What is the role of excess air during the combustion in a boiler?

Excess air plays a crucial role in ensuring complete combustion during the combustion process in a boiler. When fuel is burned, it requires an adequate supply of oxygen to react with the fuel and convert it into energy, carbon dioxide, and water. If there is not enough oxygen, incomplete combustion can occur, leading to the production of carbon monoxide and other harmful emissions.

By providing excess air, the combustion process can achieve more complete oxidation of the fuel. This means that even if there are variations in the fuel composition or burn conditions, the additional oxygen present helps to ensure that all of the fuel is consumed. Complete combustion is essential not only for maximizing energy output but also for minimizing the release of unburned fuel and harmful pollutants. Therefore, the presence of excess air directly contributes to the efficiency and environmental performance of the boiler operation.