766 QTZ40塔式起重機——臂架優(yōu)化設計(有cad圖+文獻翻譯)
766 QTZ40塔式起重機——臂架優(yōu)化設計(有cad圖+文獻翻譯),766,QTZ40塔式起重機——臂架優(yōu)化設計(有cad圖+文獻翻譯),qtz40,塔式起重機,優(yōu)化,設計,cad,文獻,翻譯
河北建筑工程學院
畢業(yè)設計(論文)任務書
課題
名稱
QTZ40塔式起重機——臂架優(yōu)化設計
系: 機械工程學院
專業(yè): 機械設計制造及其自動化
班級: 機092
姓名: 范艷東
學號: 2009307201
起迄日期: 2013年3月25日~ 2013年 6月21日
設計(論文)地點: 綜405
指導教師: 李常勝
輔導教師:
發(fā)任務書日期: 2013年3月 5 日
1、畢業(yè)設計(論文)目的:
畢業(yè)設計是對機械專業(yè)學生在畢業(yè)前的一次全面訓練,目的在于鞏固和擴大學生在校所學的基礎知識和專業(yè)知識,訓練學生綜合運用所學知識分析和解決問題的能力。是培養(yǎng)、鍛煉學生獨立工作能力和創(chuàng)新精神之最佳手段。畢業(yè)設計要求每個學生在工作過程中,要獨立思考,刻苦鉆研,有所創(chuàng)新、解決相關技術問題。通過畢業(yè)設計,使學生掌握塔式起重機的總體設計、吊臂的設計、整體穩(wěn)定性計算等內容,為今后步入社會、走上工作崗位打下良好的基礎。
2、畢業(yè)設計(論文)任務內容和要求(包括原始數(shù)據(jù)、技術要求、工作要求等):
(1) 設計任務:
① 總體參數(shù)的選擇(QTZ40級別)
② 結構形式
(2) 總體設計
① 主要技術參數(shù)性能
② 設計原則
③ 平衡重的計算
④ 塔機的風力計算
⑤ 整機傾翻穩(wěn)定性的計算
(3) 吊臂的設計和計算
① 吊臂的形式及尺寸(變截面)(雙吊點)
② 吊臂的強度、穩(wěn)定性及剛度驗算
(4) 設計要求
① 主要任務:學生應在指導教師指導下獨立完成一項給定的設計任務,編寫符合要求的設計說明書,并正確繪制機械與電氣工程圖紙,獨立撰寫一份畢業(yè)論文,并繪制有關圖表。
② 知識要求:學生在畢業(yè)設計工作中,應綜合運用多學科的理論、知識與技能,分析與解決工程問題。通過學習、鉆研與實踐,深化理論認識、擴展知識領域、延伸專業(yè)技能。
③ 能力培養(yǎng)要求:學生應學會依據(jù)技術課題任務,完成資料的調研、收集、加工與整理,正確使用工具書;培養(yǎng)學生掌握有關工程設計的程序、方法與技術規(guī)范,提高工程設計計算、圖紙繪制、編寫技術文件的能力;培養(yǎng)學生掌握實驗、測試等科學研究的基本方法;鍛煉學生分析與解決工程實際問題的能力。
④ 綜合素質要求:通過畢業(yè)設計,學生應掌握正確的設計思想;培養(yǎng)學生嚴肅認真的科學態(tài)度和嚴謹求實的工作作風;在工程設計中,應能樹立正確的生產(chǎn)觀、經(jīng)濟觀與全局觀。
⑤ 設計成果要求:
凡給定的設計內容,包括說明書、計算書、圖紙等必須完整,不得有未完的部分,不應出現(xiàn)缺頁、少圖紙現(xiàn)象。
1) 對設計的全部內容,包括設計計算、機械構造、工作原理、整機布置等,均有清晰的了解。對設計過程、計算步驟有明確的概念,能用圖紙完整的表達機械結構與工藝要求,有比較熟練的認識圖紙能力。對運輸、安裝、使用等也有一定了解。
2) 說明書、計算書內容要精練,表述要清楚,取材合理,取值合適,設計計算步驟正確,數(shù)學計算準確,各項說明要有依據(jù),插圖、表格及字跡均應工整、清楚、不得隨意涂改。制圖要符合機械機械制圖標準,且清潔整齊。
3) 對國內外塔式起重機情況有一般的了解,對各種塔式起重機有一定的分析、比較能力。
其他各項應符合本資料有關部分提出的要求。
3、畢業(yè)設計(論文)成果要求(包括圖表、實物等硬件要求):
① 計算說明書一份
內容包括:設計任務要求的選型、設計計算內容、畢業(yè)實習報告等。作到內容完整,論證充分(包括經(jīng)濟性論證),字跡清楚,插圖和表格正規(guī)(分別進行統(tǒng)一編號)、批準,字數(shù)要求不少于2萬字;撰寫中英文摘要;提倡學生應用計算機進行設計、計算與繪圖。
② 圖紙一套
不少于四張零號圖紙量。
4、主要參考文獻:
[1] 哈爾濱建筑工程學院主編.工程起重機.北京:中國建筑工業(yè)出版社
[2] 董剛、李建功主編.機械設計.機械工業(yè)出版社
[3] 機械設計手冊.化學工業(yè)出版社(5冊)
[4] GB/T9462—1999 塔式起重機技術條件
[5] GB/T13752—1992 塔式起重機設計規(guī)范
[6] GB5144—1994 塔式起重機安全規(guī)程
[7] 邢靜忠.ANSYS應用實例與分析.科學出版社.2006.
[8] 劉坤.ANSYS有限元方法精解.國防工業(yè)出版社.2005.
[9]GB/T9462—1999 塔式起重機設計條件.
[10] GB/T13752—1992 塔式起重機設計規(guī)范.
[11] GB/T5144—1994 塔式起重機安全規(guī)程
[12]劉鴻文.材料力學.北京:高等教育出版社.2002.
[13]李柱,徐振高.互換性與測量技術.北京:高等教育出版社.2002.
[14] 張東升.機械零件及建筑機械.重慶:重慶大學出版社.2003.
[15] 現(xiàn)行建筑機械規(guī)范大全.北京:中國建筑工業(yè)出版社.1995.
