Which turbine procedure holds the speed constant to allow temperature equalization between components?

Which turbine procedure holds the speed constant to allow temperature equalization between components?

• A. Isothermal hold
• B. Temperature equalization
• C. Heat soak
• D. Slow ramp

Answer: (C)

Heat soak is a turbine procedure that aims to equalize temperatures across components by running the machine at a steady speed long enough for heat to flow between parts. Maintaining a constant speed provides a stable mechanical environment, letting heat transfer occur without the disturbances of changing rotor speed. As hotter areas and cooler areas come toward the same temperature, thermal gradients thin out, reducing differential expansion and the risk of thermal stress when the turbine is later loaded. This approach is especially important after shutdown or maintenance when different components may be at different temperatures. An isothermal hold would focus on keeping temperature constant rather than allowing heat to spread between parts, the idea of temperature equalization describes the goal but isn’t the specific procedure. A slow ramp is about gradually increasing speed to avoid thermal shock during startup, not about letting temperatures balance at a fixed speed.

Heat soak is a turbine procedure that aims to equalize temperatures across components by running the machine at a steady speed long enough for heat to flow between parts. Maintaining a constant speed provides a stable mechanical environment, letting heat transfer occur without the disturbances of changing rotor speed. As hotter areas and cooler areas come toward the same temperature, thermal gradients thin out, reducing differential expansion and the risk of thermal stress when the turbine is later loaded. This approach is especially important after shutdown or maintenance when different components may be at different temperatures. An isothermal hold would focus on keeping temperature constant rather than allowing heat to spread between parts, the idea of temperature equalization describes the goal but isn’t the specific procedure. A slow ramp is about gradually increasing speed to avoid thermal shock during startup, not about letting temperatures balance at a fixed speed.