PURPOSE OF START-UP SYSTEM
The UP-Spiral once-through boiler is designed for a minimum flow in the furnace circuits to limit irregularities of flow distribution and to keep tube metal temperatures below allowable values. This minimum furnace flow must be maintained whenever the boiler is being fired. Unit operation during loads when steam flow is below the minimum flow requires the use of the boiler start-up system. The start-up system maintains the required minimum flow through the furnace, 1210.5 klb/hr (152.51 kg/s), while providing the desired flow to the turbine or turbine bypass system.
The UP-Spiral once-through boiler requires feedwater to have impurities below certain values before firing the boiler. The start-up system provides a flow path back to the feedwater system during cold water clean-up.
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| Sơ đồ Boiler Start up System |
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