熱電廠輸煤裝置的智能傳送控制系統(tǒng)外文翻譯

1、<p><b>　　中文2652字</b></p><p><b>　　1680單詞</b></p><p>　　畢 業(yè) 設(shè) 計(jì)（論 文）</p><p>　　外 文 文 獻(xiàn) 譯 文 及 原 文</p><p>　　學(xué) 生： </p

2、><p>　　學(xué) 號(hào)： </p><p>　　院 （系）： 電氣與信息工程學(xué)院 </p><p>　　專 業(yè)： 電氣工程及其自動(dòng)化 </p><p>　　指導(dǎo)教師： </p><p>　　2009 年 06月

3、10日</p><p>　　熱電廠輸煤裝置的智能傳送控制系統(tǒng)</p><p>　　作者: Makarand Joshi</p><p>　　摘要：幾乎在所有輸煤裝置（CHP）上都能看到傳送帶的身影。輸煤裝置有很多傳送帶。用于這些傳送帶的控制系統(tǒng)是非常重要的安全運(yùn)行裝置。傳送帶基本上是無(wú)輸出顯示的，但一旦配備了適當(dāng)?shù)目刂葡到y(tǒng)，他們就能高產(chǎn)高效生產(chǎn)并成為安全的操作裝置。

4、電子智能傳送帶控制技術(shù)有益于復(fù)雜的輸送任務(wù)。但是，在輸煤裝置的控制輸送系統(tǒng)仍然使用簡(jiǎn)單的開/關(guān)開關(guān)以及某些型號(hào)的高速開關(guān)。這些開關(guān)只在防護(hù)方面起到了有限的作用。這些傳送帶控制系統(tǒng)最大的問(wèn)題是設(shè)備操作員和維修工程師要是解除不安全的工廠運(yùn)行因素，那些將會(huì)迫使設(shè)備故障和中斷供應(yīng)煤鍋爐，造成損失的因素。 本文重點(diǎn)論述輸送控制系統(tǒng)的必須性，該系統(tǒng)將滿足設(shè)備平穩(wěn)，安全運(yùn)行的需求。</p><p>　　關(guān)鍵詞：傳動(dòng)帶，控制系統(tǒng)

5、</p><p><b>　　1簡(jiǎn)介：</b></p><p>　　輸煤裝置的效率取決于輸送系統(tǒng)的可用性和可靠性。如果傳送帶運(yùn)作良好，這幾乎是無(wú)形的輸煤裝置。一個(gè)單一的傳送帶可以以接近100 ％的可靠性運(yùn)行，但隨著傳送帶的數(shù)量增加，輸送系統(tǒng)的可靠性就主要取決于它的控制系統(tǒng)?？刂葡到y(tǒng)應(yīng)能滿足輸煤裝置運(yùn)行的所有需要。 </p><p>　　現(xiàn)有系統(tǒng)

6、的目的是照顧連續(xù)運(yùn)行中由于低速而停機(jī)的傳送帶。他們還保證了自動(dòng)運(yùn)行的除塵系統(tǒng)。煤炭運(yùn)輸?shù)姆Q重也可由這個(gè)系統(tǒng)自動(dòng)完成。但是，不合適的系統(tǒng)功能無(wú)法滿足輸煤裝置的要求。這種情況下可以使用簡(jiǎn)單的繼電器控制系統(tǒng)和舊式機(jī)械傳感裝置。</p><p>　　為了滿足要求，電子智能傳送帶控制系統(tǒng)要不斷發(fā)展。這個(gè)系統(tǒng)將打破一切舊體制的制約，擁有額外的功能例如進(jìn)給速度控制。</p><p>　　2現(xiàn)有的控制系統(tǒng)

