萃取精馏分离两组分中，在较高沸点组分从萃取塔顶出来的情况下，如何使流程收敛？
本帖最后由 大大木易 于 2013-2-27 08:46 编辑萃取精馏分离两组分组成的混合物中，在较高沸点组分从萃取塔顶出来的情况下，如何做才容易使流程收敛？
此时为双塔流程，溶剂从回收塔塔底出来循环至萃取塔，同时补充两塔塔顶损失的溶剂。两塔塔顶为两产品。
突然发现，这样的塔极其难以收敛，需换两三种算法，还不一定能收敛。
有时候竟然死循环了，特别是用共沸方法的时候，不知道问题出在哪里。
高手帮忙分析一下，如何做才能更易于收敛呢？
以前做过比较正常的萃取精馏双塔流程，即较低沸点组分从萃取塔顶出来，很容易就收敛了啊！
文件见附件！
感谢！ bkp贴上来，具体问题具体分析 sonic0519 发表于 2013-2-27 07:58 static/image/common/back.gif
bkp贴上来，具体问题具体分析
附件已经上传，感谢！ 笨办法一个：
多补点新溶剂，把溶剂回收塔的返回的循环溶剂量定死（多余的溶剂用分割器分出），这样比较容易收敛，收敛后再减少补充溶剂量，使分出的多余溶剂量趋于零。 不是像你说的的那样子。你自己的设置有问题。稍作修改即可。
<< All Blocks Reinitialized >>
<< Run reinitialized 18:14:44 Wed Feb 27, 2013>>
->Processing input specifications ...
Flowsheet Analysis :
Block $OLVER01 (Method: WEGSTEIN) has been defined to converge
streams: S
COMPUTATION ORDER FOR THE FLOWSHEET:
$OLVER01 C1 C2 HX C-1 MIXER
(RETURN $OLVER01)
->Calculations begin ...
> Beginning Convergence Loop $OLVER01 Method: WEGSTEIN
Block: C1 Model: RADFRAC
Convergence iterations:
OL ML IL Err/Tol
1 1 2 3161.0
2 1 2 274.51
3 9 43 756.61
4 7 30 2829.8
5 1 3 2245.7
6 1 3 817.84
7 7 24 768.85
8 7 25 1449.6
9 1 3 907.85
10 12 80 639.66
11 1 10 737.25
12 1 10 416.48
13 1 10 283.76
14 1 10 186.09
15 7 30 345.39
16 6 25 302.00
17 6 18 181.05
18 6 17 113.46
19 6 17 82.600
20 6 15 62.854
21 6 16 95.821
22 6 20 129.48
23 6 15 119.76
24 6 24 158.10
25 6 27 216.16
26 1 10 97.007
27 6 28 334.87
28 1 10 138.59
29 9 72 716.19
30 1 10 452.67
31 15131 433.42
32 1 10 641.91
33 1 10 236.96
34 1 10 106.03
35 17163 161.72
36 1 10 78.942
37 1 10 46.095
38 8 56 108.71
39 7 25 60.919
40 7 32 79.910
41 7 31 121.74
42 7 28 176.90
43 7 33 283.99
44 7 33 406.35
45 7 38 491.47
46 5 31 450.94
47 2 17 207.98
48 1 10 31.145
49 5 29 122.28
50 1 10 81.176
51 2 16 52.789
52 1 10 18.590
53 4 16 6.7327
54 2 9 1.2952
55 2 8 0.33072
Block: C2 Model: RADFRAC
Convergence iterations:
OL ML IL Err/Tol
1 1 7 2280.3
2 1 6 493.40
3 1 10 558.79
4 1 10 239.32
5 1 6 217.41
6 1 3 98.775
7 1 3 12.593
8 1 9 11.820
9 1 2 2.3542
10 1 6 2.5006
11 1 3 0.61550
Block: HX Model: HEATER
Calculator Block C-1
Block: MIXER Model: MIXER
> Loop $OLVER01 Method: WEGSTEIN Iteration 1
# Converged Max Err/Tol 0.99138E-01
->Simulation calculations completed ...
***No Warnings were issued during Input Translation ***
***No Errors or Warnings were issued during Simulation ***
->Generating results ...
