外文翻譯---抽水系統(tǒng)plc和變頻調(diào)速

1、<p>　　畢業(yè)設(shè)計(jì)(論文)外文資料翻譯</p><p>　　學(xué) 院： 能源與動力工程學(xué)院 </p><p>　　專 業(yè)： 建筑環(huán)境與設(shè)備工程 </p><p>　　姓 名： </p>&l

2、t;p>　　學(xué) 號： 0702060109 </p><p>　　外文出處： </p><p>　　附 件： 1.外文資料翻譯譯文；2.外文原文。 </p><p>　　附件1：外文資料翻譯譯文</p><p>　　抽水

3、系統(tǒng)PLC和變頻調(diào)速</p><p>　　薩拉赫Addallah</p><p>　　改造中應(yīng)注意的一些技術(shù)問題　　?。?）高壓變頻調(diào)速凝結(jié)水泵運(yùn)行時上水調(diào)整門打開，利用改變凝結(jié)水泵的轉(zhuǎn)速調(diào)節(jié)除氧器水位造成凝結(jié)水壓力較低，最大不超過2.8MPa。運(yùn)行中凝結(jié)水壓力隨負(fù)荷降低而下降，為了保證其它設(shè)備所需凝結(jié)水的壓力，所以凝結(jié)水母管壓力低聯(lián)鎖值應(yīng)重新整定，但不能太低。例如設(shè)定變頻調(diào)速系統(tǒng)的最低

4、轉(zhuǎn)速為30Hz（變頻器最低轉(zhuǎn)速設(shè)為750r/min）?！　　。?）變頻凝結(jié)水泵變頻運(yùn)行時，凝結(jié)水至除氧器副調(diào)節(jié)閥全開，主調(diào)節(jié)閥全關(guān)，所以凝結(jié)水母管壓力最低低至0.85MPa。為了保證定速凝結(jié)水泵低水壓不動作（工頻運(yùn)行時定值為1.8 MPa），將定值修改為低于0.6MPa，聯(lián)動備用泵，母管壓力0.7 MPa時熱控光字牌報(bào)警。變頻器跳閘，系統(tǒng)發(fā)出12s脈沖信號，將除氧器水位總手操指令由50％減至20％，對應(yīng)副調(diào)節(jié)閥開度約在43％左右，其它

5、熱控保護(hù)不變?！　　。?）運(yùn)行變頻凝結(jié)水泵跳閘備用定速凝結(jié)水泵聯(lián)鎖啟動后凝結(jié)水壓力突然升高；對凝結(jié)水供其它輔助設(shè)備影響很大，特別是給水泵機(jī)械密封冷卻水系統(tǒng)，由于給水泵機(jī)械密封冷卻水差壓一般維持在0.1MPa。針對此問題在給水泵機(jī)械密封冷卻水調(diào)整門上預(yù)置</p><p>　　在甘肅金川公司熱電廠、山東華泰熱電廠、山東里彥電廠、徐州詫城電廠及山東濱州魏橋熱電廠，我們先后設(shè)計(jì)了18臺135MW機(jī)組國產(chǎn)超高壓、中間再熱

6、機(jī)組。這些電廠有一個共同的特點(diǎn)，基本上是企業(yè)自發(fā)自用，企業(yè)除了有穩(wěn)定的電力需求外還有一定的供熱負(fù)荷，企業(yè)的供熱負(fù)荷波動較大。使得電廠循環(huán)水系統(tǒng)的循環(huán)水量大幅度改變。在沒有供熱負(fù)荷時，供熱機(jī)組基本上在純凝汽工況運(yùn)行，這種情況往往出現(xiàn)在每年的夏季。隨著冬季的來臨，生產(chǎn)供熱負(fù)荷與生活采暖負(fù)荷增加，使機(jī)組供熱負(fù)荷大幅度提高，極端情況下，機(jī)組會超額定抽汽工況運(yùn)行。這些企業(yè)多數(shù)位于我國的華北、東北與西北地區(qū)，采暖時間較長，每年固定采暖期有4-6個月

7、，個別年限采暖期更長。機(jī)組如此長時間抽汽供熱運(yùn)行，使得電廠循環(huán)水流量長時間在較低的情況下運(yùn)行，考慮電廠長期經(jīng)濟(jì)運(yùn)行要求，循環(huán)水泵的供水流量和揚(yáng)程的高效范圍要求很長。</p><p>　　以135MW供熱機(jī)組為例：夏季機(jī)組汽輪機(jī)VWO工況時，汽輪機(jī)凝汽器凝汽量為324.17t/h，1臺機(jī)組的循環(huán)水量為19640t/h；汽輪機(jī)額定抽汽工況時，汽輪機(jī)凝汽器凝汽量為223.36t/h，1臺機(jī)組的循環(huán)水量為12274 t/

