MOUNTING / INSTALLATION POSITIONS FOR COAL AND GAS FIRED BOILERS
KEY
SERVOTOUGH FluegasExact 2700
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SERVOTOUGH FluegasExact 2700 ( Zirconia )
SERVOTOUGH Laser 3 Plus ( TDL )
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COAL |
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GAS |
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ECONOMIZER |
O 2 |
CO e |
EMISSIONS COMBUSTION
SAFETY
SERVOTOUGH FluegasExact 2700
O 2
CO e
SERVOTOUGH FluegasExact 2700
RADIANT SECTION
SCR / SNCR
O 2
CO e
SERVOTOUGH Laser 3 Plus Combustion
O 2 |
CO |
CO + CH4 |
GAS AIR HEATER |
COMBUSTION CONTROL IN COAL AND GAS BOILERS
In a coal-fired power plant , pre-heated air and pulverized coal are fed to the boiler where combustion takes place .
As combustion processes are by nature variable and coal quality is never consistent , variable amounts of excess air are required to ensure complete combustion . Too much air , and combustion efficiency will drop , producing lower levels of CO but higher levels of NOx toxic emission gases .
NOx emissions are also created at higher temperatures as a by-product of the combustion process where excess nitrogen ( N 2 ) in the air reacts with O 2 , as well as reacting with any elemental nitrogen that may be resident in the fuel .
This temperature variation affects the production of CO 2 , CO and NOx differently , so by controlling the combustion process the boiler efficiency increases .
Recovering waste heat in a gas turbine combined cycle is 50-75 % more efficient than using separate generators .
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