the height of deflectors, the thermal performance will further improve. For instance, the enhancement in the tower's performance with a 12-m deflector at wind velocities of 5 and 20 m/s is 57 and 44 percent, respectively.