[16] 吳慶鳴,何小新.工程機械設計.武昌:武漢大學出版社.2006.
[17]劉佩衡.塔式起重機使用手冊.北京:機械工業(yè)出版社.2002.
[18] 張質文,虞和謙等.起重機設計手冊.北京:中國鐵道出版社.1997.
[19] 顧迪民.工程起重機.北京:中國建筑工業(yè)出版社.1988.
[20] 王金諾,于蘭峰.起重運輸機金屬結構.北京:中國鐵道出版社.2002.
[21] 張鳳山,董紅光.塔式起重機構造與維修.北京:人民郵電出版社.2007.
[22] 張青.工程起重機結構與設計.化學工業(yè)出版社.2008.
5、本畢業(yè)設計(論文)課題工作進度計劃:
起 迄 日 期
工 作 內 容
2013.3.25-2013.3.28
2013.3.29-2013.4.13
2013.4.14-2013.4.20
2013.4.21-2013.5.15
2013.5.16-2013.6.5
2013.6.6-2013.6.19
2013.6.20-2013.6.21
熟悉整理資料
方案選擇及總體設計
繪制總圖
臂架設計
繪制臂架裝配及結構圖紙
繪制零件圖紙
準備論文及答辯
教研室審查意見:
教研室主任簽字:
年 月 日
系審查意見:
系主任簽字:
年 月 日
河北建筑工程學院
畢業(yè)實習報告
系 別 機械工程學院
專 業(yè) 機械設計制造及其自動化
班 級 機092
姓 名 范艷東
學 號 2009307201
指導教師 李常勝
實習成績
實習報告
轉眼間四年的大學生活就快結束了,然而大多數(shù)學生對于本專業(yè)的認識還是不夠,為了使我們更多地了解機械產(chǎn)品及設備,提高對機械設計制造及其自動化的認識,加深機械在工業(yè)各領域應用的感性認識,開闊視野,老師安排了我們到長春會展中心實習。
長春國際會展中心是由市政府和長春經(jīng)濟技術開發(fā)區(qū)共同投資興建的大型現(xiàn)代化展覽場所,是集展覽、住宿、餐飲、會議、娛樂、體育、旅游、商貿、科技、信息等為一體的多功能活動中心。
一、實習目的
畢業(yè)實習是學生完成了教學計劃所規(guī)定的全部理論課程的基礎上進行的總結性實習,是培養(yǎng)和檢驗學生綜合運用所學專業(yè)的基本理論、基本技能,理論聯(lián)系實際,獨立的分析問題、解決問題的重要環(huán)節(jié)。實習在于培養(yǎng)實踐動手能力,使所學的專業(yè)理論知識與實踐相結合,為更好地適應社會的需求打下良好的基礎。通過到長春國際會展中心的實習,讓我們對各種工程機械,如裝載機、挖掘機、起重機等,以及各種數(shù)控機床、精密儀器等有了更進一步的認識和了解。通過參觀,綜合自己所學知識,以及查閱資料,這次實習我學到了不少東西。
二、實習內容
本次畢業(yè)實習,我們跟隨畢業(yè)設計導師李常勝老師,來到長春國際會展中心,為期一天。
擺在國際會展中心門口的有裝載機,挖掘機,汽車吊車等等,而塔式起重機是我著重了解的對象。
(1)裝載機
裝載機是一種廣泛用于公路、鐵路、建筑、水電、港口、礦山等建設工程的土石方施工機械,它主要用于鏟裝土壤、砂石、石灰、煤炭等散狀物料,也可對礦石、硬土等作輕度鏟挖作業(yè)。換裝不同的輔助工作裝置還可進行推土、起重和其他物料如木材的裝卸作業(yè)。因此它成為工程建設中土石方施工的主要機種之一。
(2)挖掘機
挖掘機是用鏟斗挖掘高于或低于承機面的物料,并裝入運輸車輛或卸至堆料場的土方機械。其挖掘的物料主要是土壤、煤、泥沙以及經(jīng)過預松后的土壤和巖石。從近幾年工程機械的發(fā)展來看,挖掘機的發(fā)展相對較快,挖掘機已經(jīng)成為工程建設中最主要的工程機械之一。
(3)塔式起重機
塔式起重機又稱塔機,具有適用范圍廣,回轉半徑大,操作方便,工作效率高及安裝拆卸比較簡便等特點,從而廣泛使用在建筑安裝工程中,并成為重要的施工機械之一。
塔機組成一般來說塔機按各部分功能可分為:基礎、塔身、頂升、回轉、起升、平衡臂、起重臂、起重小車、塔 頂、司機室、變幅等部分。塔機安裝在地面上需要基礎部分;塔身是塔機身子,也是升高的部分;頂升部分是使得塔機可以升高;回轉是保持塔機上半身可以水平旋轉的;起升機構用來將重物提升起來的;平衡臂架是保持力矩平衡的;起重臂架一般就是提升重物的受力部分;小車用來安裝滑輪組和鋼繩以及吊鉤的,也是直接受力部分;塔頂當然是用來保持臂架受力平衡的;司機室是操作的地方;變幅是使得小車沿軌道運行的。
塔機工作機構分為5種:起升機構;變幅機構;小車牽引機構;回轉機構和大車走行機構。在此,就讓我們簡單的看一下:動臂式塔機設臂架變幅機構,兼有架設及變幅兩種功能。小車變幅水平臂架塔機設小車牽引機構,或稱小車變幅機構。固定式塔機不設大車走行機構。起升機構、變幅機構及小車牽引機構在構造上極為近似,均由電動機、聯(lián)軸器、制動器、減速器和卷筒等部件組成。其具體介紹如下:
起升機構:起升機構是起重機機械的主要機構,用以實現(xiàn)重物的升降運動。起升機構通常由原動機、減速器、卷筒、制動器、鋼絲繩、滑輪組和吊鉤組成。
回轉機構:塔機是靠起重臂回轉來保障其工作覆蓋面的?;剞D運動的產(chǎn)生是通過上、下回轉支座分別裝在回轉支承的內外圈上并由回轉機構驅動小齒輪。小齒輪與回轉支承的大齒圈嚙合,帶動回轉上支座相對于下支座運動。我們設計的QTZ500塔式起重機的回轉機構設成單回轉式,通常由回轉電動機、液力耦合器、回轉制動器、回轉減速器和小齒輪組成。
