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

Visual Cue	Narration
Slide Number 1 Title Slide	Welcome to this tutorial on Sensitivity Analysis and Adjust in DWSIM.
Slide Number 2 Learning Objectives	In this tutorial, we will learn to: Determine the exact Reflux Ratio for a separation Perform Sensitivity Analysis and Adjust operation
Slide Number 3 System Requirements	This tutorial is recorded using, DWSIM 5. 8 (Classic UI) Update 3and Windows 10 OS But, this process is identical in Linux, Mac OS X or FOSSEE OS on ARM.
Slide Number 4 Prerequisites	To practise this tutorial you should know to - Open a simulation file in DWSIM Carry out rigorous distillation simulation Add components to a flowsheet
Slide Number 5 Prerequisite Tutorials and Files https:\\spoken-tutorial.org	The prerequisite tutorials are available on this website. You can access these tutorials and all the associated files from this site.
Slide Number 6 Code Files	rigorous.dwxmz file used in the tutorial is provided as a Code file on this tutorial page. Download the file from the Code Files link.
Slide Number 7 Problem solved in Prerequisite tutorial Point to the Purity	This slide shows the problem solved using Rigorous Distillation. The purity achieved was less than what was desired. To improve the purity, we need to increase the reflux ratio.
Switch to DWSIM	I have already opened DWSIM on my machine.
Point to the Simulation window	Open the file rigorous dot dwxmz.
Click Distillate	Click on Distillate in the flowsheet.
Cursor to the Editor Window	Go to Property Editor Window.
Input Data >> Compound Amounts	Under Input Data, click on Compound Amounts tab.
Highlight Benzene mole fraction is 0.988.	Here the Benzene mole fraction is 0.988. We would like to increase this to 0.99.
	Let us attempt this by increasing the reflux ratio.
Click on Optimization option in the Menu bar	To do so, click on Optimization option on the menu bar.
Click on Sensitivity Analysis	Now click on Sensitivity Analysis option. Sensitivity Analysis tab opens.
Highlight the 5 menus	Here we can see five menus in the menu bar of Sensitivity Analysis.
Cursor to the Sensitivity Analysis window Click on Sensitivity Studies.	Now click on Sensitivity Studies, if not already selected. On my system, by default, it is already selected.
Point to four buttons under Case Manager	Under Case Manager, we can see four buttons.
Click on New button	Click on New button. This will help in creating a new Sensitivity Analysis case.
Point to SACase0.	We see the name SACase0.
Point to reflux ratio	Here we want to increase the reflux ratio so as to get better purity. Thus, reflux ratio is the independent variable.
Click on Independent Variables button	Let us do this through the Independent Variables. Under Sensitivity Analysis, click on Independent Variables tab.
Click on Object button	Under Independent Variable 1, click on the drop-down against Object.
Click on DC-005	Select DC-005, the name of our distillation column.
Click on Property	On the right hand side, click on the drop-down against Property.
Scroll down and click on Condenser_Specification_Value	Now scroll down and select Condenser_Specification_Value. It plays the role of the reflux ratio.
	Recall that we want our reflux ratio to be greater than 2.317.
Lower limit >> 2.317	So, we will enter the Lower limit as 2.317
Upper limit >> 2.5	Change the Upper limit to 2.5
Number of Points >> 6	Change the Number of Points to 6
Click on Dependent Variable.	Now under Sensitivity Analysis, click on Dependent Variables tab.
Click on Dependent Variable	On the left hand side, we can see a column named Variables.
Under Variables, click on green Add button	Below that, locate a green coloured plus button to Add new variables. Click on it. A new row appears.
Object >> Distillate	Click on the drop-down against Object. Select Distillate.
Property >> Molar Fraction (Mixture) – Benzene.	Now click on the drop-down against Property. Scroll down and select Molar Fraction (Mixture) – Benzene.
Click on Results >> Start Sensitivity Analysis	Next click on the Results tab to the right of the Dependent Variables tab. Then click on Start Sensitivity Analysis button.
Point to the Results section.	We see the column getting simulated for reflux ratios, one by one.
Point to the Information section at the bottom.	At the end of the simulation, we get the message Done.
Cursor to the Reflux Ratio values Point to the Benzene compositions	Here we can see results for six reflux ratios, from 2.317 to 2.5 We also see the corresponding benzene compositions.
Click on Independent Variables tab Number of Points >> 11.	Now under Sensitivity Analysis, click on Independent Variables tab. Change the Number of Points to 11.
Click on Results.	Again click on Results tab.
Click on Start Sensitivity Analysis button	Click on Start Sensitivity Analysis button once again. You can see that simulation runs to show eleven results this time.
Click Independent Variables Type Lower Limit: 2.3719, Upper Limit: 2.3902	We can see that the desired purity of 0.99 will be achieved between 2.3719 and 2.3902 Choose these as the lower and upper limits in Independent Variables.
Click on Results.	Again click on Results tab.
Click on Start Sensitivity Analysis button	Click on Start Sensitivity Analysis button once again.
Point to reflux ratio	Here we get the reflux ratio value as 2.382. This way we can determine the exact reflux ratio required for 0.99 purity.
