電除(chu)塵(chen)器是一(yi)種高(gao)效的(de)除(chu)塵(chen)器，已被越(yue)來(lai)越(yue)多的(de)火力發電廠(chang)所采用。為(wei)了(le)保持電除(chu)塵(chen)器長(chang)期、高(gao)效、穩定地運行，應該對(dui)影響電除(chu)塵(chen)器效率的(de)因素進(jin)行分析，并加強對(dui)電除(chu)塵(chen)器運行、維(wei)護(hu)和檢修的(de)管理。

1 影響電除塵器除塵效率的因素

1.1 高(gao)低壓供(gong)電控制裝(zhuang)置設(she)計運行不(bu)佳

合理的電(dian)(dian)(dian)(dian)(dian)(dian)(dian)除(chu)塵(chen)器(qi)(qi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)暈功率(lv)是保證電(dian)(dian)(dian)(dian)(dian)(dian)(dian)除(chu)塵(chen)器(qi)(qi)安全、穩(wen)定運(yun)行(xing)的重要(yao)因素之一。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)除(chu)塵(chen)器(qi)(qi)直流(liu)高壓由380V交(jiao)流(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)經可控(kong)(kong)(kong)硅(gui)高壓整流(liu)設(she)(she)備(bei)供(gong)(gong)(gong)給，除(chu)塵(chen)器(qi)(qi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)場阻(zu)抗(kang)對高壓供(gong)(gong)(gong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)裝置來說是一個變(bian)化的負(fu)(fu)載(zai)。當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)場阻(zu)抗(kang)升高、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)變(bian)小(xiao)時，要(yao)求設(she)(she)備(bei)能自(zi)(zi)動升壓；而當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)場阻(zu)抗(kang)降低、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)變(bian)大時，要(yao)求設(she)(she)備(bei)能自(zi)(zi)動降壓以保持設(she)(she)定的電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)。整流(liu)變(bian)壓器(qi)(qi)內(nei)部的電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)取樣電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)，引(yin)進負(fu)(fu)反饋信號(hao)，經微機(ji)智(zhi)能處理后(hou)移相控(kong)(kong)(kong)制(zhi)(zhi)可控(kong)(kong)(kong)硅(gui)的導通角，改變(bian)負(fu)(fu)載(zai)輸出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓，達到穩(wen)定輸出(chu)的目的，使電(dian)(dian)(dian)(dian)(dian)(dian)(dian)場獲得最(zui)有效的電(dian)(dian)(dian)(dian)(dian)(dian)(dian)暈功率(lv)。然而有些(xie)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源及(ji)控(kong)(kong)(kong)制(zhi)(zhi)設(she)(she)備(bei)制(zhi)(zhi)造廠生產的控(kong)(kong)(kong)制(zhi)(zhi)器(qi)(qi)對設(she)(she)備(bei)控(kong)(kong)(kong)制(zhi)(zhi)特性和控(kong)(kong)(kong)制(zhi)(zhi)方式、保護功能等(deng)還不完善，再加上電(dian)(dian)(dian)(dian)(dian)(dian)(dian)廠運(yun)行(xing)和檢(jian)修人員對設(she)(she)備(bei)原理的理解存(cun)在一定的盲區，從而造成供(gong)(gong)(gong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)控(kong)(kong)(kong)制(zhi)(zhi)裝置運(yun)行(xing)不佳(jia)。

1.2 振打清灰裝置的運行方式不合理(li)

目前，火(huo)電廠使用的電除(chu)器，無一(yi)不是采用振打方(fang)式清(qing)灰。在振打力度和均勻性都滿足要(yao)求的情況(kuang)下，振打制度(周期、時間、方(fang)式)是否(fou)合理對電除(chu)塵(chen)器除(chu)塵(chen)效率影響極大(da)。

