火電廠循環(huán)水處理水質(zhì)穩(wěn)定劑阻垢性能評(píng)價(jià)方法的研究

1、火電廠循環(huán)水處理水質(zhì)穩(wěn)定劑阻垢性能評(píng)價(jià)方法的研究姜琪 ,閆錕 ,許建學(xué)(國(guó)電熱工研究院 ,陜西 西安710032)目前 ,水質(zhì)穩(wěn)定劑 (水穩(wěn)劑) 種類很多 ,且不斷有新產(chǎn)品誕生 ,它們的應(yīng)用性能 (主要包括阻垢和緩蝕性能) 千差萬(wàn)別 。水穩(wěn)劑的應(yīng)用性能受原水水質(zhì)的影響很大 , 目前還只能通過(guò)試驗(yàn)判別 。為合理選用水穩(wěn)劑 ,除常規(guī) 的理化性能檢測(cè)外 ,還需從應(yīng)用角度對(duì)其進(jìn)行評(píng)價(jià) 。長(zhǎng)期以來(lái) ,對(duì)于水穩(wěn)劑阻垢性能的評(píng)價(jià) ,電力行業(yè) 沒(méi)有統(tǒng)一的方法 ,因而均參照或采用國(guó)內(nèi)外其它行業(yè) 的標(biāo)準(zhǔn) ,其中使用較廣泛的為靜態(tài)阻垢率測(cè)定法 。但 在實(shí)踐過(guò)程中 ,人們發(fā)現(xiàn)此法有許多不足之處 ,尤其是 測(cè)得的各種水

2、穩(wěn)劑的阻垢率非常接近 ,不易分辨它們 阻垢性能的優(yōu)劣 ; 而其它行業(yè)標(biāo)準(zhǔn)使用條件也與電力 行業(yè)不盡相同 。目前 ,國(guó)內(nèi)電力行業(yè)使用較多的阻垢 性能評(píng)價(jià)方法還有極限碳酸鹽硬度法 ,該方法具有分 辨率高 ,數(shù)據(jù)重現(xiàn)性好 ,指導(dǎo)意義明確 ,簡(jiǎn)單實(shí)用等優(yōu) 點(diǎn) ,更適合電力行業(yè)的實(shí)際運(yùn)行情況 。該法經(jīng)在電廠 運(yùn)行中反復(fù)驗(yàn)證 ,已趨成熟 ,但它最大的缺點(diǎn)在于試驗(yàn) 時(shí)間過(guò)長(zhǎng) 。為此 ,對(duì)該方法的試驗(yàn)裝置作了改進(jìn) ,采用 強(qiáng)化循環(huán)噴淋的方式來(lái)濃縮試驗(yàn)水樣 。這樣 ,既模擬 了實(shí)際運(yùn)行情況 ,又使試驗(yàn)時(shí)間大為縮短 。本文重點(diǎn) 介紹采用極限碳酸鹽硬度法 (改進(jìn)裝置) 對(duì)水穩(wěn)劑阻垢性能進(jìn)行評(píng)價(jià)的方法 ,并與阻垢率法

3、1 進(jìn)行了比較 。1試驗(yàn)方法試驗(yàn)裝置及條件原試驗(yàn)裝置見(jiàn)圖 1 ,改進(jìn)后的試驗(yàn)裝置見(jiàn)圖 2 。本 試驗(yàn)采用改進(jìn)后的試驗(yàn)裝置 。試驗(yàn)條件 :(1) 試驗(yàn)用水為電廠循環(huán)冷卻系統(tǒng)補(bǔ)充水或配制 水 ;(2) 試驗(yàn)溫度 45 1 ,根據(jù)實(shí)際需要也可選 用其它溫度 ;(3) 水穩(wěn)劑濃度采用 2 . 0 mg/ l ( 有效固體含量) ,也可根據(jù)電廠實(shí)際需要選用其它濃度 ;(4) 每小時(shí)的循環(huán)水量和水容積比為 15 20 ,也 可根據(jù)實(shí)際情況選用其它值 。1 . 11 . 2阻垢性能的測(cè)定本方法采用恒溫恒容濃縮法 。直接使用電廠循環(huán) 冷卻系 統(tǒng) 補(bǔ) 充 水 ( 或 含 有 一 定 量 ca ( hco3 )