變幅機構:變幅機構是實現(xiàn)改變幅度的工作機構,用來擴大起重機的工作范圍,提高起重機的生產(chǎn)率。變幅機構由電動機、減速器、卷筒和制動器組成。功率和外形尺寸較小。變幅機構按其構造和不同的變幅方式分為運行小車式和吊臂俯仰式。
塔機都設有安全保護裝置,包括:起升高度限制器、起重量限制器、力矩限制器。
為了提高塔機生產(chǎn)率,加快吊裝施工進度,無論是起升機構、變幅機構、小車牽引機構、回轉機構和大車走行機構均應具備較高的工作速度,并要求從靜停到全速運行,或從全速運行轉入靜停的全過程(即啟動和制動過程),都能平緩進行,避免產(chǎn)生急劇沖動,對金屬結構產(chǎn)生破壞性影響。對于高層建筑施工用的自升塔機來說,由于起升高度大,起重臂長,起重量大,對工作機構調速系統(tǒng)有更高的要求。
由于我的畢業(yè)設計是塔機的吊臂,通過查閱資料,我了解到:吊臂是塔機的關鍵零件之一,她是由數(shù)節(jié)臂架通過臂架接頭用銷軸連接在一起的結構式焊接件,其制造質量直接影響塔式起重機的使用安全和壽命,特別是吊臂下弦桿,它既是受力桿件又是小車的軌道。為使小車運行平穩(wěn),兩下弦桿必須滿足直線度、平面度、平行度和垂直度等技術要求。因此,吊臂下弦桿接頭的制造質量直接影響整個吊臂的制造質量。
三、實習結果
“紙上得來終覺淺,絕知此事要躬行”,通過這次實習,我學到了很多知識:
(1) 了解了裝載機和挖掘機的用途;
(2) 了解了塔式起重機的特點和結構,并對其工作機構和臂架做了詳細了解,
對我的畢業(yè)設計起到了很重要的作用。
四、實習總結
在這短暫的實習過程中,我采用了看、問、查閱資料等方式,對工程機械有了更進一步的認識和了解,我深深的感覺到了自己所學知識的膚淺和在實際運用中專業(yè)知識的匱乏,這使我真正領悟到什么叫“學無止境”。實習結束并不代表什么,它讓我發(fā)現(xiàn)了更多的不足,所以在今后的學習和工作中,我會更加用心,去充實自己,完善自己,以求知者的身份警戒自己,爭取在今后的工作中做一名合格的員工。
河北建筑工程學院
畢業(yè)設計(論文)開題報告
課題
名稱
QTZ40塔式起重機——臂架優(yōu)化設計
系 別: 機械工程學院
專 業(yè): 機械設計制造及其自動化
班 級: 機092
學生姓名: 范艷東
學 號: 2009307201
指導教師: 李常勝
導師課題
課題類別
工程設計
(一)塔式起重機的研究現(xiàn)狀及發(fā)展趨勢
塔式起重機是現(xiàn)代工業(yè)與民用建筑的重要施工機械之一。在高層建筑施工中,它的幅度利用度比其他類型起重機高。塔機由于能靠近建筑物,其幅度利用率可達整體幅度的80%。塔式起重機的變幅及回轉機構是可以同時實現(xiàn)重物在垂直方向和水平方向移動的機構,所以可以擴大起重機的工作范圍,提高生產(chǎn)率。應用塔機對于加快施工速度、縮短工期、降低工程造價能夠起到重要作用。塔式起重機已經(jīng)成為建筑工程業(yè)必要的技術裝備,成為衡量建筑工程業(yè)生產(chǎn)力水平高下的重要標志之一,成為加快工程建設、確保工程整體質量、降低工程造價、提高社會效益與經(jīng)濟效益的重要手段。
塔機是在第二次世界大戰(zhàn)后才真正獲得發(fā)展的。戰(zhàn)后各國面臨著重建家園的艱巨任務,浩大的建筑工程量迫切需要大量性能良好的塔式起重機。自塔式起重機在建筑施工中顯露身手并逐漸成為工程機械一個重要分支以來,已經(jīng)有50余年歷史,其間利經(jīng)了曲折復雜的發(fā)展階段。70年代末,由于種種原因,國外塔式起重機制造業(yè)陷入了低谷,不少中小工廠紛紛停業(yè)或轉產(chǎn),僅少數(shù)大廠得以維持。直至80年代末才呈現(xiàn)逐漸復蘇態(tài)勢,1994年為復蘇年頭,復蘇勢頭最好的國家為德國。據(jù)有關資料介紹,在塔機制造業(yè)鼎盛的70年代,西德?lián)碛懈魇剿C48500臺,80年代總量減至1/3,而近幾年,東西德合并,基建規(guī)模擴大,塔機產(chǎn)量上升,現(xiàn)有塔機近40000臺,其中半數(shù)機齡不足5年。
我國的塔機行業(yè)于20世紀50年代開始起步,相對于中西歐國家由于建筑業(yè)疲軟造成的塔機業(yè)的不景氣, 我國的塔機業(yè)正處于一個迅速的發(fā)展時期。到20世紀90年代以后,塔式起重機行業(yè)隨著行業(yè)建筑任務的增加而進入了新興時期,年產(chǎn)量連年猛增,而且也有部分產(chǎn)品出口到了國外。全國塔式起重機的擁有總量也從20世紀50年代的幾十臺到2000年的60000臺左右。至此,無論從生產(chǎn)規(guī)模、應用范圍、塔式起重機總量等各個角度來衡量,我國都可以稱為塔式起重機大國。
從塔機的技術發(fā)展方面來看,雖然新的產(chǎn)品層出不窮,新產(chǎn)品在生產(chǎn)效能、操作簡便、保養(yǎng)容易和運行可靠方面均有提高,但是塔機的技術并無根本性的改變。塔機的研究正向著組合式發(fā)展。所謂的組合式,就是以塔身結構為核心,按結構和功能特點,將塔身分解成若干部分,并依據(jù)系列化和通用化要求,遵循模數(shù)制原理再將各部分劃分成若干模塊。根據(jù)參數(shù)要求,選用適當模塊分別組成具有不同技術性能特征的塔機,以滿足施工的具體需求。推行組合式的塔機有助于加快塔機產(chǎn)品開發(fā)進度,節(jié)省產(chǎn)品開發(fā)費用,并能更好的為客戶服務。
