某1 000 MW機(jī)組主蒸汽-高旁管道振動測試及分析

摘 要：針對某1 000 MW火電機(jī)組的主蒸汽-高旁管道振動問題，采用三向振動傳感器對高旁管道、主蒸汽管道及附屬支吊架根部、格柵板、格柵板支撐鋼梁結(jié)構(gòu)進(jìn)行詳細(xì)的現(xiàn)場測試，并對測試信號進(jìn)行時域及頻域分析。結(jié)果顯示，整個系統(tǒng)的振動頻率一致，最大振動區(qū)域位于高旁閥附近管段，從而明確振源并推導(dǎo)出清晰的振動傳導(dǎo)鏈，同時發(fā)現(xiàn)該管道振動特有的頻率特征，完全有別于常規(guī)汽水管道的寬頻振動情況，為后續(xù)振動處理指明方向。

關(guān)鍵詞：振動;高旁管道;主蒸汽管道;頻率;格柵板

中圖分類號：TM621.4 文獻(xiàn)標(biāo)志碼：A 文章編號：2095-2945（2024）30-0072-05

Abstract： Aiming at the vibration problem of the main steam-high pressure bypass pipeline of a 1 000 MW thermal power unit， a three-way vibration sensor was used to conduct detailed on-site testing of the high pressure bypass pipeline， the root of the main steam pipeline and its auxiliary supports and hangers， the grid plate， and the grid plate supported steel beam structure. The test signals were analyzed in the time domain and frequency domain. The results showed that the vibration frequency of the entire system was consistent， and the maximum vibration area was located in the pipe section near the high pressure bypass valve， thus clarifying the vibration source and deriving a clear vibration conduction chain. At the same time， it was found that the unique frequency characteristics of the pipe vibration were completely different from the broadband vibration of conventional steam-water pipes， pointing out the direction for subsequent vibration treatment.

Keywords： vibration; high-pressure bypass pipe; main steam pipe; frequency; grid plate

高溫汽水管道是火電廠汽水流程的重要組成部分，具有高溫、高壓的惡劣運(yùn)行工況，是火電廠核心金屬部件之一，與機(jī)組的安全穩(wěn)定運(yùn)行息息相關(guān)，也是金屬監(jiān)督工作的重點(diǎn)內(nèi)容之一。由于高溫汽水管道設(shè)計時有一定的柔性要求（滿足管道自身的熱膨脹需求）[1]，造成高溫汽水管道一般剛性較弱，加之管內(nèi)高溫汽水介質(zhì)流動狀態(tài)的不穩(wěn)定性，使得火電廠高溫汽水管道或多或少地存在一定的振動狀況[2-5]。管道振動帶來的動應(yīng)力對結(jié)構(gòu)持久性安全有著惡劣影響，管道異常振動通常導(dǎo)致管道及連接部件的疲勞破壞，強(qiáng)烈的管道振動則往往引起泄漏，甚至由于管道破裂可能引起爆炸等惡性事故，對設(shè)備甚至對人員生命造成嚴(yán)重?fù)p失，現(xiàn)實(shí)過程中因管道振動導(dǎo)致的開裂、泄漏、爆炸等失效故障更是不勝枚舉，因而對火電廠高溫汽水管道現(xiàn)場振動情況進(jìn)行測試分析，對評估管道振動危害以及進(jìn)一步消除管道振動故障具有重要的現(xiàn)實(shí)意義。……