8、h；汽輪機(jī)在最大抽汽工況時，汽輪機(jī)凝汽器凝汽量142.66t/h，機(jī)組的循環(huán)水量為4700 t/h。循環(huán)水系統(tǒng)的流量從4700t/H--19000T/H變化，按照常規(guī)等容量水泵布置為滿足機(jī)組最小熱負(fù)荷的冷卻水要求（轉(zhuǎn)載自中國教育文摘http://www.edUzhai.net，請保留此標(biāo)記。）配置循環(huán)水泵流量為9800T/H-11700T/H，供水揚(yáng)程約18.0-21.5米，二臺水泵并聯(lián)運(yùn)行。在額定抽汽工況下,一臺水泵運(yùn)行,由于循環(huán)水量

9、減少、系統(tǒng)的水阻下降,水泵的流量12274T/H,揚(yáng)程將下降至15.0-16.0米，在汽輪機(jī)在最大抽汽工況時,為滿足循環(huán)水系統(tǒng)要求運(yùn)行一臺水泵，由于供水量大幅度減少，使水泵揚(yáng)程大幅度提高,直接造成冷卻塔涌水,加大淋水裝置配水槽的流速，水流在淋水填料上熱交換的時間減少，降低了冷卻塔的冷卻效果。當(dāng)然淋水填料熱交換的效果降低在冬季不會</p><p>　　小型蒸汽鍋爐給水泵的節(jié)能   &

10、#160;    (1)蒸汽鍋爐給水泵節(jié)能須以提高效率為原則現(xiàn)在進(jìn)口的或國產(chǎn)的立式多級管道泵，其效率曲線長而平坦，對應(yīng)的流量范圍變化大，可在較大流量范圍內(nèi)保持較高的運(yùn)行效率。對DZL2-1.25蒸汽鍋爐，選擇CR3型給水泵，其效率達(dá)到50％以上。流量范圍為1.6--4.0m3/h，比GC型泵運(yùn)行效率至少提高1倍，節(jié)電達(dá)50%。該類泵規(guī)格多，流量間隔明顯，便于選型。   

11、60;    立式多級管道泵葉輪為不銹鋼沖壓成型，葉面光滑；采用機(jī)械密封，軸承為自潤滑形式，不會漏水；水泵NPSH值小。安裝方便無需現(xiàn)澆基礎(chǔ)，而且泵的振動很小，運(yùn)行時感覺不到明顯的噪聲。由于該泵NPSH值小，運(yùn)行時不易損壞，可靠性很高。        (2)應(yīng)改變設(shè)計(jì)理念     &#

12、160;  現(xiàn)有的小型蒸汽鍋爐多為臥式快裝鍋爐，多數(shù)鍋爐出力很難達(dá)到額定出力，而且用戶在選用時已經(jīng)考慮了安全系數(shù)，導(dǎo)致大馬拉小車的狀況。GC型,DG型水泵性能不穩(wěn)（高效曲線不平坦，高效段對應(yīng)的流量變化范圍?。?，因此在設(shè)計(jì)選型時考慮了較大的安全裕量。立式多級管道泵高效曲線段長且對應(yīng)的流量變化范圍大。在選用鍋爐給水泵時按鍋爐容</p><p>　　參考文獻(xiàn) [1] Wu, F. Zhang,

13、X.P. Ju, P. Control strategy for AWS based wave energy conversion system </p><p>　　[2] Garcia-Rosa, P.B. Cunha, J.P.V.S. Lizarralde, F. Turbine speed control for an ocean wave energy conversion syst

14、em </p><p>　　[3] Trapanese, M. Optimized design of a sea wave energy conversion system </p><p><b>　　附件2：外文原文</b></p><p>　　Water Pumping System with PLC and Frequen

15、cy Control </p><p>　　Salah Addallah</p><p>　　Some technical problems should be noted in the reconstruction :</p><p>　　[1]High-pressure condensate pump run-time frequency control to

16、adjust the door open when Sheung Shui. Condensate pump by changing the speed of adjustment deaerator water level caused by low pressure condensate. Sizing system is responsible for paper machine pulp through the pump, re

17、d pump, multi-level screen and other equipment delivered to the paper machine headbox, wire part of the process, in which pump and the red pump is the most important devices because they relate to the forming of paper<

18、;/p><p>　　[2]Centrifugal pumps are the most likely pump style to provide a favorable return based on energy savings when applied with a variable-frequency drive (VFD). To help illustrate this, we conducted benc

19、hmark testing to document various head and flow scenarios and their corresponding effect on energy savings. We explored the relationship of static and friction head in the energy efficiency equation and the effect of mot

