🔍 Key Concepts

• Boiler economizer purpose and effect on efficiency • Relationship between feedwater temperature and required fuel input for steam generation • Typical percentage fuel savings per degree Fahrenheit of feedwater temperature rise in marine boilers

💭 Think About

• How does raising the feedwater temperature before it enters the boiler affect the amount of heat (and therefore fuel) needed to reach steaming temperature? • Compare the options: which one suggests a realistic, moderate efficiency gain rather than an extremely large or very small improvement? • If you increase feedwater temperature by, say, 100°F, what total percent fuel saving would each choice predict? Does that seem plausible?

✅ Before You Answer

• Estimate the total percent savings implied by each choice for a reasonable temperature rise (e.g., 60–100°F) and compare which seems physically realistic. • Check that the chosen option does not imply unreasonably high savings (for example, numbers that would almost eliminate fuel use for moderate temperature rises). • Verify that your selection aligns with typical marine engineering exam references for economizer fuel savings per 10°F of feedwater temperature rise.