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1、<p><b> 附錄A 譯文</b></p><p> (一)離心泵使用時(shí)的調(diào)節(jié)方式與能源耗損分析</p><p> 離心泵是廣泛應(yīng)用于化工工業(yè)系統(tǒng)的一種通用流體機(jī)械。它具有性能適應(yīng)范圍廣(包括流量、壓頭及對(duì)輸送介質(zhì)性質(zhì)的適應(yīng)性)、體積小、結(jié)構(gòu)簡(jiǎn)單、操作容易、操作費(fèi)用低等諸多優(yōu)點(diǎn)。通常,所選離心泵的流量、壓頭可能會(huì)和管路中要求的不一致,或由于生產(chǎn)任務(wù)
2、、工藝要求發(fā)生變化,此時(shí)都要求對(duì)泵進(jìn)行流量調(diào)節(jié),實(shí)質(zhì)是改變離心泵的工作點(diǎn)。離心泵的工作點(diǎn)是由泵的特性曲線(xiàn)和管路系統(tǒng)特性曲線(xiàn)共同決定的,因此,改變?nèi)魏我粋€(gè)的特性曲線(xiàn)都可以達(dá)到流量調(diào)節(jié)的目的。目前,離心泵的流量調(diào)節(jié)方式主要有調(diào)節(jié)閥控制、變速控制以及泵的并、串聯(lián)調(diào)節(jié)等。由于各種調(diào)節(jié)方式的原理不同,除有自己的優(yōu)缺點(diǎn)外,造成的能量損耗也不一樣,為了尋求最佳、能耗最小、最節(jié)能的流量調(diào)節(jié)方式,必須全面地了解離心泵的流量調(diào)節(jié)方式與能耗之間的關(guān)系。<
3、;/p><p> 1 泵流量調(diào)節(jié)的主要方式</p><p> 1.1 改變管路特性曲線(xiàn)</p><p> 改變離心泵流量最簡(jiǎn)單的方法就是利用泵出口閥門(mén)的開(kāi)度來(lái)控制,其實(shí)質(zhì)是改變管路特性曲線(xiàn)的位置來(lái)改變泵的工作點(diǎn)。</p><p> 1.2 改變離心泵特性曲線(xiàn)</p><p> 根據(jù)比例定律和切割定律,改變泵
4、的轉(zhuǎn)速、改變泵結(jié)構(gòu)(如切削葉輪外徑法等)兩種方法都能改變離心泵的特性曲線(xiàn),從而達(dá)到調(diào)節(jié)流量(同時(shí)改變壓頭)的目的。但是對(duì)于已經(jīng)工作的泵,改變泵結(jié)構(gòu)的方法不太方便,并且由于改變了泵的結(jié)構(gòu),降低了泵的通用性,盡管它在某些時(shí)候調(diào)節(jié)流量經(jīng)濟(jì)方便[1],在生產(chǎn)中也很少采用。這里僅分析改變離心泵的轉(zhuǎn)速調(diào)節(jié)流量的方法。從圖1中分析,當(dāng)改變泵轉(zhuǎn)速調(diào)節(jié)流量從Q1下降到Q2時(shí),泵的轉(zhuǎn)速(或電機(jī)轉(zhuǎn)速)從n1下降到n2,轉(zhuǎn)速為n2下泵的特性曲線(xiàn)Q-H與管路特性
5、曲線(xiàn)He=H0+G1Qe2(管路特曲線(xiàn)不變化)交于點(diǎn)A3(Q2,H3),點(diǎn)A3為通過(guò)調(diào)速調(diào)節(jié)流量后新的工作點(diǎn)。此調(diào)節(jié)方法調(diào)節(jié)效果明顯、快捷、安全可靠,可以延長(zhǎng)泵使用壽命,節(jié)約電能,另外降低轉(zhuǎn)速運(yùn)行還能有效的降低離心泵的汽蝕余量NPSHr,使泵遠(yuǎn)離汽蝕區(qū),減小離心泵發(fā)生汽蝕的可能性[2]。缺點(diǎn)是改變泵的轉(zhuǎn)速需要有通過(guò)變頻技術(shù)來(lái)改變?cè)瓌?dòng)機(jī)(通常是電動(dòng)機(jī))的轉(zhuǎn)速,原理復(fù)雜,投資較大,且流量調(diào)節(jié)范圍小。</p><p>
6、 1.3 泵的串、并連調(diào)節(jié)方式</p><p> 當(dāng)單臺(tái)離心泵不能滿(mǎn)足輸送任務(wù)時(shí),可以采用離心泵的并聯(lián)或串聯(lián)操作。用兩臺(tái)相同型號(hào)的離心泵并聯(lián),雖然壓頭變化不大,但加大了總的輸送流量,并聯(lián)泵的總效率與單臺(tái)泵的效率相同;離心泵串聯(lián)時(shí)總的壓頭增大,流量變化不大,串聯(lián)泵的總效率與單臺(tái)泵效率相同。</p><p> 2 不同調(diào)節(jié)方式下泵的能耗分析</p><p>
7、 在對(duì)不同調(diào)節(jié)方式下的能耗分析時(shí),文章僅針對(duì)目前廣泛采用的閥門(mén)調(diào)節(jié)和泵變轉(zhuǎn)速調(diào)節(jié)兩種調(diào)節(jié)方式加以分析。由于離心泵的并、串聯(lián)操作目的在于提高壓頭或流量,在化工領(lǐng)域運(yùn)用不多,其能耗可以結(jié)合圖2進(jìn)行分析,方法基本相同。</p><p> 2.1 閥門(mén)調(diào)節(jié)流量時(shí)的功耗</p><p> 離心泵運(yùn)行時(shí),電動(dòng)機(jī)輸入泵軸的功率N為:</p><p> 式中 ——軸功率,
8、;</p><p> ——泵的有效壓頭,;</p><p> ——泵的實(shí)際流量,; </p><p><b> ——流體比重,;</b></p><p><b> η——泵的效率。</b></p><p> 當(dāng)用閥門(mén)調(diào)節(jié)流量從到,在工作點(diǎn)消耗的軸功率為:</p
9、><p> ——實(shí)際有用功率,;</p><p> ——閥門(mén)上損耗得功率,;</p><p> ——離心泵損失的功率,。</p><p> 2.2 變速調(diào)節(jié)流量時(shí)的功耗</p><p> 在進(jìn)行變速分析時(shí)因要用到離心泵的比例定律,根據(jù)其應(yīng)用條件,以下分析均指離心泵的變速范圍在±20%內(nèi),且離心泵本身效
10、率的變化不大。用電動(dòng)機(jī)變速調(diào)節(jié)流量到流量時(shí),在工作點(diǎn)泵消耗的軸功率為:</p><p><b> 同樣經(jīng)變換可得:</b></p><p> 式中 ——實(shí)際有用功率,;</p><p> ——離心泵損失的功率,。</p><p> 2.3 能耗對(duì)比分析</p><p><b>
11、; 3 結(jié)論</b></p><p> 對(duì)于目前離心泵通用的出口閥門(mén)調(diào)節(jié)和泵變轉(zhuǎn)速調(diào)節(jié)兩種主要流量調(diào)節(jié)方式,泵變轉(zhuǎn)速調(diào)節(jié)節(jié)約的能耗比出口閥門(mén)調(diào)節(jié)大得多,這點(diǎn)可以從兩者的功耗分析和功耗對(duì)比分析看出。通過(guò)離心泵的流量與揚(yáng)程的關(guān)系圖,可以更為直觀的反映出兩種調(diào)節(jié)方式下的能耗關(guān)系。通過(guò)泵變速調(diào)節(jié)來(lái)減小流量還有利于降低離心泵發(fā)生汽蝕的可能性。當(dāng)流量減小越大時(shí),變速調(diào)節(jié)的節(jié)能效率也越大,即閥門(mén)調(diào)節(jié)損耗功率越