20、or, pump and VFD efficiencies. The result is a reference point for plant enginee</p><p>　　[3]While most centrifugal pumps operate at the fixed flow established by the hard-piped “free system” needs, many sys

21、tems require variable flow to meet changing process demands. The two most common methods for controlling variable pump system output are a control valve (throttling) and a variable speed drive.Controlling the flow with a

22、 throttling valve is like modulating the speed of a car using only the brake pedal. You set the accelerator pedal at a fixed point and use the brake to change spee</p><p>　　[5]All the above considerations in

23、fluence the design of the frequency-doubled laser. For example, in a laser with a Nd:YAG rod 4.0 mm in diameter, 3" long, pumped by a Krypton arc lamp with 6 mm inside diameter and 3" arc length, a KTP crystal

24、3 mm by 3 mm and 5 mm long, with a spotsize 2.5 times smaller than the spotsize in the Nd:YAG rod, an acousto-optic Q-switch operating at 25 kHz 24W of laser output power at 532 nm may be produced. Pump power required to

25、 get this laser output power is abou</p><p>　　As described above, Q-switching the fundamental input power to the non-linear crystal can increase the average second harmonic power produced. Yao, J. Q., et al.

26、, "High Power Green Laser by Intracavity Frequency Doubling with KTP Crystal", published in High Power Solid State Lasers (1988), SPIE, Vol. 1021, p. 181, describes another way of increasing the average second

27、harmonic power for a given average pump power; that is to pulse the lamp that pumps the Nd:YAG rod in combination with the Q-swit</p><p>　　The frequency conversion velocity modulation has been recognized for

28、 is most ideal, most has one of career development velocity modulation ways, uses the general frequency changer constitution frequency conversion velocity modulation transmission system's main purpose; first, to sati

29、sfy the enhancement labor productivity, the improvement product quality, to enhance equipment requests and so on automaticity, enhancement quality of life and improvement living conditions; Second, to save the energy<

30、/p><p>　　Our company online production's frequency changer mainly has TL100B3G, TL80B3G, TL100B3M, TL100B3L, TL100B3F, to press the frequency changer six big series frequency changers. TL100B3G is the high

31、performance vector frequency changer, uses the double CPU control (MCU+DSP) the system plan, eagerly anticipates the frequency changer control technology hardware platform, not only raised the core algorithm running rate

32、, simultaneously has also made the function algorithm unlimited extent hardware fou</p><p>　　The former is the keynote, which is fine-tuning. Pulp paper machine speed and wire speed ratio is essentially cons

33、tant, so a change machine in the wire speed, V set also with the change in speed can follow the red pump change; to enhance the accuracy and speed regulator reflect the actual headbox process usually needs to take the pr

34、essure headbox PID control output value of5% of the changes in speed as the red pump additional settings.</p><p>　　Speed actual value (V actual) from the actual speed of the motor drive sampling speed motor

35、or by rotating optical encoder device for such testing.</p><p>　　While most centrifugal pumps operate at the fixed flow established by the hard-piped “free system” needs, many systems require variable flow t

36、o meet changing process demands. The two most common methods for controlling variable pump system output are a control valve (throttling) and a variable speed drive.</p><p>　　Controlling the flow with a thro

37、ttling valve is like modulating the speed of a car using only the brake pedal. You set the accelerator pedal at a fixed point and use the brake to change speed. The engine works at nearly the same rate, but applying the

38、brake restricts the work output by changing the resistance of the drive train. At low speed, the engine strains, the brakes overheat and reliability suffers — while consuming fuel at a nearly constant rate. Of course, th

39、is is a silly way to control</p><p>　　Using variable-speed control, on the other hand, can be compared with the way people drive cars, changing vehicle speed by changing the engine’s output. Variable-speed p

40、umping uses the same principle. Instead of changing the system resistance to modulate flow, the pump speed changes. This shifts the pump’s head-capacity (HQ) curve to alter the point at which it crosses the system curve.

41、 Variable-speed control changes the energy input rather than relying on a valve to strip system energy. The res</p><p>　　While a throttled pump consumes slightly less power than it would running free, it con

42、tinues to rotate at the same speed, thus maintaining high velocity in the mechanical seal and bearings, and velocity directly determines bearing and mechanical seal life. Moving the operation of a centrifugal pump equipp

43、ed with a constant pressure volute (the most common centrifugal pump type) away from BEP alters the hydraulic balance between the volute and impeller. The pump develops ever-increasing radial th</p><p><b

44、>　　參考文獻(xiàn)：</b></p><p>　　[1] Wu, F. Zhang, X.P. Ju, P. Control strategy for AWS based wave energy conversion system </p><p>　　[2] Garcia-Rosa, P.B. Cunha, J.P.V.S. Lizarralde, F.