1. Definition and Core Differences

2. Is HRSG a Type of Waste Heat Boiler?

Yes — HRSG is a type of waste heat boiler, but it's a specialized and high-end version designed for power generation systems, especially combined cycle operations.

Think of it this way:

• A waste heat boiler is like a general car.

• An HRSG is more like a Formula 1 race car — built for high-performance applications, tightly integrated with gas turbines, and optimized for efficiency.

Therefore, if you're working in a steel plant or chemical plant, you’re likely using a conventional waste heat boiler. But if you're dealing with gas turbine exhaust, the right term is HRSG.

3. Technical Comparison in Design

• HRSGs often use triple-pressure systems (HP, IP, LP), plus reheaters and bypass systems, designed for dynamic interaction with gas turbines.

• General waste heat boilers focus more on corrosion resistance, flue gas adaptability, and compactness to suit harsh industrial conditions.

4. The Risk of Misuse in Engineering Projects

Common mistakes:

• Using “HRSG” and “waste heat boiler” interchangeably in bidding documents, leading to miscommunication and incorrect quotations.

• Not clearly identifying the heat source during the design phase, resulting in mismatched systems and costly redesigns.

Best practice:

• Confirm the type of heat source → define the primary purpose (power generation vs. process steam) → select HRSG or general waste heat boiler accordingly.

5. Summary Table

Conclusion

HRSG ≠ All waste heat boilers,
but
HRSG ⊂ The broader family of waste heat boilers, specifically for power generation.

Next time you hear these terms, ask yourself:
Is the heat source a gas turbine?
If yes, you likely need an HRSG. If not, a conventional waste heat boiler is probably more suitable.