What is the role of a feedwater heater in a steam plant?

• A. To preheat feedwater using extraction steam from turbines, improving boiler efficiency and reducing fuel consumption.
• B. To cool feedwater to protect boiler tubes.
• C. To remove impurities from feedwater.
• D. To store feedwater.

Answer: (A)

The feedwater heater is used to heat the incoming feedwater by exchanging heat with steam that has already expanded in the turbine. By preheating the water before it enters the boiler, the boiler has to supply less energy to turn that water into steam. This reduces the fuel needed to achieve the desired boiler output, improving overall plant efficiency and lowering fuel consumption. The heat recovered from the extraction steam is a way to reuse energy that would otherwise be wasted, which also helps smooth temperature changes and reduce thermal stresses in the system.

Cooling the feedwater would be counterproductive, as it increases the boiler’s energy requirement. Purifying feedwater is done by water treatment equipment, not the heater. Storing feedwater is handled by feedwater storage systems, not the heater.