4、2 的 配 制 水) 和 水 穩(wěn) 劑 制 備 成 試 液 ( 水 穩(wěn) 劑 濃 度 2 mg/ l ) , 取15 l 此試液置于有機(jī)玻璃箱中 ,加熱升溫至 45 ,并使溫度保持在 45 1 ,同時(shí)啟動(dòng)循環(huán)泵使溶液循作者簡(jiǎn)介 : 姜琪 ( 1969 ) ,男 ,西北大學(xué)碩士研究生畢業(yè) ,現(xiàn)為國(guó)電熱工研究院化學(xué)工程技術(shù)中心高級(jí)工程師 ,主要從事水處理技術(shù)的研究開(kāi)發(fā)工作 。 摘要 介紹采用極限碳酸鹽硬度法 ( 改進(jìn)裝置) 對(duì)水質(zhì)穩(wěn)定劑阻垢性能進(jìn)行評(píng)價(jià)的方法 ,包括阻垢性 能測(cè)定和評(píng)價(jià)指標(biāo) 、試驗(yàn)水溫 、水質(zhì)穩(wěn)定劑濃度 、試驗(yàn)裝置循環(huán)水量等的確定 ,并與阻垢率法進(jìn)行了比較 。 實(shí)驗(yàn)表明 ,極限碳酸鹽硬

5、度法具有分辨率高 、數(shù)據(jù)重現(xiàn)性好 、指導(dǎo)意義明確 、簡(jiǎn)單實(shí)用等優(yōu)點(diǎn) ,適用于火電 廠循環(huán)冷卻水處理水質(zhì)穩(wěn)定劑阻垢性能的評(píng)價(jià) 。 關(guān)鍵詞 火電廠 ;循環(huán)冷卻水 ;水處理 ;水質(zhì)穩(wěn)定劑 ;阻垢性能評(píng)價(jià) ;極限碳酸鹽硬度法 中圖分類號(hào) tm621 . 8 文獻(xiàn)標(biāo)識(shí)碼 a 文章編號(hào) 10023364 (2004) 06006203水穩(wěn)劑的阻垢性能 ,而且能區(qū)分復(fù)配水穩(wěn)劑的阻垢性能 。(2) 數(shù)據(jù)的重現(xiàn)性好 。(3) 物理意義明確 。即在一定條件下 ,加入水穩(wěn)劑 維持運(yùn)行中不結(jié)垢所能達(dá)到的最大碳酸鹽硬度值即極 限碳酸鹽硬度值 ,與之對(duì)應(yīng)的濃縮倍率即為極限濃縮 倍率 。在一定條件下 ,便于對(duì)各種水穩(wěn)劑的極

6、限濃縮 倍率進(jìn)行直接的定量比較 ,有較強(qiáng)的實(shí)用意義 ;電廠選擇水穩(wěn)劑時(shí)直觀 ,更加貼近運(yùn)行實(shí)際 。圖 1 靜態(tài)極限碳酸鹽硬度試驗(yàn)裝置示意2 . 2試驗(yàn)溫度的確定一般情況下 ,水溫在 50 以上時(shí) ,水垢的附著速 度開(kāi)始增大 。另外 ,隨著水溫的不斷增高 ,水穩(wěn)劑的阻 垢效果也不斷降低 ,當(dāng)試驗(yàn)溫度超過(guò) 45 時(shí) ,極限濃 縮倍率開(kāi)始快速下降 ( 圖 3) ; 而在 45 以前 ,極限濃 縮倍率變化不明顯 。通常 ,我國(guó)電廠凝汽器出口最高水溫不超過(guò) 45 。因此將試驗(yàn)溫度確定為 45 。圖 2 改進(jìn)后的試驗(yàn)裝置示意環(huán)噴淋 ,并由下口瓶不斷補(bǔ)水 (補(bǔ)水中水穩(wěn)劑濃度也為2 mg/ l ) ,使箱中溶

