The Influence of Thermal Flow Field on Recirculation of Air-Cooled Tower for a Large Power Plant

Abstract

the paper introduces thermal buoyancy effects to experimental investigation of wind tunnel simulation on direct air-cooled condenser for a large power plant. In order to get thermal flow field of air-cooled tower, PIV experiments are carried out and recirculation ratio of each condition is calculated. Results show that the thermal flow field of the cooling tower has great influence on the recirculation under the cooling tower. Ameliorating the thermal flow field of the cooling tower can reduce the recirculation under the cooling tower and improve the efficiency of air-cooled condenser also.

The Discussion on Influenced Factors of Recirculation under Air Cooling Tower for a Large Power Plant

“…Literature [8,9] supplied the direct air-cooled with the constant temperature hot water, and carried out the model experiments in low-speed wind tunnel for the first time.…”

“…Literature [9] gave the relationship between average recirculation ratio and density Froude number, as shown in Figure 3。 It can be seen from the Figure 3, with the density Froude number increased, the average recirculation decreased. This is mainly because of the thermal buoyancy effect increases, the momentum of the hot air discharged from ACC increased, when the wind velocity kept constant, the hot air diffuse away from the ground to the top right of the downward position, so the hot air sucked into the cooling tower was reduced, and thus, the average recirculation under the cooling reduced.…”

“…Literature [9] got the rules of height of wind wall on recirculation through the wind tunnel model tests, meanwhile, the influence of height of wind wall on the thermal flow field was also revealed. The experiments denote that increasing the height of wind wall can reduce the average recirculation under the cooling tower, and there was an optimum value of l height of wind wall, this result is validated by numerical simulation of Literature [11].…”

Numerical Investigation of Thermal Flow Field of Air-Cooled Condensers for Yongshou Plant

“…Widen or lengthen the platform .Fig. 10 shows the relationship between the average recirculation R and height of the frontal board L. It can be seen that as L increases and recirculation under the cooling tower is also reducing, the reasons is explained as [8].…”

Numerical Investigation of Recirculation of Air-Cooled Condensers for a Large Power Plant

“…Fig. 12 also gives the relationship between the average recirculation R and height of the frontal board W. It can be seen that widen the platform can reduce the recirculation under the cooling tower, but as W increases, and recirculation under the cooling tower is un-linearly reducing, the reasons is explained as [8].…”