12、大,但是,泵變速過(guò)大時(shí)又會(huì)造成泵效率降低,超出泵比例定律范圍,因此,在實(shí)際應(yīng)用時(shí)應(yīng)該從多方面考慮,在二者之間綜合出最佳的流量調(diào)節(jié)方法。</p><p> ?。ǘ┍迷贑AD中的原理方案設(shè)計(jì)模型</p><p> 論文摘要:在詳細(xì)分析泵行業(yè)中CAD狀況的基礎(chǔ)上,闡述了建立水泵原理方案設(shè)計(jì)模型的必要性??紤]現(xiàn)有的設(shè)計(jì)方法模型的特點(diǎn)以及水泵原理設(shè)計(jì)的自身規(guī)律,在面向?qū)ο笤O(shè)計(jì)模型的基礎(chǔ)上融合了逐
13、步求精模型的閉環(huán)設(shè)計(jì)思想,在功能分解中采用了Function-Behavior-State(FBS)方法,提出了一個(gè)原理方案設(shè)計(jì)模型。并進(jìn)一步將該模型應(yīng)用于泵的原理方案設(shè)計(jì)的一實(shí)例中,得到了一個(gè)較為完整的水泵原理設(shè)計(jì)流程,表明此模型具有可操作性、可重用性、可交換性等特點(diǎn)。</p><p><b> 1 引言</b></p><p> 自90年代初我國(guó)實(shí)施CAD應(yīng)
14、用工程以來(lái),在水泵行業(yè)開(kāi)展CAD設(shè)計(jì)雖普遍受到重視,但基本仍處于初級(jí)的CAD繪圖階段,主要是應(yīng)用于整個(gè)設(shè)計(jì)過(guò)程中的“中下游”設(shè)計(jì)階段,即設(shè)計(jì)方案的具體實(shí)現(xiàn)階段,其本質(zhì)上屬于面向零件的細(xì)節(jié)設(shè)計(jì)。CAD的發(fā)展趨勢(shì)是不僅支持面向零件的細(xì)節(jié)設(shè)計(jì),更重要的是支持概念設(shè)計(jì)與方案設(shè)計(jì)等“上游”設(shè)計(jì),即是設(shè)計(jì)過(guò)程中最主要的創(chuàng)造性階段[1]。在產(chǎn)品設(shè)計(jì)過(guò)程中,創(chuàng)新性表現(xiàn)最為集中、最為突出的階段是產(chǎn)品的原理方案設(shè)計(jì)階段。為適應(yīng)泵的設(shè)計(jì)創(chuàng)新需要,有必要對(duì)水泵
15、原理方案設(shè)計(jì)機(jī)理進(jìn)行研究,建立一個(gè)滿(mǎn)足水泵設(shè)計(jì)實(shí)際需要的建模方法。在對(duì)泵的設(shè)計(jì)過(guò)程進(jìn)行總體分析,針對(duì)泵的產(chǎn)品特點(diǎn),總結(jié)設(shè)計(jì)過(guò)程中的設(shè)計(jì)規(guī)律,探討其設(shè)計(jì)創(chuàng)新機(jī)理,并適應(yīng)計(jì)算機(jī)輔助設(shè)計(jì)的需要,建立反映泵的設(shè)計(jì)經(jīng)驗(yàn)知識(shí)、設(shè)計(jì)方法以及設(shè)計(jì)規(guī)范的原理方案設(shè)計(jì)模型,并將其與已有的“中下游”設(shè)計(jì)模型耦合,以做到真正支撐和輔助設(shè)計(jì)全過(guò)程。</p><p><b> 2 模型設(shè)計(jì)方法</b></p&
16、gt;<p> 方案設(shè)計(jì)是設(shè)計(jì)過(guò)程中,在闡明任務(wù)要求后,通過(guò)抽象化認(rèn)識(shí)本質(zhì)問(wèn)題,建立功能結(jié)構(gòu),通過(guò)尋求合適的作用原理并將其組合成作用結(jié)構(gòu),從面確定原理解(原理方案)[2]。方案設(shè)計(jì)是在原理上確定一個(gè)解。其工作步聚如圖1所示。</p><p> 圖1 方案設(shè)計(jì)的工作步聚</p><p> 在建立泵原理方案設(shè)計(jì)模型中主要涉及兩方面的知識(shí)[3]:(1)設(shè)計(jì)方法學(xué)知識(shí),即解決
17、產(chǎn)品設(shè)計(jì)進(jìn)程的一般性理論、研究進(jìn)程模式、戰(zhàn)略與各步驟相應(yīng)的戰(zhàn)術(shù)。其中包括面向全過(guò)程的設(shè)計(jì)方法和對(duì)于方案設(shè)計(jì)過(guò)程中特定的設(shè)計(jì)方法。(2)設(shè)計(jì)對(duì)象領(lǐng)域的專(zhuān)業(yè)知識(shí),即關(guān)于泵這種具體的流體通用機(jī)械中所涉及的專(zhuān)業(yè)領(lǐng)域的知識(shí)。</p><p><b> 2.1 設(shè)計(jì)方法</b></p><p> 面向全過(guò)程的設(shè)計(jì)方法及模型基本可以分成三種[4]:(1)面向?qū)ο笤O(shè)計(jì)模型,它代
18、表著設(shè)計(jì)方法學(xué)的組裝創(chuàng)新設(shè)計(jì)階段;(2)GDT(General Design Theory)模型,它能體現(xiàn)創(chuàng)新設(shè)計(jì)方法學(xué)的創(chuàng)新思維過(guò)程(分解、映射、綜合),代表著開(kāi)環(huán)創(chuàng)新設(shè)計(jì)階段;(3)逐步求精模型,它充分體現(xiàn)了人的創(chuàng)新思維模式:繼承中創(chuàng)新、反復(fù)迭代,代表著工程設(shè)計(jì)方法學(xué)的閉環(huán)控制創(chuàng)新設(shè)計(jì)階段。這種方法認(rèn)為設(shè)計(jì)過(guò)程是一個(gè)逐步求精過(guò)程。它的最大優(yōu)點(diǎn)是存在解的評(píng)價(jià)層,允許對(duì)解進(jìn)行反饋控制,進(jìn)行產(chǎn)品優(yōu)化。因此它是一個(gè)閉環(huán)設(shè)計(jì)方法,比較符合工程
19、設(shè)計(jì)人員的思維模式。</p><p> 方案設(shè)計(jì)中關(guān)鍵性的一步就是如何進(jìn)行產(chǎn)品設(shè)計(jì)要求的功能分解。因?yàn)楫a(chǎn)品的設(shè)計(jì)要求是最精煉的產(chǎn)品功能描述,而形成產(chǎn)品的卻是許許多多完成一定功能的零部件的組合,如何將抽象的產(chǎn)品設(shè)計(jì)要求轉(zhuǎn)換為具體的、現(xiàn)實(shí)的功能要求充分體現(xiàn)了人的創(chuàng)造活動(dòng)。對(duì)這方面的研究,焦點(diǎn)主要集中在功能分解的依據(jù)上,有兩種方法比較典型:一種以Robert Hsturges為代表,以?xún)r(jià)值工程理論(VE)為背景,采用
20、功能分解,稱(chēng)為功能邏輯分解方法;另一種以Yasushi Umeda為代表,以人的認(rèn)知模型為背景,采用行為分解,稱(chēng)為Fuction Behavior State(FBS)方法[5]。雖然兩者都處于發(fā)展之中,但是文獻(xiàn)[4]認(rèn)為后者的分解依據(jù)更貼近工程設(shè)計(jì)的思維模式。</p><p> 2.2 泵設(shè)計(jì)領(lǐng)域的專(zhuān)業(yè)知識(shí)(泵設(shè)計(jì)的特點(diǎn))</p><p> 泵設(shè)計(jì)是一項(xiàng)復(fù)雜的過(guò)程,在設(shè)計(jì)中各種因素
