A cooling tower is a heat rejection machine which rejectswaste heat to theatmospherethrough the cooling of a water stream to a lower temperature. Cooling towers might both use theevaporation of water to take away process heat and cool the working fluid to close to thewet-bulb air temperature or, in the case of closed circuit dry cooling towers, rely solely on air to cool the working fluid to near thedry-bulb air temperature.
Common applications include cooling the circulating water used inoil refineries,petrochemical and otherchemical plants,thermal energy stations andHVAC techniques for cooling buildings. The classification is based on the type of air induction into the tower: the main sorts of cooling towers arenatural draft andinduced draft cooling towers.
Cooling towers vary in measurement from small roof-top models to very largehyperboloid buildings(as in the adjacent image) that may be as much as 200 metres (660 ft) tall and a hundred metres (330 ft) in diameter, or rectangular structures that may be over forty metres (130 ft) tall and 80 metres (260 ft) long. The hyperboloid cooling towers are often related withnuclear energy plants,
although they’re additionally utilized in some coal-fired plants and to some extent in some giant chemical and other industrial plants. Although these large towers are very outstanding, the overwhelming majority of cooling towers are much smaller, together with many items installed on or near buildings to discharge heat from air conditioning.