柴油原油换热器设计说明书

1、齐齐哈尔大学 化工原理课程设计柴油换热器化工原理课程设计柴油换热器设计说明书设计者：班级：过控132组长：吴世杰成员：刘云杰 李亚芳 郑仕业 刁昌东 王宇 学生姓名：吴世杰日期 ：2015年9月4日 指导教师：佟白 目录一设计说明书······························

2、3;·································3二设计条件及主要物性的确定··············&#

3、183;····································31定性温度的确定············

4、;·············································3 2流体有关物性···&#

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

6、183;·····3三. 确定设计方案··········································

7、3;···················41 选择换热器的类型·····························

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

9、;·······································4四 估算传热面积·········&#

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

11、183;·41. 传热器的热负荷··············································

12、83;········42. 平均传热温差········································

13、;·················43. 传热面积估算·······························&

14、#183;·························4五 工程结构尺寸······················

15、3;······································51. 管径和管内流速··········

16、;··············································52. 管程数和传热管数··

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

18、;··53. 平均传热温差校正和壳程数·············································&

19、#183;54. 传热管排列和分程方法···············································

20、;···55. 壳程内径·············································

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

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

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

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

25、············6六换热器核算·····································

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

27、183;··········································7 （1）壳程表面传热系数·····&

28、#183;·············································7 （2）管程表面传热系数··

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

30、垢热阻和管壁热阻················································

31、3;8 （4）传热系数K················································

32、·········8 （5）传热面积裕度·······································&

33、#183;···············8 2.壁温核算·································

34、;································93.换热器内流体的流动阻力···············

35、83;···································9 （1）管程流动阻力············

36、3;···········································9 （2）壳程流动阻力·····

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

38、;10七换热器主要工艺结构尺寸和计算结果表·······································11八设备参考数计算······

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

40、;···121.壳体壁厚·············································

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

42、································123.设备法兰················

43、3;··············································12 4.封头管箱··&

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

45、#183;··········12 5.设备法兰垫片（橡胶石棉板）····································&

46、#183;·········126.管法兰用垫片······································

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

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

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

50、.设备参数总表·················································

51、;··········13九设计总结······································

52、3;··························15十.主要符号说明 ······················

53、;······································16十一.参考文献··········&#

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

55、183;···17一、设计说明书1.设计任务书和设计条件 原油44000kg/h由70°C被加热到110°C与柴油换热，柴油流量34000kg/h，柴油入口温度175°C，出口温度127。已知两则污垢热阻为0.0002·C/W,管程与壳程两则降压小于或等于0.3at，热阻损失5%，初设k=250w/ m2·°C。二、设计条件及主要物性参数2.1设计条件由设计任务书可得设计条件如下表：数参类型体积流量（标准kg/h）进口温度（）出口温度（）操作压力（Mpa）设计压力（Mpa）柴 油（管内）34000175

56、1271.11.2原油（管外）4400070110 0.30.4注：要求设计的冷却器在规定压力下操作安全，必须使设计压力比最大操作压力略大，本设计的设计压力比最大操作压力大0.1MPa。2.2确定主要物性数据2.2.1定性温度的确定根据流体力学（上）P177，公式（4-109），热流量为 Qc = Wc Cpc(T1T2) ×1.05 =44000×2.2×（14842）×1.05=1.13×106kJ/h = 1.13×106 W 管程柴油的定性温度为 壳程原油的定性温度为 2.2.2流体有关物性数据根据由上面两个定性温度数据，查阅

57、参考书可得原油和柴油的物理性质。运用内插法（公式为 ）,可得壳程和管程流体的有关物性数据。原油在90，1.2MPa下的有关物性数据如下：物性密度i（kg/m3）定压比热容cpi kJ/(kg)粘度i（Pa·s）导热系数i（W·m-1·-1）原油 8152.26.65×10-3 0.128 柴油在151的物性数据如下：物性密度o（kg/m3）定压比热容cpo kJ/(kg)粘度o（Pa·s）导热系数o（W·m-1·-1）柴油715 2.480.64×10-30.133三、确定设计方案3.1 选择换热器的类型由于温差较

