🔍 Key Concepts

• Feedwater temperature and how it affects boiler efficiency and firing rate in an automatically fired boiler • Relationship between steam drum conditions (pressure, saturation temperature) and the superheater outlet temperature/degree of superheat • Difference between steam quality (moisture content) and degree of superheat

💭 Think About

• If the feedwater enters the drum at a higher temperature, does the boiler need more or less fuel to reach the same steaming rate and drum pressure? • How would warmer feedwater affect the amount of heat the superheater has available to add above the saturation temperature? • Does hotter feedwater make the steam leaving the drum wetter or drier before it enters the superheater?

✅ Before You Answer

• Be clear on the difference between steam quality (percent by weight that is vapor) and superheat temperature (degrees above saturation). • Think about whether higher feedwater temperature tends to improve or reduce overall thermal efficiency in a boiler. • Ask: in an automatically fired system that maintains constant pressure and load, would a change that improves efficiency cause an increase or decrease in fuel consumption?