當前塔機的發(fā)展具有如下一些特點和趨勢:
1、吊臂長度加長
在六十年代初,吊臂長度超過40m的較少,七十年代吊臂長度已能做到70m,快速拆裝下回轉塔式起重機的吊臂長度可達35m。自升式塔式起重機吊臂是可以接長的,標準臂長一般為30—45m,可以接長到50—60m。重型塔式起重機吊臂則更長。吊臂加長可帶來更好的技術經(jīng)濟效果。隨著塔式起重機設計水平的提高,能解決由臂長加大帶來的一些技術問題(如安裝和運輸問題)。低合金高強度鋼材及鋁合金的廣泛采用亦為加長吊臂提供了非常有利的條件。
2、工作速度提高,且能調速
由于調速技術的進步,滑輪組倍率可變,雙速、三速電動機及直流電動機調速的應
用,使塔式起重機工作速度在逐漸提高。起升機構普遍做到至少具有3種工作速度,重物起升速度超過100m/min者也很多。構件安裝就位速度可在0---10m/min范圍內進行選擇?;剞D速度一般可在0---1r/min之間進行調節(jié)。小車牽引和塔式起重機行走大多也有2-3種工作速度,小車牽引速度最快可達60m/min。
3、改善操縱條件
隨著塔式起重機向大型、大高度方向發(fā)展,操縱人員的能見度愈來愈差。因此需要
在吊臂端部(動臂變幅)或小車上(小車變幅)安裝電視攝象機,在操作室利用電視進行操作。有的還采用了雙頻道的無線電遙控系統(tǒng),不但可由地面的操作人員控制吊裝;還可根據(jù)事先編排的程序自動進行吊裝。
4、更多地采用組裝式結構
為了便于產(chǎn)品的更新?lián)Q代,簡化設計制造、使用與管理,提高塔式起重機使用的經(jīng)
濟效益,國外塔式起重機專業(yè)廠已做到產(chǎn)品系列化,部件模數(shù)化。以不同模數(shù)塔身,臂
架標準節(jié)組合成變截面塔身和臂架,不僅能提高塔身、臂架的力學性能,減輕塔式起重
機自重,而且可明顯減少使用單位塔架,臂架的儲備量,為降低成本,簡化管理創(chuàng)造了
條件。
(二)ANSYS介紹
有限單元法是隨著電子計算機的發(fā)展而迅速發(fā)展起來的一種現(xiàn)代計算方法。它是50年代首先在連續(xù)體力學領域--飛機結構靜、動態(tài)特性分析中應用的一種有效的數(shù)值分析方法,隨后很快廣泛的應用于求解熱傳導、電磁場、流體力學等連續(xù)性問題。有限元思想的核心就是把實際結構離散化,假想地使實際的結構離散為有限數(shù)目個類似結構的個體,然后通過分析這些有限個體的性能來求出滿足實際工程要求的計算結果,從而代替對于具體復雜實際結構的求解。經(jīng)過離散化,應用有限元思想,可以解決很多實際復雜的工程問題,并在理論研究和工程應用兩方面都具有極其重要的實用價值。
ANSYS作為一個大型通用軟件,廣泛應用于結構、流體、聲場、熱、耦合場、電磁場上面,利用ANSYS軟件,能夠將實際模型置于各種各樣不同的復雜實際工況之中,準確并合理的分析,優(yōu)化設計,減少實際試驗的物質和人力投入,提高工作效率,縮短研發(fā)周期從而能夠為提高利潤做出貢獻。使用ANSYS軟件分析,包含以下幾個過程:建立模型、劃分網(wǎng)格、加載和求解、結果后處理。若在實際應用過程中想對其中的某一個步驟進行改動和變化,則依然需要重新完成其中的每一個步驟,無形中浪費了太多的工作時間。針對現(xiàn)實情況,ANSYS提供了APDL參數(shù)化設計語言來處理類似問題,通過APDL語言及UIDL語言或類似VB、VC編程語言開發(fā)應用界面,即可完成在ANSYS中的二次開發(fā)。
二、本課題的目的(重點及擬解決的關鍵問題)
畢業(yè)設計是對機械專業(yè)學生在畢業(yè)前的一次全面訓練,目的在于鞏固和擴大學生在校所學的基礎知識和專業(yè)知識,訓練學生綜合運用所學知識分析和解決問題的能力。是培養(yǎng)、鍛煉學生獨立工作能力和創(chuàng)新精神之最佳手段。畢業(yè)設計要求每個學生在工作過程中,要獨立思考,刻苦鉆研,有所創(chuàng)新、解決相關技術問題。通過畢業(yè)設計,使學生掌握塔式起重機的總體設計、吊臂的設計、整體穩(wěn)定性計算等內容,為今后步入社會、走向工作崗位打下良好的基礎。
塔機臂架作為塔機的工作裝置,在塔機產(chǎn)品的設計內容中處于核心地位, 采用有限元分析的方法進行塔機臂架的設計計算將會極大地提高設計效率、保證其設計質量。我們只需借助通用有限元軟件建立模型并進行仿真分析,就能真實地反映機械產(chǎn)品的尺寸外形特征和工作過程,并進行各種類型的力學分析,盡早發(fā)現(xiàn)設計缺陷,從而有效地縮短研發(fā)周期,降低生產(chǎn)成本,使產(chǎn)品的結構和性能更加合理。
三、主要內容、研究方法、研究思路
1、主要內容
(1) 設計任務:
① 總體參數(shù)的選擇(QTZ40級別)
② 結構形式
(2) 總體設計
① 主要技術參數(shù)性能
② 設計原則
③ 平衡重的計算
④ 塔機的風力計算
⑤ 整機傾翻穩(wěn)定性的計算
(3) 吊臂的設計和計算
① 吊臂的形式及尺寸(變截面)(雙吊點)
② 吊臂的強度、穩(wěn)定性及剛度驗算
(4) 設計要求