7、液恒溫恒容濃縮 。在濃縮過(guò)程中 , 定期從箱中取樣 50 ml ,測(cè)定溶液中的 cl - 及總堿度 (試驗(yàn)初期 ,間隔時(shí)間可長(zhǎng)些 ,試驗(yàn)后期 ,間隔時(shí)間宜短 些) 。當(dāng) a 0 . 2 時(shí)停止運(yùn)行 。這時(shí)溶液的碳酸鹽 硬度值 ,即為極限碳酸鹽硬度值 ,據(jù)此可計(jì)算出極限濃 縮倍率 。測(cè)得的極限濃縮倍率越高 ,則同等條件下該 水穩(wěn)劑的阻垢性能越好 。該指標(biāo)乘以 0 . 80 . 85 即可作為循環(huán) 冷 卻 系 統(tǒng) 實(shí) 際 運(yùn) 行 控 制 指 標(biāo) 。文 中 a 為試驗(yàn)水 質(zhì) : 全 堿 度 2 . 60 mmol/ l , 氯 離 子 54 mg/ l , 總 硬 度 4 . 7mmol/ l ,

8、鈣硬度 3 . 0 mmol/ l , 水穩(wěn)劑濃度 2 . 0 mg/ l 。圖 3 溫度對(duì)阻垢性能的影響3 . 3水穩(wěn)劑濃度的確定水穩(wěn)劑的阻垢效果與其使用劑量有一定關(guān)系 。一 些常見(jiàn)的水穩(wěn)劑的極限碳酸鹽硬度與水穩(wěn)劑濃度的關(guān)系見(jiàn)圖 4 。c1 - 濃縮倍率 kcl 與總堿度濃縮倍率ka 的 差 值 , 即a = cl - cl - j d j d ,式中 c1 -與 j d 為箱內(nèi)x bx bxxc1 - 濃度和總堿度 , c1 - 與 j d 為補(bǔ)水中的 c1 - 濃度bb和總堿度 。2 阻垢性能評(píng)價(jià)方法的研究2 . 1阻垢性能評(píng)價(jià)方法及指標(biāo)的確定目前 ,對(duì)水穩(wěn)劑阻垢性能的評(píng)價(jià)方法主要有 :

9、 ( 1)阻垢率法1 。(2) 鼓泡法2 。(3) 極限碳酸鹽硬度法 。 本文采用極限碳酸鹽硬度法中的極限濃縮倍率作 為評(píng)價(jià)指標(biāo) (作為工業(yè)冷卻水系統(tǒng)控制指標(biāo)須乘以系數(shù) 0 . 80 . 85) ,其主要原因如下 :(1) 該法分辨率高 ,不僅能區(qū)分不同類型 、同一系列系列 1 a tm p 系列 2 ed tm p 系列 3 hed p 系列 4 聚丙烯酸 系列 5 三聚磷酸鈉 系列 6 六偏磷酸鈉 。試驗(yàn)水質(zhì) :p h 7 . 6 , 總硬度 3 . 6 mmol/ l , 鈣硬度1 . 4 mmol/ l , 堿度3 . 2 mmol/ l , 氯離子 12 mg/ l ; 試驗(yàn)溫度 4

10、5 1 。圖 4 不同水穩(wěn)劑的穩(wěn)定效果63熱力發(fā)電2004 (06)由圖 4 可見(jiàn) ,隨著水穩(wěn)劑濃度的增高 ,其阻垢能力增加 ,循環(huán)水極限碳酸鹽硬度值也隨之增加 。大部分 水穩(wěn)劑 (除聚丙烯酸外) ,在補(bǔ)充水中濃度增加到一定 程度時(shí) (大于 5 mg/ l ) ,循環(huán)水的極限碳酸鹽硬度值增 加緩慢 ,并漸趨穩(wěn)定 。考慮到電廠實(shí)際運(yùn)行成本等經(jīng) 濟(jì)因素 , 確 定 循 環(huán) 水 補(bǔ) 充 水 中 水 穩(wěn) 劑 的 濃 度 為 2 . 0 mg/ l (有效固體含量) ,實(shí)際試驗(yàn)中也可根據(jù)電廠實(shí)際情況和要求進(jìn)行確定 。率要高于阻垢率法 。3 . 5 . 2不同公司同種產(chǎn)品的比較atmp a ,atmpb

