Excess Air Coefficient - an overview | ScienceDirect Topics
Excess air coefficient has an important impact on the combustion conditions of boiler and thermal efficiency, analysis shows that the furnace temperature and the combustion efficiency is the linear relation of one to one correspondence. Any combustion conditions, there is an optimum excess air coefficient makes the top of furnace temperature, thus it can establish a control relationship, furnace
Combustion Efficiency and Excess Air
The excess air coefficient at the furnace exit of a typical CFB boiler is 1.2, and the sectional superficial gas velocity is 5∼6 m/s at 850°C, so the furnace cross section heat release rate is 3.6∼4.4 MW/m 2.
Typical excess air to achieve the highest possible efficiency for some common fuels: 5 - 10% for natural gas. 5 - 20% for fuel oil. 15 - 60% for coal. Carbon dioxide - CO2 - is a combustion product and the content of CO2 in a flue gas is an important indication of the combustion efficiency.