7、： </p><p>　　現(xiàn)有的系統(tǒng)已經(jīng)有像零速度傳感，傳送帶位置遙感接收器等感應(yīng)裝置。它還可以方便的選擇運(yùn)行傳送帶，以避免控制系統(tǒng)手動(dòng)運(yùn)行模式。在一些輸煤裝置的設(shè)備有三個(gè)種選擇。其中之一就是啟動(dòng)或停止裝置的自動(dòng)模式。在這種模式下選擇流后每個(gè)傳送帶會(huì)連續(xù)運(yùn)行。二是用人工方式使所有輸煤裝置啟動(dòng)或停止。三是系統(tǒng)沒(méi)有任何保護(hù)或聯(lián)鎖的運(yùn)行。</p><p><b>　　2.1工作原理：&

8、lt;/b></p><p>　　輸送系統(tǒng)開始之前有必要先開始啟動(dòng)傳送帶，然后開始物料輸送，即運(yùn)行邏輯是從下游向上游。停止輸送系統(tǒng)的運(yùn)作方式輸相反的，即從上游到下游。因此如有傳送帶停止時(shí)所有上游輸送應(yīng)停止自動(dòng)是很必要的?，F(xiàn)有的系統(tǒng)照顧到了這個(gè)邏輯。這就是所謂的輸送帶連續(xù)運(yùn)行。如果由于任何問(wèn)題使輸送帶的旋轉(zhuǎn)變得緩慢甚至為零時(shí)有必要停止輸送。這就是所謂的零速保護(hù)?，F(xiàn)行制度照顧并停止傳送帶，并進(jìn)一步阻止上游系統(tǒng)順

9、序。當(dāng)有煤流時(shí)除塵系統(tǒng)應(yīng)該運(yùn)行。這是通過(guò)遙感簡(jiǎn)單的皮帶下機(jī)械開關(guān)來(lái)實(shí)現(xiàn)的。測(cè)量煤流是通過(guò)使用稱重傳感器。</p><p>　　該框圖如圖1給出了控制系統(tǒng)的概述。</p><p><b>　　圖1</b></p><p>　　當(dāng)皮帶開關(guān)接觸煤炭且電機(jī)運(yùn)行時(shí)除塵系統(tǒng)噴頭將會(huì)打開。這兩個(gè)沒(méi)有任何的感應(yīng)，以避免當(dāng)傳送帶不旋轉(zhuǎn)時(shí)采取噴灑，但皮帶上的煤炭是

10、接觸皮帶下面開關(guān)的真正原因。 </p><p>　　2.2現(xiàn)有系統(tǒng)的反饋：</p><p>　　該系統(tǒng)的主要的問(wèn)題是必須保持不斷的監(jiān)視每條輸送帶的電流，因?yàn)閭魉筒劭赡鼙蝗』蜉斔蛶П豢ㄗ?。很多時(shí)候必須減少進(jìn)給率通過(guò)調(diào)整反饋減少輸送帶的電流。當(dāng)電流再次恢復(fù)正常時(shí)系統(tǒng)試圖建立所需的進(jìn)給速度，如果系統(tǒng)不能再次建立就要停止輸送系統(tǒng)并把問(wèn)題識(shí)別和標(biāo)示出來(lái)。這個(gè)問(wèn)題大多數(shù)發(fā)生在雨季當(dāng)煤很潮濕的條件下。

11、有時(shí)運(yùn)行特別不能認(rèn)定電流的增加將造成大量的煤溢出傳送槽。這個(gè)趨勢(shì)會(huì)中斷鍋爐的煤炭供應(yīng)。</p><p>　　感應(yīng)速度可以使用簡(jiǎn)單的代理開關(guān)。當(dāng)這些開關(guān)安裝在尾部滾筒上時(shí)，有時(shí)可能由于煤泄漏時(shí)而引起問(wèn)題。代理交換機(jī)基本上是開/關(guān)開關(guān)配備計(jì)時(shí)器，他們是不太可靠的。一些輸煤裝置采用離心開關(guān)驅(qū)動(dòng)傳送帶。當(dāng)煤突然涌出時(shí)，這個(gè)開關(guān)在減小煤涌出的拉力功能上的不合適就會(huì)顯現(xiàn)出來(lái)。</p><p>　　該系

