A WHRS tube leak moves the boiler from a steam-generation asset to a forced-stop liability in hours. Chloride and sulfate attack from kiln gas chemistry, thermal stress from cyclic operation, and material fatigue at design discontinuities are the usual mechanisms. Once a tube has perforated, the failure tends to propagate — adjacent tubes see additional flow disturbance, and a single leak can become a multi-tube event before the next inspection window. The decision is rarely whether to stop, only when.
Why this matters in the whrs
Tube failures are one of the highest-consequence WHRS events. Beyond the immediate steam-generation loss, the repair sequence — isolation, draining, tube replacement, re-pressurisation — can take days, and the schedule pressure on the kiln campaign accumulates while the boiler is offline. Plants that operate WHRS without contingency steam have to absorb the loss directly into their power balance, with grid-side cost or production-side throttling.
The upstream cause matters for prevention. Chloride and sulfate attack means the kiln-preheater volatile cycle has been running outside the design band; thermal fatigue means the boiler is seeing more cyclic operation than intended. Each leak event is also a chance to investigate the kiln-side root cause, not just replace the affected tube.