B1 B2 D1 D2 F MAKEUP RECYCLE S
C2 HX C1 MIXER MIXER C1
C1 C2 C1 C2 HX MIXER
LIQUID LIQUID LIQUID LIQUID LIQUID LIQUID LIQUID LIQUID
Substream: MIXED
Mole Flow kmol/hr
BENZE-01 25.15518 1.00237E-3 4.95595E-4 25.15418 25.15566 0.0 1.00237E-3 1.95357E-5
ACETO-01 .0478706 3.5160E-12 25.16371 .0478706 25.21158 0.0 3.5160E-12 1.2202E-11
ETHYL-01 136.9445 136.9440 1.04108E-3 5.64305E-4 0.0 1.60539E-3 136.9440 136.9456
Mass Flow kg/hr
BENZE-01 1964.963 .0782989 .0387127 1964.885 1965.000 0.0 .0782989 1.52601E-3
ACETO-01 1.965212 1.4434E-10 1033.035 1.965212 1035.000 0.0 1.4434E-10 5.0093E-10
ETHYL-01 8499.933 8499.898 .0646184 .0350255 0.0 .0996439 8499.898 8499.998
Mass Frac
BENZE-01 .1877318 9.21167E-6 3.74710E-5 .9989830 .6550000 0.0 9.21167E-6 1.79530E-7
ACETO-01 1.87756E-4 1.6982E-14 .9999000 9.99150E-4 .3450000 0.0 1.6982E-14 5.8933E-14
ETHYL-01 .8120804 .9999908 6.25458E-5 1.78076E-5 0.0 1.000000 .9999908 .9999998
Total Flowkmol/hr 162.1476 136.9450 25.16525 25.20262 50.36724 1.60539E-3 136.9450 136.9456
Total Flowkg/hr 10466.86 8499.976 1033.138 1966.885 3000.000 .0996439 8499.976 8499.999
Total Flowl/min 184.9624 150.0788 24.17003 40.24719 59.07154 1.54105E-3 131.4574 131.4577
Temperature K 428.7722 474.1915 354.6307 353.1856 303.1500 343.1500 343.1500 343.1501
Pressure atm 1.212755 1.124238 1.000000 1.000000 1.500000 1.200000 1.200000 1.200000
Vapor Frac 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Liquid Frac 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000
Solid Frac 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Enthalpy cal/mol -85625.50 -1.0242E+5 11204.56 13625.96 11028.09 -1.0794E+5 -1.0794E+5 -1.0794E+5
Enthalpy cal/gm -1326.469 -1650.059 272.9215 174.5958 185.1514 -1739.017 -1739.000 -1739.017
Enthalpy MW -16.14705 -16.31161 .3279260 .3993857 .6459933 -2.0153E-4 -17.19083 -17.19105
Entropy cal/mol-K -85.50325 -89.16759 -32.35886 -54.51854 -46.68545 -102.6185 -102.6180 -102.6178
Entropy cal/gm-K -1.324575 -1.436598 -.7881994 -.6985716 -.7838058 -1.653312 -1.653300 -1.653300
Density mol/cc .0146108 .0152081 .0173529 .0104365 .0142108 .0173624 .0173624 .0173624
Density gm/cc .9431521 .9439457 .7124098 .8145019 .8464313 1.077662 1.077659 1.077659
Average MW 64.55145 62.06856 41.05416 78.04289 59.56252 62.06844 62.06856 62.06844
Liq Vol 60F l/min 164.7548 127.6059 22.16997 37.14893 59.31885 1.49590E-3 127.6059 127.6059 非常感谢楼上。
这个模拟可以运行出来，这个是没有疑问的。
我在做优化，对已经运行出来的模拟，稍稍改变（改变1个塔板）其中某个设计参数（比如塔板数，原料和溶剂进料位置等）之后，就运行不出来了，这个时候就出现了上述我说的那些个问题了，不知道原因究竟是什么。
再次感谢！ 给你把塔板数减少1。结果：
***No Warnings were issued during Input Translation ***
***No Errors or Warnings were issued during Simulation ***
->Generating results ...
INFORMATION WHILE GENERATING REPORT FOR UNIT OPERATIONS BLOCK: "C1"
(MODEL: "RADFRAC")
TPSAR MESSAGE: 95.47%JET FLOOD IN COLUMN C1 , SECTION 1
EXCEEDS 80%.
ljjt 发表于 2013-2-27 18:55 static/image/common/back.gif
给你把塔板数减少1。结果：
***No Warnings were issued during Input Translation ***
谢谢，呵！
我再看看！ 大大木易 发表于 2013-2-27 23:31 static/image/common/back.gif
谢谢，呵！
我再看看！
不知道你稍作改动，到底改动的是什么呀？ ljjt 发表于 2013-2-27 18:09 static/image/common/back.gif
B1 B2 D1 D2 F MAKEUP RECYCLE S
C2 HX C1 MIXER MIXER C1
C1 C2 C1 C2 HX MIXER
您好，在论坛上见您经常十分热心的帮助别人解决问题，能否麻烦您看一下这个氨水提浓的文件。转向动态之后运行一会儿就会出现问题，实在不知道怎么解决了。事关我能否顺利毕业，真心请教您。
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