張建偉,江 琦,王 濤
(華北水利水電大學(xué)水利學(xué)院,鄭州 450011)
基于原型觀測的梯級泵站管道振源特性分析
張建偉,江 琦,王 濤
(華北水利水電大學(xué)水利學(xué)院,鄭州 450011)
以景電二期3泵站2號輸水管道為對象,結(jié)合原型試驗觀測數(shù)據(jù),研究該類型泵站結(jié)構(gòu)的振源組成及其對管道的影響。首先,對連接2號管道的4號、5號機(jī)組正常運行和開關(guān)機(jī)過程中引起的管道結(jié)構(gòu)振動頻率進(jìn)行識別統(tǒng)計,確定其動荷載來源;然后,分析統(tǒng)計不同工況下管道結(jié)構(gòu)主要部位達(dá)到峰值時各分頻所占比例,計算不同工況下各頻帶能量對總能量的貢獻(xiàn)率。計算結(jié)果表明:機(jī)組穩(wěn)定運行時,葉頻和轉(zhuǎn)頻倍頻引起的振動比例達(dá) 73.4%,是管道振動的主振源低頻所占比例為12%左右;機(jī)組開機(jī)過程中,低頻水流脈動所占比例增加到33.7%,葉頻所占比例保持40%左右,葉頻和低頻是主要振源;機(jī)組關(guān)機(jī)過程中,低頻水流脈動引起的振動比例達(dá)73.3%,水體-管道耦合引起的高頻振動達(dá)21.7%左右,低頻水流和高頻是主要振源,且低頻對管道順?biāo)鞣较蛘駝佑绊戄^大。研究結(jié)果有助于從量級上評價管道振動的原因及引起振動的各分頻貢獻(xiàn)率,以期為管道結(jié)構(gòu)主動控制和安全運行提供依據(jù)。
泵;振動;灌溉;泵站管道;供水;振源分析;動荷載
近年來隨著高揚程梯級輸水泵站大力興建,現(xiàn)代農(nóng)業(yè)生產(chǎn)中跨流域遠(yuǎn)距離輸水灌溉問題得到有效解決。管道作為梯級泵站長距離輸水調(diào)水的載體,通過廠房直接連接泵站機(jī)組,在泵站正常運行和開關(guān)機(jī)過程中承受不同程度的振動擾動,所以保持其穩(wěn)定運行尤為重要。并且作用在管道結(jié)構(gòu)上的各種動荷載擾動因素復(fù)雜,定量分析困難,管道振動也越來越受到人們重視[1-6]。因此,研究管道結(jié)構(gòu)的振動原因以及泵站運行對管道結(jié)構(gòu)產(chǎn)生的影響成為一項新的課題。
傳統(tǒng)的管道振動研究主要從結(jié)構(gòu)建模方面切入,從不考慮水體-管道流固耦合到考慮水體-管道流固耦合兩方面分析管道運行時的振動特性[7-13],之后又結(jié)合流體力學(xué)優(yōu)化泵站內(nèi)部結(jié)構(gòu)降低其對管道振動影響[14-24]。隨后諸多學(xué)者從泵站管道原型實測數(shù)據(jù)分析管道運行時振動特性,陳作儀等[25]通過小波分析,從導(dǎo)葉片開啟角度分析管道振動性能;馮婷等[26]通過分析不同運行工況下水錘對管道的影響,總結(jié)出針對不同工況下減弱水錘影響的措施。盡管上述研究取得了一定階段性的成果,但傳統(tǒng)的管道振動分析只單方面考慮了水體-管道的因素以及泵站內(nèi)部結(jié)構(gòu),對于復(fù)雜的水力脈沖作用、邊界條件、泵站機(jī)械、電機(jī)等其他因素并未考慮;同時也沒有系統(tǒng)地分析不同工況下引起管道振動的原因和引起管道振動的各因素在不同工況下對管道各部位的影響貢獻(xiàn)率以及因素影響量級大小。因此本文依據(jù)泵站管道原型觀測試驗,從振動信號分析出發(fā),整體分析引起管道振動的原因以及各原因量級。
以景電梯級泵站管道為研究對象,首先根據(jù)泵站原型觀測數(shù)據(jù),對振動信號進(jìn)行分析,獲得各主要頻帶動力響應(yīng),探討泵站穩(wěn)定運行及開關(guān)機(jī)過程中振源對管道結(jié)構(gòu)的振動影響,并對各種動荷載作用效果進(jìn)行評價,全面整體把握泵站管道運行期間振動原因,以期為管道采取相應(yīng)的減振措施提供理論依據(jù)和數(shù)據(jù)支持,保證管道的安全運行,為類似工程的設(shè)計和運行提供參考。
