500MW機組空預(yù)器轉(zhuǎn)子的性能分析及改造.pdf

1、華北電力大學(xué)（北京）碩士學(xué)位論文500MW機組空預(yù)器轉(zhuǎn)子的性能分析及改造姓名：莫慧敏申請學(xué)位級別：碩士專業(yè)：工程熱物理指導(dǎo)教師：梁雙印20060201華北電力大學(xué)碩士學(xué)位論文摘要空氣預(yù)熱器是電站鍋爐最廣泛使用的節(jié)能設(shè)備之一，天津國華盤山電廠224空預(yù)器在熱態(tài)運行約38104小時后，大軸發(fā)生斷裂。本文通過利用ANSYS有限元軟件對大軸進行應(yīng)力場分析，得出大軸斷裂的原因，以指導(dǎo)同類空預(yù)器的運行。首先對大軸進行靜應(yīng)力分析，證明在靜工況下，大軸

2、是安全的：然后對大軸進行瞬態(tài)沖擊載荷分析，得到當(dāng)上法蘭承受的沖擊載荷達到一定值時，上倒角處承受的最大應(yīng)力將達到其許用應(yīng)力，從而導(dǎo)致大軸疲勞斷裂。根據(jù)空預(yù)器實際工作環(huán)境和有限元計算結(jié)果，得到#22空預(yù)器斷軸的主要原因是：長期在足夠大的交變應(yīng)力作用下，大軸底部軸肩處產(chǎn)生裂紋并擴展，最終導(dǎo)致疲勞斷裂。并對空預(yù)器大軸提出改造方案，證明改造方案的合理性和可行性。關(guān)鍵詞：空氣預(yù)熱器，大軸，有限元分析，斷裂，疲勞ABSTRACTTheairprehe

3、aterisoneofthemostwidelyusedfacilitytosaveenergyinpowerplantThespindleof22”airpreheaterinTianjinPanshanpowerplantwasfracturedafterrunninginmghtemperatureconditionfor38xl礦hoursWi也mesuperFEManalysissoftwareANSYS，thispapera

4、nalyzedthestressfieldofthespindle，anddrewtheconclusionofthespindlefractureItcouldguidetherunningofthesimilarpreheatersAtfnst，thestaticstressanalysisWasproceeded，itprovedthatthespindlewassafeundernormalstaticstressThrough

5、theanalysisofinstantimpulsiveloadonthespindle，itWasfoundthatwhenthevalueofimpulsiveloadonupflangereachedsomedegree，themaximumstressonupfilletwouldreachitsallowablestress，thenresultedinthefatiguefractureAccordingtothefact

6、workingconditionofpreheaterandthecalculationresultsofthelimitedunit，theconclusionisdrew：theprimarycausetothespindlefractureof224preheateris，underlongtermadequatealternatingstress，thecrackcomesintobeingandextendsinspindle

7、shoulderofthespindlebottom，andthisleadstofatiguefractureFurthermore，amodificationprojectaboutthespindleofairpreheaterisputforward，inwhichtherationalityandfeasibilityarediscussedMoHuiMin(EngineeringThermophysies)Directedb