振(zhen)打周期對除塵(chen)效(xiao)率(lv)的(de)影響在于清灰(hui)時(shi)能(neng)否(fou)使脫落(luo)的(de)塵(chen)塊直接落(luo)入灰(hui)斗。振(zhen)打周期過(guo)長、極板積灰(hui)過(guo)厚，將(jiang)降(jiang)低(di)帶電粉塵(chen)在極板上的(de)導電性能(neng)，降(jiang)低(di)除塵(chen)效(xiao)率(lv)；振(zhen)打周期過(guo)短，粉塵(chen)會分散成(cheng)碎粉落(luo)下，引(yin)起較(jiao)大(da)的(de)二(er)(er)次揚塵(chen)，即沉積在電除塵(chen)器(qi)收塵(chen)極上的(de)粉塵(chen)再次被氣流帶出除塵(chen)器(qi)，尤其是末極電場的(de)二(er)(er)次揚塵(chen)會大(da)大(da)降(jiang)低(di)電除塵(chen)器(qi)的(de)效(xiao)率(lv)。

導(dao)致二次揚(yang)塵(chen)(chen)的(de)因素有許(xu)多，如粉塵(chen)(chen)的(de)比電阻過高(gao)，產生反(fan)電暈收(shou)塵(chen)(chen)電場的(de)煙(yan)氣流(liu)速(su)(su)分(fen)布(bu)不均或流(liu)速(su)(su)過高(gao)而產生的(de)紊流(liu)和(he)渦(wo)流(liu)。因此，要(yao)求電場的(de)煙(yan)氣流(liu)速(su)(su)不超過3m/s，一般電場中運行的(de)煙(yan)氣流(liu)速(su)(su)都在(zai)1.5m/s左右，且盡可能使煙(yan)氣流(liu)分(fen)布(bu)均勻(yun)，而振打清(qing)灰(hui)(hui)過頻，是造成除塵(chen)(chen)器二次揚(yang)塵(chen)(chen)最主要(yao)的(de)因素。遵循一定的(de)程序(xu)，采用恰當的(de)試(shi)驗方法，建(jian)立(li)正(zheng)確(que)的(de)振打制度，同時加強對灰(hui)(hui)斗(dou)排灰(hui)(hui)設(she)備的(de)維(wei)護，防止灰(hui)(hui)斗(dou)出灰(hui)(hui)口堵(du)塞，都能防止二次揚(yang)塵(chen)(chen)的(de)發(fa)生。

1.3 鍋(guo)爐的運(yun)行參數偏離正常值

在(zai)(zai)正(zheng)常負荷(he)下鍋爐(lu)的煙(yan)(yan)氣(qi)流(liu)量(liang)、排煙(yan)(yan)溫(wen)度(du)(du)、煙(yan)(yan)氣(qi)含塵濃度(du)(du)等(deng)參數(shu)值(zhi)與電(dian)除塵器設計(ji)的參數(shu)相差不大(da)，電(dian)除塵器都能正(zheng)常運(yun)行(xing)。若鍋爐(lu)煙(yan)(yan)氣(qi)流(liu)量(liang)增(zeng)大(da)、排煙(yan)(yan)溫(wen)度(du)(du)升(sheng)高、煙(yan)(yan)氣(qi)含塵濃度(du)(du)增(zeng)加，電(dian)除塵器的運(yun)行(xing)工(gong)況就(jiu)會惡化，使(shi)除塵效(xiao)率(lv)降(jiang)低(di)。當鍋爐(lu)長時間(jian)低(di)負荷(he)運(yun)行(xing)時，為穩定(ding)燃燒，必須投入重油(you)或柴油(you)助燃，造成煙(yan)(yan)氣(qi)溫(wen)度(du)(du)和煙(yan)(yan)氣(qi)中的粘稠物增(zeng)加。這些粘稠物造成陰(yin)極(ji)線肥(fei)大(da)，陽極(ji)板積(ji)(ji)灰，導致電(dian)場的除塵效(xiao)率(lv)下降(jiang)。如果鍋爐(lu)內水汽泄(xie)(xie)露，將增(zeng)加煙(yan)(yan)氣(qi)濕(shi)度(du)(du)，雖然(ran)在(zai)(zai)極(ji)短時間(jian)內因煙(yan)(yan)氣(qi)被調質而(er)降(jiang)低(di)了(le)煤灰比(bi)電(dian)阻，除塵效(xiao)率(lv)會升(sheng)高，但時間(jian)稍長，電(dian)除塵器將嚴重積(ji)(ji)灰，尤其(qi)在(zai)(zai)泄(xie)(xie)露量(liang)大(da)時，極(ji)板甚至結垢，會降(jiang)低(di)除塵器的使(shi)用壽命(ming)。

