What does feedwater heating in regenerative cycles increase?

• A. Pump power
• B. Overall cycle efficiency
• C. Boiler pressure
• D. Turbine mechanical efficiency

Answer: (B)

Regenerative feedwater heating raises the average temperature at which heat is added to the cycle, which boosts thermal efficiency. By using extracted turbine steam to preheat the feedwater, the water entering the boiler starts at a higher temperature, so less fuel energy is required to generate the same amount of steam. This reduces the heat input for the same power output, improving the cycle’s overall efficiency. It doesn’t directly change pump power, boiler pressure, or turbine mechanical efficiency—the main effect is on how efficiently energy is added in the heat-adding stage.