What is the purpose of a condenser in a steam cycle?

• A. To condense exhaust steam back to liquid, create a vacuum, and enable condensate return for reuse.
• B. To compress exhaust steam to higher pressure.
• C. To preheat combustion air.
• D. To filter feedwater.

Answer: (A)

The main idea is how a condenser supports efficiency and water reuse in a steam cycle. After the steam expands in the turbine, it still carries heat but is at low pressure. The condenser cools that exhaust steam, turning it back into liquid water. This removal of heat creates a low-pressure environment on the exhaust side—a vacuum—that allows the turbine to extract more work from the steam, boosting overall efficiency.

The condensed liquid, called condensate, is then returned to the feedwater system. Returning condensate saves energy, since it’s already hot and relatively pure, reducing the amount of makeup water that must be heated and treated. This condensate return also lowers water usage and improves feedwater quality management.

Other functions listed don’t fit the condenser’s role: it doesn’t compress exhaust steam, which would harm efficiency; it doesn’t preheat combustion air (that’s an air heater/economizer function); and it doesn’t filter feedwater (that’s a filtration step in the feedwater system).