USCG Exam PracticeBoiler and steam propulsion fundamentals
In a marine steam propulsion plant operating on the Rankine cycle, what is the primary purpose of the main condenser?
- A. To superheat steam before it enters the main turbine
- ✓ To remove latent heat from exhaust steam and condense it back to water, while producing a vacuumCorrect
- C. To deaerate feedwater and strip dissolved oxygen from the condensate
- D. To preheat incoming feedwater using waste heat from the flue gases
Why B is correct
The main condenser receives low-pressure exhaust steam from the main engine, seawater-cooled tubes remove its latent heat condensing it back to water, and the condensing process produces a vacuum that allows the engine to extract significantly more work from the steam. Deaeration is performed in the deaerating feed tank, and feedwater preheating is performed by the economizer. (NAVEDTRA 14104 §3-1)
Cited:NAVEDTRA 14104 §3-1