2025/6/2118.4Ashdeposit/Corrosion/erosionofbackheatingsurfaces

§8-4尾部受热面的积灰/磨损和低温腐蚀1.Ashdeposit尾部受热面积灰1)积灰及其危害Loose松散性积灰：烟气携带飞灰流经受热面时，部分灰粒沉积在受热面上形成的。Lowtemperaturecohesive低温粘结性：烟气中的硫酸蒸汽在低温受热面上凝结，将灰粒粘聚形成的。Harm危害:Heattransfercoefficient,heatresistance灰的传热系数很小，使受热面的热阻增大，吸热量减少，排烟温度升高，排烟热损失增加，锅炉效率降低。积灰堵塞部分烟气通道，使烟气流动阻力增大，导致引风机电耗增大甚至出力不足，造成锅炉出力降低或被迫停炉清灰。

2025/6/2128.4Ashdeposit,Corrosion,erosionofbackheatingsurfaces

§8-4尾部受热面的积灰、磨损和低温腐蚀1.Ashdeposit尾部受热面积灰2)Influencefactors积灰影响因素FluegasVelocity烟气流速：烟气流速越大，积灰越少（图10-3）Particlesize飞灰颗粒度：粗灰多，冲刷作用大，积灰少Structureoftubebank管束结构特性：错列管束积灰轻3)Measurements减轻和防止积灰的措施合理选择烟速：8~10m/s采用小管径、小节距、错列布置的管束:φ25~32;s1/d=2~2.5,s2/d=1~1.5布置吹灰装置，制定合理的吹灰制度W1=2.5～3m/sW3=8~10m/s

2025/6/2132.Erosion尾部受热面磨损Heattransfersurfacesandotherairheaterpartscansuffererosiondamagethroughimpactofhighvelocity,gas-entrainedashparticles.Erosionusuallyoccursneargasinletswherevelocitiesarehighest.图10-4受热面管子的飞灰磨损8.4Ashdeposit,Corrosion,erosionofbackheatingsurfaces

§8-4尾部受热面的积灰、磨损和低温腐蚀

2025/6/2148.4Ashdeposit,Corrosion,erosionofbackheatingsurfaces

§8-4尾部受热面的积灰、磨损和低温腐蚀

2025/6/2158.4Ashdeposit,Corrosion,erosionofbackheatingsurfaces

§8-4尾部受热面的积灰、磨损和低温腐蚀2.Erosion尾部受热面磨损1)Influencefactors因素Velocity烟气流速：金属磨损与烟气流速的3~3.5次方成正比Concentration飞灰浓度：浓度越大，磨损越严重Particlecharacteristics灰粒特性：灰粒粗、硬，磨损严重Structure管束结构特性：错列比顺列磨损严重2)Measurement减轻磨损的措施合理选择烟速limitgasinletvelocity：economizer9m/s采用合理的结构和布置:节距均匀，顺列代替错列加装防磨装置coverwithabrasionresistantparts:图10-6搪瓷涂层和防磨涂料sacrificialmaterials(ceramics):采用膜式省煤器membraneeconomizer：

2025/6/2162.Erosion尾部受热面磨损图9-30省煤器防磨装置图9-31管式空气预热器防磨8.4Ashdeposit,Corrosion,erosionofbackheatingsurfaces

§8-4尾部受热面的积灰、磨损和低温腐蚀

2025/6/2178.4Ashdeposit,Corrosion,erosionofbackheatingsurfaces

§8-4尾部受热面的积灰、磨损和低温腐蚀3.Corrosion尾部受热面低温腐蚀1)Formationandharm低温腐蚀及其危害Airheatersusedonunitsfiringsulfurbearingfuelsaresubjec