21、互相影響,使?jié)M足給定要求的水泵有不同的設(shè)計(jì)方案或結(jié)果,因此必須找到其中最優(yōu)的一個(gè)。這是一個(gè)不斷探索,多次循環(huán),逐步深化的判斷求解過(guò)程[6]。從流體機(jī)械的角度看,流體機(jī)械的反問(wèn)題是當(dāng)今流體力學(xué)領(lǐng)域的難題之一。因此現(xiàn)有的設(shè)計(jì)基本采用流體力學(xué)的正問(wèn)題設(shè)計(jì),即先由工程設(shè)計(jì)得到流道結(jié)構(gòu),確定流動(dòng)的初始條件和邊界條件,再對(duì)流場(chǎng)進(jìn)行校核。根據(jù)校核結(jié)果對(duì)流道結(jié)構(gòu)進(jìn)行調(diào)整后再次校核,如此循環(huán)直到得到較優(yōu)的結(jié)果。這表明所建立的模型應(yīng)是一個(gè)循環(huán)迭代逐步求精的
22、閉環(huán)系統(tǒng)。</p><p> 隨著成組技術(shù)的廣泛應(yīng)用,泵設(shè)計(jì)制造正趨向于模塊化,以提高零件(組件)通用性和重用性,從而降低設(shè)計(jì)制造成本,保證產(chǎn)品質(zhì)量。而面向?qū)ο蟮慕K枷胝梅夏K化的需要。這表明所建立的模型應(yīng)是一個(gè)面向?qū)ο蟮南到y(tǒng)。</p><p> 3 原理方案設(shè)計(jì)模型</p><p> 基于以上分析,在本文所提出的原理方案設(shè)計(jì)模型中,整個(gè)設(shè)計(jì)進(jìn)程是在面
23、向?qū)ο蟮脑O(shè)計(jì)模型的基礎(chǔ)上融合了逐步求精模型閉環(huán)設(shè)計(jì)思想而建立的,在功能分解中采用了FBS方法。具體模型描述如圖2所示:</p><p> 圖2 原理方案設(shè)計(jì)模型結(jié)構(gòu)圖</p><p> 在模型中各個(gè)模塊的具體功能為:</p><p> 3.1 設(shè)計(jì)模型S</p><p> 設(shè)計(jì)模型S表示要設(shè)計(jì)的目標(biāo)對(duì)象,它可以由一個(gè)或幾個(gè)設(shè)計(jì)對(duì)象
24、組成,其中包括設(shè)計(jì)實(shí)體對(duì)象(E0)和設(shè)計(jì)關(guān)系對(duì)象(R0),其中實(shí)體對(duì)象可以是功能實(shí)體或結(jié)構(gòu)實(shí)體。即:</p><p> S={[E01,E02,…,E0n],[E01,E02,…,E0m]}</p><p> 因?yàn)槊總€(gè)設(shè)計(jì)要求一般有若干個(gè)可選擇的模型與之相匹配,并在設(shè)計(jì)過(guò)程中不斷迭代更新,這里用SKG來(lái)表示設(shè)計(jì)模型K的第G代模型,則有:</p><p> SK
25、G={[E01K,E02K,…,E0nK]G,[R01K,R02K,…,E0mK]G}</p><p> 3.2 設(shè)計(jì)算法A</p><p> 設(shè)計(jì)算法A為針對(duì)某一設(shè)計(jì)模型SKG,根據(jù)要求和約束(R&C)以及知識(shí)庫(kù)中與本領(lǐng)域的專(zhuān)家知識(shí),在模型庫(kù)中搜索與其匹配的設(shè)計(jì)對(duì)象,創(chuàng)建該設(shè)計(jì)對(duì)象的一個(gè)實(shí)例Oi并將其添加到設(shè)計(jì)模型SKG中,若無(wú)匹配的設(shè)計(jì)對(duì)象,則基于知識(shí)推理創(chuàng)建一個(gè)新的滿(mǎn)足
26、要求的對(duì)象。評(píng)價(jià)算法還對(duì)設(shè)計(jì)模型進(jìn)行評(píng)價(jià)測(cè)試,對(duì)不滿(mǎn)足要求和約束部分進(jìn)行修改。</p><p> 3.3 要求和約束R & C</p><p> 在產(chǎn)品需求建模輔助工具系統(tǒng)[7]的輔助下,通過(guò)對(duì)當(dāng)前設(shè)計(jì)模型需求信息的獲取、拓展和分析所得到的要求和約束R&C;對(duì)設(shè)計(jì)模型的要求、存在的條件以及其重要性的權(quán)重。最后形成一系列的功能需求{Ro.p},Ro.p為功能需求O的屬性
27、P。</p><p> 3.4 設(shè)計(jì)實(shí)體對(duì)象E0</p><p> 設(shè)計(jì)實(shí)體對(duì)象E0i與要求與約束中的Ri相匹配。它包括功能實(shí)體對(duì)象或結(jié)構(gòu)實(shí)體對(duì)象。</p><p> 對(duì)于功能實(shí)體對(duì)象,其本身是一設(shè)計(jì)模型S,該模型的構(gòu)成將遞歸調(diào)用圖3的模型算法。遞歸結(jié)束的條件是當(dāng)所得的實(shí)體對(duì)象是結(jié)構(gòu)對(duì)象,隱含其中的功能分解算法為FBS方法。功能實(shí)體對(duì)象的遞歸求解可以并行。&
28、lt;/p><p> 3.5 設(shè)計(jì)關(guān)系對(duì)象R0</p><p> 設(shè)計(jì)關(guān)系對(duì)象R0的構(gòu)成為:構(gòu)成該關(guān)系的設(shè)計(jì)實(shí)體對(duì)象中的相關(guān)屬性為設(shè)計(jì)關(guān)系對(duì)象的屬性,它的方法為屬性間相互約束關(guān)系,包括[8]</p><p> (1)等式約束:工程中大量的計(jì)算公式,如:</p><p> (2)限制約束:對(duì)一些設(shè)主變量的某種限制,如噪聲級(jí)的限定范圍。&l
29、t;/p><p> (3)函數(shù)約束:面向?qū)ο蟮墓こ虜?shù)據(jù)庫(kù)中的操作函數(shù),如標(biāo)準(zhǔn)件庫(kù)中選型函數(shù)。</p><p> (4)規(guī)則約束:用于表達(dá)工程設(shè)計(jì)中的一些經(jīng)驗(yàn)性知識(shí)。</p><p> 對(duì)于設(shè)計(jì)關(guān)系對(duì)象則不進(jìn)行遞歸求解調(diào)用,其本身構(gòu)成評(píng)判層,主要作用為在遞歸回溯時(shí),對(duì)解進(jìn)行測(cè)試和評(píng)判。在其中某一層得到存在設(shè)計(jì)關(guān)系對(duì)象的兩個(gè)或幾個(gè)設(shè)計(jì)實(shí)體對(duì)象的解后,由該設(shè)計(jì)關(guān)系對(duì)象出
30、發(fā),測(cè)試各個(gè)設(shè)計(jì)實(shí)體對(duì)象的解是否滿(mǎn)足設(shè)計(jì)關(guān)系對(duì)象中的約束關(guān)系,如不滿(mǎn)足則對(duì)各個(gè)設(shè)計(jì)對(duì)象的解進(jìn)行調(diào)整。</p><p> 設(shè)計(jì)關(guān)系對(duì)象構(gòu)成的評(píng)判層與評(píng)價(jià)規(guī)劃(E)及要求與約束(R&C)構(gòu)成的評(píng)判層不同,后者的作用是對(duì)設(shè)計(jì)模型的整體性能的評(píng)價(jià),設(shè)計(jì)關(guān)系對(duì)象的作用則是設(shè)計(jì)模型內(nèi)部各個(gè)組成模塊間協(xié)調(diào)性、一致性的評(píng)價(jià)。</p><p> 3.6 與后續(xù)設(shè)計(jì)的接口</p>