Click on Chart tab	We can also see these results in a graphical form. Now under Sensitivity Analysis, click on Chart tab.
Click on Chart tab Draw option	On the left of the window, click on the Draw button.
Point to the graph	On the right, we can see the chart here. This graph plots between Distillate composition vs condenser specification value. That is, the reflux ratio.
File >> Save As >> sensitivity	Let me save this simulation as sensitivity.
Close	Now close the Sensitivity Analysis tab..
	We have learnt to calculate the desired reflux ratio by trial and error method.
Object Palette >> Logical Ops	DWSIM has a powerful method to directly calculate the reflux ratio. It is called Adjust. Now at the bottom of the main simulation window, click on Logical Ops tab.
Click on Controller Block >> drag and drop it >>click on Distillate	Click on Controller Block. Drag and drop it outside the column, below the distillate. Now, click on it.
Point to the left	On the left, we can see a tab displaying properties related to Adjust.
Linked Objects >> Manipulated Object >> DC-005	Under Linked Objects, click on the drop-down against Manipulated Object. Now select DC-005.
Click on the drop-down against Manipulated Property. Select Condenser_Specification_Value.	Next, click on the drop-down against Manipulated Property. Then select Condenser_Specification_Value.
Click on the drop-down against Controlled Object. Select Distillate.	Next, click on the drop-down against Controlled Object and select Distillate.
Click on the drop-down against Controlled Property. Select Molar Fraction(Mixture) / Benzene.	Next, click on the drop-down against Controlled Property. And select Molar Fraction(Mixture) / Benzene.
Go to the Parameters.	Now, go to Parameters.
Enter Set-Point/Offset (Controlled Property) as 0.9901	Enter Set-Point/Offset (Controlled Property) as 0.9901 and press Enter.
Enter 0.9901	I shall enter a slightly larger number 0.9901. I want you to think about why I have entered a slightly larger number.
Select the Solve Globally check box.	Now, select the check-box against Solve Globally.
	Then we will run the simulation.
Click on Solve Flowsheet button	So, from the toolbar, click on Solve Flowsheet button.
Click on Distillate	Let us check the distillate purity. Click on Distillate in the flowsheet.
Cursor to Input Data tab Compound Amounts >> Benzene composition 0.99	From the Property window, go to Input Data tab. Under Compound Amounts tab, we can see that the benzene composition is 0.99.
Click on the Distillation column.	Let us now check what reflux ratio is required for this. To do this, click on the Distillation column.
Column Specs >> Condenser	Under Column Specs, click on Condenser tab.
Compound >> 2.382	Under Compound, we see a value of 2.382 It is the same as what we obtained in the Sensitivity Analysis.
Save the file	Let me save this simulation as adjust.
	Let's summarize.
Slide Number 8 Summary	In this tutorial, we have learnt to: Determine the exact Reflux Ratio for a separation Performed Sensitivity Analysis and Adjust operation
	I have some assignments for you.
Slide Number 9 Assignment 1: Components: Acetone & Water Thermodynamics: Raoult’s Law Inlet Stream: Flow Rate: 100 mol/s Pressure: 1 atm Mole Fractions: Acetone = 0.7, Water = 0.3	Simulate this problem statement using a Distillation column. Here we give different Compounds, feed conditions and Thermodynamics.
Slide Number 10 Column Configuration: Number of stages: 13 (excluding total condenser) Feed Stage: 8 Reflux Ratio: 0.70611 Mole flow rate of bottoms: 29.592 mol/s	Different Column Configuration
Slide Number 11 Assignment 2: Perform sensitivity analysis on the simulated distillation column: To find the reflux ratio such that mole fraction of water in bottoms is 0.99 Using Adjust/Controller Block, verify the results obtained using the analysis	Let us go to the next assignment. Perform sensitivity analysis on the simulated distillation column. To find the reflux ratio such that mole fraction of water in bottoms is 0.99 Using Adjust/Controller Block, verify the results obtained using the analysis.
Slide Number 12 About the Spoken Tutorial Project	Watch the video available at the following link. http://spoken-tutorial.org/ It summarizes the Spoken Tutorial project.
Slide Number 13 Spoken Tutorial Workshops	The Spoken Tutorial Project Team conducts workshops and gives certificates. For more details, please write to us.
Slide Number 14 Forum Slide Do you have questions in this Spoken Tutorial? Please visit this site Choose the minute and second where you have the question. Explain your question briefly. Someone from the FOSSEE team will answer them.	Please post your timed queries in this forum.
Slide Number 15 DWSIM Flowsheeting Project	The FOSSEE team coordinates conversion of existing flowsheets into DWSIM. We give honorarium and certificates for those who do this. For more details, please visit this site.
Slide Number 16 Lab Migration Project	The FOSSEE team helps migrate commercial simulator labs to DWSIM. We give honorarium and certificates for those who do this. For more details, please visit this site
Slide Number 17 Acknowledgements	Spoken Tutorial and FOSSEE projects are funded by NMEICT, MHRD, Government of India.
Slide Number 18 Thanks	We thank the DWSIM team for making it as an open source software. 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

Kaushik Datta, Nancyvarkey