58、大和要便于清洗壳程污垢，对于油品换热器，以采用Fe系列的浮头式列管换热器为宜。采用折流挡板，可使作为被冷却的原油易形成湍流，可以提高对流表面传热系数，提高传热效率。3.2 流程安排柴油温度高，走管程课减少热损失，原油黏度较大，走壳程在较低的Re数时即可达到湍流，有利于提高其传热膜系数。四、估算传热面积4.1热流量4.2平均传热温差= (0,1atm)=614.3传热面积由于管程气体压力较高，故可选较大的总传热系数。初步设定设Ki=250 W·m-2·-1。根据化工单元过程及设备课程设计P44，公式3-8，则估算的传热面积为 m2五工程结构尺寸5.1管径和管内流速选用25&#

59、215;2.5mm的传热管(碳钢管)；由传热传质过程设备设计P7表13得管壳式换热器中常用的流速范围的数据，可设空气流速ui1m/s，用u i计算传热膜系数，然后进行校核。5.2管程数和传热管数依化工单元过程及设备课程设计P46，公式3-9可依据传热管内径和流速确定单程传热管数(根)按单程管计算，所需的传热管长度为m按单管程设计，传热管过长，宜采用多管程结构。现取传热管长 l= 7 m ，则该换热器管程数为Np=L / l=22.5/74（管程）传热管总根数 N = 42×4= 168 （根）。5.3 平均传热温差校正及壳程数依化工单元过程及设备课程设计P46，公式3-13a和3-1

60、3b，平均传热温差校正系数R1.2P0.381 依传热传质过程设备设计P16，公式3-13，温度校正系数为 0.92依传热传质过程设备设计P16，公式3-14，平均传热差校正为tm=×tm =61×0.92=56.12( )由于平均传热温差校正系数大于0.8，同时壳程流体流量较大，故取单壳程合适。5.4 传热管的排列和分程方法采用组合排列法，即每程内均按旋转45°正四边形排列，其优点为管板强度高，流体走短路的机会少，且管外流体扰动较大，因而对流传热系数较高，相同的壳程内可排列更多的管子。查化工单元过程及设备课程设计P50，表3-7 管间距，取管间距：t 1.25d

61、=1.25x25=32 mm 。由化工单元过程及设备课程设计P50，公式3-16，隔板中心到离其最近一排管中心距离S=t/2+6=32/2+6=22 mm取各程相邻管的管心距为44mm。5.5 壳体内径 采用多管程结构，取管板利用率=0.7，由化工单元过程及设备课程设计P51，公式3-20，得壳体内径为Di =1.05t=1.05×32×=520 mm , 圆整后取Di =600mm。5.6折流板采用弓形折流板，取弓形折流板圆缺高度为壳体内径的25%，则切去的圆缺高度为h=0.25×600=150 mm ，故可取h=150 mm。取折流板间距B=0.3Di，则B=

62、0.3×600=180 mm。折流板数 NB=1=138 块折流板圆缺面水平装配。5.7其他附件直径为12mm的拉杆4根。5.8接管（1）壳程流体进出口接管 取接管内液体流速u1=0.5m/s, =0.195(m)圆整后取管内直径为200mm.(2) 管程流体进出口接管 取接管内液体流速u2=1m/s,圆整后取管内直径为150mm六换热器核算6.1热量核算6.1.1壳程表面流传热系数 对于圆缺形折流板，可采用克恩公式。由化工单元过程及设备课程设计P53，公式3-22，得ho = 其中： 粘度校正为=1.05当量直径，管子为四边形角形排列时，依化工单元过程及设备课程设计P53，公式3-