甘肅景泰電力提灌二期工程(簡稱景電工程)是一項高揚程、大流量、多梯級電力提水灌溉工程。其中3泵站2號管道能夠代表大型泵站多機(jī)單管的布置模式,且2號管道相對于其他管道試驗場地更容易布置,便于操作,因此選擇2號管道為試驗對象。2號管道連接的4、5機(jī)組均為1200S-56型臥式離心泵,設(shè)計流量3 m2/s,額定轉(zhuǎn)速為600 r/min,設(shè)計揚程56 m。3泵站2號管道平面布置圖如圖1所示。
圖1 3泵站2號管道平面布置Fig.1 No.2 pipeline layout of No.3 pumping station
泵站管道原型觀測試驗共布置6個測點,各測點均放置3個拾振器(x、y、z 3個方向),這6個測點分別位于2號主管端部和A、B支管的端部和中部,其中z方向和x方向測點反映主管和支管B的耦合振動作用,y方向測點反映主管和支管A的耦合振動作用,泵站管道拾振器布置見圖2(1#、2#、3#拾振器為測點1,4#、5#、6#拾振器為測點2,…,以此類推共18個拾振器6個測點)。試驗采用中國地震局工程力學(xué)研究所研制的891-2型拾振器,該拾振器共設(shè)小速度、中速度、大速度和加速度4檔,具有小體積、小質(zhì)量、使用方便、動態(tài)范圍大和一機(jī)多用等特點。根據(jù)管道工作振動特點,選用中速度檔位,該檔位下12個水平拾振器的靈敏度范圍在7.394~7.543 V·s/m之間,6個垂直拾振器的靈敏度范圍在6.729~6.920 V·s/m之間。原型試驗共測試5種工況,工況描述、采樣時間、采樣頻率見表1,其中機(jī)組開啟過程指機(jī)組轉(zhuǎn)速由0達(dá)到穩(wěn)定,機(jī)組關(guān)機(jī)過程指轉(zhuǎn)速由穩(wěn)定降到0,穩(wěn)定運行指機(jī)組轉(zhuǎn)速處于穩(wěn)定狀態(tài)。
圖2 2號管道拾振器布置平面圖Fig.2 Vibration sensor layout of No.2 pipeline
表1 管道原型試驗測試工況Table 1 Test conditions of pipeline prototype
2.1 振源理論
根據(jù)以往關(guān)于水輪機(jī)組以及泵站機(jī)組的研究可知,泵站機(jī)組引起的管道結(jié)構(gòu)振動主要有3個因素:水力因素、機(jī)械因素和電氣因素[27-31]。水力因素表現(xiàn)形式為:1)水流脈動,在泵站運行中,水體流過管道形成的低頻脈沖振動;2)旋轉(zhuǎn)軸渦,泵站在小流量情況下,葉輪內(nèi)形成低速區(qū)及軸向旋渦較多,流動不穩(wěn)定引起的中低頻振動;3)轉(zhuǎn)輪葉片水流沖擊脈動形成葉頻,在泵站機(jī)組運行過程中,蝸殼內(nèi)不斷從前池中吸入水流,葉片轉(zhuǎn)動與水流沖擊形成的中高頻振動;4)水體-管道耦合引起的高頻振動,在泵站停機(jī)瞬間,高速水流沖擊管道形成旋轉(zhuǎn)渦帶進(jìn)而產(chǎn)生的高頻振動。機(jī)械因素表現(xiàn)形式為:1)機(jī)組轉(zhuǎn)頻倍頻,機(jī)組主軸自振頻率及轉(zhuǎn)頻;2)葉輪與隔舌動靜干涉引起的中高頻振動;3)機(jī)組轉(zhuǎn)動部分不平衡,由于機(jī)組制造、安裝誤差所致,一般不會產(chǎn)生高量級諧波;4)機(jī)組轉(zhuǎn)動軸不同軸,由不同軸造成二次諧波分量較大,且軸向振動量級大。電磁振動主要由泵站機(jī)組發(fā)電機(jī)設(shè)計不合理或制造安裝不合理產(chǎn)生的電磁力,在泵站運行時,磁拉力、三相不平衡等均可能引起管道振動。
2.2 管道振源實測分析
根據(jù)原型試驗采集的數(shù)據(jù),對各工況管道測點振動數(shù)據(jù)進(jìn)行頻譜分析,可得到各拾振器信號的振動主頻、次頻及其幅值信息。圖3為工況1和工況3下4#拾振器信號數(shù)據(jù)頻譜圖。由圖3a知,4機(jī)組開機(jī)過程中,4#拾振器凸顯頻率為0.5、23.6、33.3、60、90 Hz,其中60 Hz對應(yīng)幅值最大,0.5 Hz對應(yīng)幅值次之,33.3、23.6 Hz對應(yīng)幅值依次減少,說明60 Hz是引起管道振動的主頻,0.5、33.3 Hz等為次頻,這些頻率對管道振動貢獻(xiàn)率較大;可知4機(jī)組關(guān)機(jī)瞬間,其主頻為0.5、83、84.5 Hz。
圖3 4#拾振器信號頻譜圖Fig.3 Power spectral density of 4# vibration sensor
