能源與動(dòng)力學(xué)院 畢業(yè)設(shè)計(jì)(論文)外文翻譯-改

1、外文文獻(xiàn)翻譯能源與動(dòng)力學(xué)院School of Energy and Power專(zhuān)業(yè)班級(jí)： 能動(dòng)B141 學(xué)生姓名： 徐宇辰 學(xué)生學(xué)號(hào)： 15 指導(dǎo)教師： 杜祖成 2016年 03 月 16 日一、目的： 1了解國(guó)外相關(guān)知識(shí)的發(fā)展；2熟悉外文科技文獻(xiàn)的寫(xiě)作格式及特點(diǎn)；3熟悉和鞏固所學(xué)專(zhuān)業(yè)外語(yǔ)的有關(guān)知識(shí)；4學(xué)會(huì)中英（外）文文獻(xiàn)的檢索方法。二、選題要求：1學(xué)生自主選題，經(jīng)指導(dǎo)教師審查合格。2篇幅在3000漢字以上，較完整的一篇外文論文3內(nèi)容與所學(xué)專(zhuān)業(yè)相關(guān)，并注明來(lái)源。三、譯文要求：1譯文正確，內(nèi)容完整，圖可以復(fù)印后貼于適當(dāng)位置。2譯文打印在A4紙上，原稿復(fù)印后附在譯文后。四、時(shí)間安排： 在畢業(yè)設(shè)計(jì)開(kāi)

2、題3周內(nèi)完成。外文文獻(xiàn)資料簡(jiǎn)表學(xué)生姓名徐宇辰專(zhuān)業(yè)能動(dòng)B141英語(yǔ)程度其它外語(yǔ)A級(jí)指導(dǎo)教師杜祖成畢業(yè)設(shè)計(jì)題目300MW機(jī)組熱力系統(tǒng)局部初步設(shè)計(jì)外文文獻(xiàn)來(lái)源刊 名熱力發(fā)電 , Thermal Power Generation,2012年03期期次篇 名對(duì)300MW汽輪機(jī)凝結(jié)水的便攜式集成式孔板流量測(cè)量裝置的研究頁(yè)碼內(nèi)容提要對(duì)300MW汽輪機(jī)凝結(jié)水的便攜式集成式孔板流量測(cè)量裝置的研究1 介紹2 便攜式集成流量測(cè)量裝置的設(shè)計(jì)3 便攜式集成流量測(cè)量裝置的校準(zhǔn) 3.1簡(jiǎn)介標(biāo)準(zhǔn)校準(zhǔn) 3.2 便攜式集成流量測(cè)量裝置的校準(zhǔn) 3.3 連接法蘭的結(jié)構(gòu)分析 3.4 法蘭連接的發(fā)展4.總結(jié)指導(dǎo)教師評(píng)審意見(jiàn)指導(dǎo)教師簽名：

3、年月日 對(duì)300MW汽輪機(jī)凝結(jié)水的便攜式集成式孔板流量測(cè)量裝置的研究 為了保證電廠汽輪機(jī)熱力試驗(yàn)的準(zhǔn)確性，應(yīng)保證凝結(jié)水的流量測(cè)量精度。在本文中，對(duì)300MW汽輪機(jī)通流冷凝水的便攜式集成式流量測(cè)量裝置的設(shè)計(jì)，這是基于冷凝水的參數(shù)和具體的管道的條件下，在5號(hào)低壓加熱器出口的300MW機(jī)組。本文通過(guò)對(duì)非標(biāo)準(zhǔn)差壓式孔板流量計(jì)的一體化設(shè)計(jì)是通過(guò)在標(biāo)準(zhǔn)實(shí)驗(yàn)系統(tǒng)標(biāo)定，誤差較大的原因是，流場(chǎng)被不穩(wěn)定的起源板式向下焊接連接法蘭。流場(chǎng)連接法蘭的分布弱化，測(cè)量精度可滿(mǎn)足汽輪機(jī)熱力試驗(yàn)的要求。1 介紹 汽輪機(jī)熱力試驗(yàn)是確定汽輪機(jī)熱經(jīng)濟(jì)性的最有力的工具之一。通過(guò)汽輪機(jī)熱力試驗(yàn)、熱效率、實(shí)現(xiàn)汽輪機(jī)經(jīng)濟(jì)性能的評(píng)價(jià)。最常見(jiàn)的

