DWSIM/C2/Sensitivity-Analysis-and-Adjust/English-timed

Time	Narration
00:01	Welcome to this tutorial on Sensitivity Analysis and Adjust in DWSIM.
00:08	In this tutorial, we will learn to:
00:11	Determine the exact Reflux Ratio for a separation
00:15	Perform Sensitivity Analysis and Adjust operation
00:19	This tutorial is recorded using, DWSIM 5. 8 (Classic UI) Update 3and Windows 10 OS
00:30	But, this process is identical in Linux, Mac OS X or FOSSEE OS on ARM.
00:38	To practise this tutorial you should know to - Open a simulation file in DWSIM
00:45	Carry out rigorous distillation simulation
00:48	Add components to a flowsheet
00:51	The prerequisite tutorials are available on this website.
00:55	You can access these tutorials and all the associated files from this site.
01:01	rigorous.dwxmz file used in the tutorial is provided as a Code file on this tutorial page.
01:09	Download the file from the Code Files link.
01:13	This slide shows the problem solved using Rigorous Distillation.
01:18	The purity achieved was less than what was desired.
01:23	To improve the purity, we need to increase the reflux ratio.
01:28	I have already opened DWSIM on my machine.
01:32	Open the file rigorous dot dwxmz.
01:38	Click on Distillate in the flowsheet.
01:41	Go to Property Editor Window.
01:44	Under Input Data, click on Compound Amounts tab.
01:48	Here the Benzene mole fraction is 0.988.
01:53	We would like to increase this to 0.99.
01:57	Let us attempt this by increasing the reflux ratio.
02:01	To do so, click on Optimization option on the menu bar.
02:07	Now click on Sensitivity Analysis option. Sensitivity Analysis tab opens.
02:14	Here we can see five menus in the menu bar of Sensitivity Analysis.
02:20	Now click on Sensitivity Studies, if not already selected. On my system, by default, it is already selected.
02:30	Under Case Manager, we can see four buttons.
02:34	Click on New button.
02:36	This will help in creating a new Sensitivity Analysis case.
02:41	We see the name SACase0.
02:45	Here we want to increase the reflux ratio so as to get better purity.
02:50	Thus, reflux ratio is the independent variable.
02:54	Let us do this through the Independent Variables.
02:58	Under Sensitivity Analysis, click on Independent Variables tab.
03:04	Under Independent Variable 1, click on the drop-down against Object.
03:10	Select DC-005, the name of our distillation column.
03:16	On the right hand side, click on the drop-down against Property.
03:22	Now scroll down and select Condenser Specification Value.
03:28	It plays the role of the reflux ratio.
03:31	Recall that we want our reflux ratio to be greater than 2.317.
03:38	So, we will enter the Lower limit as 2.317
03:43	Change the Upper limit to 2.5
03:47	Change the Number of Points to 6
03:51	Now under Sensitivity Analysis, click on Dependent Variables tab.
03:57	On the left hand side, we can see a column named Variables.
04:03	Below that, locate a green coloured plus button to Add new variables.
04:09	Click on it. A new row appears.
04:12	Click on the drop-down against Object. Select Distillate.
04:20	Now click on the drop-down against Property.
04:25	Scroll down and select Molar Fraction (Mixture) – Benzene.
04:32	Next click on the Results tab to the right of the Dependent Variables tab.
04:38	Then click on Start Sensitivity Analysis button.
04:42	We see the column getting simulated for reflux ratios, one by one.
04:47	At the end of the simulation, we get the message Done.
04:52	Here we can see results for six reflux ratios, from 2.317 to 2.5
05:00	We also see the corresponding benzene compositions.
05:05	Now under Sensitivity Analysis, click on Independent Variables tab. Change the Number of Points to 11.
05:15	Again click on Results tab.
05:18	Click on Start Sensitivity Analysis button once again.
05:22	You can see that simulation runs to show eleven results this time.
05:28	We can see that the desired purity of 0.99 will be achieved between 2.3719 and 2.3902
05:37	Choose these as the lower and upper limits in Independent Variables.
05:43	Again click on Results tab.