① 主要任務:學生應在指導教師指導下獨立完成一項給定的設計任務,編寫符合要求的設計說明書,并正確繪制機械與電氣工程圖紙,獨立撰寫一份畢業(yè)論文,并繪制有關圖表。
② 知識要求:學生在畢業(yè)設計工作中,應綜合運用多學科的理論、知識與技能,分析與解決工程問題。通過學習、鉆研與實踐,深化理論認識、擴展知識領域、延伸專業(yè)技能。
③ 能力培養(yǎng)要求:學生應學會依據(jù)技術課題任務,完成資料的調研、收集、加工與整理,正確使用工具書;培養(yǎng)學生掌握有關工程設計的程序、方法與技術規(guī)范,提高工程設計計算、圖紙繪制、編寫技術文件的能力;培養(yǎng)學生掌握實驗、測試等科學研究的基本方法;鍛煉學生分析與解決工程實際問題的能力。
④ 綜合素質要求:通過畢業(yè)設計,學生應掌握正確的設計思想;培養(yǎng)學生嚴肅認真的科學態(tài)度和嚴謹求實的工作作風;在工程設計中,應能樹立正確的生產(chǎn)觀、經(jīng)濟觀與全局觀。
⑤ 設計成果要求:
凡給定的設計內容,包括說明書、計算書、圖紙等必須完整,不得有未完的部分,不應出現(xiàn)缺頁、少圖紙現(xiàn)象。
1) 對設計的全部內容,包括設計計算、機械構造、工作原理、整機布置等,均有清晰的了解。對設計過程、計算步驟有明確的概念,能用圖紙完整的表達機械結構與工藝要求,有比較熟練的認識圖紙能力。對運輸、安裝、使用等也有一定了解。
2) 說明書、計算書內容要精練,表述要清楚,取材合理,取值合適,設計計算步驟正確,數(shù)學計算準確,各項說明要有依據(jù),插圖、表格及字跡均應工整、清楚、不得隨意涂改。制圖要符合機械機械制圖標準,且清潔整齊。
3) 對國內外塔式起重機情況有一般的了解,對各種塔式起重機有一定的分析、比較能力。
2、 研究方法
(1)資料的準備
通過上網(wǎng)和畢業(yè)實習,搜集同類已研發(fā)產(chǎn)品相關資料,了解國內外塔式起重機總體設計和起升系統(tǒng)的設計的已研發(fā)的產(chǎn)品,借鑒這些產(chǎn)品的設計思路為自己的設計做準備。了解所做設計中的標準部件的相關信息,為以后設計做好準備。
(2)參數(shù)確定
根據(jù)所查資料,了解到起重機的相關參數(shù),和對標準部件的了解,選擇能免租條件的相關零件。根據(jù)傳統(tǒng)設計方法并結合相似的產(chǎn)品結構進行具體的設計,在設計中確定個關節(jié)的合理尺寸和形狀。整體和各個部件的形狀和尺寸確定后,用二維作圖工具(autoCAD等)繪制出各主要部件的圖形圖和總裝圖。明確產(chǎn)品的具體設計尺寸和形狀。
3、 研究思路
伴隨著計算機技術的進步,目前國內外先進的機械產(chǎn)品設計制造都離不開有限元分析(Finite ElementAnalysis, FEA)計算,在工程設計和分析中受到越來越廣泛的重視,其計算結果不僅詳盡,更具可靠性。采用有限元分析的方法進行機械產(chǎn)品的設計計算將會極大提高設計效率、保證其設計質量。設計者只需借助通用有限元軟件建立模型并進行仿真分析,就能真實地反映機械產(chǎn)品的尺寸外形特征和工作過程,并進行各種類型的力學分析,盡早發(fā)現(xiàn)設計缺陷,從而有效地縮短研發(fā)周期,降低生產(chǎn)成本,使產(chǎn)品的結構和性能更加合理。本文應用有限元軟件對塔機總體及臂架結構進行快速校核分析。
四、總體安排和進度(包括階段性工作內容及完成日期)
2013.3.25-2013.3.28 熟悉整理資料
2013.3.29-2013.4.13 方案選擇及總體設計
2013.4.14-2013.4.20 繪制總圖
2013.4.21-2013.5.15 臂架設計
2013.5.16-2013.6.5 繪制塔身裝配及結構圖紙
2013.6.6-2013.6.19 繪制零件圖紙
2013.6.20-2013.6.21 準備論文及答辯
五、主要參考文獻
[1] 哈爾濱建筑工程學院主編.工程起重機.北京:中國建筑工業(yè)出版社
[2] 董剛、李建功主編.機械設計.機械工業(yè)出版社
[3] 機械設計手冊.化學工業(yè)出版社(5冊)
[4] GB/T9462—1999 塔式起重機技術條件
[5] GB/T13752—1992 塔式起重機設計規(guī)范
[6] GB5144—1994 塔式起重機安全規(guī)程
[7] 邢靜忠.ANSYS應用實例與分析.科學出版社.2006.
[8] 劉坤.ANSYS有限元方法精解.國防工業(yè)出版社.2005.
[9]GB/T9462—1999 塔式起重機設計條件.
[10] GB/T13752—1992 塔式起重機設計規(guī)范.
[11] GB/T5144—1994 塔式起重機安全規(guī)程
[12]劉鴻文.材料力學.北京:高等教育出版社.2002.
[13]李柱,徐振高.互換性與測量技術.北京:高等教育出版社.2002.
[14] 張東升.機械零件及建筑機械.重慶:重慶大學出版社.2003.
[15] 現(xiàn)行建筑機械規(guī)范大全.北京:中國建筑工業(yè)出版社.1995.
[16] 吳慶鳴,何小新.工程機械設計.武昌:武漢大學出版社.2006.
[17]劉佩衡.塔式起重機使用手冊.北京:機械工業(yè)出版社.2002.
[18] 張質文,虞和謙等.起重機設計手冊.北京:中國鐵道出版社.1997.