限于篇幅其他工況下各測點各方向拾振器信號數(shù)據(jù)頻譜分析圖不再列出,根據(jù)各拾振器信號頻譜圖統(tǒng)計各工況下測點振動主頻出現(xiàn)次數(shù),表2為5種工況下主頻出現(xiàn)次數(shù)統(tǒng)計。由表2可知,測點頻率在0.5、0.8、1.0、1.5、2.0、10、23.6、33.2、40、60以及83 Hz均有分布。其中0.5、60 Hz出現(xiàn)次數(shù)占各測點主頻出現(xiàn)次數(shù)的半數(shù)以上。5種工況主要振源頻率為0.5、0.8、1.0、1.5、2.0、10、12.6、14、16.4、20、23.6、26、30、33.2、35.8、40、46.8、48.2、50、60、73、83、89、92、110 Hz等。
表2 各工況主要頻率出現(xiàn)次數(shù)Table 2 Number of dominant frequency appeared in each condition 次
2.3 振源組成
由實測數(shù)據(jù)頻譜分析和表2可知,影響管道結(jié)構(gòu)振動較大的頻率成分主要有低頻水流、轉(zhuǎn)頻倍頻、葉頻、主軸不對稱引起的二次諧波、葉輪與隔舌動靜干涉引起的中頻、水體-管道耦合引起的高頻等,具體描述如下。
1)低頻成分。主要由泵站管道輸水產(chǎn)生的水流脈動所致。由水力因素中的各種激振源理論可知,汽蝕通常為頻帶較寬的高頻振動,湍流激勵引起的是比汽蝕頻帶更寬的振動,葉頻通過轉(zhuǎn)速計算可知為60 Hz。由工程經(jīng)驗可知,水流脈動頻率常為低頻,且在2 Hz以下。工況1低頻振動在0.5~1.5 Hz;工況2、4、5低頻為0.6、0.8 Hz;工況3低頻為0.5 Hz、0.8~2.0 Hz。主要體現(xiàn)為:① 0.5和0.8 Hz出現(xiàn)在工況1、3所有振動測點,且在支管A彎管處、支管A與主管連接中部、支管B靠近機(jī)組部位以及遠(yuǎn)離機(jī)組部位低頻能量非常大;② 2、4、5工況下,在遠(yuǎn)離機(jī)組部位、支管A彎管處和主管端部的測點低頻振動為主頻。低頻多在離機(jī)組較遠(yuǎn)的測點以及機(jī)組開關(guān)機(jī)時表現(xiàn)為主頻,此時葉頻、轉(zhuǎn)頻倍頻等影響較小且隨著距離的增加逐漸減小,管道內(nèi)水流脈動頻率相對凸顯。但離心泵內(nèi)部構(gòu)造復(fù)雜,水流脈動機(jī)理還在進(jìn)一步研究中,具體的水力激振源細(xì)致分類還需要進(jìn)一步討論。
2)轉(zhuǎn)頻倍頻、轉(zhuǎn)軸高級諧波成分。轉(zhuǎn)頻為機(jī)組旋轉(zhuǎn)主頻率,該泵站機(jī)組額定轉(zhuǎn)速為600 r/min,轉(zhuǎn)頻在10 Hz附近;在工況2、4、5情況下,2倍轉(zhuǎn)頻和因轉(zhuǎn)軸不對稱引起的高階頻率出現(xiàn)在管道測點的各向振動中。
3)葉頻振動。該泵站轉(zhuǎn)輪葉片與水流沖擊引起的振動頻率為60 Hz左右,屬于中高頻率,在1、2、4、5工況所有測點各向振動均有體現(xiàn),常為主頻,且能量突出;在工況3中偶爾體出現(xiàn),且能量很小。
4)水體-管道耦合引起的高頻成分??紤]到汽蝕、湍流激勵等為振動頻帶較寬的激勵源,且83 Hz左右頻率在其他4種工況下能量非常微弱,而83 Hz在工況3各測點且能量貢獻(xiàn)率較大,此時機(jī)組轉(zhuǎn)速從穩(wěn)定狀態(tài)逐漸降到0,轉(zhuǎn)頻、葉頻等影響逐漸降低,但輸水管道中水體因機(jī)組停機(jī)形成高速水流沖擊管道,導(dǎo)致水體-管道耦合振動,多表現(xiàn)為主頻出現(xiàn)在管道各測點中,并且在支管彎管處能量最突出。
3.1 主要測點達(dá)振動峰值時各分頻比例
試驗結(jié)果采用平穩(wěn)隨機(jī)過程 95%置信度雙幅值,對各工況狀態(tài)下管道各拾振器振動達(dá)峰值時各分頻所占的比例進(jìn)行計算,說明在不同工況下,各分頻能量所占比例對管道結(jié)構(gòu)振動的影響。各工況分頻比例見表3。
表3 各工況下管道不同方向分頻比例Table 3 Frequency division proportion of pipeline under each working condition in different vibration directions %