31、<p> 原理方案設(shè)計(jì)的后續(xù)步驟為詳細(xì)設(shè)計(jì),即確定各個(gè)零件或組件的形狀、尺寸、材料要素,進(jìn)而得到各個(gè)零件的詳細(xì)描述,同時(shí)還需確定各個(gè)組件(零件)間的關(guān)系,當(dāng)某一組件(零件)的涉及其他組件(零件)的要素變動(dòng)時(shí),能將此變動(dòng)擴(kuò)展到各個(gè)零件[9]。與原理方案設(shè)計(jì)層相對(duì)應(yīng),詳細(xì)設(shè)計(jì)層的產(chǎn)品可由裝配實(shí)體對(duì)象和裝配關(guān)系對(duì)象來(lái)描述。從本文所給出的原理方案模型出發(fā),可建立設(shè)計(jì)實(shí)體對(duì)象與裝配實(shí)體對(duì)象、設(shè)計(jì)關(guān)系對(duì)象和裝配關(guān)系對(duì)象的對(duì)應(yīng)轉(zhuǎn)換關(guān)系。因
32、此本文所給出的原理方案模型具有較好的擴(kuò)展性。</p><p> 從以上分析可見(jiàn),本原理方案設(shè)計(jì)模型考慮了設(shè)計(jì)中各種因素互相影響和相互獨(dú)立的特點(diǎn),以及工程設(shè)計(jì)中大量存在的問(wèn)題求解策略的調(diào)整概念,即先產(chǎn)生一個(gè)不費(fèi)事的有錯(cuò)誤的解,然后再修改它,使它逐步與精確解逼近(實(shí)踐證明這種做法一般比堅(jiān)持要求第一個(gè)解就完全沒(méi)有缺陷的做法有效得多),融合了面向?qū)ο蟮脑O(shè)計(jì)思想和逐步求精模型閉環(huán)設(shè)計(jì)思想,使泵設(shè)計(jì)的自身特點(diǎn)對(duì)其原理方案設(shè)
33、計(jì)模型所提出的兩個(gè)要求得到滿(mǎn)足。同時(shí)利用本模型進(jìn)行設(shè)計(jì)時(shí)可以進(jìn)行并行求解,提高求解效率,并可與后續(xù)設(shè)計(jì)環(huán)節(jié)較好地銜接。</p><p> 4 泵原理方案設(shè)計(jì)應(yīng)用實(shí)例</p><p> 基于上述的原理方案設(shè)計(jì)模型,將該模型應(yīng)用于具體的水泵原理方案設(shè)計(jì),得到其部分設(shè)計(jì)流程如圖3、4所示。</p><p><b> 設(shè)計(jì)流程說(shuō)明如下:</b>
34、</p><p> (1)確定設(shè)計(jì)要求并將其抽象化,得到泵設(shè)計(jì)的本質(zhì):通過(guò)一定的手段增加流體的機(jī)械能(動(dòng)能、勢(shì)能)或壓力能[10]。</p><p> (2)以泵的設(shè)計(jì)模型為當(dāng)前設(shè)計(jì)模型S。確定其第一層的設(shè)計(jì)對(duì)象組成。即各個(gè)功能實(shí)體對(duì)象組成及功能關(guān)系對(duì)象。設(shè)不存在已有對(duì)象,則需創(chuàng)建一系列新的對(duì)象。用FBS方法對(duì)功能進(jìn)行分解。從物料流的觀點(diǎn)出發(fā),泵的物料流為流體(液體),由泵的設(shè)計(jì)要求可
35、得到其核心功能為流體接收能量,此功能的完成可由幾個(gè)子行為來(lái)完成:導(dǎo)入流體,提供流體接收能量的空間(容納),流體接收能量(能量傳遞),導(dǎo)出流體(導(dǎo)出)。從能量流的觀點(diǎn)出發(fā),泵的核心功能將能量傳遞給流體,其可由調(diào)節(jié)輸入能量的大小、將輸入能量轉(zhuǎn)換為能量傳遞中所需的能量形式和能量傳遞給流體及能量隨流體導(dǎo)出四個(gè)子行為來(lái)完成。從信息流的觀點(diǎn)出發(fā),主要功能為調(diào)節(jié)和控制設(shè)定的要求與得到的結(jié)果的一致性。測(cè)量輸出量、比較設(shè)定值與測(cè)量值、調(diào)節(jié)和控制等行為可完
36、成信息流所需功能。最后還需一個(gè)輔助功能模塊即連結(jié)與支撐。各功能對(duì)象之間的關(guān)系如圖5所示。</p><p> 圖3 泵原理方案設(shè)計(jì)流程(部分) </p><p> 圖4 泵原理方案設(shè)計(jì)流程(部分)</p><p> (3)以各個(gè)設(shè)計(jì)功能對(duì)象為設(shè)計(jì)模S,進(jìn)行第二層設(shè)計(jì),在條件滿(mǎn)足的情況下(如“能量轉(zhuǎn)換”的求解需要“能量傳遞”求解結(jié)果)可以并行進(jìn)行設(shè)計(jì)
37、。以“能量傳遞”為例,針對(duì)該功能,從模型庫(kù)中搜尋可能的作用原理對(duì)象。如果模型庫(kù)中存在相應(yīng)的作用原理對(duì)象,則生成該原理對(duì)象的一個(gè)實(shí)例加入到當(dāng)前的設(shè)計(jì)模型S中。否則由知識(shí)庫(kù)中的專(zhuān)家知識(shí)推理得到可能的作用原理對(duì)象。由此可得張力、離心力、升力、電磁力等原理對(duì)象。設(shè)計(jì)者根據(jù)各個(gè)原理對(duì)象的特性,從自身的經(jīng)驗(yàn)出發(fā)選擇比較適合的一個(gè)到幾個(gè)原理對(duì)象進(jìn)入下一層設(shè)計(jì)。</p><p> 圖5 泵功能分解及結(jié)構(gòu)</p>
38、<p> (4)假設(shè)所選擇的作用原理對(duì)象為升力,則以升力原理為當(dāng)前設(shè)計(jì)模型S,搜索模型庫(kù)得到與其對(duì)應(yīng)的原理結(jié)構(gòu)模型:軸流式葉輪原型。</p><p> (5)對(duì)所得的軸流式葉輪原型進(jìn)行技術(shù)、經(jīng)濟(jì)評(píng)價(jià)。并根據(jù)評(píng)價(jià)結(jié)果逐層修改求精。</p><p> (6)對(duì)其它功能實(shí)體進(jìn)行類(lèi)似的求解。</p><p> (7)協(xié)調(diào)各個(gè)功能的原理結(jié)構(gòu)解之間的關(guān)系,如
39、圖4所示中為能量轉(zhuǎn)換的原理解與能量傳遞的原理解之間的制約關(guān)系,通過(guò)協(xié)同求精確定各個(gè)功能實(shí)體的結(jié)構(gòu)解。</p><p> (8)總體評(píng)價(jià)。從總的要求和約束R&C,以及評(píng)價(jià)規(guī)劃出發(fā),最終確定原理解。</p><p> 很明顯,以上給出例子所得出的原理解不是唯一的,根據(jù)模型庫(kù)和知識(shí)庫(kù)中等構(gòu)成的不同,設(shè)計(jì)者給出的判斷不同,得到的解是不一樣的。本應(yīng)用實(shí)例說(shuō)明,利用前面給出的模型進(jìn)行泵的原
40、理方案設(shè)計(jì)是可行的,基本滿(mǎn)足了泵設(shè)計(jì)的要求和特點(diǎn)。同時(shí)從模型本身框架和從實(shí)際應(yīng)用中可以發(fā)現(xiàn)模型具有以下特點(diǎn):</p><p> (1)可操作性。本模型泵設(shè)計(jì)的本身特點(diǎn)出發(fā),并與現(xiàn)有的設(shè)計(jì)方法模型相結(jié)合而成。該模型有效地應(yīng)用于實(shí)例中,表明本模型具有相當(dāng)?shù)目刹僮餍浴?lt;/p><p> (2)可重用性。面向?qū)ο蟮慕K枷胧沟玫降母鱾€(gè)設(shè)計(jì)對(duì)象可以在不同的產(chǎn)品中應(yīng)用。如實(shí)例中得到的能量轉(zhuǎn)換的功能
