列管式換熱器的工藝設(shè)計(jì)和選用

1、.wd化工原理課程設(shè)計(jì)說(shuō)明書題 目： 列管式換熱器的工藝設(shè)計(jì)和選用 課程名稱： 化工原理課程設(shè)計(jì) 設(shè) 計(jì) 人： 吳琳瑜 專 業(yè)： 化學(xué)工程與工藝 班 級(jí)： 化工B081 學(xué) 號(hào)： 20xx01034119 指導(dǎo)教師： 李辰明 日期： 20xx.12.19學(xué)校：華北科技學(xué)院目錄設(shè)計(jì)條件··························&#

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3、183;·······3設(shè)計(jì)題目·········································

4、83;···········································3設(shè)計(jì)任務(wù)·····

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6、3;····························3設(shè)計(jì)原那么····················

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8、3;···········3設(shè)計(jì)流程······································

9、;···············································3一、確定設(shè)計(jì)方案·&#

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11、183;·····················31.選擇換熱器類型··························

12、3;···········································32.確定冷、熱流體流徑途徑····&#

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14、183;···4二、流體有關(guān)物性數(shù)據(jù)············································

15、83;······················4三、估算傳熱面積··························

16、···············································41.計(jì)算熱負(fù)荷·

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18、3;························42.冷卻水用量························&#

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20、183;··43.傳熱平均傳溫差·············································

21、3;·························4四、初算傳熱面積·······················&

22、#183;·················································4

23、五、工藝構(gòu)造尺寸················································

24、3;························51.選管子規(guī)格························&#

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26、183;··52.總管數(shù)和管程數(shù)·············································

27、3;························53.初選換熱器類型與型號(hào)·······················

28、83;·····································54.確定管子在管板上的排列方式··········

29、;········································55管子與管板、管板與殼體的連接·······&

30、#183;·······································66.殼體內(nèi)徑確實(shí)定 ········&#

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32、183;··········67.確定實(shí)際管子數(shù)目·····································

33、83;····························68.折流擋板····················&#

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35、183;·······69.其他附件·········································&

36、#183;····································710.接收············&

37、#183;·················································&

38、#183;····················7六、換熱器核算····························

39、;·············································· 81. 總傳熱系數(shù)K的計(jì)算·

40、83;·················································

41、83;·········8 管內(nèi)傳熱膜系數(shù)·······································

42、···························8 管外傳熱膜系數(shù)·····················

43、83;···········································8 污垢熱阻和管壁熱阻····

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45、3;·····9 總傳熱系數(shù)K···········································&#

46、183;··························9傳熱面積校核······················&

47、#183;··············································92. 壁溫的計(jì)算·

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49、3;······················93.核算壓力降··························&#

50、183;················································10 管程壓力降

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52、······················10 殼程壓力降··························

53、3;·············································10七、設(shè)計(jì)計(jì)算結(jié)果匯總表··

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55、83;········11八、總結(jié)········································

56、83;············································12參考文獻(xiàn)····

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58、83;······························13CAD圖紙··················&#

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60、183;···············14設(shè)計(jì)題目：列管式換熱器的工藝設(shè)計(jì)和選用設(shè)計(jì)條件煉油廠用原油將柴油從175冷卻到130。柴油流量為12500 kg/h原油初溫為70，經(jīng)換熱后升溫到110。換熱器的熱損失可忽。管、殼程阻力壓降不大于30kpa。污垢熱阻均取0.0003 m2··W-1 。試設(shè)計(jì)一臺(tái)列管式換熱器，完成該生產(chǎn)任務(wù)。設(shè)計(jì)任務(wù)（1） 根據(jù)設(shè)計(jì)條件選擇適宜的換熱器型號(hào)，并核算換熱面積，壓力降是否滿要求，并設(shè)計(jì)管道與

61、殼體的連接，管板與殼體的連接，折流板數(shù)目、形式等。（2） 繪制列管式換熱器的裝配圖。（3） 編寫課程設(shè)計(jì)說(shuō)明書。設(shè)計(jì)原那么1.滿足工藝和操作要求設(shè)計(jì)出來(lái)的流程和設(shè)備首先要保證質(zhì)量，操作穩(wěn)定，這就必須配置必要的閥門和計(jì)量?jī)x表等，并自確定方案時(shí)，考慮到各種流體的流程，溫度和壓強(qiáng)變化使采取什么措施來(lái)調(diào)節(jié)，而在設(shè)備發(fā)生故障時(shí)，加修應(yīng)方便。2.滿足經(jīng)濟(jì)上的要求在確定某些操作指標(biāo)和治標(biāo)和選定設(shè)備型式以及儀表配置時(shí)，要有經(jīng)濟(jì)核算的觀點(diǎn)，既能滿足工藝和操作要求，又使施工簡(jiǎn)便，材料來(lái)源容易，造價(jià)低廉。如果有廢熱可以利用，要盡量節(jié)省熱能，充分利用，或者采取適當(dāng)?shù)拇胧┑竭_(dá)降低本錢的目的。3.保證安全生產(chǎn) 在工藝流程

62、和操作中假設(shè)有爆炸、燃燒、中毒、燙傷等危險(xiǎn)，就要考慮必要的安全措施。又如設(shè)備的材料強(qiáng)度的演算，除按規(guī)定應(yīng)有一定的安全系數(shù)外，還應(yīng)考慮防止由于設(shè)備中壓力突然升高或者造成真空而需要裝置安全閥等，以上提到的都是為了保證安全生產(chǎn)所需要的。設(shè)計(jì)方案也可能一次定不好，后來(lái)需要修改，但各物料流通路線和操作指標(biāo)的改動(dòng)都對(duì)后面的計(jì)算的影響，所以最好第一次確立就考慮周到些。設(shè)計(jì)流程一、確定設(shè)計(jì)方案1.選擇換熱器類型兩流體的溫度變化情況：熱流體進(jìn)口溫度為175，出口溫度為130。冷流體進(jìn)口溫度為70，出口溫度為110由于冷、熱流體溫差較大，同時(shí)為了便于拆卸清洗，選用浮頭式列管換熱器。2.確定冷、熱流體流徑途徑由于柴

