from natural gas-fired boilers are flue gas recirculation (FGR) and low NOx burners. In an FGR system, a portion of the flue gas is recycled from the stack to the burner windbox. Upon entering the windbox, the recirculated gas is mixed with combustion air prior to being fed to the burner. The recycled flue gas
Natural gas boilers operate at lower excess air (O2) and a different airflow requirement for stoichiometric combustion. Coal fired boilers normally operate with 3-3.5% O2 (about 20% excess air). Whereas natural gas boilers normally operate at 1-1.5% O2 (about 7% excess air).
Early boilers provided this stream of air, or draught, through the natural action of convection in a chimney connected to the exhaust of the combustion chamber. Since the heated flue gas is less dense than the ambient air surrounding the boiler, the flue gas rises in the chimney, pulling denser, fresh air into the combustion chamber.
Flue Gas Analysis Table Introduction. See Flue Gas Analysis. Operation. Using a Flue Gas Analyzer or any meter designed to measure oxygen or carbon-monoxide, and taking the flue gas temperature and the temperature of the combustion air, the following Table can be used to determine combustion efficiency when operating on natural gas.
When fuel is burned in a boiler, it produces flue gas, similar to the exhaust from your car. This gas leaves the combustion chamber and enters the flue passages. The combustion chamber and flue passages (called the heat exchanger) are surrounded by water… the same water that is circulated throughout your home to deliver heat.
Gas-Fired Boilers and Furnaces ... the shape/size of the combustion chamber and/or adjusting the fuel pump pressure. ... capacity of your gas boiler or furnace to ...
Flue gas recirculation, or FGR, is the most effective method of reducing NOx emission from industrial boilers with inputs below 100 MMBtu/hr. FGR entails recirculating a portion of relatively cool exhaust gases back into the combustion process in order to lower the flame temperature and reduce NOx formation.
The Peerless® PUREFIRE® Series gas-fired condensing boiler from PB Heat, LLC is a high-efficiency 95% AFUE boiler for residential applications and is available for either natural or LP gas systems. The direct vent, sealed combustion boiler features a fully modulating, stainless steel burner and is environmentally friendly with LoNox operation.