41、對(duì)象實(shí)現(xiàn)后,其結(jié)果列入模型庫(kù),在下一個(gè)產(chǎn)品設(shè)計(jì)時(shí),它將作為已有對(duì)象被檢索,實(shí)現(xiàn)重用性。</p><p> (3)可交換性。各個(gè)設(shè)計(jì)對(duì)象不是獨(dú)一無(wú)二的,每一個(gè)設(shè)計(jì)目標(biāo)可以有不同的設(shè)計(jì)模型來(lái)完成。如能量傳遞的解就可能有張力、離心力、升力、電磁力等幾種通過(guò)做功實(shí)現(xiàn)能量傳遞的原理對(duì)象,為設(shè)計(jì)提供了多種選擇。</p><p><b> 5 結(jié)論</b></p>
42、<p> 泵的原理方案設(shè)計(jì)模型涉及到設(shè)計(jì)方法學(xué)和泵本身的許多專(zhuān)業(yè)知識(shí)和經(jīng)驗(yàn)。以原理方案設(shè)計(jì)本身來(lái)說(shuō),現(xiàn)正處于起步和發(fā)展階段,是計(jì)算機(jī)輔助設(shè)計(jì)(CAD)中的熱點(diǎn)和前沿問(wèn)題。原理方案設(shè)計(jì)是產(chǎn)品設(shè)計(jì)過(guò)程中創(chuàng)新設(shè)計(jì)的關(guān)鍵,已成為國(guó)內(nèi)外專(zhuān)家學(xué)者的共識(shí)。本文只是在這一方面進(jìn)行了初步研究,并得到以下結(jié)論:</p><p> (1)為了提高泵產(chǎn)品的設(shè)計(jì)創(chuàng)新能力,有必要利用先進(jìn)的CAD產(chǎn)品開(kāi)發(fā)設(shè)計(jì)方法,建立泵原理
43、設(shè)計(jì)方案模型。</p><p> (2)泵設(shè)計(jì)的自身特點(diǎn)要求泵原理方案設(shè)計(jì)模型滿(mǎn)足兩個(gè)要求:</p><p> (a)是一個(gè)逐步求精的閉環(huán)系統(tǒng);</p><p> (b)是一個(gè)滿(mǎn)足模塊化的面向?qū)ο蟮哪P汀?lt;/p><p> (3)本文提出的模型基本滿(mǎn)足了泵原理方案設(shè)計(jì)模型中兩個(gè)要求并具有可操作性、可重用性、可交換性等特點(diǎn)。</p
44、><p><b> 附錄B 外文文獻(xiàn)</b></p><p> The centrifugal pump uses when the adjustment way and the energyconsume the analysis</p><p> The centrifugal pump is widely applies in the
45、 chemical industry industrial system one kind of general fluid machinery. It has the performance adaptation scope broad (including current capacity, discharge head and to transports medium nature slightly compatibility),
46、 the volume, the structure simple, the operation easy, the operating cost low status many merits. Usually, chooses the centrifugal pump the current capacity, the discharge head possibly to be able to request with the pip
47、eline in not to</p><p> 1st, the pump flow control fundamental mode</p><p> 1.1 change pipeline characteristic curve</p><p> Change centrifugal pump current capacity simple metho
48、d is exports the valve using the pump the opening to control, its essence is changes the pipeline characteristic curve the position to change the pump the operating point.</p><p> 1.2 change centrifugal pum
49、p characteristic curve</p><p> Basis proportionality law and the cutting law, change the pump the rotational speed, the change pump structure (for example cutting impeller outer diameter law and so on) two
50、methods both can change the centrifugal pump the characteristic curve, thus achieved the adjustment current capacity (simultaneously changes discharge head) goal.But regarding the pump which already works, changes the pu
51、mp structure the method not too conveniently, and because changed the pump structure, reduced the pump ve</p><p> 1.3 pump strings, and the company adjusts the way</p><p> When the single Taiw
52、an centrifugal pump cannot satisfy the transportation duty, may use the centrifugal pump parallel or the series operation.Are parallel with two same model centrifugal pumps, although the discharge head change is not big,
53、 but has enlarged the total transportation current capacity, the parallel pumps overall effectiveness index and Shan Taibeng the efficiency is same; When centrifugal pump series the total discharge head increases, the cu
54、rrent capacity change is not big, the se</p><p> 2nd, under different adjustment way pump energy consumption analysis</p><p> When to under different adjustment way energy consumption analysis
55、, the article only aims at the valve regulation and the pump which at present widely uses changes the rotational speed to adjust two adjustment ways to analyze.Because the centrifugal pump and, the series operation goal
