USCG Exam PracticeThermodynamics and heat exchangers
In a steam plant condenser, why must non-condensable gases be continuously removed?
- A. They increase the latent heat of the steam, reducing turbine work.
- ✓ They blanket the tubes, raise back-pressure, and reduce heat transfer.Correct
- C. They cause the condensate to become acidic, corroding the hotwell.
- D. They lower the seawater flow velocity through the condenser tubes.
Why B is correct
DOE-HDBK-1018 Vol.1 §2-3 states that non-condensable gases must be continuously removed by an air ejector or vacuum pump, or they blanket the tubes, raise back-pressure, and reduce heat transfer.
Cited:DOE-HDBK-1018 Vol.1 §2-3