DWSIM/C2/Heat-Exchanger/English

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Visual Cue Narration
Slide Number 1

Title Slide

Welcome to this tutorial on Simulating a Heat Exchanger in DWSIM.
Slide Number 2

Learning Objective

In this tutorial, we will learn to:
  • Simulate a Heat Exchanger
  • Calculate the Outlet stream temperatures
  • Calculate Thermal Efficiency and LMTD
Slide Number 3

System Requirements

To record this tutorial, I am using
  • DWSIM 4.3 and
  • Windows 7

The process demonstrated in this tutorial is identical in other OS also, such as-

  • Linux,
  • Mac OS X or
  • FOSSEE OS on ARM.
Slide Number 4

Pre-requisites

To practice this tutorial, you should know how to
  • add components to a flowsheet
  • select thermodynamic packages
  • add material stream and specify their properties.
Slide Number 5


Prerequisite Tutorials and Files

The prerequisite tutorials are mentioned on our website, spoken-tutorial.org


You can access these tutorials and all the associated files from this site.

Slide Number 6


Compounds and Inlet Condition


Cold Stream: Water

Hot Stream: Methanol


Cold Inlet Stream:


Mass Flow: 15000 kg/h

Mole Fraction(CH3OH): 0

Mole Fraction(H2O): 1

Temperature: 10 degree C

Pressure: 1 bar


Hot Inlet Stream:


Mass Flow: 25000kg/h

Mole Fraction(CH3OH): 1

Mole Fraction(H2O): 0

Temperature: 80 degree C

Pressure: 5 bar

We will develop a flowsheet to determine the Outlet stream temperatures.

Here we give Compounds and Inlet stream conditions.

Slide Number 6


Heat Exchanger Properties


Flow type: Counter-Current

Overall Heat Transfer Coefficient: 450 W/[m2.K]

Heat Exchanger Area: 250 m2

Cold Fluid Pressure Drop: 0.002 bar

Hot Fluid Pressure Drop: 0.025 bar

Property Package: Raoult’s Law

Here we give Heat Exchanger properties and Property package.
I have already opened DWSIM on my machine.
File >>New Steady-state Simulation Go to File menu and select New Steady-state Simulation.
Point to Simulation Configuration Wizard window Simulation Configuration Wizard window appears.
Click on Next. At the bottom, click on Next button.
Type Methanol in the Search tab Now, in the Compounds Search tab, type Methanol.
ChemSep database >>Methanol Select Methanol from ChemSep database.
Type Water in the Search tab Similarly, add Water.
Click on Next. At the bottom, click on Next button.
Point to Property Packages Now comes Property Packages.
Property Packages>> Available Property Package

Double click on Raoult’s Law

From Available Property Packages, double-click on Raoult’s Law.
Click on Next. Then click on Next button.
Point to Flash Algorithm We are moved to a new window named Flash Algorithm.
Default Flash Algorithm >>Nested Loops (VLE) From Default Flash Algorithm select Nested Loops(VLE)
Click Next Click on Next button.
Point to System of Units Next option is System of Units.
System of Units >> C5 Under System of Units, select C5.
Click on Finish At the bottom, click on Finish button.
Let us maximize the simulation window for better visibility.
Now let’s insert two material stream that enter the Heat Exchanger.
Point to Flowsheet Objects. On the right hand side of the main simulation window, go to Flowsheet Objects.
In the Filter List tab, type Material Stream In the Filter List tab, type Material Stream.
Click and drag Material Stream to the flowsheet From the displayed list, drag and drop a Material Stream to the Flowsheet.
Click on MSTR-000 Click on the Material Stream MSTR-000” to view its properties.
Type Water In Let’s change the name of this stream to Water In.
Now we will specify the Water In stream properties.
Input Data>>Flash Spec>>Temperature and Pressure(TP) Go to Input Data.


Select Flash Spec as Temperature and Pressure (TP), if not already selected.


By default, Temperature and Pressure are already selected as Flash Spec.

Input Data >>Temperature >>10C

Press Enter

Change Temperature to 10 degC and press Enter.
Input Data >>Pressure >>1bar

Press Enter

Change Pressure to 1 bar and press Enter.
Input Data >>Mass Flow >>15000kg/h

Press Enter

Change Mass Flow to 15000 kg/h and press Enter.
Now let us specify the feed stream compositions.
Composition >>Basis >>Mole Fractions Under Composition, choose the Basis as Mole Fractions, if not already selected.


By default, Mole Fractions is selected as Basis.