56、lies in enhances the discharge head or the current capacity, are not many in the chemical domain utilization, its energy consumption may unify Figure 2 to carry on the analysis basically, the method same.</p><
57、p> 2.1 valve regulation current capacity</p><p> Power loss centrifugal pump moves, the electric motor inputs the pump spindle power N is:</p><p> in the formula -- shaft power, ;</p&g
58、t;<p> -- pump effective head, ;</p><p> -- pump actual flow, ;</p><p> v-- fluid proportion, ;</p><p> η- - pump efficiency.</p><p> When uses the valve re
59、gulation current capacity from Q1 to Q2, in the operating point A2 consumption shaft power is: </p><p> -- actual useful power, ;</p><p> -- valve loses results in the power, ;</p><
60、p> - - the centrifugal pump loses power, .</p><p> 2.2 speed change adjustment current capacity power loss</p><p> when carries on the speed change analysis because must use the centrifuga
61、l pump the proportionality law, according to its application condition, the following analyzes refers to the centrifugal pump the speed change scope in ±20%, also centrifugal pump itself efficiency change not big [3
62、].When uses electricity the motive speed change adjustment current capacity to current capacity Q2, consumes the shaft power in the operating point A3 pump is: </p><p> may result in similarly after the tra
63、nsformation:</p><p> in the formula -- actual useful power, ;</p><p> - - the centrifugal pump loses power, .</p><p> 2.3 energy consumption contrast analysis</p><p&g
64、t; 3rd, the conclusion</p><p> General exports the valve regulation and the pump regarding the present centrifugal pump changes the rotational speed to adjust two main flow control way, the pump changes th
65、e rotational speed adjustment frugal energy consumption to export the valve regulation to be much bigger than, this spot may sees from both power loss analysis and the power loss contrast analysis.Through the centrifugal
66、 pump current capacity and the lifting relational graph, may under the more direct-viewing reflection two </p><p> Application Study on Conceptual Design Model in Pump</p><p> Abstract :Concer
67、ned with some current design process model and the specializationin pump conceptual designan architecture of conceptual design model
68、60;for pump is presented.Which is combined the object-oriented design model and self-maintenance design model.The Function-Behavior-State(FBS)model
69、60;is also used in the function decomposition in the mentioned model. And further applies this model in a pump principle project design example, obtained a more complete
70、water pump principle design flow, indic</p><p> 1 introduction</p><p> Our country has implemented the CAD application project since the beginning of the 90's, although carries out the CAD
71、 design in the water pump profession to receive generally takes, but basic still is at the primary CAD cartography stage, mainly was applies in the entire design process “middle and lower reaches” the design stage, namel
72、y the design proposal concrete realization stage, it essentially belongs face the components detailing. Not only the CAD trend of development is supports face the </p><p> 2 model design method</p>&
73、lt;p> The project design is designs in the process, after the exposition mission requirement, through the abstraction understanding essence question, establishes the function structure, through seeks the appropriate