4、是，經(jīng)過(guò)技術(shù)改造，新建的單元和單元機(jī)組大修前后應(yīng)進(jìn)行測(cè)試，對(duì)汽輪機(jī)的經(jīng)濟(jì)性分析?？紤]到如節(jié)流損失的因素，流量測(cè)量裝置不應(yīng)安裝用來(lái)測(cè)量汽輪機(jī)主蒸汽流量，蒸汽流量的每個(gè)再生器的提取以及加熱蒸汽流量。在整個(gè)蒸汽循環(huán)系統(tǒng)，只有流動(dòng)的給水和凝結(jié)水流量測(cè)量裝置的進(jìn)水流量位于給水泵，承受相對(duì)高的壓力。焊接是比較常見(jiàn)的連接給水和主給水管道流量測(cè)量裝置在一起的方式，但在規(guī)范給水流量測(cè)量裝置的時(shí)候，會(huì)面臨一系列的困難。凝結(jié)水流量測(cè)量裝置在給水泵前，具有相對(duì)較低的壓力。采用法蘭連接冷凝管，規(guī)范凝結(jié)水流量測(cè)量裝置將更方便。目前，通過(guò)測(cè)量凝結(jié)水流量間接獲得所需的給水流量和蒸汽流量以及再熱蒸汽流量的汽輪機(jī)熱力試驗(yàn)。因此，

5、凝結(jié)水流量是最重要和最基本的測(cè)量方法。在汽輪機(jī)熱力試驗(yàn)中，測(cè)量精度直接影響汽輪機(jī)熱力試驗(yàn)的準(zhǔn)確性，汽輪機(jī)運(yùn)行的經(jīng)濟(jì)性。換句話(huà)說(shuō)，提高測(cè)量的精度是汽輪機(jī)熱力試驗(yàn)的一個(gè)重要階段，節(jié)能降耗。 根據(jù)標(biāo)準(zhǔn)ASME，高精度差壓元件應(yīng)采用高精度流量測(cè)量。冷凝水流量測(cè)量裝置大多采用標(biāo)準(zhǔn)孔表測(cè)量裝置，具有測(cè)量精度高、應(yīng)用范圍廣、價(jià)格低的特點(diǎn)。它的安裝定位一般在除氧器或凝結(jié)水泵出口處。但傳統(tǒng)的差壓流量計(jì)具有耗散結(jié)構(gòu)，需要安裝在高標(biāo)準(zhǔn)，具有既不同軸也不垂直節(jié)流元件，除了節(jié)流副室生產(chǎn)步驟和偏心或環(huán)形的大小。所有這些因素的會(huì)導(dǎo)致標(biāo)準(zhǔn)值有偏差影響的精度。根據(jù)gb2624-81規(guī)定，孔應(yīng)與節(jié)流裝置精確的直線長(zhǎng)度為中心，通過(guò)

6、孔的偏心距在2%所引起的測(cè)量誤差，和偏心影響較大而孔徑比的變化。同時(shí)，由于錯(cuò)誤的設(shè)計(jì)和裝配，使孔彎曲或讓步，導(dǎo)致了低的測(cè)量誤差數(shù)據(jù)。最大的錯(cuò)誤是通過(guò)彎曲孔3.5%甚至以上。這樣的話(huà)，它對(duì)提高測(cè)量精度，會(huì)導(dǎo)致更大的誤差甚至在使用之前就出現(xiàn)了。但它只能對(duì)節(jié)流元件本身而不是差壓變送器與節(jié)流模型，流量測(cè)量誤差的實(shí)際流量測(cè)量工作現(xiàn)場(chǎng)表演中的差壓變送器測(cè)量誤差。目前，為了解決現(xiàn)有的孔表的不足之處，有廣泛的文件，尋找有前途的方法來(lái)提高精度。但現(xiàn)有的參考提高儀表的精度，提高安裝質(zhì)量和消除安裝誤差。這些文獻(xiàn)提出了一些解決方案，但沒(méi)有從根本上解決了孔板流量計(jì)精度低的解決方案。采用集成式流量測(cè)量裝置，是為克服現(xiàn)有孔

