How does steam temperature respond to an increasing load in boilers equipped with radiation superheaters________________?
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Answer: B. decreases
Explanation
Radiation superheaters experience a decrease in steam temperature as the boiler load increases. Fuel firing rate increases less proportionally than steam flow at higher loads, reducing radiant heat absorption per unit mass. This characteristic contrasts with convection superheaters, which exhibit rising steam temperatures under heavier operating loads. Superheaters raise steam temperatures above saturation levels to improve thermodynamic cycle efficiency in power plants. Radiation superheaters receive heat primarily through direct thermal radiation from furnace flames and refractory walls. Combustion gas temperatures and steam flow rates determine the final outlet enthalpy of superheated steam.
Power plant operators monitor superheater performance curves to maintain safe turbine inlet steam temperature limits. Combining radiation and convection superheaters helps stabilize final steam temperatures across varying boiler loads. Thermal stress management in high-pressure boilers depends on understanding superheater temperature response characteristics. Option A describes convection superheaters, where higher gas flow rates increase steam temperature at heavier loads. Option C is incorrect because steam temperatures change dynamically with varying boiler operating loads. Option D incorrectly suggests non-monotonic temperature behavior that does not match radiation superheater physics.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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