0引言
近年來,振動測量技術得以在航空、航天、電子、船(chuan)舶(bo)等(deng)多(duo)領(ling)域(yu)發(fa)展(zhan)和(he)應(ying)用(yong),呈(cheng)現(xian)出(chu)良(liang)好(hao)的(de)發(fa)展(zhan)態(tai)勢(shi),也(ye)因(yin)此(ci)成(cheng)為(wei)了(le)學(xue)者(zhe)們(men)爭(zheng)相(xiang)研(yan)究(jiu)的(de)熱(re)點(dian)話(hua)題(ti)。振(zhen)動(dong)測(ce)量(liang)技(ji)術(shu)是(shi)運(yun)用(yong)現(xian)代(dai)檢(jian)測(ce)手(shou)段(duan)實(shi)現(xian)對(dui)機(ji)械(xie)結(jie)構(gou)振(zhen)動(dong)的(de)檢(jian)測(ce),測(ce)量(liang)其(qi)流(liu)體(ti)的(de)振(zhen)動(dong)頻(pin)率(lv),進(jin)而(er)確(que)定(ding)流(liu)體(ti)在(zai)管(guan)道(dao)中(zhong)流(liu)速(su)與(yu)流(liu)量(liang),而(er)渦街流量計zhengshiyizhongjiyuzhendongceliangyuanlideliuliangceliangyibiao,qizhuyaoyonglaiceliangwojieliutizaiguandaozhongchanshengdexuanwopinlv,shiyijuliutizhendongpinlvyuliusuzhijiandebiliguanxideyuanlilaigongzuode。wojieliuliangjiyingyongguochengzhongxuyaoliyongzhendongjiancejishu,jiangzhendongliangzhuanhuaweixiangduiyingdedianheliang,bingjiangdianheliangzhuanhuaweidianyaliang,erdianhefangdaqizaizheqizhongqileguanjianxingzuoyong,youciyechenglebenwendeyanjiuzhongdian,weiletishengwojieliuliangjideceliangjingdu。
1振動測量內容介紹
振(zhen)動(dong)測(ce)量(liang)技(ji)術(shu)是(shi)一(yi)種(zhong)現(xian)代(dai)常(chang)用(yong)的(de)流(liu)量(liang)測(ce)量(liang)方(fang)法(fa)之(zhi)一(yi),其(qi)依(yi)據(ju)振(zhen)動(dong)測(ce)量(liang)基(ji)本(ben)原(yuan)理(li)對(dui)機(ji)械(xie)結(jie)構(gou)振(zhen)動(dong)進(jin)行(xing)檢(jian)測(ce),並(bing)將(jiang)振(zhen)動(dong)運(yun)動(dong)量(liang)轉(zhuan)化(hua)為(wei)與(yu)之(zhi)成(cheng)一(yi)定(ding)比(bi)例(li)的(de)電(dian)學(xue)或(huo)是(shi)其(qi)它(ta)易(yi)於(yu)觀(guan)察(cha)、分析和處理的物理信號,最後通過對該信號頻率的計算分析,獲取機械振動結構的振動特性,從而實現對機械設備振動的測量。
振動測量可根據結構振動的類型,將儀器設備的振動信號分為兩類:確que定ding性xing振zhen動dong和he隨sui機ji振zhen動dong,本ben文wen所suo研yan究jiu渦wo街jie流liu量liang計ji中zhong流liu體ti所suo引yin起qi的de振zhen動dong,是shi其qi中zhong的de確que定ding性xing振zhen動dong,利li用yong振zhen動dong傳chuan感gan器qi實shi現xian振zhen動dong信xin號hao的de采cai集ji,對dui流liu體ti的de振zhen動dong頻pin率lv進jin行xing測ce量liang,從cong而er可ke以yi推tui算suan出chu流liu體ti的de流liu量liang與yu速su度du。該gai基ji於yu振zhen動dong測ce量liang技ji術shu原yuan理li的de渦wo街jie流liu量liang計ji目mu前qian已yi經jing被bei廣guang泛fan用yong於yu氣qi體ti、液體和蒸汽流量的測量。同時,渦街流量計對於振動測量來說是檢測流體振動的特征參數,在具體的測量過程中可采用的方法有三類:機械量法、光測法和電測法,本文所研究的渦街流量計中的振動測量技術采用的是電測法,運用振動測量傳感器獲取機械振動信號,並將其轉化成電信號,通過電荷放大器進行調理放大,進而確定流體在管道中流速與流量。
