Why is scale buildup a concern in boiler operations?

Scale buildup in boiler operations is a significant concern primarily because it can lead to increased fuel consumption. When scale forms on the heat transfer surfaces of a boiler, it acts as an insulating layer. This decreased thermal conductivity means that the boiler has to work harder to achieve the desired water temperature and steam production. Consequently, the boiler consumes more fuel to compensate for the reduced efficiency, driving up operating costs and potentially leading to more frequent maintenance needs.

In contrast, the other options do not accurately reflect the implications of scale buildup. While it may seem that scale could improve heat transfer efficiency, the reverse is true; scale actually hampers heat transfer. Raising the temperature of water is not a direct consequence of scale—rather, the scale buildup creates inefficiencies that prevent the boiler from reaching optimal operational temperatures without additional fuel. Lastly, steam quality can be compromised due to poor heat transfer and subsequent overheating issues caused by scale, but this is a secondary concern compared to the immediate impact on fuel consumption and operational costs.