柴油原油換熱器設計說明書

1、齊齊哈爾大學 化工原理課程設計柴油換熱器化工原理課程設計柴油換熱器設計說明書設計者：班級：過控132組長：吳世杰成員：劉云杰 李亞芳 鄭仕業(yè) 刁昌東 王宇 學生姓名：吳世杰日期 ：2015年9月4日 指導教師：佟白 目錄一設計說明書······························

2、3;·································3二設計條件及主要物性的確定··············&#

3、183;····································31定性溫度的確定············

4、;·············································3 2流體有關物性···&#

5、183;·················································&#

6、183;·····3三. 確定設計方案··········································

7、3;···················41 選擇換熱器的類型·····························

8、;·························42流程安排························

9、;·······································4四 估算傳熱面積·········&#

10、183;·················································&#

11、183;·41. 傳熱器的熱負荷··············································

12、83;········42. 平均傳熱溫差········································

13、;·················43. 傳熱面積估算·······························&

14、#183;·························4五 工程結構尺寸······················

15、3;······································51. 管徑和管內流速··········

16、;··············································52. 管程數和傳熱管數··

17、;··················································

18、;··53. 平均傳熱溫差校正和殼程數·············································&

19、#183;54. 傳熱管排列和分程方法···············································

20、;···55. 殼程內徑·············································

21、83;················66. 折流板································&#

22、183;·······························67. 其他附件·················

23、·············································68. 接管····

24、··················································

25、············6六換熱器核算·····································

26、;····························7 1.熱流量核算····················&#

27、183;··········································7 （1）殼程表面?zhèn)鳠嵯禂?#183;····&

28、#183;·············································7 （2）管程表面?zhèn)鳠嵯禂?#183;·

29、·················································7 （3）污

30、垢熱阻和管壁熱阻················································

31、3;8 （4）傳熱系數K················································

32、·········8 （5）傳熱面積裕度·······································&

33、#183;···············8 2.壁溫核算·································

34、;································93.換熱器內流體的流動阻力···············

35、83;···································9 （1）管程流動阻力············

36、3;···········································9 （2）殼程流動阻力·····

37、;··················································

38、;10七換熱器主要工藝結構尺寸和計算結果表·······································11八設備參考數計算······

39、;··················································

40、;···121.殼體壁厚·············································

41、83;·················12 2.接管法蘭·······························

42、································123.設備法蘭················

43、3;··············································12 4.封頭管箱··&

44、#183;·················································&

45、#183;··········12 5.設備法蘭墊片（橡膠石棉板）····································&

46、#183;·········126.管法蘭用墊片······································

47、83;····················137.管板····························

48、83;·······································138.支墊（鞍式支座）········

49、83;·················································139

50、.設備參數總表·················································

51、;··········13九設計總結······································

52、3;··························15十.主要符號說明 ······················

53、;······································16十一.參考文獻··········&#

54、183;·················································&#

55、183;···17一、設計說明書1.設計任務書和設計條件 原油44000kg/h由70°C被加熱到110°C與柴油換熱，柴油流量34000kg/h，柴油入口溫度175°C，出口溫度127。已知兩則污垢熱阻為0.0002·C/W,管程與殼程兩則降壓小于或等于0.3at，熱阻損失5%，初設k=250w/ m2·°C。二、設計條件及主要物性參數2.1設計條件由設計任務書可得設計條件如下表：數參類型體積流量（標準kg/h）進口溫度（）出口溫度（）操作壓力（Mpa）設計壓力（Mpa）柴 油（管內）34000175

56、1271.11.2原油（管外）4400070110 0.30.4注：要求設計的冷卻器在規(guī)定壓力下操作安全，必須使設計壓力比最大操作壓力略大，本設計的設計壓力比最大操作壓力大0.1MPa。2.2確定主要物性數據2.2.1定性溫度的確定根據流體力學（上）P177，公式（4-109），熱流量為 Qc = Wc Cpc(T1T2) ×1.05 =44000×2.2×（14842）×1.05=1.13×106kJ/h = 1.13×106 W 管程柴油的定性溫度為 殼程原油的定性溫度為 2.2.2流體有關物性數據根據由上面兩個定性溫度數據，查閱

