why cooling tower is used in steam power plant
Cooling tower Cooling towers originated in the 19th century through the development of condensers for use with the steam engine.[2] Condensers use relatively cool water, via various means, to condense the steam coming out of the cylinders or turbines. This reduces the back pressure, which in turn reduces the steam consumption, and thus the fuel consumption, while at the same time increasing power and recycling boiler-water.[3] However the condensers require an ample supply of cooling water, without which they are impractical.[4][5] The consumption of cooling water by inland processing and power plants is estimated to reduce power availability for the majority of thermal power plants by 2040â€“2069.[6] While water usage is not an issue with marine engines, it forms a significant limitation for many land-based systems.
Air-cooled engine Most modern internal combustion engines are cooled by a closed circuit carrying liquid coolant through channels in the engine block and cylinder head, where the coolant absorbs heat, to a heat exchanger or radiator where the coolant releases heat into the air (or raw water, in the case of marine engines). Thus, while they are not ultimately cooled by the liquid, because of the liquid-coolant circuit they are known as water-cooled. In contrast, heat generated by an air-cooled engine is released directly into the air. (Direct Cooled Engine) Typically this is facilitated with metal fins covering the outside of the Cylinder Head and cylinders which increase the surface area that air can act on. Air may be force fed with the use of a fan and shroud to achieve efficient cooling with high volumes of air or simply by natural air flow with well designed and angled fins.