[19] 顧迪民.工程起重機.北京:中國建筑工業(yè)出版社.1988.
指導教師意見:
指導教師簽名: 日期:
教研室意見:
教研室主任簽名: 日期:
系意見:
系領導簽名: 日期:
系蓋章
Ocean Engineering 29 (2002) 1463–1477 Analysis of Wells turbine design parameters by numerical simulation of the OWC performance A. Brito-Melo, L.M.C. Gato * , A.J.N.A. Sarmento Mechanical Engineering Department, Instituto Superior Te′cnico, Technical University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal Received 22 May 2001; accepted 30 August 2001 Abstract This paper investigates by numerical simulation the influence of the Wells turbine aerody- namic design on the overall plant performance, as affected by the turbine peak efficiency and the range of flow rates within which the turbine can operate efficiently. The problem of match- ing the turbine to an oscillating water column (OWC) is illustrated by taking the wave climate and the OWC of the Azores power converter. The study was performed using a time-domain mathematical model based on linear water wave theory and on model experiments in a wave tank. Results are presented of numerical simulations considering several aerodynamic designs of the Wells turbine, with and without guide vanes, and with the use of a bypass pressure- relief valve. ? 2002 Elsevier Science Ltd. All rights reserved. Keywords: Wave energy; Oscillating water column; Equipment; Wells turbine 1. Introduction The Wells turbine has been the most commonly adopted solution to the air-to- electricity energy conversion problem in oscillating water column (OWC) wave energy converters. These essentially consist of a capture pneumatic chamber, open at the bottom front to the incident wave, a turbine and an electrical generator. The incident wave motion excites the oscillation of the internal free surface of the entrained water mass in the pneumatic chamber, which produces a low-pressure reci- * Corresponding author. Tel.: +351-21-841-7411; fax: +351-21-841-7398. E-mail address: lgato@hidro1.ist.utl.pt (L.M.C. Gato). 0029-8018/02/$ - see front matter ? 2002 Elsevier Science Ltd. All rights reserved. PII: S 00 29 -8018(01)00099-3 1464 A. Brito-Melo et al. / Ocean Engineering 29 (2002) 1463–1477 procating flow that drives the turbine. A few full-scale turbine prototypes have been built and installed in grid-connected power plants in European countries, e.g. the 500 kW Wells monoplane turbine with guide vanes installed in the Island of Pico, Azores (Falca?o, 2000), and 2×250 kW biplane contrarotating turbine of the LIMPET plant, at Islay, Scotland (Heath et al., 2000). The greatest challenges to designers of equipment for wave energy converters are the intrinsically oscillating nature and the random distribution of the wave energy resource. These features are absent or much less severe in other competing energy technologies. The air turbine in an OWC converter is subject to flow conditions (randomly reciprocating flow), which, with respect to efficiency, are much more demanding than in turbines in almost any other application. The Wells turbine, while reaching only a moderately high peak efficiency as compared with conventional tur- bines, can operate in reciprocating flow without the need of a rectifying valve system. The turbine, on the one hand, is required to extract energy from air whose flow rate, in each of the two directions, oscillates between zero and a maximum value, which in turn has an extremely large variation from wave to wave and with sea conditions. On the other hand, at fixed rotational speed, turbines in general, and Wells turbines in particular, are capable of operating with good efficiency only within a limited range of flow conditions around the peak efficiency point. The power output of Wells turbines is known to be low (or even negative) at small flow rates (the flow rate passes through zero twice in a wave cycle) and it drops sharply for flow rates above a critical value due to aerodynamic losses produced by rotor blade stalling. Therefore, the turbine is expected to perform poorly in very energetic sea-states or whenever violent wave peaks occur. Mounting a bypass pressure-relief valve on the top of the air chamber as proposed in the Azores plant may prevent this problem. The valve is controlled to limit the maximum pressure and suction in the chamber (depending on the turbine rotational speed) to prevent the instantaneous air flow rate through the turbine from exceeding the values above which aerodynamic stalling at the rotor blades would produce a severe fall in power output. Numerical simulations (Brito- Melo et al., 1996; Falca?o and Justino, 1999) indicate that a reduction in turbine size and a substantial increase in the annual production of electrical energy might be achieved by the use of a bypass pressure-relief valve. Moreover, recent studies (theoretical and model testing) indicate that blade sections especially designed for Wells turbine rotors can significantly enlarge the range of flow rates within which the turbine operates efficiently and reduce aerodynamic losses under partially stalled flow conditions, in comparison with other blade designs which give a higher peak efficiency within a narrower range of flow rates through the turbine. This raises the question of whether, in view of the total annual produced electrical energy and taking into account the hydrodynamic performance of the OWC device, it is more appropri- ate to select a turbine aerodynamic design which allows an enlarged range of flow rates at which the turbine operates efficiently or whether it is better to adopt a turbine design which gives a higher peak efficiency value with a reduced range of flow rates at which the turbine operates efficiently. Furthermore, it is of interest to know to what extent this issue might be dependent on the use of a pressure-relief valve. The main objective of the present work is to investigate the influence of the Wells 1465A. Brito-Melo et al. / Ocean Engineering 29 (2002) 1463–1477 turbine aerodynamic design on the overall plant performance, as affected by the turbine peak efficiency and the range of flow rates within which the turbine can operate efficiently. Realistic characteristics are assumed for the turbine and the use of a bypass pressure-relief valve is also considered. Since the resulting pressure changes in the chamber are dependent on the turbine characteristics and the pressure- relief valve influences the turbine operation, the hydrodynamic process of energy extraction is also modified. The hydrodynamics of the conversion of wave energy into pneumatic energy is predicted by using a time-domain mathematical model based on linear water wave theory and on model experiments in a wave tank as described in Sarmento and Brito-Melo (1996). The conversion of pneumatic energy into electrical energy is predicted by a suitable computational model of the power take-off equipment based on the results extrapolated from aerodynamic tests on a scale-model and on empirical approximations for the generator losses (Brito-Melo et al., 1996). This paper presents the results of numerical simulations considering several aerodynamic designs of the Wells turbine, with and without guide vanes, and the use of the pressure-relief valve. The problem of matching the turbine to an OWC is illustrated by taking the wave climate and the OWC of the Azores wave power converter. 