57、參考書可得原油和柴油的物理性質。運用內插法（公式為 ）,可得殼程和管程流體的有關物性數據。原油在90，1.2MPa下的有關物性數據如下：物性密度i（kg/m3）定壓比熱容cpi kJ/(kg)粘度i（Pa·s）導熱系數i（W·m-1·-1）原油 8152.26.65×10-3 0.128 柴油在151的物性數據如下：物性密度o（kg/m3）定壓比熱容cpo kJ/(kg)粘度o（Pa·s）導熱系數o（W·m-1·-1）柴油715 2.480.64×10-30.133三、確定設計方案3.1 選擇換熱器的類型由于溫差較

58、大和要便于清洗殼程污垢，對于油品換熱器，以采用Fe系列的浮頭式列管換熱器為宜。采用折流擋板，可使作為被冷卻的原油易形成湍流，可以提高對流表面?zhèn)鳠嵯禂?，提高傳熱效率?.2 流程安排柴油溫度高，走管程課減少熱損失，原油黏度較大，走殼程在較低的Re數時即可達到湍流，有利于提高其傳熱膜系數。四、估算傳熱面積4.1熱流量4.2平均傳熱溫差= (0,1atm)=614.3傳熱面積由于管程氣體壓力較高，故可選較大的總傳熱系數。初步設定設Ki=250 W·m-2·-1。根據化工單元過程及設備課程設計P44，公式3-8，則估算的傳熱面積為 m2五工程結構尺寸5.1管徑和管內流速選用25&#

59、215;2.5mm的傳熱管(碳鋼管)；由傳熱傳質過程設備設計P7表13得管殼式換熱器中常用的流速范圍的數據，可設空氣流速ui1m/s，用u i計算傳熱膜系數，然后進行校核。5.2管程數和傳熱管數依化工單元過程及設備課程設計P46，公式3-9可依據傳熱管內徑和流速確定單程傳熱管數(根)按單程管計算，所需的傳熱管長度為m按單管程設計，傳熱管過長，宜采用多管程結構?，F(xiàn)取傳熱管長 l= 7 m ，則該換熱器管程數為Np=L / l=22.5/74（管程）傳熱管總根數 N = 42×4= 168 （根）。5.3 平均傳熱溫差校正及殼程數依化工單元過程及設備課程設計P46，公式3-13a和3-1

60、3b，平均傳熱溫差校正系數R1.2P0.381 依傳熱傳質過程設備設計P16，公式3-13，溫度校正系數為 0.92依傳熱傳質過程設備設計P16，公式3-14，平均傳熱差校正為tm=×tm =61×0.92=56.12( )由于平均傳熱溫差校正系數大于0.8，同時殼程流體流量較大，故取單殼程合適。5.4 傳熱管的排列和分程方法采用組合排列法，即每程內均按旋轉45°正四邊形排列，其優(yōu)點為管板強度高，流體走短路的機會少，且管外流體擾動較大，因而對流傳熱系數較高，相同的殼程內可排列更多的管子。查化工單元過程及設備課程設計P50，表3-7 管間距，取管間距：t 1.25d

61、=1.25x25=32 mm 。由化工單元過程及設備課程設計P50，公式3-16，隔板中心到離其最近一排管中心距離S=t/2+6=32/2+6=22 mm取各程相鄰管的管心距為44mm。5.5 殼體內徑 采用多管程結構，取管板利用率=0.7，由化工單元過程及設備課程設計P51，公式3-20，得殼體內徑為Di =1.05t=1.05×32×=520 mm , 圓整后取Di =600mm。5.6折流板采用弓形折流板，取弓形折流板圓缺高度為殼體內徑的25%，則切去的圓缺高度為h=0.25×600=150 mm ，故可取h=150 mm。取折流板間距B=0.3Di，則B=

62、0.3×600=180 mm。折流板數 NB=1=138 塊折流板圓缺面水平裝配。5.7其他附件直徑為12mm的拉桿4根。5.8接管（1）殼程流體進出口接管 取接管內液體流速u1=0.5m/s, =0.195(m)圓整后取管內直徑為200mm.(2) 管程流體進出口接管 取接管內液體流速u2=1m/s,圓整后取管內直徑為150mm六換熱器核算6.1熱量核算6.1.1殼程表面流傳熱系數 對于圓缺形折流板，可采用克恩公式。由化工單元過程及設備課程設計P53，公式3-22，得ho = 其中： 粘度校正為=1.05當量直徑，管子為四邊形角形排列時，依化工單元過程及設備課程設計P53，公式3-

