甲苯精餾塔冷凝冷卻(水冷) 換熱系統(tǒng)工藝設(shè)計(jì)-廣東石油化工學(xué)院

1、 化工原理課程設(shè)計(jì)甲苯換熱器成績(jī) 化工原理課程設(shè)計(jì)設(shè)計(jì)說明書設(shè)計(jì)題目：甲苯精餾塔冷凝冷卻(水冷) 換熱系統(tǒng)工藝設(shè)計(jì)姓 名 班 級(jí) 裝控10-2 學(xué) 號(hào) 10024100206 完成日期 2012.3.08 指導(dǎo)教師 梁伯行 目錄1 設(shè)計(jì)說明書······························

2、;··································2二設(shè)計(jì)要求···············

3、;··················································

4、;·21. 設(shè)計(jì)說明書必須包括下述內(nèi)容·············································22. 設(shè)計(jì)

5、計(jì)算書應(yīng)包括的主要內(nèi)容和設(shè)計(jì)計(jì)算的步驟·····························23. 符號(hào)說明的格式················

6、·········································34. 參考文獻(xiàn)的格式·······&

7、#183;················································3三. 主要物

8、性參數(shù)·················································

9、83;············31 確定主要物性數(shù)據(jù)···································

10、3;··················32流體有關(guān)物性數(shù)據(jù)······························

11、························3四 換熱器的選用························

12、83;····································41. 甲苯的流量············

13、···············································42. 甲苯冷凝時(shí)放出的熱量

14、3;················································43. 甲苯冷卻時(shí)放

15、出的熱量·················································44

16、. 換熱器總的傳熱量················································&#

17、183;····45. 用循環(huán)水冷凝時(shí)的用量···········································

18、······46. 用新鮮水冷卻時(shí)的用量·········································

19、3;·······47. 冷凝時(shí)選用浮頭換熱器的計(jì)算········································

20、;···48. 冷卻時(shí)選用固定管板式管殼式換熱器的計(jì)算·······························7五換熱器的臺(tái)數(shù)··········

21、3;·················································

22、3;10六換熱器主要結(jié)構(gòu)尺寸和計(jì)算結(jié)果表···········································111. 冷凝浮頭式換熱器·

23、83;·················································

24、83;112. 冷卻固定管板式管殼式換熱器··········································12七設(shè)計(jì)總結(jié)···&#

25、183;·················································&#

26、183;···········13八. 主要符號(hào)說明····································

27、83;························14九參考文獻(xiàn)························&#

28、183;········································15一、設(shè)計(jì)說明書1.設(shè)計(jì)任務(wù)書和設(shè)計(jì)條件 熱流條件：流量為（6000(1班) 或12000(2班) 或1800

29、0(3班)+500×學(xué)號(hào)）kg/h的甲苯蒸汽從120，0.14 MPa(絕壓)冷凝到120，0.14 MPa(絕壓) 甲苯液，再冷卻到30；120甲苯汽相熱焓 140 Kcal/Kg，液相焓53 Kcal/Kg，30甲苯液相焓13 Kcal/Kg ；定性溫度80時(shí)甲苯密度810Kg/m3 , 比熱 0.446(Kcal/Kg. ) 絕對(duì)粘度0.32(cp) ，比熱0.104 (Kcal/(m.h. ) 。 冷流條件新鮮水初始溫度25，循環(huán)水初始溫度45，換熱后水溫升15(1班) ，25(2班) ，35(2班)。水的物性數(shù)據(jù)由化原上冊(cè)附錄查取。 管殼式換熱器類型提示 設(shè)計(jì)壓力1.6MP

