Difference between revisions of "DWSIM-3.4/C2/Sensitivity-Analysis-and-Adjust/English-timed"

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| To practice this tutorial, you should know:
 
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How to open a '''simulation file''' in '''DWSIM'''  
* How to open a '''simulation file''' in '''DWSIM'''  
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How to carry out '''rigorous distillation simulation'''.  
 
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How to add components to a '''flowsheet'''.
* How to carry out '''rigorous distillation simulation'''.  
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* How to add components to a '''flowsheet'''.
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|* how to do '''Sensitivity Analysis'''
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| how to do '''Sensitivity Analysis'''
  
 
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| 13:16
|* how to narrow the solution range
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| how to narrow the solution range
  
 
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| 13:18
|* how to directly achieve the same results using '''Adjust'''
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| how to directly achieve the same results using '''Adjust'''
  
 
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|* how to use '''Adjust''' to push a plant to deliver more.
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| how to use '''Adjust''' to push a plant to deliver more.
  
 
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Revision as of 17:03, 7 March 2017

Time
Narration
00:00 Welcome to this spoken tutorial on DWSIM.
00:04 In this tutorial, we will learn how to do sensitivity analysis and adjust.
00:10 My name is Kannan Moudgalya.
00:12 In this tutorial, We will determine the exact Reflux Ratio for a separation.
00:19 We will first do this through Sensitivity Analysis.
00:24 We will repeat this through the Adjust operation.
00:28 To record this tutorial, I am using DWSIM 3.4.
00:34 To practice this tutorial, you should know:

How to open a simulation file in DWSIM How to carry out rigorous distillation simulation. How to add components to a flowsheet.