1.4 煤種的變化

如(ru)果鍋爐燃(ran)燒煤(mei)種發(fa)生了(le)(le)變化，其熱值較設計煤(mei)種低，灰(hui)(hui)分較設計煤(mei)種高(gao)，則會加(jia)(jia)大(da)對輸(shu)煤(mei)、制粉、除(chu)(chu)塵(chen)(chen)(chen)(chen)、輸(shu)灰(hui)(hui)設備的磨損，縮短設備的檢修周(zhou)期。使(shi)用低熱值燃(ran)煤(mei)，會使(shi)鍋爐實際燃(ran)煤(mei)量(liang)增(zeng)加(jia)(jia)，使(shi)煙氣的含(han)灰(hui)(hui)量(liang)增(zeng)大(da)。這(zhe)樣會使(shi)電(dian)除(chu)(chu)塵(chen)(chen)(chen)(chen)器處理(li)煙氣含(han)塵(chen)(chen)(chen)(chen)濃度超過設計值，除(chu)(chu)塵(chen)(chen)(chen)(chen)效(xiao)率(lv)將(jiang)受到(dao)嚴重影響(xiang)。為了(le)(le)消除(chu)(chu)因煤(mei)種發(fa)生變化而(er)影響(xiang)電(dian)除(chu)(chu)塵(chen)(chen)(chen)(chen)器的除(chu)(chu)塵(chen)(chen)(chen)(chen)效(xiao)率(lv)，在除(chu)(chu)塵(chen)(chen)(chen)(chen)設備系(xi)統運行正常的情況下，每套電(dian)除(chu)(chu)塵(chen)(chen)(chen)(chen)器至少(shao)應進行一次(ci)針對典(dian)型煤(mei)種的特性試驗，以確(que)定煤(mei)種、供電(dian)、振打對電(dian)除(chu)(chu)塵(chen)(chen)(chen)(chen)器效(xiao)率(lv)的綜合(he)影響(xiang)，找出電(dian)除(chu)(chu)塵(chen)(chen)(chen)(chen)器的最(zui)佳運行方式。

2 加強對電除塵器的維護和檢修工作

(1) 國電(dian)(dian)環保(bao)所(suo)生產的(de)(de)(de)DJ系列微(wei)機自控(kong)高(gao)低壓(ya)供(gong)電(dian)(dian)裝置，它(ta)的(de)(de)(de)高(gao)壓(ya)控(kong)制(zhi)部分采用(yong)先進的(de)(de)(de)8098單片(pian)機和外圍芯(xin)片(pian)，具有控(kong)制(zhi)、保(bao)護功(gong)能完(wan)善、結構簡單、使用(yong)方便的(de)(de)(de)特(te)點(dian)，并(bing)針對火電(dian)(dian)廠鍋爐(lu)燃燒(shao)排放粉(fen)塵(chen)(飛灰)比電(dian)(dian)阻的(de)(de)(de)變化提供(gong)多種供(gong)電(dian)(dian)運行方式，滿(man)足(zu)各種不同工況(kuang)條件的(de)(de)(de)要求。采用(yong)這種供(gong)電(dian)(dian)裝置對原(yuan)有的(de)(de)(de)設(she)備進行改造，可實現中央(yang)機遠程(cheng)并(bing)借助(zhu)粉(fen)塵(chen)濁度檢(jian)測(ce)儀的(de)(de)(de)反饋(kui)信號(hao)構成電(dian)(dian)除塵(chen)器的(de)(de)(de)閉環控(kong)制(zhi)，達(da)到高(gao)效節能運行的(de)(de)(de)效果。其(qi)保(bao)護和報(bao)警功(gong)能涉及輸(shu)(shu)入過流、輸(shu)(shu)出開路、輸(shu)(shu)出短路、欠壓(ya)保(bao)護、偏勵(li)磁(ci)、可控(kong)硅開路和臨界危(wei)險(xian)油溫，幾乎涵蓋了(le)火電(dian)(dian)廠電(dian)(dian)除塵(chen)器運行中的(de)(de)(de)所(suo)有故障類型(xing)。

