In a steam plant, what component uses high-pressure exhaust steam?

• A. Closed feed water heater
• B. Deaerator
• C. Condenser
• D. Economizer

Answer: (A)

Using high-pressure exhaust steam to heat feedwater is the job of the closed feedwater heater. The turbine’s exhaust steam, still hot and under pressure, is diverted into this heater where it transfers heat to the feedwater returning to the boiler. Heating the feedwater before it enters the boiler reduces the energy needed to produce steam and lowers overall fuel consumption, improving cycle efficiency.

The other components have different roles. The deaerator removes dissolved gases from feedwater and uses steam mainly for that purpose. The condenser takes the turbine exhaust steam and condenses it into condensate with cooling water, not for preheating feedwater with high-pressure steam. The economizer uses heat from boiler exhaust gases (flue gas) to preheat feedwater, not the turbine’s high-pressure exhaust steam.