7、板流量計(jì)的短的主要手段。集成式流量測(cè)量裝置是一個(gè)完整的流量測(cè)量，它由節(jié)流裝置，差壓變送器的流量，并顯示裝置組成。節(jié)流裝置及差壓變送器作為一個(gè)整體，節(jié)流裝置和低故障率，保證了安裝精度，使動(dòng)態(tài)特性得到改善。差壓流量計(jì)已達(dá)到一個(gè)更高的發(fā)展階段，由于各種現(xiàn)代技術(shù)，在本文中，創(chuàng)造便攜式，集成式流量測(cè)量裝置的意義是，考慮到汽輪機(jī)凝結(jié)水的孔板流量計(jì)不便對(duì)現(xiàn)有植物的在線標(biāo)定。它是一個(gè)完整的流量測(cè)量，它由節(jié)流裝置，差壓變送器流量，顯示結(jié)構(gòu)。焊接法蘭對(duì)管道的領(lǐng)口對(duì)于連接法蘭孔影響有所減少。便攜式集成式流量測(cè)量裝置的設(shè)計(jì)有助于電力試驗(yàn)做汽輪機(jī)熱力試驗(yàn)的研究。通過(guò)標(biāo)定，結(jié)果表明，便攜式集成式流量測(cè)量裝置具有較高的精度

8、，可以輕松地滿(mǎn)足在熱力實(shí)驗(yàn)中汽輪機(jī)的測(cè)量精度。如固定節(jié)流裝置，一個(gè)新的差壓變送器，流量顯示裝置，計(jì)算機(jī)軟件和先進(jìn)的加工技術(shù)。2便攜式和集成式流量測(cè)量裝置的設(shè)計(jì) 當(dāng)標(biāo)準(zhǔn)節(jié)流裝置的設(shè)計(jì)，制造和使用，基于國(guó)際標(biāo)準(zhǔn)iso5167技術(shù)條件，iso9300和國(guó)家標(biāo)準(zhǔn)GB / t2624-2006采用。標(biāo)準(zhǔn)節(jié)流裝置是由三部分組成：標(biāo)準(zhǔn)節(jié)流元件，用于開(kāi)發(fā)一個(gè)標(biāo)準(zhǔn)的方法，挖掘和管道條件在節(jié)流裝置的裝置，可用于無(wú)誤差校準(zhǔn)和記錄流量數(shù)據(jù)。所有不符合以上三個(gè)條件，被稱(chēng)為非標(biāo)準(zhǔn)節(jié)流裝置。在本文中，對(duì)300MW汽輪機(jī)通流冷凝水的便攜式集成式流量測(cè)量裝置的設(shè)計(jì)，這是基于冷凝水參數(shù)及在300MW機(jī)組5號(hào)低壓加熱器出口特定管道

9、條件，如圖1所示。它的孔徑比X是0.640439孔，采用標(biāo)準(zhǔn)孔板流量計(jì)。連接法蘭直管的標(biāo)準(zhǔn)節(jié)流孔裝置的寬度約為3、2前后長(zhǎng)度分別為。在連接法蘭在實(shí)際安裝過(guò)程中長(zhǎng)度為15d和6D的上游和下游直管。與連接對(duì)直管的上游和下游之間的法蘭，便攜式和集成式流量測(cè)量裝置，屬于非標(biāo)準(zhǔn)節(jié)流裝置，實(shí)流校準(zhǔn)要求。3 便攜式集成流量測(cè)量裝置的校準(zhǔn) 3.1簡(jiǎn)介標(biāo)準(zhǔn)校準(zhǔn) 在標(biāo)定實(shí)驗(yàn)中，長(zhǎng)春流量測(cè)量裝置被采用。如下面的圖2所示。該系統(tǒng)主要由液壓系統(tǒng)，標(biāo)準(zhǔn)體積管的標(biāo)準(zhǔn)流量計(jì)組，校準(zhǔn)表，控制和數(shù)據(jù)處理系統(tǒng)組成?；钊襟w積管S-25人加里布朗公司引入標(biāo)準(zhǔn)體積管。它的測(cè)量比是1200:1，流量測(cè)量范圍從0.48立方米/小時(shí)到567

