Effect mechanism of air deflectors on the cooling performance of dry cooling tower with vertical delta radiators under crosswind

Highlights: • A 3D numerical model was set for NDDCTV to study the effect of air deflectors. • The air deflectors improve the tower performance by 1.375 °C at u_c = 6 m/s for a case. • The air deflectors reduce the air inflow deviation angle θ_d at most delta entries. • The reduced θ_d can improve the cooling performance of former deteriorated columns. • Both the radial inflow air velocity and θ_d impact the cooling performance of delta. - Abstract: To study the effect mechanism of air deflectors on dry cooling tower, a three dimensional numerical model was established, with full consideration of the delta structure. The accuracy and credibility of dry cooling tower numerical model were validated. By numerical model, the average air static pressure and the average radial inflow air velocity were computed and analyzed at delta air entry, sector air entry and exit faces. By the air inflow deviation angle θ_d, the effect of air deflectors on the aerodynamic field around tower was analyzed. The water exit temperatures of θ₋₁ columns, θ₊₂ columns and cooling sectors were also presented to clarify the effect of air deflectors. It was found that the air deflectors improved the aerodynamic field around cooling columns. The reduced air inflow deviation degree at delta entry improved the cooling performance of deteriorated columns. Referring to the radial inflow air velocity u_ra and the air inflow deviation degree at delta entry, the effect mechanism of air deflectors are clarified under crosswind