外文翻譯-----恒壓供水的控制與節(jié)能的探索

1、<p>　　畢業(yè)設計(論文)翻譯資料</p><p>　　課題名稱：S7-200 PLC控制的變頻</p><p>　　調速恒壓供水系統(tǒng)設計</p><p>　　畢業(yè)設計(論文)起止時間：</p><p>　　2007　年　3 月　1 日～　6 月　10 日(共　17　周)</p><p>　　學生姓名：

2、 學號： </p><p>　　指導教師： </p><p>　　報告日期： </p><p>　　The control and Energy-saving of automatic Water Supply Syste

3、m</p><p>　　Abstract: Based one simple analysis of the methods for water supply used domestically and abroad, this paper discusses the principe and system’s structure of automatic water supply system by using

4、 frequency conversion speed regulation in detail. Then the system’s advantages are discussed and some key problems that should be pay attention to designing are presented.</p><p>　　Keyword: Frequency convers

5、ion speed regulation; water supply with stable pressure: PID regulator.</p><p><b>　　Foreword</b></p><p>　　At present , supply water in residential area and life of the skyscraper of

6、our country generally adopt the way common frequently . It has heavy energy consumption, high noise ,and there has a great deal of questions in the source of water, such as secondary pollution etc. And it is a kind of co

7、mparatively ideal mode to adjust the watersupply device controlled rapidly with frequency conversion .Entering the middle and later periods of the 1990s, as the speed technology of frequency conversion ac</p><

8、p>　　In recent years, author has made some real work on rapidly to the transformation in frequency conversion supply water design and construction of control system , have accumulated some experience, and has formed th

9、e view on some questions. The reason why the energy-conserving principle frequency conversion of the water pump system of speed adjustment  becomes popularized , is mainly because that it has a better energy- c

10、onserving result. To pump system of frequency conversion, the water pump afte</p><p>　　Q1/Q2 =n1/n2  (1)   H1/H2 = (n1/n2)2  (2)  of the type. Q1, Q2 represents the fl

11、ow before and after the speed for the water pump respectively; N1, n2 represents the rotational speed before and after the speed for the water pump respectively; H1, H2 represents the lift before and after the speed for

12、the water pump respectively . </p><p>　　According the above:H1/H2=(f1/f2)2  Namely real lift of a water pump is power the square of  frequency in direct radio. Therefore changing the powe

13、r supply frequency of the electrical machinery of water pump through the frequency converter , can control supporting water pressure strength of the water pump . 2 constant pressure as Fig. 1 shows supply water of the au

14、tomatically controlled frequency conversion water -supply system principle block diagram. P1  is the give pressure value, p2 for the </p><p>　　This system can measure users' instantaneous water

15、 pressure adjust automatically  , regulate the amount of quantity of supplying water and operation conditions of the electrical machinery in view of the above. Can according to give water pressure strength to s

16、et for and control pressure value which needed , make the equipment in the constant pressure state all the time, can know from load characteristic of electrical machinery axle power and its the third power of in direct r

17、adio rotational spee</p><p>　　Case  analyse</p><p>　　Constant pressure is it regulate flow of water to the purpose to up to constant pressure through suiting well rapidly in frequency

18、conversion to supply water, the goal that it controls finally is the water pressure. Controlling the target has non-linear , lagging characteristics. The quality of PID regulator performance , has determined the quality

19、of the water -supply system to a great extent When the system is during the course of starting and stopping, or the pressure establishing value chang</p><p>　　Frequency converter is various in kind, for inst

20、ance the types , such as Mitsubishi , Fuji , three Kenya and ABB ,etc.. Generally often select the pumps , special-purpose series of air blower for use. Whether take Mitsubishi FR-A140E as an example, it except general f

21、unction had of brand , there are the following characteristics : The inside adopts the intellectual power module of IPM, it is lowest to make the noise of the electrical machinery to reduce  ; Frequency convert

22、er, and work-frequency</p><p>　　pressure sensor P monitors the size of the water pressure signal in real time, the signal is dealt with by PID, input it to the frequency converter. At the small flow, water p

23、ump electrical machinery 1M turn round (whether 1KM1 is it shut to suck), and through feedback password change his rotational speed constantly, it is invariable in order to keep the pressure; In case of large flow , comp

24、are frequency conversion by pressure circuit send out through PLC " constant/changed switch over frequent</p><p>　　Several questions while apply are in case of great majority</p><p>　　The e

25、nvironment for use of the scene is comparatively abominable . Though frequency converter has very strong protection functions itself, such as owe keep , excessive pressure , is it flow to pass, electric current amplitude

26、 limiting is it make exactly to choose, overload, overheated lacking looking , shorting out and disconnected ink protect the function But must prevent trouble before it happens . Through using finding , two kinds of bran

27、ds of Mitsubishi , Fuji, because has fully considered v</p><p>　　Conclusions</p><p>　　Are by way of adjusting the speed as the central water supply in frequency conversion, the result is obvious

28、 to economize on water , economize on electricity, can be extensively suitable for 20-10000 residents the biotope , skyscraper , hotels and retaurants , fire control or district pressurize and supply water, it is ideal f

29、acilities that the medium and small- scale waterworks supplied water too. Its amount of water quality supported is high, the economic benefits are obvious, the social benef</p><p>　　List of references </p

30、><p>　　Zhang Wanzhong, Zhu Jie, Wang Mingquan. A kind of new-type frequency conversion constant pressure supplies water of the plan of design of the pump station. Electrical age, 1999 (10): 22-232　Liu YingChun.