10、立方米/小時(shí)，重現(xiàn)性在0.01%誤差內(nèi)，測(cè)量精度在0.05%誤差內(nèi)。三組并聯(lián)連接的高精度標(biāo)定系統(tǒng)k-2d來(lái)自美國(guó)的史密斯公司介紹了渦輪流量計(jì)的標(biāo)準(zhǔn)流量計(jì)集團(tuán)，作為檢驗(yàn)工作的流程。它的流量測(cè)量的范圍從80立方米/小時(shí)到1500立方米/小時(shí)，再現(xiàn)性是0.02%，其測(cè)量精度為0.01%。它可用于在兩個(gè)標(biāo)準(zhǔn)體積管和流量計(jì)作為衡量工作流程，重疊時(shí)流量測(cè)量范圍是80立方米/小時(shí)到567立方米/小時(shí)，但是應(yīng)用時(shí)取決于在給定流量計(jì)流量標(biāo)定的具體范圍。3.2 便攜式集成流量測(cè)量裝置的校準(zhǔn) 在標(biāo)定實(shí)驗(yàn)，集成式流量測(cè)量裝置和流量標(biāo)準(zhǔn)裝置是由標(biāo)準(zhǔn)的焊接法蘭連接，上游和下游直管是在實(shí)際安裝過(guò)程中長(zhǎng)度分別為15、6d，和

11、300MW汽輪機(jī)實(shí)際情況大致相同。考慮到最大的300MW汽輪機(jī)凝結(jié)水流量為770立方米/小時(shí)，峰值電負(fù)載或凝結(jié)水流量一定的變化范圍在汽輪機(jī)熱力試驗(yàn)。校準(zhǔn)實(shí)驗(yàn)流量范圍在500-1000立方米/小時(shí)范圍內(nèi)。通過(guò)實(shí)驗(yàn)，獲得數(shù)據(jù)庫(kù)的便攜式集成流量測(cè)量裝置如表一所示。從上表可得出結(jié)論，該便攜式集成流量測(cè)量裝置的最大誤差達(dá)到4.09%，不再能夠滿(mǎn)足汽輪機(jī)熱力試驗(yàn)要求。更大的流量測(cè)量誤差引起的比較標(biāo)準(zhǔn)孔板流量計(jì)的安裝要求和創(chuàng)建連接法蘭的漩渦在直管的二維和三維的長(zhǎng)度之前和之后的節(jié)流元件。內(nèi)部的流體的流場(chǎng)變化，這將影響節(jié)流元件的壓力差測(cè)量。因此，連接法蘭的內(nèi)流體流場(chǎng)的影響應(yīng)該被淘汰，并找出解決問(wèn)題的方法。3.3

12、 連接法蘭的結(jié)構(gòu)分析 對(duì)于標(biāo)準(zhǔn)節(jié)流元件的直管的長(zhǎng)度不足的缺點(diǎn)進(jìn)行了討論，并在不同的文學(xué)和各種材料開(kāi)展研究。一系列的標(biāo)準(zhǔn)噴嘴流量計(jì)進(jìn)行標(biāo)定的孔板流量計(jì)在 7 房流。應(yīng)用積分標(biāo)定方法，但它幾乎沒(méi)有對(duì)直管段起到任何作用。內(nèi)流量計(jì)應(yīng)用于解決直管長(zhǎng)度不足的問(wèn)題。但這種流量計(jì)的測(cè)量結(jié)果會(huì)有很大的影響，尤其是在使用不當(dāng)?shù)腻F角的時(shí)候。在這里，有一種改進(jìn)的法蘭連接結(jié)構(gòu)的方法，以減少測(cè)量誤差。在300MW機(jī)組凝結(jié)水系統(tǒng)，焊接板式法蘭作為冷凝水管道的連接類(lèi)型，如在圖3看到。其公稱(chēng)直徑（DN）為300mm，公稱(chēng)壓力1.6MPa（PN），內(nèi)徑三二八毫米，與法蘭厚度32mm。同時(shí)，直徑和300MW汽輪機(jī)凝結(jié)水管道外徑30

13、9mm 325mm，分別，和凹槽臺(tái)寬24mm，19毫米深將出現(xiàn)在法蘭連接。圖3可知，當(dāng)凹臺(tái)被襯托在法蘭的連接處，內(nèi)部的流體分布發(fā)生變化，壓力和內(nèi)部的流體的速度分布的改變，最終導(dǎo)致非標(biāo)準(zhǔn)節(jié)流元件的壓力差測(cè)量的影響。 3.4 法蘭連接的發(fā)展 傳統(tǒng)的法蘭上的內(nèi)部流體的流場(chǎng)有很大的影響。長(zhǎng)頸法蘭類(lèi)是能夠減少的影響，是具有最小的影響的法蘭種類(lèi)，甚至消除對(duì)內(nèi)部流體流場(chǎng)的影響在連接法蘭，如圖4所示。做切割氧常規(guī)連接焊接板式法蘭，磨切槽和保持一個(gè)平面切割后。然后，做焊接對(duì)新設(shè)計(jì)的焊頸法蘭，保持對(duì)新設(shè)計(jì)的焊頸法蘭焊接過(guò)程中對(duì)焊法蘭與管的軸線的中心線。 進(jìn)行完善的集成式流量重復(fù)測(cè)量裝置的標(biāo)定實(shí)驗(yàn)，驗(yàn)證了法蘭連接對(duì)

