Variable regimes
Boiler design and calculation: behavior and performance

The basic approach requires a high level of efficiency and justifies a high level of investment, possibly including a supercritical pressure solution if the number of operating hours is around 8,000 per year and fuel is cheap.

In general, we do not require rapid load variation, but solutions that ensure good temperatures over a fairly wide operating range: for example, between 35 and 100% for superheating and 60 and 100% for resuperheating(s), the minimum resuperheating threshold being referred to as the control point. The quest for good availability means installing more back-up devices and complementary circuits; fault detection requires more sophisticated, redundant systems to avoid shutdowns due to fictitious faults.

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