what is range & approach in cooling tower.?

Question

it is related to temperature difference phenomena.

Answer 1

The range is the difference between the temperature of the hot water entering the cooling tower and the cooled water leaving the cooling tower.

The approach is the difference between the atmospheric wet bulb temperature and the temperature of the cooled water.

Since the cooling tower relies mainly on evaporation of water to get cooling, the wet bulb temperature limits how much evaporation can be achieved and therefore the amount of cooling.