2. Wave-to-wire model 2.1. Plant operation The wave-to-wire model concerns the operation of an OWC equipped with a Wells turbine, a bypass valve of unlimited capacity and a variable speed turbo-generator, under a set of representative sea-state conditions. The Wells turbine is known to exhibit an approximately linear relationship between the turbine pressure drop p(t) and the flow rate q t (t). Then we may write the turbine characteristic as K H11005 p(t)/q t (t) H11005 p s (H9024)/q s (H9024), where p s (H9024), and q s (H9024) are maximum values of pressure and flow rate (prior to the onset of aerodynamic stall at the turbine rotor blades), which (for a given turbine) depend on the turbine rotational speed H9024. The use of a properly controlled bypass pressure-relief valve prevents the occurrence of stall at the turbine rotor blades. The valve is controlled to ensure that |p(t)|H11349p s (H9024). Then |q s (t)|H11349q s (H9024). The excess flow rate q v (t) passes through the valve to (or from) the atmosphere. The inertia of the rotating parts is assumed large enough so that rotational speed H9024 may be considered approximately constant over the time-intervals simulating a given sea-state (about 15 minutes). This allows H9024 to be optimized for each represen- tative record of the sea-state, in order to maximize the electrical energy production. The turbine rotational speed is allowed to vary between the synchronous speed of the generator and twice its value. Summing the product of the time-averaged electri- cal power output with the occurrence frequency for all data records gives the overall annual average electrical power output. 1466 A. Brito-Melo et al. / Ocean Engineering 29 (2002) 1463–1477 2.2. Hydrodynamic model The hydrodynamic model is based on the pressure model presented in Sarmento and Falca?o (1985). According to the OWC performance description presented in Section 2.1, the mass balance across a control surface enclosing the pneumatic chamber is given by p(t) K H11001 q v (t) H11005 q(t)H11002 V 0 gP a dp(t) dt (1) where q(t) is the volume flow rate displaced by the free-surface inside the chamber, V 0 denotes the volume of the air in the chamber under undisturbed conditions, P a is the atmospheric pressure and g is the ratio of specific heats. As stated in Section 2.1, q v (t) H11005 0if|p(t)| H11021 p s (H9024) (i.e. when the valve is not operating). According to the linear water wave theory, the volume flow rate displaced by the free-surface inside the chamber may be decomposed as q(t) H11005 q d (t) H11001 q r (t), where q d (t) is the diffraction flow rate, due to incident wave action assuming the internal and the exter- nal free-surfaces at constant atmospheric pressure, and q r (t) is the radiation flow rate due only to the pressure oscillation p(t) in otherwise calm waters. Under the assump- tions of the linearized wave theory, we may apply the convolution theorem to obtain the solution of a linear problem in terms of an impulse response (Pipes and Harvill, 1970), as follows: q r (t) H11005 H20885 H11002H11009 t h r (tH11002t)pH11032(t)dt (2) where pH11032(t) is the time-derivative of the pressure inside the chamber and t represents a time-lag. The upper limit of the integral in Eq. (2) represents the present instant t because the process is causal (Cummins, 1962). The impulse response function h r (t) can be obtained from the hydrodynamic coefficients of the OWC computed with a numerical model, such as the WAMIT (Lee et al., 1996) or the AQUADYN- OWC (Brito-Melo et al., 1999), or by tank testing. Here we use an estimate of the impulse response function obtained in free-oscillation transient experiments from 1:35 scale testing of the Azores OWC wave power plant (see Sarmento and Brito- Melo, 1996, for details). Time series for the diffraction flow, q d (t), have also been obtained in energy extrac- tion experiments with the scaled model subject to a set of 44 sea-states representative of the Azores power plant site. In these experiments a device producing an equivalent air pressure drop simulated the turbine. The flow rate q t (t) could be obtained as a function of p(t) from the device calibration curve. The diffraction flow time-series for each of the 44 sea-states was estimated by solving Eq. (1) (with q v (t) H11005 0) using the pressure records from the energy extraction experiments, and the experimental estimate of h r (t) previously obtained in the transient experiments. 1467A. Brito-Melo et al. / Ocean Engineering 29 (2002) 1463–1477 2.3. Power take-off equipment The power take-off sub-model is based on results extrapolated from small-scale turbine tests (Gato et al., 1996; Webster and Gato, 1999a,b) and on empirical data for the turbine and generator losses (Brito-Melo et al., 1996). The average power at the turbine shaft for a period T is given by W s H11005 H9024 T H20885 0 T [L(H9024,q t (t))H11002L m (H9024)] dt (3) where L is the aerodynamically produced turbine-torque and L m the torque due to mechanical losses (especially bearing losses). For stall-free conditions, L is approxi- mated by a second-order polynomial. In order to provide the necessary performance data to study the matching of the power take-off equipment and the pneumatic chamber, the data from small-scale turbine tests are modified using a simple mean- line turbine flow analysis method to take into account the rotor solidity S and the hub-to-tip ratio. Ignoring the postponement of stall when the Reynolds number is increased, scale effects are taken into account by correcting the torque curve of the turbine model. This is done multiplying (dividing) the positive (negative) values of L by f H11005 0.8/0.706. This corrects the torque curve of the unswept NACA 0015 bladed rotor with guide-vanes to match a peak efficiency of h max H11005 0.80. For the preliminary design of the turbine a maximum blade tip speed of 160 ms H110021 is assumed. The average electrical power output is obtained by subtracting the generator losses from the average power at the turbine shaft. The model for the generator losses includes the Joule losses, the iron losses, the ventilation losses and the mechanical losses (Brito-Melo et al., 1996). 