2振動測量係統的構成
根gen據ju上shang述shu內nei容rong可ke知zhi,本ben文wen振zhen動dong測ce量liang係xi統tong研yan究jiu中zhong采cai用yong的de是shi電dian測ce法fa,這zhe是shi振zhen動dong測ce量liang中zhong常chang用yong方fang法fa,與yu光guang測ce法fa和he機ji械xie法fa比bi較jiao而er言yan,該gai方fang法fa具ju有you使shi用yong頻pin率lv範fan圍wei寬kuan,動dong態tai範fan圍wei廣guang,測ce量liang靈ling敏min度du高gao等deng優you勢shi,而er且qie電dian測ce法fa能neng夠gou適shi用yong於yu不bu同tong的de測ce振zhen傳chuan感gan器qi,而er信xin號hao也ye便bian於yu被bei記ji錄lu、處理和傳送。由此,本文中的振動測量係統主要由:振動傳感器、電荷放大器、信號分析儀等構成,如圖1所示。

2.1振動測量傳感器
zhendongceliangchuanganqishihuoquzhendongxinxidezhongyaozhuangzhi,shizhendongceliangxitongdehexinbufen,qizhongleihenduo,zaijutideyingyongceliangzhongyingjiehebutongdeceliangfangfahemudexuanyongbutongdechuanganqi,yibaozhengceliangxiaoguo。xiandaizhendongceliangchuanganqiwanquangaibianlechuantongdedulijixieceliangzhuangzhi,yijingchengweizhenggezhendongceliangxitongdeyigezhongyaozuchengbufen,yonglaijianceweiyi、速度、加速度、頻率和相位,而且還與電荷放大器等相關電子線路存在密切相關性。
同時,振動測量傳感其在機電變換原理方麵存在差異性,輸出的電量形式並不相同,一般會將機械量的振動信號轉化為電阻、電感等電參數的變化,而且要設置專有的測量路線以便針對不同的機電變化原理,將傳感器的輸出電量轉化成為後續顯示、記錄、分析儀所接受的電信號形式。
2.2電荷放大器
dianhefangdaqinenggoujiangchuanganqishuchudeweiruodianhexinhaozhuanhuaweifangdadedianyaxinhao,tongshiyounenggoujiangchuanganqidegaozukangshuchuzhuanhuanchengdizukangshuchu,bingchenggongqudonghouxudianlu。tongshi,zaizhendongceliangzhong,jianyuzhendongchuanganqizaitexingshangchengxianchudechayixing,celiangcanshushejiweiyi、速度以及加速度,而且這些被測振動量的峰值、振動頻率、周zhou期qi和he相xiang位wei差cha等deng相xiang關guan參can數shu也ye應ying該gai包bao含han其qi中zhong,由you此ci,為wei了le使shi測ce量liang參can數shu能neng夠gou以yi最zui佳jia的de方fang式shi獲huo得de,在zai振zhen動dong傳chuan感gan器qi與yu信xin號hao分fen析xi儀yi之zhi間jian需xu要yao設she置zhi電dian荷he放fang大da器qi以yi實shi現xian對dui位wei移yi、速度和加速度等不同電荷量信號的放大,並將其轉化成電壓或是電流信號。
2.3振動信號分析儀
振動信號分析儀能夠顯示振動的測量參數“加速度,速度,位移值”,現場數據采集及分析功能,還可以正確診斷(如:不平衡,不對中,機械鬆動,軸承故障,齒輪箱故障)引起的振動過大,指出故障發生的位置及損壞程度,從而全麵的掌握機器設備的運行狀況及發展趨勢。
3渦街流量計的工作原理