14、便攜式集成式流量測(cè)量裝置。獲得校準(zhǔn)數(shù)據(jù)庫(kù)表中所示的。表表明，當(dāng)使用改進(jìn)的集成式流量測(cè)量裝置0.85%最大流量誤差，能滿(mǎn)足需求的汽輪機(jī)熱力和例行試驗(yàn)，其凝結(jié)水流量測(cè)量誤差小于1%。這主要是由于采用對(duì)焊法蘭，其上游和下游的孔是改進(jìn)的內(nèi)部流場(chǎng)，測(cè)量差壓孔周?chē)袷菢?biāo)準(zhǔn)孔板節(jié)流裝置的直線長(zhǎng)度標(biāo)準(zhǔn)的壓差。 4、 總結(jié)本文分析了便攜式集成流量測(cè)量裝置，我們可以得到以下主要結(jié)論：連接法蘭，安裝在便攜式集成式流量測(cè)量裝置。然后，上游和標(biāo)準(zhǔn)孔板下游直管變小，渦流在連接法蘭，內(nèi)部的流體的流場(chǎng)發(fā)生變化。標(biāo)定實(shí)驗(yàn)的便攜式集成式流量測(cè)量裝置顯示的標(biāo)準(zhǔn)孔板節(jié)流裝置得到較小的壓差，流量系數(shù)變大，隨后，最大流量測(cè)量誤差達(dá)到4

15、.89%，嚴(yán)重影響測(cè)量精度的孔板流量計(jì)。 通過(guò)對(duì)便攜式集成式流量測(cè)量裝置的連接法蘭的改進(jìn)，該便攜式集成式流量測(cè)量裝置的最大誤差可達(dá)到約0.85%。采用對(duì)焊法蘭代替原來(lái)的板式平焊法蘭連接，它可以滿(mǎn)足汽輪機(jī)熱力試驗(yàn)要求。參考文獻(xiàn)1The RELAP5 Code Development Tcam. RELAP5/MOD3. 3 CODE MANUAL VOLUME V巨M習(xí).USA:In-formation Systems Laboratorics,lnc. 2001.2Westinghouse Electric Company LLC.AP1000 Design control Document

16、Z.Revision 10.2004. 原文Study on the Portable and Integrated Type Pore Plate Flow Measuring Device for Condensate Water of 300MW Steam Turbine In order to insure the accuracy of steam turbine thermal test in power plant, the flowrate measurement accuracy of condensate water should be insured. In this

17、paper, the portable and integrated type flow measuring device for condensate water of 300MW steam turbine flow is designed, which is based on the condensate water parameters and the specific pipeline conditions at the exit of the No. 5 low pressure heater for 300MW unit. A integration of nonstandard

18、 differential pressure orifice flow meter is designed in this paper Through calibration in standard experimental system, the reason of the large error is that the flow field is disturbed by the origin plate type downward welding connecting flanges. Then the welding neck flanges is designed for the c

19、onnecting flanges. The distribution of connecting flanges of flow field is weaken, and the measurement accuracy can meet the demand of steam turbine thermal test. 1 Introduction Steam turbine thermal test is one of the most powerful tools to identify the heat economy of steam turbine. Through steam

20、turbine thermal test, heat rate and achieve evaluation on economic performance of steam turbine can be acquired. Most commonly, the newly-built unit and unit after technological upgrading, unit before and after overhaul should be tested and analyzed on economic performance of steam turbine. Consider

21、ing the factors such as the loss of throttling, the flow measurement device should not be installed to measure the main steam flow of steam turbine, the steam flow of each regenerator extraction aswell as heated steam flow. In the whole steam circulatory system, only the flow of feedwater and the fl

22、ow of condensate The flow measurement device of feed water is situated behind feed pump, bearing a relatively high pressure. Welding is a more common way of joining the flow measurement device of feed water and main feed water pipe together, will bring somedifficulties when standardize the flow meas