11、,atmp c 分別為 a ,b , c 3 家公司 生產(chǎn)的 atmp ,用極限碳酸鹽硬度法測(cè)定各藥劑的阻垢 性能 ,并與阻垢率法進(jìn)行比較 ,結(jié)果如表 3 和表 4 。表 3 極限碳酸鹽硬度法試驗(yàn)結(jié)果補(bǔ)充水中水穩(wěn)劑 含量/ mg l - 1極限濃 縮倍率極限碳酸鹽 硬度/ mmol l - 1水穩(wěn)劑種類a tm paa tm pb3 . 03 . 02 . 862 . 5411 . 09 . 82 . 4循環(huán)水量的確定“工業(yè)企業(yè)循環(huán)冷卻水處理設(shè)計(jì)規(guī)范”中規(guī)定 ,循 環(huán)冷卻系統(tǒng)的循環(huán)水流量 ( q ) 和水容積 ( v ) 的比 ( q / v ) 一般選用 35 。該比值越大 ,系統(tǒng)濃縮越快

12、,即達(dá) 到某一濃縮倍率的時(shí)間就越短 。采用改進(jìn)后的試驗(yàn)裝 置 (圖 2) 進(jìn)行試驗(yàn)時(shí) ,循環(huán)水流量過(guò)大 ,易造成水噴濺 和水蒸汽攜帶鹽分 。結(jié)合實(shí)際經(jīng)驗(yàn) ,并考慮減少濃縮時(shí)間 ,循環(huán)水流量體積比 ( q / v ) 選為 1520 。 a tm pc 3 . 0 2 . 44 9 . 4 試驗(yàn)水 質(zhì) : 全 堿 度 3 . 85 mmol/ l , 全 硬 度 4 . 40 mmol/ l , 鈣 硬 度3 . 15 mmol/ l ,氯離子 16 . 5 mg/ l ;試驗(yàn)溫度 45 1 ;水穩(wěn)劑濃度 2 mg/ l 。表 4 阻垢率法試驗(yàn)結(jié)果原水中鈣離子/ mmol l - 1過(guò)濾水中鈣離

13、子/ mmol l - 1水穩(wěn)劑阻垢率/ %a tm paa tm pb10 . 010 . 08 . 07 . 78077 a tm pc 10 . 0 7 . 6 76 原水組分 : cacl2 10 mmol/ l , mgso4 3 mmol/ l , na hco3 10 mmol/ l ;水穩(wěn)劑濃度 2 mg/ l ;試驗(yàn)溫度 80 1 ;試驗(yàn)時(shí)間 6 h 。2 . 5分辨率2 . 5 . 1同類水穩(wěn)劑的比較 用極限碳酸鹽硬度法對(duì)同類水穩(wěn)劑的阻垢性能進(jìn)行了試驗(yàn) ,并與阻垢率法進(jìn)行了比較 ,結(jié)果見(jiàn)表 1 和表 2 。表 1 極限碳酸鹽硬度法試驗(yàn)結(jié)果表 3 和表 4 結(jié)果表明 ,阻垢率

14、法測(cè)得的結(jié)果明顯難以區(qū)分 3 種藥劑阻垢性能的優(yōu)劣 。而極限碳酸鹽硬 度法則可以容易地分辨出它們之間的差別 。如果以 a 公司產(chǎn)品為比較基準(zhǔn) 100 % ,則用 2 種方法測(cè)得結(jié)果 的相對(duì)值如下 :(1) 極限碳酸鹽硬度法 ab c = 100 %89 . 1 %85 . 5 % ;(2) 阻垢率法 abc = 100 %96 . 3 %95 . 0 % 。 由此可見(jiàn) ,極限碳酸鹽硬度法的分辨率要高于阻垢率法 。補(bǔ)充水中水穩(wěn)劑 含量/ mg l - 1極限濃 縮倍率極限碳酸鹽 硬度/ mmol l - 1水穩(wěn)劑tr trtr2003004001 . 51 . 51 . 52 . 732 . 8

15、12 . 5610 . 811 . 110 . 1試驗(yàn)水 質(zhì) : 全 堿 度 3 . 95 mmol/ l , 全 硬 度 3 . 72 mmol/ l , 鈣 硬 度2 . 52 mmol/ l ,氯離子 63 . 5 mg/ l ; 試驗(yàn)溫度 45 1 ; 水穩(wěn)劑濃度2 mg/ l 。表 2 阻垢率法試驗(yàn)結(jié)果結(jié)論3原水中鈣離子/ mmol l - 1過(guò)濾水中鈣離子/ mmol l - 1水穩(wěn)劑阻垢率/ %極限碳酸鹽硬度法對(duì)水穩(wěn)劑的阻垢性能分辨率高 ,試驗(yàn)結(jié)果重現(xiàn)性好 ,并可實(shí)際指導(dǎo)現(xiàn)場(chǎng)操作 。此法適用 于火電廠循環(huán)冷卻水處理水穩(wěn)劑阻垢性能的評(píng)價(jià) 。tr trtr20030040010 .