30、a，要求管程和殼程的壓降不大于30kPa，冷凝采用浮頭式，冷卻采用固定管板式管殼式換熱器。 二、設(shè)計(jì)要求2.1 設(shè)計(jì)說明書必須包括下述內(nèi)容：封面、目錄、設(shè)計(jì)任務(wù)書、設(shè)計(jì)計(jì)算書、設(shè)計(jì)結(jié)果匯總表、設(shè)計(jì)自評(píng)和符號(hào)說明、參考文獻(xiàn)等。 2.2 設(shè)計(jì)計(jì)算書應(yīng)包括的主要內(nèi)容和設(shè)計(jì)計(jì)算的步驟: 1) 計(jì)算熱負(fù)荷、收集物性常數(shù)。 根據(jù)設(shè)計(jì)任務(wù)作冷凝冷卻系統(tǒng)熱衡算確定流體放熱速率或冷流體吸熱速率，和新鮮水、循環(huán)水流率?？紤]了熱損失后即可確定換熱器應(yīng)達(dá)到的傳熱能力Q；按定性溫度確定已知條件中未給出的物性常數(shù)。2) 根據(jù)換熱流體的特性和操作參數(shù)決定流體走向（哪個(gè)走管程、哪個(gè)走殼程）；計(jì)算平均溫差。 3) 初步估計(jì)一個(gè)

31、總傳熱速率常數(shù)K估(查上冊(cè)附錄23) ，計(jì)算傳熱面積A估。 4) 根據(jù)A估初選標(biāo)準(zhǔn)換熱器（由換熱器手冊(cè)查取,初定型號(hào)及系列結(jié)構(gòu)參數(shù)）；5) 換熱面積的核算。分別選關(guān)聯(lián)式求出管內(nèi)、外傳熱膜系數(shù)，估計(jì)污垢熱阻，求出總傳熱速率常數(shù)K核，得出所需傳熱面積A需，將A需與A實(shí)際進(jìn)行比較，若A實(shí)際比A需大15%-25%，則設(shè)計(jì)成功；否則重新計(jì)算。2.3 符號(hào)說明的格式：分為英文字母、希臘字母，要按字母排序，要寫出中文名稱和單位；2.4 參考文獻(xiàn)的格式： 按GB7714-87的要求。三、主要物性參數(shù)3.1確定設(shè)計(jì)方案3.1.1選擇換熱器的類型設(shè)計(jì)壓力1.6MPa，要求管程和殼程的壓降不大于30kPa，冷凝采用

32、浮頭式，冷卻采用固定管板式管殼式換熱器。 3.1.2 流動(dòng)空間及流速的確定由于循環(huán)冷卻甲苯較易結(jié)垢，應(yīng)使循環(huán)冷卻甲苯走管程。甲苯有相變，走殼程，凝液跟流體方向是并流。3.1.3性溫度的確定 甲苯冷凝時(shí)的定性溫度取為120度，冷卻時(shí)的定性溫度取80度，循環(huán)水的定性溫度取60度，新鮮水的定性溫度取為30度 3.2流體有關(guān)物性數(shù)據(jù)根據(jù)由上面四個(gè)定性溫度數(shù)據(jù)，查閱參考書可得甲苯和水的物理性質(zhì)。甲苯在120，0.14MPa下的有關(guān)物性數(shù)據(jù)如下：物性密度i（kg/m3）定壓比熱容cpi kJ/(kg)粘度i（Pa·s）導(dǎo)熱系數(shù)i（kcal·m-1·-1·h-1）甲苯

33、 8960.4×10-3 0.232 甲苯在80的物性數(shù)據(jù)如下：物性密度o（kg/m3）定壓比熱容cpo kJ/(kg)粘度o（Pa·s）導(dǎo)熱系數(shù)o（kcal·m-1·-1·h-11）甲苯810 1.8660.32×10-30.104循環(huán)水在60的物性數(shù)據(jù)如下：物性密度o（kg/m3）定壓比熱容cpo kJ/(kg)普朗特?cái)?shù)pr導(dǎo)熱系數(shù)o（W·m-1·-1）粘度o（Pa·s）循環(huán)水983.24.1782.980.65940.0004688新鮮水在30的物性數(shù)據(jù)如下：物性密度o（kg/m3）定壓比熱容cpo