74、mechanism and combines it the function structure, determines the original understanding from the surface (principle plan) [2]. The project design is determines a solution in the principle.Its work step gathers as shown i
75、n Figure 1.</p><p> Figure 1 the project design work step gathers</p><p> Mainly involves two aspects in the establishment pump principle project design model the knowledge [3]:(1) design met
76、hodology knowledge, namely solution product design advancement general theory, research advancement pattern, strategy and various steps corresponding tactic.In which including face entire process design method and regard
77、ing project design process in specific design method.(2) design object domain specialized knowledge, namely the professional field knowledge which involves about t</p><p> 2.1 design methods</p><
78、p> Basic may divide into three kind of [4]:(1) object-oriented design models face the entire process design method and the model, it is representing the design methodology assembly innovation design stage; (2) GDT (G
79、eneral Design Theory) the model, it can manifest the innovation design methodology the innovation thought process (decomposition, mapping, synthesis), is representing the split-ring innovation design stage; (3) asks the
80、fine model gradually, it has fully manifested human's innovation th</p><p> How in the project design crucial one step is carries on the product design request the function decomposition.Because the pro
81、duct design request is the most fining product functional description, but forms the product is actually many completes certain function the spare part combination, will abstract how the product design request transforme
82、d concretely into, the reality function request has manifested human's creation fully.To this aspect research, the focal point mainly concentrates in the </p><p> 2.2 pump design domain specialized know
83、ledge (pump designs characteristic)</p><p> The pump design is a complex process, in the design each kind of factor mutual influence, causes to assign the request the water pump to have the different design
84、 proposal or the result satisfiedly, therefore must find most superior one.This is one explores unceasingly, circulates many times, deepens gradually judgment solution process [6].Looked from the fluid machinery angle th
85、at, the fluid machinery inverse is now one of hydromechanics domain difficult problems.Therefore the existing design u</p><p> Along with the underwriter widespread application, the pump design manufacture
86、is tending to the modulation, enhances the components (module) the versatility and entrusts with heavy responsibility the nature, thus reduces the design production cost, the guarantee product quality.But the object-orie
87、nted modelling thought happen to conforms to the modular need.This indicated establishes the model should be an object-oriented system.</p><p> 3 principle project design model</p><p> Analyze
88、s based on above, proposed in this article in the principle project design model, the entire design advancement was fuses in the object-oriented design model foundation has striven for gradually, in the function which th
89、e fine model closed loop design concept established decomposes has used the FBS method.Concrete model description as shown in Figure 2:</p><p> 3.1 design model S</p><p> The design model S ex