工況1:4號機(jī)組開啟過程中,垂直水流方法(x方向)振動最大值處對應(yīng)功率譜主頻為60和0.5 Hz,是水流沖擊轉(zhuǎn)輪葉片引起的葉頻振動和低頻水流脈動。由表3可知,葉頻所占比例達(dá)41.3%,低頻占29.4%,轉(zhuǎn)頻倍頻等成分占15.4%。順?biāo)鞣较颍▂方向)振動最大值處對應(yīng)主頻為0.5和60 Hz。低頻水流脈動成分增加到33.7%,葉頻比例降低到28.9%,轉(zhuǎn)頻倍頻增加到25.3%。垂直管道方向(z方向)振動最大值對應(yīng)主頻為60和0.5 Hz,其中低頻水流脈動成分占27.8%,葉頻成分占34.3%,轉(zhuǎn)頻倍頻成分占22.5%。各方向中高頻所占成分比例均在5%以下。
上述分析知,機(jī)組開啟過程中,葉頻和低頻水流脈動是引起管道振動的主要頻率。由表3知,管道徑向(x、z向)各分頻能量對管道振動影響基本一致,葉頻振動占比例最大,低頻水流脈動次之。在管道軸向,葉頻振動能量所占比例明顯降低,水流脈動振動占主要比例,說明順?biāo)鞣较虻皖l擾動占主要作用。
工況2:測點振動幅值整體較開機(jī)時減小,3個方向主頻均為60 Hz。由表3中工況1和工況2數(shù)據(jù)對比知,葉頻比例增加到50%左右,低頻水流能量比例較工況1明顯減少,降低到12%左右,轉(zhuǎn)頻倍頻能量比例基本不變,葉頻和轉(zhuǎn)頻倍頻引起的振動比例達(dá)73.4%。說明機(jī)組穩(wěn)定運行時,分頻能量在3個方向分布較均衡,葉頻是管道振動的主要原因,機(jī)組轉(zhuǎn)軸不對稱引起的高階諧波分量次之,且能量基本不變。
工況3:4號機(jī)組停機(jī)過程中,垂直水流方向(x方向)振動最大值處對應(yīng)主頻為0.5和83 Hz,是低頻水流脈動及水體-管道耦合引起的高頻振動。由表3中工況3數(shù)據(jù)知,低頻水流脈動能量比例占66.2%,高頻比例為18.3%。順?biāo)鞣较颍▂方向)振動最大值處對應(yīng)功率譜主頻也為0.5和83 Hz,低頻成分為73.3%,高頻能量比例增加到11.4%。垂直管道方向(z方向)振動最大值處對應(yīng)功率譜主頻為0.5 Hz,該分頻能量所占比例為62.5%,高頻能量所占比例為21.7%。
上述分析可知,低頻振動與工況1、2相比明顯增加,最高達(dá)73.3%,高頻能量比例也大幅增加,兩振源比例占總能量的85%左右;葉頻及轉(zhuǎn)頻倍頻降低到6%左右,相對于工況1、2明顯下降。說明4號機(jī)組停機(jī)過程中,低頻水流脈動和水體-管道耦合引起的高頻振動是主要振源。且低頻振動在y方向尤其突出,說明在停機(jī)過程中,高速水流沿著管道流動是引起管道振動的主要原因。高頻能量為泵站停機(jī)后,主管中的水體倒流到支管造成水體與管道沖擊引起的高頻振動。
工況4:由表3知,該工況下各分頻能量對管道3個方向振動影響基本一致,且比例分布與工況1相似,說明機(jī)組開機(jī)瞬間,高速水流形成的低頻脈動對管道影響也較大。葉頻較工況2降低到40%左右,說明突然開啟5機(jī)組時,5機(jī)組的振動相當(dāng)于阻尼器作用,減弱了水流沖擊轉(zhuǎn)輪葉片引起的振動。轉(zhuǎn)頻倍頻比例與工況2基本一致。
工況5:4、5機(jī)組穩(wěn)定運行。該工況下管道各向測點振動主頻為60 Hz,由表3看出,各分頻能量在各方向比例基本一致,且各分頻所占比例分布與工況2相似,轉(zhuǎn)頻倍頻能量比例基本不變,葉頻較工況2小幅度增加。
3.2 各種工況下分頻引起的振動能量比例
設(shè)某工況下分頻振動能量占振動總能量為:
式中e為各分頻振動能量,E為振動總能量。將xi劃分為0~0.1、>0.1~0.2…>0.9~1.0共10個區(qū)間段,對所有工況進(jìn)行分析統(tǒng)計,獲得各區(qū)間內(nèi)總數(shù)為si,進(jìn)而得到該段區(qū)間工況拾振器數(shù)占總統(tǒng)計拾振器數(shù)的百分比為:
式中m為總統(tǒng)計工況拾振器數(shù)。
表4給出了5種工況下低頻水流脈動、葉頻轉(zhuǎn)頻倍頻、高頻統(tǒng)計結(jié)果。