63、油較易結(jié)垢，為便于清洗，應(yīng)使柴油走管程，原油的粘度大，在裝有折流擋板的殼程中流動(dòng)。有利于提高湍動(dòng)，增大傳熱系數(shù)，原油走殼程。二、流體有關(guān)物性數(shù)據(jù)物料 kg/m3kJ/(kg)W·m-1·-1Pa·s原油815 0.128柴油 715 0.133三、估算傳熱面積1. 計(jì)算熱負(fù)荷忽略熱損失 W2. 冷卻水用量(忽略熱損失) kg/s3. 傳熱平均傳溫差先按逆流計(jì)算= 溫度校正：R0.38P1.13據(jù)R、P值，查溫差校正系數(shù)圖，得溫度校正系數(shù)=×=0.92×62.5=57.50四、初算傳熱面積參照傳熱系數(shù)K的大致范圍，取=230 W/ (m2

64、3;),那么估算面積為：=取實(shí)際面積為估算面積的1.1倍，那么實(shí)際估算面積為： A=1.1=1.1×29.30=32.23 m2五、工藝構(gòu)造尺寸1.選管子規(guī)格選用252.5mm的無(wú)縫鋼管，管長(zhǎng)L=6m。2.總管數(shù)和管程數(shù)總管數(shù) 根單程流速 =單程流速較低，為提高傳熱效果考慮采用多管程。按管程流速的推薦范圍，選管程流速為=1m/s，所以管程數(shù)為= 取4管程3. 初選換熱器類型與型號(hào)由于冷、熱流體溫差較大，同時(shí)為了便于拆卸清洗，選用浮頭式列管換熱器為宜，且初步選定的具體型號(hào)為 BES400-1.0-31.6-6/25-4IIBES400-1.0-31.6-6/25-4II的具體參數(shù)殼徑/

65、mm400管子尺寸25mm×2.5mm公稱壓力/MPa1.00管長(zhǎng)/m6計(jì)算換熱面積/m31.6管子總數(shù)68管程數(shù)4管子排列方式四邊形錯(cuò)列殼程數(shù)1折流擋板形式弓形4. 確定管子在管板上的排列方式管子布置應(yīng)在換熱器的截面上均勻而緊湊的分布，此外還有考慮流體的性質(zhì)和構(gòu)造設(shè)計(jì)及制造等方面的問(wèn)題 管子的排列方式有等邊三角形和正方形兩種。如圖a、圖b所示。與正方形相比，等邊三角形排列比較緊湊，管外流體湍動(dòng)稱帝高、外表傳熱系數(shù)大。正方形排列雖比較松散，傳熱效果也較差，但管外清洗方便，對(duì)易結(jié)垢流體更為適用。如將正方形排列的管束轉(zhuǎn)45度安裝如圖c可在一定的程度上提高對(duì)流傳熱系數(shù)，采用正方形錯(cuò)列。5管

66、子與管板、管板與殼體的連接 在管殼式換熱器的構(gòu)造設(shè)計(jì)中，管子與管板的連接是否嚴(yán)密十分中。如果連接不嚴(yán)密，在操作時(shí)連接處發(fā)生泄漏，冷熱流體互相混合，會(huì)造成物料和熱量損失；假設(shè)物料帶有腐蝕性、放射性或者兩種流體接觸會(huì)產(chǎn)生易燃易爆物質(zhì)，后果將更加嚴(yán)重。在固定管板式換熱器的連接方法處還應(yīng)考慮能承受一定的軸向力，以防止溫度變化較大時(shí)，產(chǎn)生的熱應(yīng)力使管子從管板脫出。焊接法由于具有很多的優(yōu)點(diǎn)加工簡(jiǎn)單、對(duì)管空的加工要求不高，較強(qiáng)的抗脫能力使之在高溫高壓下仍能保持連接處的嚴(yán)密性，同時(shí)在壓力不太高時(shí)還可采用薄型管板，在一些要求較高的場(chǎng)合被廣泛應(yīng)用。管子與管板采用焊接構(gòu)造。 浮頭式換熱器通常是把管板夾在殼體法蘭與管

67、箱法蘭之間便于管殼程一起清洗。管心距取 a=1.25d0 =1.25×25=31.2532mm 隔板兩側(cè)相鄰管心距 6. 殼體內(nèi)徑確實(shí)定 取管板利用率=0.8，那么殼體內(nèi)徑為：按殼體標(biāo)準(zhǔn)圓整取 7.確定實(shí)際管子數(shù)目N=688.折流擋板換熱器內(nèi)安裝折流擋板是為了提高殼程流體的對(duì)流傳熱系數(shù)。為了獲得良好效果，折流擋板的尺寸和間距必須適當(dāng)。對(duì)于常用的圓缺形擋板，弓形切口太大或太小，都會(huì)產(chǎn)生流動(dòng)“死區(qū)，如以下列圖，不利于傳熱，且增加流體阻力。一般切口高度與直徑之比為0.15-0.45，常見的有0.20和0.25兩種。 擋板的間距對(duì)殼程的流動(dòng)有重要的影響，間距太大不能保證流體垂直流過(guò)管束，使得管外給熱系數(shù)降低，間距太小又不方便檢修，阻力損失也很大。一般采用間距為殼體的0.2-1.0倍。取板間距B200mm。 而對(duì)圓缺形擋板而