中國水網(wang)近期(qi)舉(ju)辦的第(di)八期(qi)專(zhuan)家(jia)精(jing)品解(jie)答活動正開展得如火(huo)如荼。在活動中，許多網(wang)友提出(chu)污(wu)水廠(chang)(chang)如何節(jie)能(neng)(neng)降耗(hao)等相關(guan)(guan)問題(ti)，首創愛(ai)華運營總監(jian)劉智曉指出(chu)，精(jing)確(que)曝(pu)氣系統是污(wu)水廠(chang)(chang)節(jie)能(neng)(neng)降耗(hao)的關(guan)(guan)鍵。劉智曉指出(chu)，污(wu)水廠(chang)(chang)中曝(pu)氣系統能(neng)(neng)耗(hao)約占全廠(chang)(chang)能(neng)(neng)耗(hao)的50%-70%，是污(wu)水廠(chang)(chang)節(jie)能(neng)(neng)降耗(hao)的關(guan)(guan)鍵環節(jie)。

     眾所周(zhou)知(zhi)，污(wu)水廠運行(xing)控制(zhi)特(te)性不(bu)同于(yu)(yu)其它(ta)反(fan)應系統，污(wu)水處理(li)過(guo)程(cheng)屬(shu)于(yu)(yu)“非(fei)線性、大(da)滯后(hou)”系統，目前常見的(de)生物池曝氣(qi)(qi)控制(zhi)回(hui)路采(cai)用(yong)DO-閥門調節(jie)或PID定值調節(jie)，這(zhe)種(zhong)控制(zhi)方(fang)式(shi)經(jing)實踐(jian)證明存在很(hen)大(da)缺欠。常規的(de)PID控制(zhi)不(bu)但存在較大(da)的(de)滯后(hou)效(xiao)應，而且控制(zhi)過(guo)程(cheng)易引起(qi)系統振蕩。據(ju)不(bu)完全調查，國內采(cai)用(yong)此(ci)種(zhong)控制(zhi)方(fang)式(shi)實現穩定運行(xing)的(de)案例很(hen)少。很(hen)多污(wu)水廠由開始的(de)“自動(dong)”逐漸變成(cheng)(cheng)“半(ban)自動(dong)”，甚至到最后(hou)變成(cheng)(cheng)手(shou)動(dong)“衡量控制(zhi)”。因此(ci)，近些年大(da)家開始關注和(he)(he)嘗試采(cai)用(yong)“精(jing)(jing)確(que)曝氣(qi)(qi)”技(ji)術，但是在實施過(guo)程(cheng)中存在或者出現了一(yi)些問題。精(jing)(jing)確(que)曝氣(qi)(qi)量控制(zhi)原理(li)圖“精(jing)(jing)確(que)曝氣(qi)(qi)”技(ji)術成(cheng)(cheng)效(xiao)面臨各(ge)種(zhong)考驗，甚至有人(ren)認為精(jing)(jing)確(que)曝氣(qi)(qi)屬(shu)于(yu)(yu)“商業炒作”，之所以(yi)出現以(yi)上情況和(he)(he)現象，劉智曉博士(shi)認為有以(yi)下(xia)四個方(fang)面的(de)原因。

     目前污水廠自控系統的溶氣氣浮機方(fang)案設(she)(she)計環節與精確(que)曝(pu)(pu)(pu)氣(qi)(qi)技(ji)術的(de)(de)(de)要求(qiu)上(shang)存在脫(tuo)節，也(ye)就是設(she)(she)計院的(de)(de)(de)自控方(fang)案往(wang)往(wang)采(cai)用傳統的(de)(de)(de)“DO-閥(fa)門開度”調節方(fang)式，設(she)(she)計之初并沒有考慮(lv)嵌入(ru)精確(que)曝(pu)(pu)(pu)氣(qi)(qi)技(ji)術。主要因為精確(que)曝(pu)(pu)(pu)氣(qi)(qi)技(ji)術往(wang)往(wang)掌握(wo)在一些專業公司，同時(shi)業主也(ye)往(wang)往(wang)缺乏這(zhe)方(fang)面的(de)(de)(de)經驗(yan)或者不想增加這(zhe)部分投(tou)資，因此按常規(gui)的(de)(de)(de)曝(pu)(pu)(pu)氣(qi)(qi)控制方(fang)式很難穩(wen)定地實現精確(que)曝(pu)(pu)(pu)氣(qi)(qi)進而實現節能目的(de)(de)(de)。對于(yu)改造項目，在原有系統上(shang)嵌入(ru)基于(yu)精確(que)曝(pu)(pu)(pu)氣(qi)(qi)算法的(de)(de)(de)新的(de)(de)(de)鼓風曝(pu)(pu)(pu)氣(qi)(qi)控制回路(lu)，實施起來確(que)實不易。因此劉博士建議，盡量(liang)在污(wu)水(shui)廠設(she)(she)計、設(she)(she)備(bei)采(cai)購時(shi)將精確(que)曝(pu)(pu)(pu)氣(qi)(qi)技(ji)術融入(ru)整(zheng)個(ge)污(wu)水(shui)廠投(tou)資范圍內。

