Types of cooling tower


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Cooling towers
The circulating-water system supplies cooling water to the turbine condensers and thus acts as the vehicle by which heat is rejected from the steam cycle to the environment
The cooling tower represents an effective device in the circulating water system that supplies power plants with cooling water specifically when the natural sources of water are not available
The heat rejected by the circulating-water system is greater than that converted to useful work by steam cycle
Types of cooling towers
cooling towers are classified as:wet,dry or wet-dry cooling towers
Wet cooling towers
The heat rejected by the plant to the environment by these mechanisms
1addition of sensible heat to the air
2evaporation of a portion of the circulation water itself
Wet cooling towers have a hot water distribution system that sprays the water evenly over a lattice work of closely set horizontal slats or bars called fill.The fill throughly mixis the falling water with air moving through the fill.Outside air enters the tower via lonvers in the form of horizontal slats on the side of the tower
The intimate mix between water and air enhances heat and mass transfer which cools the water.cold water is then collected at bottom of the tower when itis pumped to condenser
Dry cooling towers
Adry cooling tower is one in which the circulating water is passed throgh finned tubes over which the cooling air is passed.All heat rejected from the circulating water is thus in the form of sensible heat to the cooling air, a dry cooling tower can be ,either mechanical-drafts or natural-drafts
1least efficient of all types of cooling towers
2it requires no make up water
Wet-Dry cooling towers
This type of cooling towers operates by a combination of wet and dry cooling .wet-dry cooling tower has been developed that reduces the disadvantages of wet and dry cooling towers.The water is precooled in the dry section and then gravitates through the fill of the wet section to ward the cold-water basin.The subsaturated exit air provides a less visible plume than wet cooling tower.Evaporative losses and hence make up are substantially reduced

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