In boiler operation, what does the term "thermal shock" refer to?

Thermal shock refers to the rapid change in temperature of water, which can occur when cold water suddenly enters a hot boiler or when there is a quick drop in temperature due to operational changes. This rapid temperature change can induce significant stress on the materials of the boiler, potentially leading to cracks or failures in the boiler components.

In the context of boiler operation, it is crucial to maintain a steady temperature to prevent such thermal shock incidents. Often, thermal shock is a concern during the startup and shutdown of the boiler or when there are sudden adjustments in fuel supply or feedwater temperatures. The integrity of boiler materials and effective operation relies on careful management of temperature changes to avoid the risks associated with thermal shock.