    因此，濃縮脫水機污(wu)水(shui)(shui)廠實(shi)(shi)施并實(shi)(shi)現(xian)精(jing)確(que)曝(pu)(pu)氣(qi)的(de)(de)(de)(de)(de)(de)預定功效(xiao)(xiao)，以上條件缺一(yi)(yi)不(bu)(bu)可。另外(wai)，目前(qian)國(guo)內已(yi)經有(you)(you)多家公司提供(gong)精(jing)確(que)曝(pu)(pu)氣(qi)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)的(de)(de)(de)(de)(de)(de)服務(wu)，盡(jin)管(guan)在(zai)技術細節、控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)方(fang)(fang)式及(ji)原理有(you)(you)較大不(bu)(bu)同，但是(shi)(shi)基(ji)本(ben)原理是(shi)(shi)相(xiang)似的(de)(de)(de)(de)(de)(de)，即實(shi)(shi)現(xian)“按需(xu)曝(pu)(pu)氣(qi)”，采用(yong)(yong)閉(bi)環控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)，不(bu)(bu)但采集生物池DO等工(gong)藝在(zai)線監測數(shu)據，甚(shen)(shen)至(zhi)(zhi)也(ye)采集NH3-N等水(shui)(shui)質(zhi)指標(biao)作為反(fan)(fan)饋(kui)控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)信號參與系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)。此外(wai)在(zai)前(qian)饋(kui)方(fang)(fang)面(mian)，采集進水(shui)(shui)流(liu)量Q、進水(shui)(shui)水(shui)(shui)質(zhi)指標(biao)，如COD、NH3-N等。這樣形成(cheng)了(le)(le)一(yi)(yi)個(ge)“前(qian)饋(kui)-后(hou)饋(kui)”閉(bi)環控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)回路。在(zai)閉(bi)環控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)方(fang)(fang)面(mian)，劉(liu)總建議將NH3-N甚(shen)(shen)至(zhi)(zhi)PO4-P引入控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)回路。他認為，DO只是(shi)(shi)一(yi)(yi)個(ge)工(gong)藝指標(biao)，而(er)我們控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)的(de)(de)(de)(de)(de)(de)實(shi)(shi)際(ji)上是(shi)(shi)出水(shui)(shui)水(shui)(shui)質(zhi)指標(biao)。控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)不(bu)(bu)但對(dui)生物池每個(ge)反(fan)(fan)應(ying)區域(yu)進行單獨的(de)(de)(de)(de)(de)(de)DO控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)，而(er)且對(dui)出水(shui)(shui)NH3-N進行反(fan)(fan)饋(kui)控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)。除了(le)(le)此種(zhong)方(fang)(fang)式的(de)(de)(de)(de)(de)(de)“精(jing)確(que)控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)”曝(pu)(pu)氣(qi)方(fang)(fang)式外(wai)，也(ye)有(you)(you)一(yi)(yi)些國(guo)外(wai)的(de)(de)(de)(de)(de)(de)公司推出了(le)(le)基(ji)于(yu)ASM2、ASM2D等活性污(wu)泥數(shu)學模型的(de)(de)(de)(de)(de)(de)精(jing)確(que)曝(pu)(pu)氣(qi)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)，這些系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)在(zai)國(guo)內有(you)(you)應(ying)用(yong)(yong)案例，但是(shi)(shi)這種(zhong)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)較依賴(lai)(lai)(lai)一(yi)(yi)些生化過(guo)程動(dong)力學參數(shu)及(ji)化學計(ji)量學系(xi)(xi)(xi)數(shu)的(de)(de)(de)(de)(de)(de)提取及(ji)準(zhun)(zhun)確(que)設定，其(qi)中(zhong)有(you)(you)幾個(ge)關鍵(jian)參數(shu)需(xu)要定期測定、校(xiao)準(zhun)(zhun)。而(er)這些關鍵(jian)參數(shu)依賴(lai)(lai)(lai)污(wu)水(shui)(shui)廠長(chang)周期的(de)(de)(de)(de)(de)(de)運行數(shu)據作為支撐，所以實(shi)(shi)際(ji)運行數(shu)據的(de)(de)(de)(de)(de)(de)準(zhun)(zhun)確(que)性影響該系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)是(shi)(shi)否能真正發揮作用(yong)(yong)。因此此種(zhong)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)到(dao)底(di)應(ying)用(yong)(yong)效(xiao)(xiao)果如何，尚待時間驗證(zheng)。最(zui)后(hou)劉(liu)智曉強調(diao)，即使擁有(you)(you)精(jing)確(que)曝(pu)(pu)氣(qi)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)，也(ye)需(xu)要強化運營維護及(ji)管(guan)理，而(er)不(bu)(bu)能僅(jin)僅(jin)單純依賴(lai)(lai)(lai)自控(kong)(kong)(kong)(kong)(kong)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)。再先進的(de)(de)(de)(de)(de)(de)控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)，沒(mei)有(you)(you)高(gao)質(zhi)量的(de)(de)(de)(de)(de)(de)維護和管(guan)理也(ye)是(shi)(shi)不(bu)(bu)能持久的(de)(de)(de)(de)(de)(de)。因此，真正具(ju)有(you)(you)效(xiao)(xiao)果的(de)(de)(de)(de)(de)(de)控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)(tong)一(yi)(yi)定是(shi)(shi)“自動(dong)”和“手動(dong)”相(xiang)結合的(de)(de)(de)(de)(de)(de)。