本文渦街流量計是基於”卡門渦街“yuanlierfazhanerlaideyizhongliuliangceliangyiqi,qiliyongliutizhendongyuanlishixianliuliangdeceliang。wojieliuliangjishizailiutidechuizhiliuxiangshanganzhuangyigenhuoshiduogenfeiliuxianxingxuanwofashengti,zailiutideliusudadaotedingbizhishi,huizaizuliutideliangcegezishifangfenlichuliangchuanguizedexuanzhuanfangxiangxiangfandexuanwo,erqiezaiyidingdeyidingleinuoshufanweineiliutidezhendongpinlvyuliusuchengxiangguanxing,yunyongzhendongjiancejishujiancexuanwofenlipinlvjiunenggoutuisuanchuliutidepingjunliusuheliuliang,jutidegongzuoyuanlirutu2所示。

當前,渦街流量計已經成為主要流量測量儀器之一,因其測量可靠性好,測量範圍寬而被廣泛應用於石油、化工、發電等領域,在對液體、氣體、蒸zheng汽qi的de流liu量liang計ji量liang及ji檢jian測ce和he控kong製zhi方fang麵mian呈cheng現xian良liang好hao的de利li用yong價jia值zhi。然ran而er,因yin為wei渦wo街jie流liu量liang計ji是shi利li用yong振zhen動dong測ce量liang技ji術shu實shi現xian流liu體ti測ce量liang的de,其qi較jiao易yi受shou到dao外wai界jie的de幹gan擾rao,影ying響xiang了le其qi測ce量liang精jing度du;同(tong)時(shi),由(you)於(yu)渦(wo)街(jie)傳(chuan)感(gan)器(qi)傳(chuan)輸(shu)的(de)信(xin)號(hao)微(wei)弱(ruo),在(zai)噪(zao)聲(sheng)的(de)影(ying)響(xiang)下(xia)小(xiao)流(liu)量(liang)測(ce)量(liang)受(shou)限(xian)。為(wei)了(le)保(bao)證(zheng)渦(wo)街(jie)流(liu)量(liang)計(ji)的(de)測(ce)量(liang)精(jing)度(du),應(ying)充(chong)分(fen)地(di)利(li)用(yong)振(zhen)動(dong)檢(jian)測(ce)技(ji)術(shu),並(bing)減(jian)小(xiao)電(dian)荷(he)放(fang)大(da)電(dian)路(lu)的(de)噪(zao)聲(sheng),從(cong)而(er)提(ti)高(gao)其(qi)應(ying)用(yong)性(xing)能(neng)。
4振動檢測技術在渦街流量計中的應用
4.1渦街流量計流體振動檢測
渦wo街jie流liu量liang計ji采cai用yong的de是shi上shang述shu振zhen動dong測ce量liang技ji術shu實shi現xian流liu體ti檢jian測ce的de,對dui於yu渦wo街jie流liu量liang計ji的de振zhen動dong檢jian測ce而er言yan,其qi隻zhi需xu檢jian測ce流liu體ti振zhen動dong的de特te征zheng參can數shu,也ye即ji流liu體ti在zai具ju體ti應ying用yong管guan道dao中zhong產chan生sheng的de旋xuan渦wo頻pin率lv即ji可ke實shi現xian振zhen動dong測ce量liang獲huo取qu振zhen動dong測ce量liang信xin號hao。當dang前qian,渦wo街jie流liu量liang計ji中zhong應ying用yong的de振zhen動dong檢jian測ce方fang式shi可ke采cai用yong:壓ya電dian式shi和he電dian容rong式shi,壓ya電dian式shi是shi通tong過guo交jiao替ti旋xuan渦wo導dao致zhi的de壓ya力li脈mai動dong使shi其qi檢jian測ce元yuan件jian壓ya電dian晶jing體ti產chan生sheng電dian脈mai衝chong來lai進jin行xing檢jian測ce的de,而er電dian容rong式shi的de檢jian測ce元yuan件jian是shi電dian容rong,其qi通tong過guo旋xuan渦wo產chan生sheng的de壓ya差cha促cu使shi電dian容rong量liang改gai變bian差cha值zhi來lai實shi現xian振zhen動dong測ce量liang,其qi中zhong壓ya電dian元yuan件jian在zai響xiang應ying速su度du,以yi及ji其qi不bu易yi受shou流liu體ti密mi度du、粘度和溫度的影響,具有良好的穩定性,由此得以在渦街流量計中廣泛應用。渦街流量計流體振動檢測具體如圖3所示。