Methanol: 0


Now for Methanol, enter the Amount as 0 and press Enter.
Water: 1 Similarly, for Water, enter it as 1 and press Enter.
Click Accept Changes On the right, click on this green tick to Accept Changes.
Now drag and drop another Material Stream to the flowsheet.
Click on MSTR-000 Click on Material Stream MSTR-001” to view its properties.
Type Methanol In Let’s change the name of this stream to Methanol In.
Now we will specify the Methanol In stream properties.
Input Data>>Flash Spec>>Temperature and Pressure(TP) Go to Input Data.


Select Flash Spec as Temperature and Pressure(TP).


By default, Temperature and Pressure are again already selected as Flash Spec.

Input Data >>Temperature >> 80 degC

Press Enter

Change Temperature to 80 degC and press Enter.
Input Data >>Pressure >>5 bar

Press Enter

Change Pressure to 5 bar and press Enter.
Input Data >>Mass Flow >>25000 kg/h

Press Enter

Change Mass Flow to 25000 kg/h and press Enter.
Now let us specify the Methanol In stream compositions.
Composition >>Basis >>Mole Fractions Under Composition, choose the Basis as Mole Fractions, if not already selected.


By default, Mole Fractions is selected as Basis.

Methanol: 1


Now for Methanol, enter the Amount as 1 and press Enter.
Water: 0 Similarly, for Water, enter it as 0 and press Enter.
Click Accept Changes On the right, click on this green tick to Accept Changes.
Now let’s insert two more material streams that exit the Heat Exchanger.
Click and Drag Material Stream to the flowsheet To do that, let us drag one Material Stream.
Let us now arrange it.
Leave that stream as unspecified.
Type Water Out We will change the name of this stream to Water Out.
Click and drag Material Stream to the flowsheet Next, we will insert another Material Stream.
Let us once again arrange it.
Leave that stream as unspecified.
Type Methanol Out And name this stream as Methanol Out.
Now let us insert a Heat Exchanger into the flowsheet.
Go to the Flowsheet Objects Go to the Flowsheet Objects.
In the Filter list tab, type Heat Exchanger. In the Filter list tab, type Heat Exchanger.
Click and drag Heat Exchanger to the flowsheet Click on the Heat Exchanger displayed.


Drag and drop it to the flowsheet.

Let us now arrange it as required for better visibility.
Click Heat Exchanger We are now ready to specify the Heat Exchanger.


Let's click on it.

On the left, we can see a tab called Property Editor Window.
Go to Connections


Click on drop down arrow against Inlet Stream 1


Select Methanol In.

Under Connections, click on the drop-down against Inlet Stream 1.


And select Methanol In.

Click on drop down arrow against Outlet Stream 1


Select Methanol Out.

Next, click on drop-down against Outlet Stream 1.


And select Methanol Out.

Click on drop down against Inlet Stream 2


Select Water In.

Then click on drop-down against Inlet Stream 2.


And select Water In.

Click on drop down against Outlet Stream 2


Select Water Out.

Then click on drop-down against Outlet Stream 2.


And select Water Out.

Hover mouse at Calculation Parameters Now go to the next section- Calculation Parameters.
Here, the first option is Calculation Type.
Click drop down against Calculation Type Click on the drop-down against Calculation Type.
Select Outlet Temperatures (UA) Select Outlet Temperatures (UA)
Click drop down against Flow Direction.


Select Counter Current

Next, click on the drop-down against Flow Direction


Select Counter Current.

Cold Fluid Pressure Drop>>0.002 bar


Press Enter

Then click on the field against Cold Fluid Pressure Drop and enter 0.002 bar.


Then press Enter.

Hot Fluid Pressure Drop>>0.025bar


Click on the field against Hot Fluid Pressure Drop and enter it as 0.025 bar.
Press Enter Then press Enter.
Overall Heat Transfer Coefficient >>450W[m2.K]


Press Enter

Click on the field against Overall Heat Transfer Coefficient and enter it as 450W[m2.K]


Then press Enter.

Heat Exchange Area>>250 m2


Press Enter

Click on the field against Heat Exchange Area and enter it as 250 m2.


Then press Enter.

Now we will run the simulation.
Click Solve Flowsheet So, from the toolbar, click on Solve Flowsheet button.
Click Heat Exchanger When the calculations are completed, click on Heat Exchanger in the Flowsheet.
Hover mouse at Results From the Property Editor Window of Heat Exchanger, locate Results section.
Results Check Thermal efficiency; it is 94.5%


Check Log Mean Temperature Difference; it is 10.29 degree C.

