What does "cold startup" refer to in power plants?

"Cold startup" in power plants refers to the process of bringing a plant online from ambient temperature. This occurs when the equipment, including the boiler and turbines, has not been heated or operated for some time, and thus, the initial conditions are at or near the surrounding environmental temperature.

During a cold startup, careful procedures are followed to gradually increase the temperature of various components to ensure the integrity of the materials and the overall system while avoiding thermal shock. This process involves heating the boiler water to create steam, bringing pumps and other auxiliary equipment online, and carefully ramping up the turbines.

The other options do not accurately represent the concept of a cold startup. Shutting down a plant refers to the opposite process of interrupting operations, while starting a plant with preheated systems indicates a warm or hot startup scenario, which is different as those systems are already above ambient temperature. Running a plant at maximum capacity is unrelated to the startup process itself, as it focuses on operational efficiency rather than the initial phase of bringing the plant online.