1. How do HRSG (Heat Recovery Steam Generator) tubes differ from conventional boiler tubes?
HRSG tubes recover waste heat from gas turbines, operating at lower pressures but high thermal cycling. Materials like TP347H resist fatigue. Design focuses on compactness and rapid steam generation.
2. What are "rifled" boiler tubes, and where are they used?
Rifled tubes have internal spiral grooves to enhance water circulation in subcritical boilers, preventing film boiling and dryout. Common in coal-fired power plants.
3. Why are finned tubes used in certain boilers?
Finned tubes increase surface area for heat transfer in economizers or air heaters. Materials include carbon steel or Corten alloys.
4. How do nuclear boiler tubes handle unique challenges?
They withstand neutron irradiation and high-pressure water, using Inconel 600/690. Leak-tightness is critical to prevent radioactive contamination.
5. What are "co-extruded" boiler tubes?
These tubes combine a corrosion-resistant inner layer (e.g., stainless steel) with a strong outer layer (e.g., carbon steel), reducing costs while maintaining performance.