23、urement device of feed water. And the flow measurement device of condensate water is situated before feed pump, bearing a relatively low pressure. Adopting the connection of flange and condensate pipe, standardizing the flow measurement device of condensate waste will more convenient. Currently, the

24、 required feed water flow and main steam flow as well as reheated steam flow of steam turbine thermal test are obtained indirectly via measuring condensed water flow. Therefore, condensed water flow is the most important and basic measurement in steam turbine thermal test. The measurement accuracy d

25、irectly influences the accuracy of steam turbine thermal test, the economy situation of steam turbine operation. In other words, enhance the measurement accuracy is an important stage in steam turbine thermal test and saving energy and lowing consumption. According to standard ASME, high precision d

26、ifference pressure elements should be adopted to do high precision flow measurement. Available flow measuring device of condensate water are mostly implemented in standard orifice meter, which features high measuring accuracy, wide application area, low prices. Its installation locates before the de

27、fecator or the export of condensate pumps generally. But traditional difference pressure flow meter has dissipative structure, needs fitted in the high standard, possesses neither coaxial nor vertical throttling element, besides the size of throttling accessory or annular chamber produce steps and e

28、ccentric. All those factors make the discharge coefficient out of standard value, influence measuring accuracy subsequently. According to the regulations of GB2624-81, orifices should be centered with the straight length of throttling device accurately, The measurement error caused by orifices eccen

29、tricity within 2% , and eccentricity has greater influence while aperture ratio changes. Meanwhile, due to faulty design and assembly, it makes orifices bend or give way, leads to the errors off low measurement dates bigger. The maximum error is about 3.5% by bending orifices. Thus, remark it to imp

30、rove the precision of measuring further before used. But it could only calibrate throttling element in itself instead of differential pressure transmitters and throttle molds, the flow measurement error is caused by the measurement error of differential pressure transmitter during the performance of

31、 the actual flow measurement work on site. Currently, for resolving the deficiency of existing orifice meter, there are extensive documentation such as in 3, 4, searching for promising ways to improve the precision. But all present reference increase the precision of instrument accuracy by enhancing

32、 the quality of installation and eliminating installation errors.These literature puts forward some solutions, but not find the solutions to solve the low precision of orifice meter fundamentally. As shown in 5, adopting the integrated type flow measuring device is the prime means to overcome the sh

33、ort of existing orifice meter. The integrated type flow measuring device is a complete flow measurement, which consists of throttling device, differential pressure transmitter flow, and display device. Throttling device and differential pressure transmitter are marked an integral whole, installation

34、 accuracy of throttling device and lows breakdown rates are guaranteed, the dynamic characteristics is improved. Differential pressure flow meters has reached a higher stage of development, because a variety of modern technologies such as fixed throttling device, a new type of differential pressure

35、transmitter, flow display device, computer software and advanced processing technology are assembled. In this paper, the portable and integrated type flow measuring device is proposed, considering that orifice meter of steam-turbine condensate water is inconvenient on line calibration in existing pl

36、ants. It is a complete flow measurement, which consists of throttling device, differential pressure transmitter flow, display structure. Meanwhile, for carrying it, the integrated type flow measuring device self-contains straight pipe about 3D and 2D separately before and after it, welded flange to

37、pipelines is connected by neckband in order to reduce the effect of flange to orifice. The design of the portable and integrated type flow measuring device is helpful for Electric Power Test and the Research Department to do steam turbine thermal test. Through the calibration, results show that the

38、portable and integrated type flow measuring device has high precision, can meet the need of the measuring precision in steam turbine thermal test easily. 2 The Design of the Portable and Integrated Type Flow Measuring Device When the standard throttling device is designed, manufactured and used, the

39、 technical conditions based on international standards ISO5167, ISO9300 and state standards GB/T2624-2006 are adopted. The standard throttling device is composed of three parts: standard throttle element, a standard way for tapping, the device of tapping and pipeline conditions around throttling dev

40、ice, can be used without error calibrate and the flow coefficients. All that can not meet the above three conditions, are called non-standard throttling device. In this paper, the portable and integrated type flow measuring device for condensate water of 300MW steam turbine flow is designed, which i

41、s based on the condensate water parameters and the specific pipeline conditions at the exit of the No. 5 low pressure heater for 300MW unit, as shown in Fig. 1. The orifices which aperture ratio x is 0.640439, the standard orifice flow-meter is adopted. The width of standard throttling orifice devic