Now we will check the stream-wise temperature results and Material balance.
Insert >>Master Property Table Go to Insert menu and select Master Property Table.
Double click on Master Property Table Double-click on Master Property Table to edit it.
Point to Configure Master Property Table Configure Master Property Table window opens.
Type Heat Exchanger – Stream Wise Results Enter Name as Heat Exchanger – Stream Wise Results
Object Type >>Material Stream Enter Object Type as Material Stream.


By default, Material Stream is already selected.

So we will not change it.
Object >>Water In, Methanol In, Water Out and Methanol Out. Under Properties to display, select Object as:


Water In, Methanol In, Water Out, Methanol Out

Configure Master Property Table>>Property Under Property, scroll down to see all the parameters.


Now select the properties as:


Temperature

Pressure

Mass Flow

Molar Flow

Molar Fraction(Mixture) / Methanol

Molar Fraction(Mixture) / Water

Close this window. Close this window.
Move the Master Property Table for better visibility.


Here we can see the corresponding results for Inlet and Outlet streams.

Now we will check the properties of Heat Exchanger.
Insert >>Master Property Table Go to Insert menu and select Master Property Table.
Double click on Master Property Table Double-click on Master Property Table.
Point to Configure Master Property Table Configure Master Property Table window opens.
Type Heat Exchanger – Results Enter Name as Heat Exchanger – Results.
Object Type >>Material Stream Enter Object Type as Heat Exchanger.
Object >>HE-004. Under Properties to display, select Object as HE-004
Configure Master Property Table>>Property Under Property, scroll down to see all the parameters.


Now select the properties as:


Global Heat Transfer Coefficient (U)

Heat Exchange Area (A)

Heat Load

Cold fluid outlet temperature

Hot fluid outlet temperature

Logarithmic mean temperature difference(LMTD) and

Thermal Efficiency

Close this window. Close this window.
Move the Master Property Table for better visibility.


Here we can see the corresponding results for Heat Exchanger.

Let's summarize.
Slide Number 7


Summary

In this tutorial, we have learnt to


  • Simulate a Heat Exchanger
  • Calculate the Outlet stream temperatures
  • Calculate Thermal Efficiency and LMTD
Slide Number 8


Assignment


Compounds and Inlet Condition


Cold Stream: Toluene

Hot Stream: Acetone


Cold Inlet Stream:


Mass Flow: 30000 lb/hr

Mole Fraction(C3H6O): 0

Mole Fraction(C6H5-CH3): 1

Temperature: 100 degree F

Pressure: 1 bar


Hot Inlet Stream:


Mass Flow: 15000 lb/hr

Mole Fraction(C3H6O): 1

Mole Fraction(C6H5-CH3): 0

Temperature: 200 degree F

Pressure: 5 bar


Heat Exchanger Properties


Flow type: Counter-Current

Overall Heat Transfer Coefficient: 270 W/[m2.K]

Heat Exchanger Area: 75 m2

Cold Fluid Pressure Drop: 0.0035 bar

Hot Fluid Pressure Drop: 0.0025 bar

Property Package: Raoult’s Law


As an assignment,


Repeat this simulation with different Compounds, feed conditions and Thermodynamics.

Slide Number 9

About the Spoken Tutorial Project

Watch the video available at following link.

http://spoken-tutorial.org/

It summarizes the Spoken Tutorial project.

Slide Number 10

Spoken Tutorial Workshops

The Spoken Tutorial Project Team
  • Conducts workshops and
  • Gives certificates
  • For more details, please write to us.
Slide Number 11


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 times queries in this forum.
Slide Number 12

DWSIM Flowsheeting Project


The FOSSEE team coordinates conversion of existing flow sheets into DWSIM.


We give honorarium and certificates.


For more details, please visit this site.

Slide Number 13

TextBook Companion Project

The FOSSEE team coordinates coding of solved examples of popular books.


We give honorarium and certificates.


For more details, please visit this site.

Slide Number 14

Lab Migration Project

The FOSSEE team helps migrate commercial simulator labs to DWSIM.


We give honorarium and certificates.


For more details, please visit this site.

Slide Number 15

Acknowledgements

Spoken Tutorial and FOSSEE projects are funded by NMEICT, MHRD, Government of India.
Slide Number 16

Thanks

This tutorial is contributed by Kaushik Datta and Priyam Nayak.


Thanks for joining.

Contributors and Content Editors

Kaushik Datta