限于篇幅僅詳細(xì)說明工況1分頻能量貢獻(xiàn)率。由表4知,4機(jī)組開機(jī)過程中,葉頻、轉(zhuǎn)頻倍頻所占分頻能量百分比加權(quán)最大,61.0%的拾振器該段分頻能量占振動總能量比例在0.5~0.8之間,77.7%的拾振器其低頻振動成分占振動總能量比例在0.1~0.3之間,而83.2%拾振器高頻成分占總振動能量比例在0~0.2之間。說明4機(jī)組開機(jī)過程中,葉頻振動引起的中高頻60 Hz和低頻水流脈動是管道結(jié)構(gòu)振動的主要原因,高頻振動對管道影響很微弱。其余4種工況按照上述思路分析,此處不再贅述。
表4 各工況下管道分頻振動能量比例Table 4 Vibrational energy proportion of frequency division of pipeline under different working conditions %
根據(jù)表4中各分頻能量對總能量振動響應(yīng)貢獻(xiàn)率分析可知,機(jī)組穩(wěn)定運行時,83.2%的拾振器葉頻、轉(zhuǎn)頻倍頻引起的振動能量比例在0.5~0.9之間;當(dāng)4、5機(jī)組同時運行時,管道各測點能量較4機(jī)組單獨穩(wěn)定運行時能量大,但各分頻能量對總能量貢獻(xiàn)率相似,85.7%拾振器低頻和高頻能量比例在0~0.2區(qū)間內(nèi)。機(jī)組開啟時,水流脈動對管道振動總能量貢獻(xiàn)率有所增加,與機(jī)組穩(wěn)定運行時相比,42.1%的拾振器低頻成分所占比例在0.2~0.3區(qū)間內(nèi),但葉頻等引起振動仍是主要振動因素。機(jī)組關(guān)機(jī)過程中,低頻脈動水流和水體-管道耦合高頻振動對管道振動總能量貢獻(xiàn)率驟增,與工況2、5相比,78%的拾振器低頻振動能量比例分布在0.5~0.8區(qū)間,48%的拾振器其高頻振動能量所占比例在0.3~0.5區(qū)間內(nèi)。
通過對該管道原型觀測資料分析統(tǒng)計,可得如下結(jié)論:
1)機(jī)組穩(wěn)定運行,管道主要測點振動幅值達(dá)最大值時,葉頻、轉(zhuǎn)頻倍頻產(chǎn)生的振動所占比例達(dá)73.4%,是管道振動的主要影響因素;管道內(nèi)低頻水流脈動雖在某些部位能量較大,但影響非常有限,其所占比例為12%。
2)機(jī)組開啟過程中,葉頻振動所占比例達(dá)41.3%;低頻水流脈動對管道振動能量較機(jī)組穩(wěn)定運行時有所增加,尤其在管道順?biāo)鞣较蛟黾用黠@,最大比例為33.7%,但就管道整體而言葉頻仍是主要振源。一機(jī)組穩(wěn)定運行,另一機(jī)組開啟時,低頻水流對管道振動影響增加,但沒有單一機(jī)組開啟時增量大,低頻比例最大為27.3%;相鄰機(jī)組的運行起到阻尼器的作用,對兩機(jī)組轉(zhuǎn)輪葉片引起的振動有一定的削弱作用,其所占比例為40%左右,但依舊是主要振源,轉(zhuǎn)頻倍頻在機(jī)組運行過程中占比例在各測點基本穩(wěn)定在20%左右。
3)機(jī)組停機(jī)過程中,低頻水流脈動引起的振動比例最大,達(dá)73.3%,尤其在管道順?biāo)鞣较蛞鸬恼駝痈怀?。水體-管道耦合引起的高頻振動主要體現(xiàn)在管道彎管處和兩管連接處,相對于其他4種工況該分頻在停機(jī)過程中影響比例突出,達(dá)21.7%,說明停機(jī)時,管道內(nèi)水體回流對管道安全運行影響較大。
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Analysis of vibration characteristics of pipeline of trapezoid pumping station based on prototype observation
Zhang Jianwei,Jiang Qi,Wang Tao
(College of Water Conservancy,North China University of Water Conservancy and Electric Power,Zhengzhou 450011,China)