63、23a得de0.027 m壳程流通截面积，由化工单元过程及设备课程设计P54，公式3-25，得So = BD(1)=0.18×0.6×（1）0.023625 m2壳程冷却水的流速及其雷诺数分别为uo =0.635 m/sReo1556普朗特准数（<传热传质过程设备设计>P26，公式1-43）Pr =114.29因此，壳程水的传热膜系数ho为ho = =668 W/(m2·)6.1.2管程表面流传热系数由化工单元过程及设备课程设计P55，公式3-22，3-33,得hi = 0.023Re0.8Pr0.3其中：管程流通截面积Si =0.02637 m2管程

64、空气的流速及其雷诺数分别为ui =0.5 m/sRe11172>10000普兰特准数Pr =11.93因此，管程空气的传热膜系数hi为hi=0.023×111720.8×11.930.3×=557.3W/(m2·)6.1.3污垢热阻和管壁热阻l 冷却水侧的热阻Rso0.0002m2··W-1l 热空气侧的热阻Rsi0.0002m2··W-1l 碳钢的导热系数50W·m-1·-16.1.4总传热系数Ki因此，依化工单元过程及设备课程设计P53，公式3-21 Rso 0.0002解得：236

65、W/ (m2·) 6.1.5 传热面积裕度依化工单元过程及设备课程设计P56，公式3-35：QiSitm得：SiQi/(tm)78.49 m2该换热器的实际传热面积SpSp=3.14×0.05×7×168=92.316 m2依化工单元过程及设备课程设计P56，公式3-36该换热器的面积裕度为=17.6%6.2 壁温核算 因管壁很薄，且管壁热阻很小，故管壁温度可按化工单元过程及设备课程设计P77，公式3-42计算。由于传热管内侧污垢热阻较大，会使传热管壁温升高，降低了壳体和传热管壁温之差。但在操作早期，污垢热阻较小，壳体和传热管间壁温差可能较大。计算中，应

66、按最不利的操作条件考虑。因此，取两侧污垢热阻为零计算传热管壁温。于是按式3-42有式中，冷流体的平均温度tm和热流体的平均温度Tm分别按化工单元过程及设备课程设计P77，公式3-44、3-45计算Tm=0.4×175+0.6×125=146tm=0.4×110+0.6×70=86 hc = ho = 668 W/ (m2·) hh = hi = 557W/ (m2·)传热管平均壁温=113.6 壳体壁温，可近似取为壳程流体的平均温度，即T=90 壳体壁温和传热管壁温之差为 t=113.690 =23.6 该温差不大，不需要建立温度补偿

67、装置。6.3换热器内流体的流动阻力(压降)6.3.1管程流动阻力由，传热管相对粗超度为0.01，查莫狄图得，流速u=0.05m/s, (pa)(pa)总压降：pi（p1+p2）Ft Ns Np（1188.68+268.125）×1.5×1×48740Pa < 9800 Pa（符合设计要求） 其中， Ft为结垢校正系数，取1.5；Ns为串联壳程数，取1；Np为管程数，取4。 6.3.2壳程流动阻力：由化工单元过程及设备课程设计P58，公式3-51,3-52，得： 流体横过管束的压降：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总压降：po（p1p2）Fs Ns（36989+18107）×1.15×163360.4Pa 其中，Fs为壳程压强降的校正系数，对于液体取1.15；Ns为串联的壳程数，取1。七.换热器主要结构尺寸和计算结果表参数管程壳程流量，kg/h3400044000物性操作温度，175/12770/11

69、0定性温度，15190流体密度，kg/m3715815定压比热容，kj/(kg.k)2.482.2黏度，pa.s传热系数，W/（m2·）0.1330.128普朗特数11.93114.2设备结构参数形式浮头式台数1壳体内径，mm600壳程数1管径，mm管心距，mm32管长，mm7000管子排列正方形旋转45°管数目，根168折流板数38传热面积，92.316折流板间距，mm180管程数4材质碳钢主要计算结果管程壳程流速，m/s0.50.634表面传热系数，W/（m2·）668557.3污垢系数，m2·K/W0.00020.0002阻力降，Pa0.00870