How can excess secondary air affect boiler efficiency?

Excess secondary air can significantly impact boiler efficiency by affecting how heat is managed within the system. When there is too much secondary air introduced into the combustion process, it can lead to incomplete combustion and inefficient heat transfer.

The presence of excess air dilutes the concentration of combustible gases, leading to a situation where a portion of the generated heat is carried away by the excess air without contributing to the intended heating of the system. This excess air exits the furnace, taking with it energy that could have been harnessed for generating steam or heating water, resulting in wasted heat. This inefficiency can manifest as higher fuel consumption because the boiler has to work harder to maintain the desired temperature and output.

Thus, by allowing unutilized heat to escape, the overall efficiency of the boiler is compromised, necessitating more fuel input for the same energy output. Understanding the balance between air supply and fuel is crucial for maintaining high efficiency in boiler operations.