34、 kJ/(kg)普朗特?cái)?shù)pr導(dǎo)熱系數(shù)o（W·m-1·-1）粘度o（Pa·s）新鮮水992.24.1744.320.63380.000656四、換熱器的選用4.1甲苯的流量W=12000+500 x 6=150000Kg/h4.2甲苯冷凝時(shí)放出的熱量 = =4.3甲苯冷卻時(shí)放出的熱量 = =4.4換熱器總的傳熱量 =4.5用循環(huán)水冷凝時(shí)的用量 =4.6用新鮮水冷卻時(shí)的用量 =4.7 冷凝時(shí)選用浮頭換熱器的計(jì)算 4.7.1甲苯冷凝時(shí)的平均溫度差 甲苯：120(V)1120(L) 循環(huán)水: 70(L)45(L) =120-70=50 =120-45=75 4.7.2 換

35、熱器所需面積的估算 K取值（附錄23）取K=1200 W/m2· 由換熱器手冊(cè)查取標(biāo)準(zhǔn)浮頭換熱器（JB/T4714-92）的參數(shù) DN=500mm 4.7.3 換熱面積的核算 1.管程傳熱系數(shù) 2.污垢熱阻系數(shù) 3.管壁的傳熱系數(shù) 4.殼程傳熱系數(shù) 冷凝負(fù)荷 冷凝膜系數(shù) 5.總傳熱系數(shù)K 6.所需的傳熱面積 設(shè)計(jì)的面積裕度 設(shè)計(jì)合格4.8 冷卻時(shí)選用固定管板式管殼式換熱器的計(jì)算 4.8.1甲苯冷卻時(shí)的平均溫度差 甲苯：120(V)130(L) 新鮮水: 50(L)25(L) =120-50=70 =30-25=5 因?yàn)槎こ虄晒艹?，既有錯(cuò)流，又有折流，故需采用伍德和鮑曼提出圖算法修正

36、，即 式中 按逆流計(jì)算的對(duì)數(shù)平均溫度差， 溫度差校正系數(shù)，量綱為1溫度差校正系數(shù)與冷、熱流體的溫度變化有關(guān)，是P和R兩因數(shù)的函數(shù)，式中 查表得=0.97于是 4.8.2 換熱器所需面積的估算 K取值（附錄23）取K=600W/m2· 由換熱器手冊(cè)查取標(biāo)準(zhǔn)固定板式換熱器（JB/T4714-92）的參數(shù) DN=500 4.8.3 換熱面積的核算 1.管程傳熱系數(shù) 2.污垢熱阻系數(shù) 3.管壁的傳熱系數(shù) 4.殼程傳熱系數(shù) 冷凝負(fù)荷 冷凝膜系數(shù) 5.總傳熱系數(shù)K 6.所需的傳熱面積 設(shè)計(jì)的面積裕度 設(shè)計(jì)合格5. 換熱器的臺(tái)數(shù)5.5.1取臺(tái)數(shù)的備用利為25% 所以浮頭式、固定管板式管殼式換熱器各

37、取兩臺(tái)六.換熱器主要結(jié)構(gòu)尺寸和計(jì)算結(jié)果表 冷凝浮頭式換熱器參數(shù)管程殼程流量，kg/h14.5215000物性操作溫度，45/70120/120定性溫度， 60120流體密度，kg/m3983.2896定壓比熱容，kj/(kg.k)4.178黏度，pa.s傳熱系數(shù)，W/（m2·）0.65940.27普朗特?cái)?shù)2.98設(shè)備結(jié)構(gòu)參數(shù)形式浮頭式臺(tái)數(shù)2殼體內(nèi)徑，mm500殼程數(shù)4管徑，mm管心距，mm管長(zhǎng)，mm3000管子排列正方形旋轉(zhuǎn)45°管數(shù)目，根116折流板數(shù)傳熱面積，26.4折流板間距，mm管程數(shù)4材質(zhì)碳鋼主要計(jì)算結(jié)果管程殼程流速，m/s1.62表面?zhèn)鳠嵯禂?shù)，W/（m2·）8615.73822.2污垢系數(shù)，m2·K/W0.0003440.000086阻力降，Pa熱流量，kw1516.736傳熱溫差，k61.7傳熱系數(shù)，W/（m2·）1015.8裕度9.09% 冷卻固定管板式管殼式換熱器參