63、23a得de0.027 m殼程流通截面積，由化工單元過程及設備課程設計P54，公式3-25，得So = BD(1)=0.18×0.6×（1）0.023625 m2殼程冷卻水的流速及其雷諾數分別為uo =0.635 m/sReo1556普朗特準數（<傳熱傳質過程設備設計>P26，公式1-43）Pr =114.29因此，殼程水的傳熱膜系數ho為ho = =668 W/(m2·)6.1.2管程表面流傳熱系數由化工單元過程及設備課程設計P55，公式3-22，3-33,得hi = 0.023Re0.8Pr0.3其中：管程流通截面積Si =0.02637 m2管程

64、空氣的流速及其雷諾數分別為ui =0.5 m/sRe11172>10000普蘭特準數Pr =11.93因此，管程空氣的傳熱膜系數hi為hi=0.023×111720.8×11.930.3×=557.3W/(m2·)6.1.3污垢熱阻和管壁熱阻l 冷卻水側的熱阻Rso0.0002m2··W-1l 熱空氣側的熱阻Rsi0.0002m2··W-1l 碳鋼的導熱系數50W·m-1·-16.1.4總傳熱系數Ki因此，依化工單元過程及設備課程設計P53，公式3-21 Rso 0.0002解得：236

65、W/ (m2·) 6.1.5 傳熱面積裕度依化工單元過程及設備課程設計P56，公式3-35：QiSitm得：SiQi/(tm)78.49 m2該換熱器的實際傳熱面積SpSp=3.14×0.05×7×168=92.316 m2依化工單元過程及設備課程設計P56，公式3-36該換熱器的面積裕度為=17.6%6.2 壁溫核算 因管壁很薄，且管壁熱阻很小，故管壁溫度可按化工單元過程及設備課程設計P77，公式3-42計算。由于傳熱管內側污垢熱阻較大，會使傳熱管壁溫升高，降低了殼體和傳熱管壁溫之差。但在操作早期，污垢熱阻較小，殼體和傳熱管間壁溫差可能較大。計算中，應

66、按最不利的操作條件考慮。因此，取兩側污垢熱阻為零計算傳熱管壁溫。于是按式3-42有式中，冷流體的平均溫度tm和熱流體的平均溫度Tm分別按化工單元過程及設備課程設計P77，公式3-44、3-45計算Tm=0.4×175+0.6×125=146tm=0.4×110+0.6×70=86 hc = ho = 668 W/ (m2·) hh = hi = 557W/ (m2·)傳熱管平均壁溫=113.6 殼體壁溫，可近似取為殼程流體的平均溫度，即T=90 殼體壁溫和傳熱管壁溫之差為 t=113.690 =23.6 該溫差不大，不需要建立溫度補償

67、裝置。6.3換熱器內流體的流動阻力(壓降)6.3.1管程流動阻力由，傳熱管相對粗超度為0.01，查莫狄圖得，流速u=0.05m/s, (pa)(pa)總壓降：pi（p1+p2）Ft Ns Np（1188.68+268.125）×1.5×1×48740Pa < 9800 Pa（符合設計要求） 其中， Ft為結垢校正系數，取1.5；Ns為串聯(lián)殼程數，取1；Np為管程數，取4。 6.3.2殼程流動阻力：由化工單元過程及設備課程設計P58，公式3-51,3-52，得： 流體橫過管束的壓降：其中：F=0.4fo=5.0×1556-0.228=0.9358NB

68、=38uo=0.635 m/spO=0.4×0.9358×15.42×(38+1)×(815×0.6352)/2 36989 PapINB（3.5）38×（3.5）×(815×0.6352)/218107Pa總壓降：po（p1p2）Fs Ns（36989+18107）×1.15×163360.4Pa 其中，F(xiàn)s為殼程壓強降的校正系數，對于液體取1.15；Ns為串聯(lián)的殼程數，取1。七.換熱器主要結構尺寸和計算結果表參數管程殼程流量，kg/h3400044000物性操作溫度，175/12770/11

69、0定性溫度，15190流體密度，kg/m3715815定壓比熱容，kj/(kg.k)2.482.2黏度，pa.s傳熱系數，W/（m2·）0.1330.128普朗特數11.93114.2設備結構參數形式浮頭式臺數1殼體內徑，mm600殼程數1管徑，mm管心距，mm32管長，mm7000管子排列正方形旋轉45°管數目，根168折流板數38傳熱面積，92.316折流板間距，mm180管程數4材質碳鋼主要計算結果管程殼程流速，m/s0.50.634表面?zhèn)鳠嵯禂担琖/（m2·）668557.3污垢系數，m2·K/W0.00020.0002阻力降，Pa0.00870