3. Results and discussion Experimental research on different types of rotor blades has been conducted recently to improve the aerodynamic performance of the Wells turbine (Raghunathan, 1995; Gato et al., 1996; Curran and Gato, 1997; Webster and Gato, 1999a,b). Among these types, we consider two turbine blade configurations, which may give a wider range of flow rates within which the turbine can operate with fairly good efficiency, in comparison with that of the more standard NACA 0015 unswept bladed turbine rotor: they are the backward-swept NACA 0015 blades (Webster and Gato, 1999a), Fig. 1, and the optimized HSIM-15-262123-1576 unswept blades (Gato and Hen- riques, 1996), Fig. 2. For comparison we take results for the NACA 0015 unswept blades (Gato et al., 1996). Figs. 3 and 4 show experimental results from unidirectional-flow small-scale test- ing at the IST rig (Webster and Gato, 1999a,b). Results presented in Figs. 3 and 4 refer to high-solidity Wells turbine rotors (rotor outer radius R H11005 0.295 m, constant chord c H11005 125 mm, rotor solidity S H11005 0.64, equipped with the blades referred to 1468 A. Brito-Melo et al. / Ocean Engineering 29 (2002) 1463–1477 Fig. 1. Rotor blade sweep angle. Fig. 2. The NACA 0015 and HSIM 15-262123-1576 sections. above, with and without guide vanes. The figures show, in dimensionless form, experimental results for the efficiency h H11005 LH9024/(q t p), pressure drop p ? H11005 p/(rH9024 2 R 2 ), and torque L ? H11005 L/(rH9024 2 R 5 ) as functions of the flow rate coefficient U* (r is the air density). Results in Fig. 3 for the turbines without guide vanes show that the NACA 0015 unswept rotor has h max H11005 0.583 at U ? H11005 0.114, and stalls at U ? H11005 0.21. The NACA 0015 30° backward-swept rotor has a lower h max H11005 0.583, with a lower flow rate for the onset of stall, U ? H11005 0.17, but without exhibiting the sharp decrease in the torque that occurs in the unswept rotor. Furthermore, under stall conditions, the torque of the swept rotor becomes negative at a much higher flow rate, U ? H11022 0.45, whereas for the unswept blades the efficiency becomes nega- tive for U ? H11022 0.3. The unswept HSIM bladed rotor shows a h max similar to that of the backward-swept rotor, but produces a soft progressive stall of the flow through the rotor blades, with notably higher efficiency for a wide range of flow rates after the onset of stall. Fig. 4 shows a corresponding plot for the same turbine rotors when equipped with a double row of guide vanes. The experimental results plotted in Fig. 4 show that the use of guide vanes increases h max for any of the above geometries, i.e. from 0.583 to 0.706, 0.551 to 0.613 and 0.553 to 0.669, for the NACA 0015 unswept and 1469A. Brito-Melo et al. / Ocean Engineering 29 (2002) 1463–1477 Fig. 3. Unswept and 30° backward-swept NACA 0015 and unswept HSIM bladed rotor turbines, without guide vanes: measured values of efficiency (a), pressure drop (b) and torque (c) against flow rate coef- ficient. 1470 A. Brito-Melo et al. / Ocean Engineering 29 (2002) 1463–1477 Fig. 4. Unswept and 30° backward-swept NACA 0015 and unswept HSIM bladed rotor turbines, with guide vanes: measured values of efficiency (a), pressure drop (b) and torque (c) against flow rate coef- ficient. 1471A. Brito-Melo et al. / Ocean Engineering 29 (2002) 1463–1477 backward-swept rotors and the HSIM unswept rotor, respectively. Furthermore, we find that the use of guide vanes narrows the range of flow rates within which the turbine works with positive torque. Table 1 summarizes the performance data for the six turbines, where U ? a and U ? b are the minimum and maximum flow rate coefficients respectively, at which the efficiency is nominally h H11005 0.5h max . Therefore, H9021H11005U ? a /U ? b and H9004H11005U ? a H11002U ? b give an indication of the operational range while (H9004p ? 0 /U ? ) h H11005 h max is the pressure–flow ratio in the approximately rectilinear region. In the above performance comparison, constant overall solidity was assumed for the different turbine configurations. Results in Table 1 show that the rotor blade geometry has a remarkable influence on the turbine performance. In particular, some rotor geometries give a considerable wider range of flow rates within which the turbine operates efficiently, in comparison with others that have higher peak efficiency within a narrower range of flow rates. Figs. 5–7 plot the average electrical power output as given by the numerical simul- ation for the set of the 44 representative records of the wave climate for the Azores Plant site, taking into account the frequency of occurrence of each sea-state. The results give the turbine characteristic K for several values of the rated power W 0 H11005 p s q s . Table 2 indicates the values of the flow coefficient U ? s at which the different types of turbine rotor were designed and the bypass pressure-relief valve is actuated. 3.1. NACA 0015 unswept bladed rotor with and without guide vanes Fig. 5 presents the results of the numerical simulation to study the effect of the use of guide vanes with the NACA 0015 unswept bladed rotor. Fig. 5 shows that the use of guide vanes provides a significant increase in the average electrical power output, both with and without the presence of the bypass pressure-relief valve. The curves plotted in Figs. 3 and 4 for the unswept NACA 0015 rotor, with and without guide vanes, respectively, show that the turbine with guide vanes has h max H110150.72 Table 1 Peak efficiency, useful flow rate range and damping ratio for several turbine models (overall solidity S=0.64) Turbine rotor With guide vanes Without guide vanes NACA 0015 NACA 0015 HSIM NACA 0015 NACA 0015 HSIM unswept swept-back unswept unswept swept-back unswept h max 0.706 0.613 0.669 0.583 0.551 0.553 (U ? ) h H11005h max 0.124 0.137 0.154 0.114 0.129 0.131 U ? a 0.050 0.062 0.057 0.051 0.058 0.059 U ? b 0.197 0.209 0.275 0.251 0.232 0.360 H9021 0.254 0.297 0.207 0.203 0.250 0.164 H9004 0.147 0.147 0.218 0.200 0.174 0.301 (H9004p ? 0 /U ? ) h H11005h max 2.19 1.87 2.38 2.54 2.04 2.79 1472 A. Brito-Melo et al. / Ocean Engineering 29 (2002) 1463–1477 Fig. 5. Unswept NACA 0015 bladed rotor turbine with and without guide vanes working (a) with and (b) without the bypass valve: average electrical power conversion as a function of the turbine characteristic K, for several values of the turbine-rated power. whereas for the turbine without guide vanes
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