00:48 Our website- spoken tutorial dot org gives details of the prerequisite tutorials.
00:55 You can access these tutorials and also all the associated files from this site.
01:02 This slide shows the problem solved in one of the prerequisite tutorials.
01:08 This was solved using Rigorous distillation.
01:12 The purity achieved was less than what was desired.
01:17 How do we improve the purity?
01:19 We need to increase the reflux ratio.
01:23 Let us open the corresponding file in DWSIM.
01:28 The file name is in the heading.
01:30 I have already opened DWSIM.
01:34 I have already opened the file rigorous dot dwxml.
01:40 This file is available to you for download from our website spoken-tutorial.org.
01:48 Let us click Distillate.
01:50 In the Properties section, let us locate Molar Composition, item 2.
02:00 Let us click the arrow next to Mixture.
02:04 The Benzene mole fraction is 0.945.
02:09 We would like to increase this to 0.95.
02:13 Let us attempt this by increasing the reflux ratio.
02:18 This is what we saw in the slide, a little while ago.
02:22 Locate the Optimization option from the Menu bar, to the right of the File button.
02:28 Let me click it.
02:29 Let me click the option Sensitivity Analysis. A window appears.
02:37 We can see five menus in the menu bar of sensitivity analysis.
02:43 Locate Sensitivity Studies.
02:47 If it is not already selected, click it.
02:51 Now we can see a box with four options under the title Case Manager.
02:58 Click on New option.
03:01 This will help in creating a new Sensitivity Analysis case.
03:07 We see the name SACase0.
03:12 Recall the problem that we want to solve:
03:14 We want to increase the reflux ratio so as to get better purity.
03:19 Thus, reflux ratio is the independent variable.
03:24 Let us enforce this through the Independent Variables button.
03:29 Let me click on empty space besides the Object button.
03:34 Click on DC-000, the name of our distillation column.
03:40 On the right hand side, there is an option called Property.
03:45 Let me bring this inside.
03:47 Let me click the down-arrow.
03:50 Let me scroll down and identify Condenser_Specification_Value.
03:55 It comes at the bottom of this menu.
03:57 It plays the role of reflux ratio.
03:59 Click and select it.
04:03 You can see it here, selected.
04:07 Recall that we want our reflux ratio to be greater than 2.
04:12 So, we will enter the Lower limit as 2.
04:16 Change the Upper limit to 2.5.
04:20 Change the Number of Points to 6.
04:24 Let us next click on Dependent Variable.
04:27 On the left hand side, see a column called Variables.
04:33 Below that, see a plus button in green to Add variables. Click it.
04:41 A new row appears. Click the down-arrow below the Object.
04:46 You may have to click it twice.
04:48 Click on the option named Distillate.
04:52 Let me click the down-arrow below Property.
04:56 You may have to click this also twice, to open a drop-down menu.
05:01 Locate Molar Fraction (Mixture) – Benzene.
05:05 You will have to scroll down to reach it.
05:08 There are also other options that sound very similar to it.
05:12 Make sure that you choose this. Click it.
05:17 It gets selected and appears on the tab. Then click on Results.
05:24 We can see the option called Start Sensitivity Analysis.. Let me click it.
05:31 We see the column getting simulated for reflux ratios, one by one.
05:36 At the end of the simulation, we get the message Done.
05:40 You see results for six reflux ratios, from 2 to 2.5.
05:49 We also see the corresponding benzene compositions.
05:54 We can go back to Independent Variables.
05:58 Change the number of points to 11. Return to Results.
06:05 Click Start Sensitivity Analysis once again.
06:10 You can see that eleven runs get completed.
06:14 Let us scroll up.
06:17 See that the desired purity of 0.95 will be achieved between 2.05 and 2.1.
06:26 You may choose these as the lower and upper limits in Independent Variables and repeat.
06:34 But, I will not do that now.
06:36 Continuing in this manner, we can determine the exact reflux ratio required for 0.95 purity.
06:45 I have an assignment for you.
06:46 Can you find out the reflux ratio required for 0.95 purity?
06:52 Follow the procedure I explained just now.
06:56 I will give you the answer: It is approximately 2.067.
07:01 We can also see these results in a graphical form.
07:07 Click on Chart option.
07:10 Click on Draw option. You can see the chart here.
07:15 Distillate composition versus condenser specification value, that is, the reflux ratio.
07:24 Let me close this pop-up.
07:26 Let me save this simulation as "sensitivity".
07:36 Let us go to the next assignment.
07:39 In the previous assignment, include a second dependent variable: Benzene mole fraction in the bottoms.
07:46 Observe both distillate and bottoms compositions.
07:51 Find out how to plot two profiles using Chart.
07:55 Let us do another assignment.
07:59 Verify whether the reflux ratio of 2.067 that we saw in assignment 1 will work.
08:06 For this, start with rigorous.dwxml once again.
08:11 Change the reflux ratio to 2.067.
08:15 Simulate.
08:17 What distillate composition do you get?
08:20 We calculated the desired reflux ratio by trial and error.
08:27 DWSIM has a powerful method to directly calculate this.
08:32 It is called Adjust.
08:35 Let us locate Adjust from the object palette on the right hand side.
08:42 Drag it to flowsheet and drop it outside the column, below the distillate.
08:49 Let me click and choose it.
08:52 In the Properties tab, we see an option called Controlled variable.
08:58 This corresponds to the dependent variable, namely, distillate composition.
09:05 If it is not already opened, click the arrow to the left of the Controlled Variable and, this will open up.
09:13 Click where it says Click to Select.
09:17 Click the button that comes at the right end.
09:19 A pop-up appears.
09:20 It has three columns.
09:23 Below Type, click on Material Stream, if it is not already selected.
09:29 In the Object column, that is, in the middle column, choose Distillate.
09:35 This produces a lot of variables on the right most column.
09:39 Locate Molar Fraction (Mixture) – Benzene .
09:44 It comes after Solid Phase entries are over. Click it.
09:51 Once again, be careful, as there are many similar sounding options.
09:55 Click OK.
09:58 Verify that this gets reflected in the Properties menu.
10:04 Repeat the above process; but now, with Manipulated Variable.
10:09 Click the button on the right.
10:12 In the pop up, scroll down and locate Distillation column. Click on it.
10:18 Then click DC-000. Then locate Condenser_Specification_Value.
10:26 Click it and then OK.
10:31 Follow the usual procedure, now for Parameters property.
10:36 Scroll down to see this.
10:40 We can see an option called Adjust Property Value.
10:43 This value is generally 1.
10:48 Delete 1 and enter 0.95.
10:52 I shall enter a slightly larger number 0.95001.
11:00 I want you to think about why I have entered a slightly larger number.
11:06 A few lines below this, see an option called Simultaneous Adjust.
11:11 Following the usual way, change its value to True.
11:18 If it does not automatically calculate, press Play and then Recalculate All.
11:26 In my case, it calculated automatically. So, I shall not click those.
11:32 In a short time, calculations get completed.
11:35 Let us check whether our objective of 0.95 for distillate purity is achieved.
11:42 Choose Distillate.
11:44 Check Mixture under Molar Composition.
11:49 We can see that benzene composition is 0.95.
11:53 Let us now check what reflux ratio is required for this.
11:59 For this, click on the Distillation column.
12:02 Check the value under Condenser Specification.
12:08 We see a value of 2.067.
12:13 It is the same as what we obtained in the Sensitivity Analysis.
12:18 Let me save this simulation as "adjust".
12:27 I have the next assignment for you.
12:29 Supposing that I want 0.96 benzene mole fraction in the distillate.
12:36 What reflux ratio is required?
12:39 As in the problems we solved, you may change only the reflux ratio.
12:44 Solve this first by Sensitivity Analysis.
12:47 Check your calculations with Adjust.
12:51 Let us do one more assignment.
12:52 Find the highest distillate purity you can get in this column.
12:58 You may vary the reflux ratio only, as in the earlier assignments.
13:03 I could go up to a mole fraction of 0.99, by proceeding gradually.
13:10 Let me summarize.
13:12 We learnt the following in this tutorial:
13:14 how to do Sensitivity Analysis
13:16 how to narrow the solution range
13:18 how to directly achieve the same results using Adjust
13:22 how to use Adjust to push a plant to deliver more.
13:27 We have come to the end of this tutorial.
13:31 This video summarizes the Spoken Tutorial project.
13:35 If you do not have good bandwidth, you can download and watch it.
13:39 We conduct workshops using Spoken Tutorials; give certificates. Please contact us.
13:47 Do you have questions in THIS Spoken Tutorial?
13:51 Choose the minute and second where you have the question.
13:54 Explain your question briefly.
13:56 Someone from the FOSSEE team will answer them.
13:59 Please visit this site.
14:02 The FOSSEE team coordinates coding of solved examples of popular books.
14:08 We give honorarium and certificates for those who do this.
14:12 For more details, please visit this site.
14:16 The FOSSEE team helps migrate commercial simulator labs to DWSIM.
14:21 We give honorarium and certificates for those who do this.
14:25 For more details, please visit this site.
14:28 Spoken Tutorial and FOSSEE projects are funded by NMEICT, MHRD, Government of India.
14:36 Thanks for joining.

Contributors and Content Editors

Nancyvarkey, PoojaMoolya, Pratik kamble, Sandhya.np14