16、010 . 010 . 09 . 19 . 28 . 5919285原水組分 : cacl2 10 mmol/ l , mgso4 3 mmol/ l , na hco3 10 mmol/ l ;水穩(wěn)劑濃度 2 mg/ l ;試驗(yàn)溫度 80 1 ;試驗(yàn)時(shí)間 6 h 。表 1 、表 2 結(jié)果表明 ,極限碳酸鹽硬度法和阻垢率 法試驗(yàn)結(jié)果是一致的 。對(duì)于 tr200 和 tr300 2 參考文獻(xiàn) gb/ t16632 1996 ,水處理劑阻垢性能的測(cè)定 : 碳酸鈣沉 積法 s .1種藥劑 ,阻垢效果相近 。但用極限碳酸鹽硬度法測(cè)得兩者結(jié)果的差別為 2 . 93 % ,而用阻垢率法測(cè)得兩者結(jié) 果的差別

17、為 1 . 09 % 。說(shuō)明極限碳酸鹽硬度法的分辨h g/ t2024 91 ,水處理藥劑阻垢性能測(cè)定方法 : 鼓泡法s .23高秀山 ,楊東方 . 火電廠循環(huán)冷卻水處理 m .出版社 ,2002 .中國(guó)電力64熱力發(fā)電2004 (06)scaling and clogging. practice shows t hat t he developed scheme of anti scaling and clogging to be feasible.key words :medium and small scale indust rial boilers ; desulf uratio n

18、; scaling ; clogging ; anti scaling and cloggingsim ul atio n a nd em ul atio n system of service l ife p red ictio n fo r roto r of steam tur2bine wa ng qi , l ia ng zhihong , y ue jianhua et al( 35)abstract :at first , t wo main kinds of rotor damage for steam t urbines , i . e. creepage and fatig

19、ue damage , have been analysed , detail analysis and discussio n of calculatio n p rinciple and calculatio n met hod of t wo said kinds of damage being carried out . taking a 330 mw steam t urbine in o ne power plant in inner mo ngolia as st udied object , t he simulatio n and emulatio n calculatio

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21、ing ind ices fo r thermal powerunits wa ng l i l in , y e yongsong , wa ng jiajun ( 39)abstract :scientifically and reaso nably launching t he system of checking small operating indices in t hermal power plant s , t he ent husiam of operators for imp roving operating skill can be mobilized , and can

22、 benefit t he enhancing of eco no mic behavior for units operatio n. an app roach to t he p rinciple of checking small operat2 ing indices , t he calculating met hod of checked result s , and t he establishment of check database have been carried out , a realtime algorit hm for determining checked r

23、esult s based o n different operating co nditio ns and test values being reco mmended. the said met hod has been used o n many operating 300 mw unit s ,t he real time algorit hm not o nly can really reflect p ractical operatio n level of t he operator , but also can be helpf ul to discover p roblems

24、 existing in t he operatio n ,obtaining good result s in guiding p roductio n of t hermal power plant s , and in aspect s of enhancing eco no mic behavior and safe operatio n of unit s.key words :small operating indices ; check standard ; average value checking met hod ; real time algorit hmno ise c

25、o ntrol of d iesel generato r sets wa ng shu xin , mao shanyong , hua ng xinghua ( 42)abstract :alo ng wit h t he develop ment of boat s and ship s towards t he directio n of high speed and large capacit y , pollutio n p roblems of vibratio n and noise f ro m diesel generator set s are beco ming inc

26、reasingly serious wit h each passing day. taking diesel generator set o n a ship of medium capacit y as example , co mp rehen2 sive measures , such as isolating vibratio n , erecting noise reducer , and pasting bind damper and noise absorbing materials etc. , have been taken for co nt rollingnoise ,

27、 obtaining excellent effectiveness of noise co nt rol . the said measures are reaso nable , having low cost , p roviding reference value for co nt rolling noise of ot h2er power unit s.key words :diesel generator set ; noise co nt rol ; vibratio n ; noise pollutio nsway ing a nalysis of the servomot