本ben文wen渦wo街jie流liu量liang計ji振zhen動dong測ce量liang係xi統tong中zhong的de壓ya電dian式shi傳chuan感gan器qi的de輸shu出chu的de微wei弱ruo電dian信xin號hao,同tong上shang述shu振zhen動dong測ce量liang係xi統tong一yi樣yang需xu要yao將jiang電dian荷he信xin號hao經jing過guo高gao輸shu入ru阻zu抗kang的de前qian置zhi放fang大da器qi的de阻zu抗kang交jiao換huan之zhi後hou,才cai能neng夠gou將jiang借jie助zhu於yu放fang大da檢jian波bo電dian路lu將jiang傳chuan感gan器qi信xin號hao傳chuan輸shu到dao顯xian示shi儀yi表biao或huo實shi現xian遠yuan程cheng傳chuan輸shu,這zhe一yi過guo程cheng都dou是shi依yi據ju振zhen動dong檢jian測ce的de相xiang關guan原yuan理li和he技ji術shu來lai完wan成cheng的de。
4.2渦街流量計傳感器
渦(wo)街(jie)流(liu)量(liang)計(ji)傳(chuan)感(gan)器(qi)采(cai)用(yong)壓(ya)電(dian)傳(chuan)感(gan)器(qi),該(gai)傳(chuan)感(gan)器(qi)測(ce)量(liang)效(xiao)率(lv)高(gao),可(ke)不(bu)用(yong)直(zhi)接(jie)接(jie)觸(chu)測(ce)量(liang)介(jie)質(zhi)就(jiu)能(neng)實(shi)現(xian)流(liu)體(ti)測(ce)量(liang),通(tong)常(chang)運(yun)用(yong)壓(ya)電(dian)元(yuan)件(jian)的(de)應(ying)力(li)檢(jian)測(ce)方(fang)法(fa)來(lai)進(jin)行(xing)振(zhen)動(dong)頻(pin)率(lv)的(de)測(ce)量(liang),具(ju)體(ti)操(cao)作(zuo)過(guo)程(cheng)是(shi)將(jiang)有(you)漩(xuan)渦(wo)產(chan)生(sheng)的(de)交(jiao)替(ti)變(bian)化(hua)的(de)壓(ya)力(li)轉(zhuan)化(hua)為(wei)壓(ya)電(dian)傳(chuan)感(gan)器(qi)電(dian)荷(he)信(xin)號(hao),電(dian)荷(he)信(xin)號(hao)的(de)變(bian)化(hua)頻(pin)率(lv)與(yu)旋(xuan)渦(wo)脫(tuo)落(luo)頻(pin)率(lv)相(xiang)同(tong),經(jing)過(guo)電(dian)子(zi)線(xian)路(lu)處(chu)理(li)後(hou)的(de)交(jiao)變(bian)電(dian)荷(he)轉(zhuan)化(hua)成(cheng)旋(xuan)渦(wo)頻(pin)率(lv),因(yin)旋(xuan)渦(wo)頻(pin)率(lv)與(yu)流(liu)體(ti)流(liu)量(liang)成(cheng)正(zheng)相(xiang)關(guan)性(xing),由(you)此(ci)也(ye)就(jiu)得(de)到(dao)了(le)流(liu)體(ti)流(liu)量(liang)。利(li)用(yong)壓(ya)電(dian)晶(jing)體(ti)元(yuan)件(jian)進(jin)行(xing)旋(xuan)渦(wo)分(fen)離(li)頻(pin)率(lv)的(de)檢(jian)測(ce),在(zai)柱(zhu)體(ti)後(hou)部(bu)兩(liang)側(ce)實(shi)現(xian)旋(xuan)渦(wo)的(de)交(jiao)替(ti)分(fen)離(li),從(cong)而(er)促(cu)使(shi)壓(ya)力(li)脈(mai)動(dong)的(de)產(chan)生(sheng),經(jing)安(an)裝(zhuang)在(zai)主(zhu)體(ti)候(hou)補(bu)尾(wei)流(liu)中(zhong)順(shun)的(de)探(tan)頭(tou)檢(jian)測(ce)到(dao)交(jiao)變(bian)力(li),並(bing)使(shi)得(de)位(wei)於(yu)探(tan)頭(tou)內(nei)部(bu)的(de)壓(ya)電(dian)晶(jing)體(ti)