When we first heard about Nuclear, the first thing pop-out from our mind is some "smoke" coming out from the cooling towers. We all actually does thought the same as all of us didn't actually know what is the function of that tower at first. Some power plants, usually located on lakes or rivers, use cooling towers as a method of cooling the circulating water that has been heated in the condenser.A cooling tower is a heat rejection device, which extracts waste heat to the atmosphere though the cooling of a water stream to a lower temperature.
The type of heat rejection in a cooling tower is termed "evaporative" in that it allows a small portion of the water being cooled to evaporate into a moving air stream to provide significant cooling to the rest of that water stream. The heat from the water stream transferred to the air stream raises the air's temperature and its relative humidity to 100% and this air discharged to the atmosphere. Evaporative heat rejection devices such as cooling towers are commonly used to provide significantly lower water temperatures than achievable with "air cooled" or "dry" heat rejection devices, like radiator in a car to achieve more cost-effective and energy efficient operation of systems in need of cooling.
But when cooling towers are used, plant efficiency usually drops. One reason is that the cooling tower pumps and fans, if used consume a lot of power.
There are 2 types of towers - mechanical draft and natural draft.
Mechanical Draft Towers
Natural Draft Towers
The type of heat rejection in a cooling tower is termed "evaporative" in that it allows a small portion of the water being cooled to evaporate into a moving air stream to provide significant cooling to the rest of that water stream. The heat from the water stream transferred to the air stream raises the air's temperature and its relative humidity to 100% and this air discharged to the atmosphere. Evaporative heat rejection devices such as cooling towers are commonly used to provide significantly lower water temperatures than achievable with "air cooled" or "dry" heat rejection devices, like radiator in a car to achieve more cost-effective and energy efficient operation of systems in need of cooling.
But when cooling towers are used, plant efficiency usually drops. One reason is that the cooling tower pumps and fans, if used consume a lot of power.
There are 2 types of towers - mechanical draft and natural draft.
Mechanical Draft Towers
Mechanical draft cooling towers have long piping runs that spray the water downward. Large fans pull air across the dropping water to remove the heat. As the water drops downward onto the "fill" or slats in the cooling tower, the drops break up into a finer spray.
Natural Draft Towers
This picture shows a single natural draft cooling tower as used at a European plant. Natural draft towers are typically about 120 m high, depending on the differential pressure between cold outside air and the hot humid air on the inside of the tower as the driving force. No fans are used.
More info here : Natural draft towers , Mechanical draft towers , Cooling tower , Components of Nuclear Reactors
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