In addition to reducing heat transfer, what other effect do soot and ash have on fireside tubes?

Soot and ash buildup on the fireside tubes of a boiler can significantly impact the operational performance, particularly in terms of the draft fan power requirements. When soot and ash accumulate, they create an insulating layer on the heat exchange surfaces, leading to a reduction in overall heat transfer efficiency. As a result, the fire requires more energy to maintain the desired temperature and pressure within the system.

This increased resistance to airflow means that the draft fan must work harder to move the same volume of air through the combustion chamber. Consequently, the power requirements of the draft fan increase to provide adequate airflow for combustion, which can lead to higher operational costs and increased energy consumption.

Understanding this relationship is crucial for effective boiler operation and maintenance, as it emphasizes the importance of regular cleaning and maintenance to ensure optimal efficiency and reduce wear on equipment. In contrast, the other options do not align with the effects that soot and ash have on fireside tubes and their associated performance metrics. Decreased fuel consumption, improved combustion efficiency, and enhanced boiler performance are generally outcomes of clean and well-maintained systems rather than a result of soot and ash deposits.