🔍 Key Concepts

• Regenerative air heater operation in marine boilers and what happens to gas temperatures at low load • The relationship between flue gas temperature, dew point, and condensation of corrosive components (like sulfur compounds) • Effects of low load on air and gas flow through heat exchangers

💭 Think About

• What happens to exhaust gas temperature when the boiler is operating at low load but the air heater is still transferring a lot of heat? • If the gas side of the air heater gets too cool, what could begin to form on the cold surfaces, and why is that undesirable? • Which option specifically connects low-load operation with changes in gas temperature and phase (vapor vs. liquid)?

✅ Before You Answer

• Verify which choice directly refers to temperature and condensation of exhaust gases, not mechanical issues like coatings or seals. • Check your steam plant theory: does low load usually increase or decrease the risk of condensation and corrosion in gas paths? • Eliminate any answers that don’t involve the gas side temperature behavior of a regenerative air heater at low firing rates.