42、e to the straight pipe of connecting flange is about 3D and 2D in length before and after it respectively. The straight pipe of upstream and downstream in connecting flange is about 15D and 6D in length respectively in the actual installation process. With connecting flange between upstream and down

43、stream of the straight pipe, the portable and integrated type flow measuring device belongs to non-standard throttling device, real-flow calibration is demanded. 3. Calibration of the Portable and Integrated Type Flow Measuring Device 3.1 Brief Introduction about Standard Calibration In the process

44、of the calibration experiment , the flow measurement device of Chang Chun was adopted. As the following shown in Fig. 2 The system is mainly constituted of hydraulic system, standard volume pipe, standard flow meter group, calibration tables, control and data handling system. Its measure ratio is 12

45、00:1, flow measuring ranges from 0.48 m3/h to 567 m3/h, the reproducibility is ±0.01%, and the measurement accuracy is ±0.05%. Three set of parallel connected high accuracy calibration system K-2D from US Smith Corporation for turbine flow meters are introduced in standard flow meter group

46、, as admeasure of flow work. Its flow measuring ranges from 80 m3/h to 1500 m3/h, the reproducibility is 0.02%,the measurement accuracy is ±0.01%. It can be used in both standard volume pipe and flow meter as a measure of flow work when overlapped flow is 80 m3/h to 567 m3/h, which one is appli

47、ed depends on the specific range of flow calibration of the given flow meter. 3.2. The Calibration of the Portable and Integrated Type Flow Measuring Device In the calibration experiment the integrated type flow measuring device and the flow meter standard device are linked by the standard welded fl

48、ange, the straight pipe of upstream and downstream is about 15D and 6D in length respectively in the actual installation process, which is approximately identical to the actual situation of 300MW steam turbine. Considering that the maximum condensed water flow of 300MW steam turbine is 770 m3/h, do

49、steam turbine thermal test under the peak electrical load or the certain variation scope of condensed water flow. The flow scope of the calibration experiment is 500-1000 m3/h. Through experiments, obtained database about the calibration of the portable and integrated type flow measuring device as s

50、hown in Table I. From the above Table, the maximum error of the portable and integrated type flow measuring device has reached 4.09%, no longer able to meet the demand of steam turbine thermal test. Greater flow rate measurement error is caused by comparing installation requirements of the standard

51、orifice flow meter and creating vortexes around connecting flange which the straight pipe is 3D and 2D in length before and after throttle element. The flow field of the internal fluid is changed, which will affect the differential pressure measurement of throttle element. Therefore, the influence o

52、f connecting flange to the flow field of the internal fluid should be eliminated, and find out some methods to solve the problems.I. 3.3. The Structural Analysis of Connecting Flange The drawbacks of length insufficient in the straight tube of the standard throttle element are discussed and research

53、ed in different literature and various materials. A series of the standard nozzle flow meter is adopted to demarcate the real-flow of orifice meter in 7. The method of integral demarcating is applied, the discharge coefficient of flow meter is obtained as shown in 8. But it is limited practically wi

54、thout being implemented for the straight tube. An inner flow meter is applied to solve the straight tube insufficient length problem in 9. But this flow meter will have great impact on measurement results when an improper cone angle is adopted in 10. Here, a method of improving the flange connection

55、 structure is adopted in order to minimize the measurement error. In the condensate water system of 300MW steam turbine, welding plate flange is used as the connection types of condensate water pipes, as seen in the Fig. 3. It nominal diameter(DN) is 300mm, nominal pressure(PN) is 1.6Mpa, internal d

56、iameter is 328mm, and the thickness of the flange is 32mm. Meanwhile, the diameter and external diameter of 300MW steam turbines condensate water pipes is 309mm, 325mm respectively, and that concave station width 24mm, 19mm deep will be appeared in the flange connecting. As seen in Fig. 3, when conc

57、ave station is recommended in the flange connecting, the fluid distribution of the internal fluid is changed, the pressure and velocity distributions of the internal fluid is changed, the differential pressure measurement of the non-standard throttle element is affected ultimately. 3.4. Development

58、of Flange Connecting Traditional flanges have great influence on the flow field of the internal fluid. The new kind of welding neck flange is able to reduce the influence, which has minimal impact, or even eliminate the influence on the flow field of the internal fluid at connecting flanges, as shown in Fig. 4. Do oxygen cutting on conventional connecting welding plate flange, grind the cut grooves and keep it one plane after cutting. And then, d