12、統(tǒng)的主要的問(wèn)題是，當(dāng)輸送電機(jī)保險(xiǎn)絲被燒時(shí)，它將會(huì)停止輸送機(jī)的旋轉(zhuǎn)，但不會(huì)停止上游傳送帶的控制器感應(yīng)電機(jī)運(yùn)行控制供應(yīng)，因?yàn)闆](méi)有將電機(jī)繼電器關(guān)閉。由于這些系統(tǒng)的邏輯會(huì)出錯(cuò)。</p><p>　　系統(tǒng)的控制沒(méi)有根據(jù)[ 1 ]去測(cè)量粉塵排放量和煤流的數(shù)量，沒(méi)有為控制系統(tǒng)發(fā)揮任何作用。 </p><p>　　3智能輸送控制系統(tǒng)：</p><p>　　控制系統(tǒng)將取代現(xiàn)有的系統(tǒng)，

13、必須要克服所有舊系統(tǒng)的缺點(diǎn)。該系統(tǒng)，將建議使用測(cè)速傳感器，稱重傳感器和電子芯片取代繼電器。</p><p><b>　　3.1工作原理： </b></p><p>　　皮帶速度是通過(guò)一個(gè)可連接到任何非驅(qū)動(dòng)滑輪的測(cè)速發(fā)電機(jī)來(lái)衡量的。這個(gè)皮帶運(yùn)輸機(jī)速度的測(cè)量是用于煤的稱重。在新系統(tǒng)中測(cè)速是主要的部分，這有助于控制系統(tǒng)的順利運(yùn)行。這將判斷非驅(qū)動(dòng)滑輪的速度。產(chǎn)量將不斷通過(guò)傳送

14、帶電機(jī)和稱重傳感器（傳送帶稱重）與目前的比較得出輸出結(jié)果。這將控制進(jìn)給率。</p><p>　　轉(zhuǎn)速表安裝在非驅(qū)動(dòng)皮帶輪上</p><p>　　令Et1 =給定電壓， KT1 =常數(shù)，? (t1) =非驅(qū)動(dòng)滑輪的速度。</p><p>　　得Et1 = KT1 . ? (t1). ??…… 1. </p><p>　　稱重傳感器安裝在傳

15、送帶下面 </p><p>　　令Ec =給定電壓，Kc =常數(shù)，W(c) =煤的瞬時(shí)重量。</p><p>　　得Ec = Kc . W(c). ??…… 2. </p><p>　　進(jìn)給速度的計(jì)算需要比較稱重平衡橋（Wb）</p><p>　　令Ect =輸出電壓的比較值， Kct =常數(shù)，W(ct) =煤的進(jìn)給速度</p>

16、<p>　　得Ect = Kct . W(ct). ??…… 3.</p><p>　　及Ect = Ec / Et1.</p><p>　　令SR =參考信號(hào)，SE =錯(cuò)誤信號(hào)，SF =反饋信號(hào)，SO =輸出信號(hào)（反饋調(diào)速） </p><p>　　SF = Ect …… 隨著輸出電壓平衡橋衡反饋信號(hào)同時(shí)輸出</p><p>

17、<b>　　把值帶入3中</b></p><p>　　SF = Kct . W(ct). ??…… 4. </p><p>　　電流互感器Mc判斷通過(guò)發(fā)動(dòng)機(jī)的電流</p><p>　　令Em =輸出電壓參考電機(jī)電流互感器Mc</p><p>　　T.F. =傳輸功能，這取決于調(diào)節(jié)系統(tǒng)的類型</p><

18、p>　　比較器Cml比較電流互感器輸出信號(hào)與稱重平衡橋（Wb）的輸出信號(hào)</p><p>　　令Eml =比較器Cml的輸出電壓，Kml =常數(shù)，W(ml) =煤的每個(gè)電機(jī)進(jìn)給速度</p><p>　　得Eml = Kml . W(ml). ??…… 5.</p><p>　　和Eml = Ect / Em</p><p>　　Sml

