Page 334 - Subyek Teknik Mesin - Forsthoffers Best Practice Handbook for Rotating Machinery by William E Forsthoffer
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Be st Practice 5 .13 Steam Turbine Best Practices
Steam turbines are not usually shop performance tested
They are only tested mechanically (vibration, bearing
temperatures, etc.) at no load
Because:
Performance (steam rate, efficiency) varies directly with steam
velocity
Steam velocity varies directly with steam flow
Steam flow varies directly with power requirement because:
Power = ΔH (energy per unit mass) mass flow rate
Testing at full load is not cost effective
Fig 5.13.9 Steam turbine performance testing
Non-extraction turbines present performance on a Willans-line
A Willans-line describes the amount of steam flow (throttle
flow) required for a given load at a given speed
An extraction map describes throttle flow for a given load and
extraction flow
Note: all curves are for a specific set of steam conditions
Fig 5.13.10 Steam turbine performance curves
Fig 5.13.12 Performance curve for a typical extraction steam
turbine (Courtesy of IMO Industries)
Fig 5.13.11 Typical performance curve for a single stage turbine with manual hand valves (Courtesy of IMO Industries)
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