(2)努力改善(shan)電除塵(chen)器的運行(xing)現狀，嚴格執行(xing)《電除塵(chen)器運行(xing)維護導則》，對于(yu)設備運行(xing)中存在(zai)的故障和(he)缺陷應(ying)及時處理，制訂完(wan)善(shan)、合理的檢修周(zhou)期和(he)項目。

(3)機(ji)務(wu)方面。大(da)修(xiu)時對(dui)電除塵器(qi)(qi)(qi)內陰、陽間距(ju)進(jin)行(xing)調(diao)(diao)整，并記錄調(diao)(diao)整前后的測量結果。對(dui)陰、陽極振打裝置(zhi)(zhi)的設備(主要有振打電機(ji)、減器(qi)(qi)(qi)機(ji)、轉軸(zhou)、軸(zhou)承(cheng)、撓臂錘(chui)、絕緣連桿等)磨(mo)損情況進(jin)行(xing)檢查并處理；對(dui)出(chu)灰系統(tong)、保溫、加熱(re)系統(tong)、灰斗料位計、鎖氣器(qi)(qi)(qi)等裝置(zhi)(zhi)進(jin)行(xing)檢查和調(diao)(diao)試。

(4)電(dian)氣(qi)方面(mian)。大修時嚴格執行(xing)《電(dian)力設備預(yu)防性(xing)試(shi)驗(yan)規程》中電(dian)除塵器章節對高壓(ya)硅(gui)整(zheng)流(liu)(liu)變壓(ya)器、低(di)壓(ya)電(dian)抗(kang)器、絕緣支撐(cheng)及連(lian)接元件、高壓(ya)直流(liu)(liu)電(dian)纜(lan)等(deng)設備的(de)(de)試(shi)驗(yan)項目和周(zhou)期所(suo)作的(de)(de)明(ming)文規定，要對供電(dian)裝置(zhi)的(de)(de)觸發裝置(zhi)進(jin)(jin)(jin)行(xing)性(xing)能測試(shi)，對各種(zhong)保護(hu)進(jin)(jin)(jin)行(xing)整(zheng)定試(shi)驗(yan)，對電(dian)氣(qi)高低(di)壓(ya)回路與儀表(biao)開關進(jin)(jin)(jin)行(xing)校檢(jian)，并(bing)對整(zheng)流(liu)(liu)變進(jin)(jin)(jin)行(xing)吊(diao)芯(xin)檢(jian)查(cha)。

(5)電除塵(chen)器大修(xiu)(xiu)后的整體調試。大修(xiu)(xiu)結束后，對(dui)整流變壓(ya)器、電場進(jin)(jin)行(xing)(xing)空載升壓(ya)試驗，并在運行(xing)(xing)時進(jin)(jin)行(xing)(xing)額(e)定工況(kuang)下的U-I特性(xing)測(ce)試；對(dui)進(jin)(jin)、出(chu)口(kou)煙氣(qi)溫度(du)與壓(ya)力指(zhi)示進(jin)(jin)行(xing)(xing)測(ce)試；對(dui)濁度(du)儀、照(zhao)明設備(bei)進(jin)(jin)行(xing)(xing)測(ce)試。如(ru)果有條件的話，還應該對(dui)電除塵(chen)器大修(xiu)(xiu)前后的除塵(chen)效率進(jin)(jin)行(xing)(xing)對(dui)比試驗，以檢驗大修(xiu)(xiu)工作的效果。

  使用微信“掃一掃”功能添加“谷騰環保網”

相關文章