90、pression must design the goal object, it may is composed by or a several design object, including the design entity object (E0) and the design relations object (R0), in which entity object may be the function entity or t
91、he structure entity.Namely:</p><p> S={[E01,E02,…,E0n],[E01,E02,…,E0m]}</p><p> Because each design request generally has the model which certain may choose with it to match, and iterates unce
92、asingly in the design process renews, here expresses the design model K Gth generation of model with SKG, then has:</p><p> SKG={[E01K,E02K,…,E0nK]G,[R01K,R02K,…,E0mK]G}</p><p> Figure 2 prin
93、ciple project design model structure drawing</p><p> 3.2 design algorithm A</p><p> Design algorithm A aims at some design model SKG, according to requests and restrains in (R&C) as well a
94、s the knowledge library with this domain expert knowledge, searches the design object if in the model base which matches, founds this design object example Oi and increases it to design model SKG in, if non-match design
95、object, then founds one based on the knowledge inference newly to satisfy the request the object.The appraisal algorithm also carries on the appraisal test to the design model,</p><p> 3.3 requests and rest
96、rains R & C</p><p> In under the product demand modelling auxiliary means system [7] assistance, through the request which to the current design model demand information gain, the development and the an
97、alysis obtains and restrains R&C; To designs the model the request, the existence condition as well as its important weight.Finally forms a series of function demand {Ro.p}, Ro.p is function demand O attribute P.<
98、/p><p> 3.4 design entity object E0</p><p> In design entity object E0i and the request and restraint Ri matches.It including function entity object or structure entity object.</p><p&g
99、t; Regarding the function entity object, its itself is design model S, this model constitution recursion transfer chart 3 model algorithms.The recursion ended the condition is works as the obtained entity object is the
100、structure object, conceals function decomposition algorithm is the FBS method.The function entity object recursion solves may parallel.</p><p> 3.5 design relations object R0</p><p> The desig
101、n relations object R0 constitution is: Constitutes in this relational design entity object related attribute for the design relations object attribute, its method restrains the relations mutually for the attribute, inclu
102、ding [8]</p><p> (1) equality constraint: In project massive formula, for example:</p><p> (2) limit restraint: Supposes the host variable to some some kind of limit, like noise level definiti
103、on scope.</p><p> (3) function restraint: In object-oriented project database operation function, like in standard letter storehouse shaping function.</p><p> (4) rule restraint: Uses in expre
104、ssing in the engineering design some empirical knowledge.</p><p> Does not carry on the recursion solution regarding the design relations object to transfer, its itself constitutes the judgment level, the m
105、ain function for recalls when the recursion, to the solution carries on the test and the judgment.Obtains the existence design relations object after among some one two or several design entity object solution, embarks b
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