Pipeline is a carrier of cascade pumping station with long distance water conveyance. Therefore,it is particularly important to keep the stable operation of pipeline structure. In order to ensure the safe operation of pipeline structure,it is significant to research the main influence factors of pipeline vibration and the contributions of different factors to pipeline structure. Based on prototype observation data,vibration source compositions and their influences on pipeline structure were investigated through analyzing the power spectral density of vibration data. Taking the No.2 pipeline of Pumping Station 3 in Jindian River pumping irrigation as the research object,six points were set up in different parts of pipeline. Three vibration sensors were placed in each measuring point,from which vibration data were collected in three directions of pipeline. First of all,on the basis of mathematical statistics theory and the observation data of vibration sensors,vibration frequencies of pipeline structure excited by four and five units in the process of normal operation and switch machine were identified according to the spectrum analysis. Dominant frequencies of pipeline structure were counted under different working conditions to determine the dynamic load sources and to introduce the vibration source compositions of pipeline structure. Furthermore,the contributions of different frequencies were calculated when the vibrations of main points reached the maximum values under different working conditions. At the same time,the contributions of the measured frequency bands energy to the whole vibration response were calculated. The analysis results showed that,under the working condition of steady operation of units,the contribution of vibration energy caused by blade frequency and rotation frequency was 73.4%,and the contribution of low frequency water-flow pulsation was about 12%. During unit start-up,the vibration energy contribution of low