In a Rankine cycle, what happens to the steam after it expands in the turbine?

• A. It is compressed to higher pressure.
• B. It is vented to atmosphere.
• C. It is condensed back to liquid in a condenser.
• D. It remains as saturated steam.

Answer: (C)

After the turbine expands the steam, it exits at a much lower pressure and temperature. In a Rankine cycle, that exhaust is sent to a condenser where cooling water removes heat and the steam changes phase back to liquid. This liquid water, or condensate, is then pumped back to boiler pressure to be reheated into steam, closing the loop. Condensing to a liquid is essential because it allows high-pressure pumping of liquid water and efficient reuse of the working fluid. The other options don’t fit the cycle: you don’t compress the steam to higher pressure after expansion; venting to atmosphere wastes energy and mass; and remaining as saturated steam would prevent returning the fluid to the high-pressure liquid state needed to continue the cycle.