19、= Eml …… 由于輸出電壓比較器是一樣的反饋信號(hào)</p><p><b>　　把值帶入5中</b></p><p>　　Sml = Kml . W(ml). ??…… 6.</p><p>　　進(jìn)給速度決定好后，然后通過(guò)調(diào)整位置設(shè)定控制器。反饋調(diào)速器的速度是隨著從稱重平衡橋接收到的反饋改變的。在同一時(shí)間收到的反饋是進(jìn)給率電機(jī)功率。由于電機(jī)

20、功率進(jìn)給率降低，反饋裝置的速度也將降低，以保護(hù)系統(tǒng)。同時(shí)，它會(huì)通過(guò)報(bào)警提醒操作者?？驁D如圖2將給予同樣的概述。</p><p><b>　　圖 2</b></p><p>　　皮帶灑水裝置也將從平衡器收到信號(hào)。作為流動(dòng)的煤炭設(shè)立了無(wú)噴嘴上安裝安全帶的運(yùn)作中所占的比例煤炭進(jìn)給速度。通過(guò)測(cè)量粉塵排放量將產(chǎn)生反饋和采取糾正動(dòng)作。見(jiàn)圖3 。 </p><p

21、>　　令SR1 =參考信號(hào)， SE1 =錯(cuò)誤信號(hào)， SF1 =反饋信號(hào)， SO1 =輸出信號(hào)（無(wú)噴嘴打開） </p><p><b>　　由4 可得</b></p><p>　　SF1 = SF = Kct . W(ct)??…… 7.</p><p>　　用敏感光電式裝置測(cè)量粉塵量。這個(gè)裝置Md將會(huì)傳送信號(hào)。</p>&l

22、t;p>　　令Emd =輸出電壓Md， Kmd =常數(shù)，W(md) =粉塵排放率。 </p><p>　　得Emd = Kmd . W(md). ??…… 8.</p><p>　　Smd = Emd …… 由于輸出電壓比較器和反饋信號(hào)大小是一樣的。 </p><p><b>　　把值帶入8中 。 </b></p>&l

23、t;p>　　SF1 = Kmd . W(md).??…… 9. </p><p><b>　　圖 3</b></p><p>　　這兩個(gè)控制器將確保輸送系統(tǒng)的運(yùn)行非常順利?？驁D如圖4將清楚地表明這一系統(tǒng)。使用模擬到數(shù)字轉(zhuǎn)換器可以很容易地將所有數(shù)據(jù)記錄在計(jì)算機(jī)中。</p><p><b>　　圖 4</b></p

24、><p><b>　　4結(jié)論：</b></p><p>　　該系統(tǒng)易于安裝。該系統(tǒng)具有更高的可靠性和保護(hù)性。該系統(tǒng)不需要任何復(fù)雜的傳感器?，F(xiàn)有的系統(tǒng)中所有的缺點(diǎn)將在該系統(tǒng)中被改正。</p><p><b>　　參考文獻(xiàn)：</b></p><p>　　1 .科技論文“Failure of Dust Sup

25、pression Systems in Coal Handling Plants”，作者 Makarand Joshi，M-News Edition 19 of Plant Maintenance Resource Center [Industrial Maintenance Portal] www.plant-maintenance.com/articles/dust_suppression.pdf</p><p&

26、gt;　　An Intelligent Conveyor Control System For Coal Handling Plant Of Thermal Power Plant</p><p>　　By: Makarand Joshi</p><p>　　Abstract: Conveyors are seen on virtually all in the Coal Handlin

27、g Plant (CHP). CHP are having number of conveyors. The control systems used for these conveyors are important for operating safe plant. Basically conveyors are dumb, but once equipped with proper control system they yiel

28、d efficient and safe plant operation. Electronic intelligent conveyor control technology is useful for complex conveying tasks. But in CHP for control of conveyer system still use of simple on/off switches and some</p

29、><p>　　Key words: conveyor, control systerm</p><p>　　1 Introduction:</p><p>　　The efficiency of CHP is depending upon availability and reliability of conveyor system. If a conveyor sys

30、tem is working well, it is almost invisible to the CHP. A single conveyor can run at close to 100% reliability, but as the number of conveyor increases, the reliability of the conveyor system is mostly depend upon its co

