What occurs when boiler efficiency decreases?

When boiler efficiency decreases, it results in increased fuel consumption. This is because a less efficient boiler requires more fuel to produce the same amount of energy or steam. Essentially, the energy that should be generated from a given amount of fuel is not being maximized, leading to waste.

For example, if the heat transfer processes are not operating at optimal levels due to fouling or other issues, more fuel must be burned to compensate for the lost energy efficiency. Therefore, as the efficiency drops, operators need to supply additional fuel to achieve the desired output, directly impacting operational costs and resource management.

In contrast, maintaining heat transfer, decreased operational capacity, and reduced emissions are all outcomes that may either remain stable or improve as a result of proper maintenance and operation, but they do not align with what typically occurs when efficiency decreases.