Recover flue-gas heat without crossing unsafe acid-dew-point limits.
Core concept
Start with the physical mechanism rather than a memorised definition. Trace the relevant flow and identify where energy, pressure, temperature or material condition changes.
Plant significance
Relate the concept to readings, alarms, operator actions, maintenance evidence and inspection findings.
Key takeaways
- Know the system boundary and flow path.
- Recognise normal and abnormal indications.
- Explain the failure mechanism.
- State the preventive control.