28、o r fo r do ubl e extractio n steam turbine a nd co un2term eas ures of the co ntrol system y u tiebing ( 45)abstract :the causes leading to swaying of servo motor for double ext ractio n steam t urbine in anqing pet rochemical thermal power plant have been analysed f ro m so me main aspect s , such

29、 as set up of system parameters , delay rate of t he servo motor , and closed loop co nt rol of t he double ext ractio n steam t urbine etc. ,and countermeasures for eliminating t he t roubles being p ut forward. af ter implementatio n of t hese said measures , effectiveness is good , enhancing t he

30、 safety of steam t urbine operatio n.key words :double ext ractio n steam t urbine ; governing system ; elect ro hydraulic co nt rol ; servo motor ; delay rate ; decoupling co nt rola n air l ea ka ge co ntrol m ethod of air p reheaters based o n adaptive mod e ni yun f eng ( 48)abstract :directing

31、against t he p roblem existing currently in air leakage co nt rol system of air p reheaters for ho me made large scale t hermal power generatingunit s , a new met hod of air leakage co nt rol based o n adoptive mode has been p ut forward by using co mp uter database technology. result s of p ractice

32、 show t hatt he said met hod can effectively enhance t he co nt rolability of system , decreasing air leakage rate of t he air p reheater , p roviding guarant y for safe and f ull load op2eratio n of t he unit s.key words :t hermal power unit ; air p reheater ; clearance ; air leakage co nt rol ; ad

33、aptive modebrief d escriptio n of the negative p ress ure co ntrol system fo r bo il ers in seco ndp hase p roj ect of hua neng fuzho u power pl a nt c hen jian f eng , wa ng zhenhao ( 51)abstract :the design feat ures of negative p ressure co nt rol system in siemens made t xp dist ributed co nt ro

34、l system used for 2 300 mw unit s imported f ro mu k in t he seco nd p hase p roject of huaneng fuzhou power plant have been briefly p resented , including : ( 1) inp ut deviatio n signal of t he regulator and feedforward signal of forced draf t air flow ; ( 2) t reat ment of inp ut signal fluct uat

35、io n for t he regulator ; ( 3) adjust ment of gain for single and double unit s ; ( 4) bal2anced circuit ; ( 5) explosive p rotectio n in t he f urnace ; ( 6) high and low speed changing for induced draf t fan. the said co nt rol system has been p ut into opera2tio n and reliable performace under op

36、erating co nditio ns , such as start up and shut down of t he boiler , main f uel t rip , run back act uatio n , high and low speed switching etc. .key words :boller ; p ressure co nt rol system in f urnace ; negative p ressure co nt rol ; huaneng fuzhou power plantd evelopm ent of spa re space fo r

37、 d istributed co ntrol system a nd its appl icatio n in en2gineering ya ng hua , hu ba i yong , c hen heng zhong ( 54)abstract :through st udy o n spare space and load dist ributio n of dist ributed co nt rol system (dcs) for unit no1 of j iaxin power generatio n co mpany limited , t he expansible s

38、pace of t he said co nt rol system has been co nfirmed. hence , a technical ret rofit has been carried out , having revised t he t ransmit ting mode and t he cy2 cle time of original switching and analog signals , averaging t he load of various sub system for dcs , co nverting partial o n site pl c

39、co nt rol into dcs co nt rol ,enhancing t he auto matic level and operatio n reliabilit y of t he unit .key words :t hermal power unit ; dcs ; spare space ; switching quantit y ; analog quantit yclosed loop co ntrol system of cfb bo il ers c hen xiu ping , hua ng wei gang ( 57)abstract :the sit uati

40、o n and p roblems existing in co nt rol circuit s of analog variable co nt rol system for circulating fluidized bed ( cfb) boilers in daliuta thermalpower plant have been analysed , emp hatically describing t he st ruct ure of co nt rol circuit s for t he feed water and t he main steam temperat ure

41、, as well as t he sit u2atio n of t heir imp rovement . through debugging , t he co nt rol circuit of main steam temperat ure can be p ut into auto matic operatio n under operatio n co nditio n of main steam flow quantit y to be greater t han 50 % , and opening degree of t he desuperheating water va