31、ntrol system. The control system should be capable to fulfill all the need of CHP operation. </p><p>　　The existing systems are designed to take care of only conveyor stoppage due to conveyor zero speed and

32、sequential operation. They also ensured of auto operation of dust spray system. The measurement of coal transported is done automatically by this system. But improper system feature could not fulfill CHP operation requir

33、ement. At maximum places the simple relay control system with old style mechanical sensing devices are used. </p><p>　　For fulfilling the requirement Electronic intelligent conveyor control system has develo

34、ped. This system will take all the constraints of old system and also having additional feature like feed rate control. </p><p>　　2 Existing Control System:</p><p>　　The existing system has sens

35、ing device like zero speed sensing, receiving conveyor position sensing. It has also facility for selection to operate conveyor avoiding control system i.e. manual run mod. In some CHP there is facility of three type of

36、selection. One is for start or stop plant with auto mode. In this mod each conveyor will operate sequentially after selecting the stream. Second which is in all CHP for start or stop of plant with manual mode. Third is o

37、perating the system without any </p><p>　　2.1 Operating Principle:</p><p>　　Before starting conveyor system it is necessary to start first receiving conveyor and then start feeding conveyor i.e.

38、 operating logic is from down stream to upstream. For stopping of conveyor system the operation will be opposite i.e. from upstream to down stream. So it is necessary if any conveyor is stopped in the system all the upst

39、ream conveyor should stop automatically. The existing system takes care of this logic. This is known as conveyor sequential operation. If due to any problem the r</p><p>　　The block diagram of shown in figur

40、e no 1 will give idea about control system. </p><p>　　Figure No 1</p><p>　　For dust suppression system the spray header will be on when the contact of under belt switch is true and motor is in o

41、n. This two no of sensing is taken to avoid spraying when conveyor is not rotating but contact of under belt switch is true due to coal is laying on belt. </p><p>　　2.2 Draw Back Of Existing System:</p>

42、;<p>　　The main problem of this system is required to keep continuous watch on each conveyor current because of choking of transfer chute or jamming of conveyor. Many times it is required to reduce the feeding rat

43、e by adjusting feeder to reduce the current of conveyor. When current comes to normal again it is tried to establish the required feed rate, if it is not again establish by stopping the conveyor system the problem is ide

44、ntify and attended. This problem majorly occurs in rainy season when coal </p><p>　　For sensing of speed simple proxy switches are used. These switches many times causes problem due to coal spillage when the

45、y are mounted on tail end pulley. As proxy switches are basically on/off switches equipped with timer, they are less reliable. Some of CHP used centrifugal switch, which is driven by the conveyor. The main problem of thi

46、s witch occurs when the spring functioning is improper i.e. reduction of spring tension. </p><p>　　The major problem of this system when the conveyor motor power fuses blown off, it will stop the rotation of

47、 conveyor but will not stop the upstream conveyors as controller sense motor is running because the control supply does not pick up motor off relay. Because of this the logic of system fails. </p><p>　　The c

48、ontrol of the system is not depending [1] on the quantity of dust emission and measurement of coal flow is not play any roll for controlling the system. </p><p>　　3 An Intelligent Conveyor Control System:<

49、;/p><p>　　The control system, which will replace the existing system, must overcome all the drawbacks of old system. The system, which is suggested, will work by only using tachometer, load cell and electronic

50、cards in place of relays. </p><p>　　3.1 Operating Principle:</p><p>　　Belt speed is measured by a tacho-generator, which may be attached to any non-drive pulley. This speed measurement is used f

51、or weighment of coal, which is with conveyor. In new system tachometer is main part, which helps for controlling system smoothly. This will sense non-drive pulley speed. The output of this will be compared continuously w

52、ith current drawn by conveyor motor and load cell （conveyor weighbridge} output. This will govern the feeder rate. </p><p>　　For tachometer, which is mounted on non- drive pulley </p><p>　　Let E

53、t1 = generated voltage, KT1 = the constant, ? (t1) = the speed of non-drive pulley. </p><p>　　Then Et1 = KT1 . ? (t1). ?…… 1.</p><p>　　For load cell which is mounted below conveyor </p>

