MOUNTING / INSTALLATION POSITIONS FOR COAL AND GAS FIRED BOILERS
KEY
SERVOTOUGH FluegasExact 2700
|
SERVOTOUGH FluegasExact 2700( Zirconia)
SERVOTOUGH Laser 3 Plus( TDL)
|
|
|
|
COAL |
|
|
|
|
GAS |
|
|
|
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.
P08