Explain the role of an auxiliary boiler.

An auxiliary boiler plays a crucial role in power generation and heating systems by ensuring a consistent supply of steam during peak load periods or when the primary boiler is unable to operate, such as during maintenance or unexpected outages. This capability helps to stabilize the system and maintain operational reliability, particularly in situations where demand for steam is high or when the main boiler is offline.

By providing additional steam, the auxiliary boiler allows the facility to handle load variations without disrupting service, thus ensuring that processes that depend on steam can continue to function smoothly. Moreover, it supports the overall efficiency of the energy system by preventing downtimes that could affect production or service delivery.

In contrast, the other options, while potentially related to boiler operations, do not accurately describe the main function of an auxiliary boiler. The storage of excess fuel, enhancement of combustion efficiency, and reduction of emissions are important aspects of boiler operation but are not the core focus of an auxiliary boiler's purpose.