54、<p>　　Let Ec = generated voltage, Kc = the constant, W(c) = the weight of coal at that time. </p><p>　　Then Ec = Kc . W(c). ??…… 2. </p><p>　　For calculating feed rate it is required to co

55、mpare by comparator of weighbridge (Wb) </p><p>　　Let Ect = out put voltage of comparator, Kct = the constant, W(ct) = the feed rate of coal </p><p>　　Then Ect = Kct . W(ct). …… 3. </p>

56、<p>　　And Ect = Ec / Et1. </p><p>　　Let SR = Reference signal, SE = Error signal, SF = Feed back signal, SO = Out put signal (for feeder speed adjustment), </p><p>　　SF = Ect ?…… As the ou

57、t put voltage of weighbridge is same as feed back signal. </p><p>　　Putting value in 3. </p><p>　　SF = Kct . W(ct). …… 4. </p><p>　　The current transformer Mc senses the current d

58、rawn by motor. </p><p>　　Let Em = equivalent output voltage with reference to motor current transformer Mc </p><p>　　T.F. = Transfer function, it depends on the type of regulating system. </p

59、><p>　　The comparator Cml compare current transformer output signal with out put signal of comparator of weighbridge (Wb) </p><p>　　Let Eml = out put voltage of comparator Cml, Kml = the constant,

60、W(ml) = the feed rate of coal per motor power </p><p>　　Then Eml = Kml . W(ml). …… 5. </p><p>　　And Eml = Ect / Em </p><p>　　Sml = Eml …… As the out put voltage of comparator is

61、same as feed back signal. </p><p>　　Putting value in 5. </p><p>　　Sml = Kml . W(ml). …… 6. </p><p>　　The feed rate is to be decided and then it is to be set for controller by adju

62、sting pot position. The speed of feeder is change as per feedback received from weighbridge. Then at same time feedback is received for feed rate per motor power. As the feed rate per motor power is reduced the speed of

63、feeder will be reduced and will protect the system. At the same time it will alert the operator by blowing alarm. The block diagram shown in figure no 2 will give idea about the same. </p><p>　　Figure No 2&l

64、t;/p><p>　　For spraying the water on the belt the signal will receive from the weighbridge. As flow of coal is established the no of nozzles mounted on belt will operate in proportion to the coal feed rate. The

65、 feedback will take by measuring dust emission and corrective action will be taken. See figure no 3. </p><p>　　Let SR1 = Reference signal, SE1 = Error signal, SF1 = Feed back signal, SO1 = Out put signal (fo

66、r no of nozzle opening), </p><p><b>　　From 4 </b></p><p>　　SF1 = SF = Kct . W(ct) …… 7.</p><p>　　For measuring the dust emission the Sensitive phototransistor type dev

67、ice used. This device Md will transfer signals. </p><p>　　Let Emd = out put voltage Md, Kmd = the constant, W(md) = dust emission rate. </p><p>　　Then Emd = Kmd . W(md). …… 8.</p><p

68、>　　Smd = Emd …… As the out put voltage of comparator is same as feed back signal. </p><p>　　Putting value in 8. </p><p>　　SF1 = Kmd . W(md). …… 9. </p><p>　　Figure No 3</p>

69、;<p>　　This two controller will ensure the conveyor system operation very smooth. The block diagram shown in figure no 4 will give clear idea about this system. Using analog to digital converter all the data can b

70、e easily recorded in computer. </p><p>　　Figure No 4</p><p>　　4 Conclusion:</p><p>　　The system suggested is easy to install. The system is having greater reliability and protection

71、. The system does not require any complicated sensors. All the drawbacks of existing system are removed in the suggested system. </p><p>　　Reference:</p><p>　　1. Technical paper on “Failure of D

72、ust Suppression Systems in Coal Handling Plants” by Makarand Joshi, in M-News Edition 19 of Plant Maintenance Resource Center [Industrial Maintenance Portal] at web site www.plant-maintenance.com/articles/dust_suppressio