system
Given the following post, respond as if you're commenting on Reddit:
human
How does the shape of a hyperbolic cooling tower (like those in nuclear plants) help evaporate water/remove heat?
gpt
The hyperbolic shape itself does not help the cooling of a power plant. 

What makes the cooling successful is the height of the tower: by "protecting" the warm and moist air further up, it will maintain an updraft inside the tower.

The hyperbolic shape is just to have a stronger structure to deal with the high winds you get by increasing altitude..

Edit: If you are curious, the updraft is caused by pressure difference between inside/outside the tower. Big cooling towers have holes at the bottom, where ambiant air can rush in. Since hot moist air is less dense than the cool ambient air, it will tend to rise. This rise is then directed directly upwards by the tower.

If there was no tower, the moist air would rise, but with enough warm air exhaust, you could reach a stagnation point where the moist air just doesn't really move away much, hampering your cooling. Higher towers are necessary for big enough power plants, as they prevent the mixing of the rising up air with the cooler air around.