frequency water-flow pulsation was increased to 33.7%,and the contribution of blade frequency still was about 40%. During unit shutdown,compared with the steady operation conditions,the vibration energy contributions of low frequency and high frequency induced by water-pipeline coupling were increased by 73.3% and 21.7%,respectively. The study showed that the vibration of blade frequency and rotation frequency were the main vibration sources when the unit was stable in operation. The vibration of blade frequency and low frequency water-flow were the main vibration resources during unit start-up. The low frequency water-flow and high frequency induced by water-pipeline coupling were the main vibration resources during unit shutdown,and low frequency water-flow had greater effect on pipeline vibration along the direction of flow. The research results can be used for evaluating the sources of pipeline vibration and the contributions of different frequencies. This study provides a scientific basis for the safe operation and active control of pipeline structure.
pumps;vibrations;irrigation;pipeline of pumping station;water supply;vibration sources analysis;dynamic load
10.11975/j.issn.1002-6819.2017.01.010
TV93,TB53
A
1002-6819(2017)-01-0077-07
張建偉,江 琦,王 濤. 基于原型觀測的梯級泵站管道振源特性分析[J]. 農(nóng)業(yè)工程學(xué)報,2017,33(1):77-83.
10.11975/j.issn.1002-6819.2017.01.010 http://www.tcsae.org
Zhang Jianwei,Jiang Qi,Wang Tao. Analysis of vibration characteristics of pipeline of trapezoid pumping station based on prototype observation[J]. Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2017,33(1):77-83.(in Chinese with English abstract)doi:10.11975/j.issn.1002-6819.2017.01.010 http://www.tcsae.org
2016-04-29
2016-10-21
國家自然科學(xué)基金(51679091);華北水利水電大學(xué)研究生教育創(chuàng)新計劃基金(YK2015-02)資助。
張建偉,男,河南洛陽,副教授,博士,主要從事水利水電工程的研究與教學(xué)工作。鄭州 華北水利水電大學(xué)水利學(xué)院,450011。Email:zjwcivil@126.com