 行車式刮泥機的精確(que)曝氣(qi)技(ji)術要(yao)依賴高(gao)(gao)質量(liang)的硬件設備，如空氣(qi)線性調節閥（如菱形調節閥），高(gao)(gao)質量(liang)的DO儀等，而(er)(er)這部分投資較大(da)，無論是對新建(jian)或對改造而(er)(er)言確(que)實(shi)都需要(yao)斟酌，而(er)(er)常規的電動(dong)調節蝶(die)閥無法做到曝氣(qi)量(liang)的精確(que)控制。

    精(jing)確(que)曝氣(qi)技術依(yi)賴比較可靠的(de)(de)控(kong)(kong)(kong)制(zhi)算法(fa)及(ji)軟件編(bian)程，而(er)目(mu)(mu)前基于(yu)精(jing)確(que)曝氣(qi)的(de)(de)算法(fa)和(he)實現方(fang)式很(hen)多，不同公司的(de)(de)算法(fa)也是“各顯神(shen)通”，甚至“獨(du)辟(pi)蹊徑(jing)”，感(gan)覺確(que)實有些(xie)“眼花繚亂(luan)”，實際上(shang)這(zhe)(zhe)些(xie)不同的(de)(de)實施方(fang)式基于(yu)控(kong)(kong)(kong)制(zhi)原理方(fang)面(mian)(mian)存在(zai)很(hen)大差異，因(yin)(yin)此(ci)在(zai)實施效果、控(kong)(kong)(kong)制(zhi)過程穩定(ding)性(xing)方(fang)面(mian)(mian)肯定(ding)不同。目(mu)(mu)前，污水廠(chang)主流的(de)(de)精(jing)確(que)曝氣(qi)系統還是基于(yu)生物(wu)池DO設定(ding)值的(de)(de)精(jing)確(que)控(kong)(kong)(kong)制(zhi)，實際上(shang)這(zhe)(zhe)種控(kong)(kong)(kong)制(zhi)存在(zai)非常大的(de)(de)工藝、技術缺欠。因(yin)(yin)此(ci)，目(mu)(mu)前國際上(shang)先進的(de)(de)一些(xie)控(kong)(kong)(kong)制(zhi)系統正逐漸采用基于(yu)NH3-N、NO3-N、TP等(deng)在(zai)線水質儀表參與過程控(kong)(kong)(kong)制(zhi)，當然這(zhe)(zhe)需要高質量高穩定(ding)性(xing)的(de)(de)傳感(gan)器和(he)維護水準。

    精確曝(pu)氣(qi)系統(tong)需要(yao)高素質的(de)運營維護(hu)，很多污水廠(chang)即使(shi)擁有硬件，但管理(li)往往跟(gen)不(bu)上，也(ye)是導致精確曝(pu)氣(qi)系統(tong)不(bu)能實現既定功能的(de)重要(yao)原因。