Warm water[ edit ] Elevated temperature typically decreases the level of dissolved oxygen of water, as gases are less soluble in hotter liquids.
Flue-gas stack For units over about MW capacity, redundancy of key components is provided by installing duplicates of the forced and induced draft fans, air preheaters, and fly ash collectors. The list of coal power stations has the largest power stations ranging in size from 2,MW to 5,MW. Boiler and steam cycle[ edit ] In the nuclear plant field, steam generator refers to a Thearmal power plant type of large heat exchanger used in a pressurized water reactor PWR to thermally connect Thearmal power plant primary reactor plant and secondary steam plant systems, which generates steam.
In a nuclear reactor called a boiling water reactor BWRwater is boiled to generate steam directly in the reactor itself and there are no units called steam generators. In some industrial settings, there can also be steam-producing heat exchangers called heat recovery steam generators HRSG which utilize heat from some industrial process, most commonly utilizing hot exhaust from a gas turbine.
The steam generating boiler has to produce steam at the high purity, pressure and temperature required for the steam turbine that drives the electrical generator. Geothermal plants do not need boilers because they use naturally occurring steam sources.
Heat exchangers may be used where the geothermal steam is very corrosive or contains excessive suspended solids. A fossil fuel steam generator includes an economizera steam drumand the furnace with its steam generating tubes and superheater coils. Necessary safety valves are located at suitable points to relieve excessive boiler pressure.
The air and flue gas path equipment include: The total feed water consists of recirculated condensate water and purified makeup water. Because the metallic materials it contacts are subject to corrosion at high temperatures and pressures, the makeup water is highly purified before use.
A system of water softeners and ion exchange demineralizers produces water so pure that it coincidentally becomes an electrical insulatorwith conductivity in the range of 0.
The feed water cycle begins with condensate water being pumped out of the condenser after traveling through the steam turbines. Diagram of boiler feed water deaerator with vertical, domed aeration section and horizontal water storage section. The water is pressurized in two stages, and flows through a series of six or seven intermediate feed water heaters, heated up at each point with steam extracted from an appropriate duct on the turbines and gaining temperature at each stage.
Typically, in the middle of this series of feedwater heaters, and before the second stage of pressurization, the condensate plus the makeup water flows through a deaerator   that removes dissolved air from the water, further purifying and reducing its corrosiveness.
The water may be dosed following this point with hydrazinea chemical that removes the remaining oxygen in the water to below 5 parts per billion ppb.
Its walls are made of a web of high pressure steel tubes about 2. Pulverized coal is air-blown into the furnace through burners located at the four corners, or along one wall, or two opposite walls, and it is ignited to rapidly burn, forming a large fireball at the center.
The thermal radiation of the fireball heats the water that circulates through the boiler tubes near the boiler perimeter. The water circulation rate in the boiler is three to four times the throughput. As the water in the boiler circulates it absorbs heat and changes into steam.
It is separated from the water inside a drum at the top of the furnace. The saturated steam is introduced into superheat pendant tubes that hang in the hottest part of the combustion gases as they exit the furnace.
Plants designed for lignite brown coal are increasingly used in locations as varied as GermanyVictoriaAustralia, and North Dakota. Lignite is a much younger form of coal than black coal. It has a lower energy density than black coal and requires a much larger furnace for equivalent heat output.
The firing systems also differ from black coal and typically draw hot gas from the furnace-exit level and mix it with the incoming coal in fan-type mills that inject the pulverized coal and hot gas mixture into the boiler. Plants that use gas turbines to heat the water for conversion into steam use boilers known as heat recovery steam generators HRSG.
The exhaust heat from the gas turbines is used to make superheated steam that is then used in a conventional water-steam generation cycle, as described in the gas turbine combined-cycle plants section.
Boiler furnace and steam drum[ edit ] The water enters the boiler through a section in the convection pass called the economizer. From the economizer it passes to the steam drum and from there it goes through downcomers to inlet headers at the bottom of the water walls.
From these headers the water rises through the water walls of the furnace where some of it is turned into steam and the mixture of water and steam then re-enters the steam drum. In the steam drum, the water is returned to the downcomers and the steam is passed through a series of steam separators and dryers that remove water droplets from the steam.
The dry steam then flows into the superheater coils. The boiler furnace auxiliary equipment includes coal feed nozzles and igniter guns, soot blowerswater lancing, and observation ports in the furnace walls for observation of the furnace interior.
Furnace explosions due to any accumulation of combustible gases after a trip-out are avoided by flushing out such gases from the combustion zone before igniting the coal.
The steam drum as well as the superheater coils and headers have air vents and drains needed for initial start up. Superheater[ edit ] Fossil fuel power stations often have a superheater section in the steam generating furnace.The direct cost of electric energy produced by a thermal power station is the result of cost of fuel, capital cost for the plant, operator labour, maintenance, and such factors as ash handling and disposal.
Thermal power point 1.
THERMAL POWER PLANT 2. A Thermal Power Plant converts the heat energy of coal into electrical energy. Coal is burnt in a boiler which converts water into steam. The expansion of steam in turbine produces mechanical power which drives the alternator coupled to the leslutinsduphoenix.coml Power Plants contribute maximum to the.
Nov 02, · Find Thermal Power Plant Latest News, Videos & Pictures on Thermal Power Plant and see latest updates, news, information from leslutinsduphoenix.com Explore more on Thermal Power Plant.
Diesel Power Plant Figure shows the arrangements of the engine and its auxiliaries in a diesel power plant. The major components of the plant are: a) Engine Engine is the heart of a diesel power plant.
Engine is directly connected through a gear box to the generator. Generally two-stroke engines are used for power generation.
Use of Electrostatic Precipitators (ESP) in Thermal Power Plants Use of Electrostatic Precipitators: The electrostatic precipitators (ESP) are extensively used in the thermal power plant or steam power plant for removal of fly ash from the electric utility boiler emissions.
Thermal pollution is the degradation of water quality by any process that changes ambient water temperature. An extreme case is derived from the aggregational habits of the manatee, which often uses power plant discharge sites during winter.
Projections suggest that manatee populations would decline upon the removal of these discharges.