42、lve to be greater t han 60 %. during t he time of co mpara2 tively stable boiler load , t he main steam temperat ure can be maintained in t he range 5 of t he set value.key words :cfb boiler ; feed water ; main steam temperat ure ; wdp e ; co nt rol system ; closed loop circuitretrofitting of water

43、l evel co ntrol system fo r high p ress ure heater of 350mw u2nits hu min , s hen qi ( 60)abstract :the defect s existing in t he co nt rol and p rotectio n sytem of high p ressure ( hp) heater for 350 mw untis iin huaneng nanto ng power plant have beenanalysed , and co ncrete ret rofit ting scheme

44、being p ut forward as follows : ( 1) eliminating p neumatic co nt roller , to realize co nt rol by using dist ributed co nt rol sys2 tem (dcs) ; ( 2) imp roving emergency drain mode of t he hp heater ; ( 3) increasing t he number of t ransducers ; ( 4) imp roving t he p rotectio n logic and set ting

45、 of p rotectio n parameters. af ter ret rofit ting , t he operatio n sit uatio n of t he said co nt rol system is good.key words :350 mw unit ; hp heater ; co nt rol system ; water level co nt rol ; huaneng nanto ng power planteval uatio n m ethod fo r scal ing reta rdatio n behavio r of water qual

46、ity stabil izinga gent used in circul ating water treatm ent at thermal power pl a nt j ia ng qi , ya n kun , xu jianxue ( 62)abstract :an evaluatio n met hod for scaling retardatio n behavior of water qualit y stabilizing agent by using ultimate carbo nate hardness met hod has been p re2sented , in

47、cluding measurment of scaling retardatio n behavier , as well as diterminatio n of evaluatio n indices , water temperat ure in test , co ncent ratio n of waterqualit y stabilizing agent , and circulating water flow rate of t he test facility etc. , and a co mpariso n wit h t he scaling retardatio n

48、rate met hod being carried out .result s of test show t hat t he ultimate carbo nate hardness met hod has many advantages , namely having high distinguish abilit y , good data rep roducibilit y , clear and definite guiding significance , as well as simplicit y and applicabilit y etc. , being suitabl

49、e for evaluating t he scaling retardatio n behavior of water qualit y sta2bilizing agent used in circulating water t reament at t hermal power plant skey words :termal power plant ; circulating cooling water ; water t reat ment ; water qualit y stabilizing agent ; eraluatio n of scaling retardatio n

50、 beharior ; ultimate carbo nate hardness met hodstudy o n watersaving, as well as a ntiscal e a nd a ntico rrosio n of circul atingwater in l a nzho u thermal power pl a nt no. 2 zha ng l ihua , zha ng zhengda ( 65)abstract :in view of t he qualit y of supplementary water for t he circulating water

51、in lanzhou thermal power plant no . 2 , a field test has been carried out by us2ing l y 8088 t ype scale retarding and corrosio n inhibiting agent , and optimal operatio n co nditio n being selected. af ter p ractical applicatio n , t he enrichmentfactor of circulating water has been enhanced f ro m

52、 original value about 2 . 0 to t he p resent value of 2 . 83 . 0 , having remarkable effectiveness for water saving ,and t he quantit y of agent dosing being small , t he corrosio n inhibiting and scale p reventing aim can be achieved o nly by using a dose of 46 mg/ l .key words :thermal power plant

53、 ; circulating water ; water saving ; scale retarding and corrosio n inhibiting agent ; anti corrosio n ; anti scaleappl icatio n of resid ential sewa ge in heze power pl a nt xu zhen , l i xiu juan , ya ng baohong et al( 68)abstract : the residential sewage in heze power plant has been t reated by

54、using aerated biological filt ratio n basin air floatatio n sand filt ratio n technology ,making t he qualit y of sewage af ter t reat ment to reach t he requirement s of supplementary water for circulatory cooling system. the technological p rocess , t he fea2 t ures of main t reat ment facilities

55、, as well as t he key point for at tentio n in t he t heir debugging have been briefly described. practice shows t hat t he said sewage t reat ment system is stable in operatio n , having high efficiency , various indices reaching t he requirement s of design ; af ter recycling utilizatio n of t he sewage , ef2fectiveness of water saving is remarkable.key words :power plant ; water saving ; residential sewage ; aerated biological filt ra