31、 Principle design of the sensor and application. Beijing: University of Science and Technology of the national defence publishing Presss, 1989.59-623  </p><p>　　Lu Guangda. Electric installation pr

32、oject manual of the building . Beijing: The electric publishing house of water conservancy, write the group in 1995.222- 2244 " </p><p>　　The automatic projecting ". Give and drain off water the au

33、tomatic project. Beijing: The electric publishing house of water conservancy, 1997.301-312</p><p>　　恒壓供水的控制與節(jié)能的探索</p><p>　　摘要:在簡要分析國內外給水系統(tǒng)現狀的基礎上,介紹了系統(tǒng)的組成,提出了以變頻調速為核心所構成的全自動給水系統(tǒng)控制方式,并以實例詳細分析了該系統(tǒng)的

34、組成、工作原理以及在控制與節(jié)能方面所表現出的優(yōu)越性.文中根據作者的實際使用經驗,簡要闡述了該系統(tǒng)在應用中應注意的一些問題。</p><p>　　關鍵詞: 變頻調速;恒壓供水。PID調節(jié)器中圖法   </p><p><b>　　一、引　　言</b></p><p>　　目前,我國居民小區(qū)與高層建筑的生活供水,普遍采用工頻方式

35、.它存在著能耗大,噪音高,水源存在二次污染等諸多問題.而用變頻調速控制的給水裝置是一種較為理想的模式.進入90年代中后期,隨著變頻調速技術的不斷發(fā)展與完善,基于該項技術的全自動恒壓給水方式已在發(fā)達國家得到廣泛的應用,且日趨成熟.近幾年來,作者在變頻調速給水控制系統(tǒng)的設計與施工方面做了些實際工作,積累了一些經驗,并形成了對于一些問題的看法.水泵節(jié)能原理變頻調速系統(tǒng)之所以得到推廣,一個很重要的原因就是它有較好的節(jié)能效果.</p>

36、<p>　　一臺水泵的實際揚程與電源頻率的平方成正比.因而通過變頻器改變水泵電機的供電頻率,就可控制水泵的供水壓力.恒壓供水自動控制變頻恒壓供水原理框圖如圖1所示. 為給定的壓力值, 為壓力傳感器從管道上所測得的實際壓力值,PID調節(jié)器通過對兩者的誤差運算,并經過控制變頻器的頻率輸出,從而使管道的壓力始終保持在設定值上。</p><p>　　該系統(tǒng)能自動檢測用戶的瞬時水壓,據此調節(jié)給水量的多少及電機

37、的運行狀況.還可根據所需的給水壓力設定控制壓力值,讓設備始終處于恒壓狀態(tài),從負載電機的特性可知,所配電機的軸功率與其轉速的三次方成正比,即 .例如,當變頻器輸出頻率為35Hz(最高設定為50Hz),也就是實際轉速為額定轉速的70%時,調速器的用電量為0.343,約占額定的35%.也就是說,水泵總處于恒壓變流量匹配方式的工作狀態(tài),從而消除了超壓和回流的無功損耗.恒速與變頻調速軸功率變化曲線如圖2所示,比較可知,變頻調速方式節(jié)能效果最為明顯

38、。</p><p><b>　　二、實例分析：</b></p><p>　　恒壓供水是通過變頻調速來調節(jié)水的流量從而達到恒壓的目的,它最終控制的目標是水壓.控制對象具有非線性、滯后特性.PID調節(jié)器性能的好壞,在很大程度上決定了恒壓供水的質量.當系統(tǒng)在啟動與停止階段,或壓力設定值大幅度變化時,由于在短時間內存在很大的偏差,因而無論PID調節(jié)器的控制算法采用增量式還是位

39、置式,其積分項將取蓄水池、水泵組(1M,2M)及相關輔配件構成.本系統(tǒng)的核心是變頻調速控制柜,它通過壓力傳感器對管網壓力進行實時監(jiān)測,并轉換為電信號提供給變頻器進行運算,通過變頻器、可編程控制器PLC與繼電器陣列的共同控制,構成了完善的全自動變頻調速給水系統(tǒng)。</p><p>　　變頻器的品種繁多,如三菱、富士、三肯及ABB等型號.一般常選用泵類、風機專用系列.以三菱FR-A140E為例,它除了一般品牌所具有的功