元(yuan)件(jian)在(zai)交(jiao)變(bian)力(li)的(de)壓(ya)力(li)作(zuo)用(yong)下(xia)產(chan)生(sheng)變(bian)電(dian)荷(he),交(jiao)變(bian)電(dian)荷(he)信(xin)號(hao)在(zai)被(bei)檢(jian)測(ce)放(fang)大(da)器(qi)處(chu)理(li)或(huo)數(shu)字(zi)信(xin)號(hao)處(chu)理(li)後(hou),輸(shu)出(chu)頻(pin)率(lv)信(xin)號(hao),或(huo)是(shi)轉(zhuan)化(hua)成(cheng)與(yu)流(liu)量(liang)成(cheng)比(bi)例(li)的(de)4~20mA直流標準信號輸出。
4.3渦街流量計放大電路
渦(wo)街(jie)流(liu)量(liang)計(ji)中(zhong)傳(chuan)感(gan)器(qi)所(suo)輸(shu)出(chu)的(de)電(dian)壓(ya)信(xin)號(hao),需(xu)要(yao)放(fang)大(da)電(dian)路(lu)將(jiang)其(qi)放(fang)大(da)並(bing)對(dui)信(xin)號(hao)進(jin)行(xing)處(chu)理(li),利(li)用(yong)振(zhen)動(dong)測(ce)量(liang)技(ji)術(shu)的(de)測(ce)量(liang)電(dian)路(lu)關(guan)鍵(jian)在(zai)於(yu)前(qian)置(zhi)放(fang)大(da)器(qi)的(de)設(she)置(zhi),其(qi)不(bu)僅(jin)能(neng)夠(gou)將(jiang)傳(chuan)感(gan)器(qi)的(de)輸(shu)出(chu)信(xin)號(hao)從(cong)高(gao)阻(zu)抗(kang)變(bian)為(wei)低(di)阻(zu)抗(kang),還(hai)能(neng)夠(gou)將(jiang)傳(chuan)感(gan)器(qi)微(wei)弱(ruo)的(de)電(dian)信(xin)號(hao)進(jin)行(xing)放(fang)大(da)。前(qian)置(zhi)放(fang)大(da)電(dian)路(lu)可(ke)采(cai)用(yong)電(dian)壓(ya)放(fang)大(da)器(qi)或(huo)是(shi)用(yong)帶(dai)電(dian)融(rong)反(fan)饋(kui)的(de)電(dian)荷(he)放(fang)大(da)器(qi),本(ben)文(wen)采(cai)用(yong)電(dian)荷(he)放(fang)大(da)器(qi)作(zuo)為(wei)渦(wo)街(jie)流(liu)量(liang)計(ji)的(de)轉(zhuan)換(huan)裝(zhuang)置(zhi),放(fang)大(da)、濾波、整形後變成頻率與流速成正比的脈衝信號,然後進行計數處理得到流量信號,以此來提高渦街流量計的抗幹擾能力。
5結語
機ji械xie振zhen動dong是shi一yi種zhong常chang見jian的de現xian象xiang,其qi直zhi接jie影ying響xiang著zhe機ji器qi精jing度du和he正zheng常chang運yun轉zhuan,而er通tong過guo機ji械xie振zhen動dong原yuan理li發fa展zhan而er來lai的de振zhen動dong測ce量liang技ji術shu則ze是shi工gong業ye控kong製zhi和he生sheng產chan中zhong的de重zhong要yao內nei容rong之zhi一yi,尤you其qi與yu渦wo街jie流liu量liang計ji中zhong的de振zhen動dong檢jian測ce原yuan理li存cun在zai眾zhong多duo相xiang通tong處chu,為wei振zhen動dong檢jian測ce技ji術shu在zai渦wo街jie流liu量liang計ji中zhong的de應ying用yong提ti供gong了le可ke能neng性xing,由you此ci,本ben文wen針zhen對dui渦wo街jie流liu量liang計ji中zhong振zhen動dong檢jian測ce技ji術shu的de應ying用yong具ju有you重zhong要yao的de理li論lun意yi義yi和he使shi用yong價jia值zhi,並bing能neng夠gou推tui動dong渦wo街jie流liu量liang計ji的de不bu斷duan創chuang新xin發fa展zhan提ti供gong相xiang關guan依yi據ju。
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