05:46	Click on Start Sensitivity Analysis button once again.
05:51	Here we get the reflux ratio value as 2.382.
05:56	This way we can determine the exact reflux ratio required for 0.99 purity.
06:03	We can also see these results in a graphical form. Now under Sensitivity Analysis, click on Chart tab.
06:13	On the left of the window, click on the Draw button.
06:17	On the right, we can see the chart here.
06:21	This graph plots between Distillate composition vs condenser specification value. That is, the reflux ratio.
06:30	Let me save this simulation as sensitivity.
06:37	Now close the Sensitivity Analysis tab..
06:42	We have learnt to calculate the desired reflux ratio by trial and error method.
06;46	DWSIM has a powerful method to directly calculate the reflux ratio. It is called Adjust.
06:55	Now at the bottom of the main simulation window, click on Logical Ops tab.
07:01	Click on Controller Block. Drag and drop it outside the column, below the distillate. Now, click on it.
07:11	On the left, we can see a tab displaying properties related to Adjust.
07:17	Under Linked Objects, click on the drop-down against Manipulated Object. Now select DC-005.
07:28	Next, click on the drop-down against Manipulated Property.
07:34	Then select Condenser Specification Value.
07:38	Next, click on the drop-down against Controlled Object and select Distillate.
07:46	Next, click on the drop-down against Controlled Property. And select Molar Fraction(Mixture) / Benzene.
07:57	Now, go to Parameters.
08:00	Enter Set-Point/Offset (Controlled Property) as 0.9901 and press Enter.
08:09	I shall enter a slightly larger number 0.9901.
08:14	I want you to think about why I have entered a slightly larger number.
08:19	Now, select the check-box against Solve Globally.
08:24	Then we will run the simulation.
08:27	So, from the toolbar, click on Solve Flowsheet button.
08:31	Let us check the distillate purity. Click on Distillate in the flowsheet.
08:37	From the Property Editor window, go to Input Data tab.
08:41	Under Compound Amounts tab, we can see that the benzene composition is 0.99.
08:49	Let us now check what reflux ratio is required for this. To do this, click on the Distillation column.
08:58	Under Column Specs, click on Condenser tab.
09:02	Under Compound, we see a value of 2.382
09:07	It is the same as what we obtained in the Sensitivity Analysis.
09:13	Let me save this simulation as adjust.
09:20	Let's summarize.
09:22	In this tutorial, we have learnt to: Determine the exact Reflux Ratio for a separation
09:29	Performed Sensitivity Analysis and Adjust operation
09:33	I have some assignments for you.
09:36	Simulate this problem statement using a Distillation column.
09:40	Here we give different Compounds, feed conditions and Thermodynamics.
09:46	Different Column Configuration
09:49	Let us go to the next assignment.
09:52	Perform sensitivity analysis on the simulated distillation column.
09:57	To find the reflux ratio such that mole fraction of water in bottoms is 0.99
10:05	Using Adjust/Controller Block, verify the results obtained using the analysis.
10:12	Watch the video available at the following link. It summarizes the Spoken Tutorial project.
10:19	The Spoken Tutorial Project Team conducts workshops and gives certificates. For more details, please write to us.
10:29	Please post your timed queries in this forum.
10:33	The FOSSEE team coordinates conversion of existing flowsheets into DWSIM.
10:39	We give honorarium and certificates for those who do this. For more details, please visit this site.
10:48	The FOSSEE team helps migrate commercial simulator labs to DWSIM.
10:55	We give honorarium and certificates for those who do this. For more details, please visit this site
11:04	Spoken Tutorial and FOSSEE projects are funded by NMEICT, MHRD, Government of India.
11:13	We thank the DWSIM team for making it as an open source software.
11:20	This tutorial was originally recorded by Prof Kannan Moudgalya in September 2015. This is Kaushik Datta from IIT Bombay. Thanks for joining.

Contributors and Content Editors

PoojaMoolya