2025/6/2117.1FunctionandperformancecharacteristicofSR

§7-1过热器和再热器的作用和工作特点1.FunctionofS/R过热器和再热器的作用Superheater:arespeciallydesignedin-linetubebundlesthatincreasethetemperatureofsaturatedsteam.(RankinecycleFig.2-6)540~550oC 过热器:是将饱和蒸汽加热成具有一定温度的过热蒸汽的部件.Reheater:increasethetemperatureofexhaustedsteamfromhigh-pressurecylinderofsteamturbine. 再热器:是将汽轮机高压缸的排汽加热成具有一定温度的再热蒸汽的部件。SH/RH是锅炉用于提高蒸汽温度的部件

2025/6/2127.1FunctionandperformancecharacteristicofSR

§7-1过热器和再热器的作用和工作特点1.FunctionofS/R过热器和再热器的作用Increasethedrynessofsteaminturbine 提高汽轮机末级蒸汽干度Thereheatedsteampressureisabout20~25%ofsuperheatedsteam 再热蒸汽压力为过热蒸汽压力的20~25%Increasetheheatefficiencyof4~6%withoncereheatsystem 采用一次再热系统可以提高电厂热效率4~6%Increasetheheatefficiencyof2%withtwotimereheatsystem 二次再热可提高热效率2%,但系统复杂

2025/6/2137.1FunctionandperformancecharacteristicofSR

§7-1过热器和再热器的作用和工作特点2.WorkingcharacteristicsofS/R工作特点Workingconditionisverybad工作环境恶劣Inordertogethighertheinitialtemperaturedifferencebetweenthehotandcoldfluids,thesuperheatersarelocatedinhightemperaturezone,sothetemperatureoftubewallisveryhigh. 为保证合理传热温差，布置在高温区，其管壁温度很高。Hightemperaturesteamflowinsidethetubes,heattransfercoefficientofthetubewallisverysmall.管内流过高温蒸汽，管壁对蒸汽的对流放热系数小，传热性能较差，蒸汽对管壁的冷却能力较低。Thepressureofreheaterislow,thecoolingabilityisbad.再热器内蒸汽压力低，冷却管子的能力更差。

2025/6/2147.1FunctionandperformancecharacteristicofSR

§7-1过热器和再热器的作用和工作特点2.WorkingcharacteristicsofS/R工作特点Steamtemperatureiskeptat540~550oCduetothelimitofmetalmaterial.受金属材料限制，蒸汽温度限制在540-550oC(pp.171表7-1)Allowabletemperature锅炉常用钢材的许用温度)Preventheatingsurfacetemperaturefromoverheating,andexceedingthematerialallowancetemp.防止受热面金属温度超过材料的许用温度;Goodtemperatureadjustmentcharacteristics,keepingSToverawideloadrange.过热器与再热器温度特性好，在较大的负荷范围内能通过调节维持额定汽温;Preventashdeposit,erosion防止受热面管束积灰、磨损和腐蚀。

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