Power Plant Engineering

A: Governing principle: Non-condensable gases accumulate and degrade heat transfer without changing CW conditions. Applied here: Stable CW temperature and flow rule out fouling; the trend tied to repeated cycles points to trapped air that isn't fully removed between runs. Distractor trap: Tube fouling explains higher backpressure, but not a stepwise increase over short cycles with unchanged CW parameters.

A: Governing principle: Auxiliary power scales with thermal cycle losses and fluid handling duty. Applied here: Coal plants carry FD/ID fans, BFPs, mills, and ash systems, landing near high single-digit percentages of gross output. Distractor trap: The gas turbine comparison borrows a rule from a different cycle with far fewer auxiliaries.

A: Governing principle: Proof testing establishes integrity against plastic deformation and gross leakage. Applied here: Ambient hydro avoids stored energy while stressing the piping beyond design to expose fabrication or material defects. Distractor trap: Water hammer is a transient dynamic load and isn't represented by a static hydro.

A: Governing principle: NPSHa equals absolute suction head minus vapor pressure and losses. Applied here: 5 − 0.5 − 1.2 gives 3.3 m available at the eye. Distractor trap: Adding vapor pressure instead of subtracting it shows up often when engineers switch between pressure and head forms.