40、能外,還有如下特點:內部采用IPM智能功率模塊,使電機的噪音減至最低;變頻器與工頻電源之間可進行切換,用戶只需通過PLC輸入啟動、停止及自動切換指令,就可方便地通過接觸器的互鎖動作來切換不同的水泵,而不需要像以往那樣自行設計繁瑣的控制程序,這是該變頻器所特有的功能之一;內置的瞬時停電再啟動與再試啟動功能,在無人看管的情況下,即使變頻器停機后也可自行啟動,完全實現了以自動化方式的運行.本系統(tǒng)中的PID調節(jié)器可用變頻器內置式值很大,這就會存

41、在偏差調節(jié).在消除偏差調節(jié)的過程中,必然導致系統(tǒng)出現較大的超調和長時間的振蕩,同時還會產生嚴重的積分飽和現象,從而影響了設備的正常運行.要把這種影響降至最低,就應在控制算法中采用積分分離的PID控制方式,以達到預期效果.經這樣處理后,可大大縮短系統(tǒng)達到穩(wěn)定的過渡過程時間.系統(tǒng)中配備兩臺11kW水泵(1M為主泵,2M為備用泵)供600余戶居民用水.兩臺泵同時工作時提供最大高峰流量,單臺則滿足小流量和夜間供水.另外,所有水泵均</p&

42、gt;<p>　　變頻調速系統(tǒng)的主回路原理圖,壓力傳感器P實時監(jiān)測水壓信號的大小,信號經PID處理,輸入至變頻器.小流量時,水泵電機1M運轉(1KM1吸合),并通過反饋通道不斷調整其轉速,以保持壓力的恒定;在大流量的情況下,經壓力比較電路通過PLC發(fā)出“變頻/工頻切換”與“運行聯鎖”指令,機械聯鎖接觸器(2KM(2KM1+2KM2)中的2KM2、接觸器3KM得電.這時,電機2M以變頻方式啟動,1M則切換至工頻全速運行.這樣

43、,本系統(tǒng)能始終將用水量維持在一個恒定的壓力上.前述小區(qū)建成初期,供水采用工頻方式,因能耗大,可靠性差,住戶反映強烈.改用變頻供水后,裝機總容量較原設備減小25%,實際綜合節(jié)電指標接近30%,效果顯著。</p><p>　　三、應用中的幾個問題</p><p>　　在大多數情況下,現場的使用環(huán)境較為惡劣.變頻器雖然本身具有很強的保護功能,如欠壓、過壓、過流、電流限幅選擇整定、過載、過熱、缺相

44、、短路及斷水保護功能等,但仍應做到防患于未然.經使用發(fā)現,三菱、富士兩種品牌,由于在設計和制造中充分考慮了各種惡劣的運行環(huán)境.在同樣條件下的可靠性和使用壽命較某些品牌高.湖北鄂西山區(qū)某小城市,平均海拔1200m,常年大部分時間濕度偏高(80%左右),二氧化硫污染嚴重,某廠生產的一套變頻供水設備,因未考慮上述因素,以至于不到一年的時間,設備的有關部件嚴重腐蝕.而我們在同一地區(qū)設計、安裝的同類產品,因充分考慮了各種不同的情況,在設備與元件的

45、選型上,采用了船用標準.經兩年多的使用,運行良好,經受了各種嚴峻的考驗.在實際使用中發(fā)現,變頻器本身就是一個強大的干擾發(fā)生源,往往會影響設備的正常運行.特別是水泵低轉速運轉時,變頻器上顯示的頻率與實際運行頻率不符.干擾的傳播途徑一般有兩種:線路串擾和空間輻射干擾.根據現場的實際情況可采取相應的措施予以解決.例如,對可編程控制器的電源端增加濾波與吸收回路,PID調節(jié)器單元的輸入輸出一定要有可靠屏蔽,將變頻器、電機上的接地端子牢固地<

46、/p><p><b>　　四、結束語</b></p><p>　　以變頻調速為核心的供水方式,節(jié)水、節(jié)電效果明顯,可廣泛適用于20～10000戶居民生活區(qū)、高層建筑、賓館、飯店、消防或小區(qū)加壓供水,也是中小型自來水廠給水的理想設施.其供水質量高,經濟效益明顯,社會效益巨大,隨著國民經濟的發(fā)展和人民生活水平的不斷提高,它一定會在我國逐步得到應用與推廣。</p>

47、<p><b>　　五、參考文獻</b></p><p>　　張萬忠,王民權.《一種新型變頻恒壓供水泵站的設計方案》.電氣時代,1999(10):22～232　</p><p>　　劉迎春.《傳感器原理設計與應用.》北京:國防科技大學出版社,1989.59～623　</p><p>　　呂光大.《建筑電氣安裝工程手冊》.北京:水利電