Difference between revisions of "ASCEND/C2/Simulating-flowsheet/English"
Nancyvarkey (Talk | contribs) |
|||
Line 10: | Line 10: | ||
Title slide | Title slide | ||
− | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Welcome to the tutorial on | + | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Welcome to the tutorial on how to model a '''Flowsheet''' in '''ASCEND''' |
|- | |- | ||
| style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Show Slide 2 | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Show Slide 2 | ||
− | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| In this tutorial, | + | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| In this tutorial,we will learn how to |
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
+ | * Model a '''mixer''' and execute it | ||
+ | * Model a '''reactor''' | ||
+ | * Connect different components in a single '''flowsheet''' | ||
+ | * Run the '''flowsheet''' | ||
|- | |- | ||
Line 32: | Line 27: | ||
| style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Here I am using | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Here I am using | ||
− | '''Ubuntu Linux''' OS v. 12.04 | + | *'''Ubuntu Linux''' OS v. 12.04 |
− | + | ||
− | + | ||
− | + | ||
− | + | ||
+ | *'''ASCEND''' v. 0.9.8 | ||
|- | |- | ||
Line 45: | Line 37: | ||
| style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| To follow this tutorial, user must have basic knowledge of | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| To follow this tutorial, user must have basic knowledge of | ||
− | '''Linux''' and | + | *'''Linux''' and |
− | + | *'''ASCEND''' | |
− | '''ASCEND''' | + | |
− | To know more about ASCEND please visit '''ascend4.org''' | + | To know more about '''ASCEND''' please visit '''ascend4.org''' |
− | |||
− | http://spoken-tutorial.org | + | For relevant tutorials, please visit our website http://spoken-tutorial.org |
|- | |- | ||
Line 60: | Line 50: | ||
Show the complete Flowsheet | Show the complete Flowsheet | ||
| style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Let's begin the tutorial with the example problem '''10.32''' from the book ''''Elementary Principles of Chemical Processes by Felder and Rousseau'''.' | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Let's begin the tutorial with the example problem '''10.32''' from the book ''''Elementary Principles of Chemical Processes by Felder and Rousseau'''.' | ||
+ | |||
This example is available on page 508 of the book. | This example is available on page 508 of the book. | ||
− | We will model the 3 components of this Flowsheet- mixer, reactor and separator | + | |
+ | |- | ||
+ | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| | ||
+ | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| We will model the 3 components of this''' Flowsheet- mixer, reactor''' and '''separator'''. | ||
+ | |||
+ | |||
+ | We will then assemble them to '''model''' the '''complete flowsheet'''. | ||
|- | |- | ||
Line 71: | Line 68: | ||
| style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Here''' Ethane''' is dehydrogenated to''' ethylene''' and '''acetylene''' in the following pair of reactions. | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Here''' Ethane''' is dehydrogenated to''' ethylene''' and '''acetylene''' in the following pair of reactions. | ||
− | |||
− | |||
− | |||
+ | The '''equilibrium conditions''' are also given as follows | ||
+ | Here '''yi''' signifies mole-fraction | ||
|- | |- | ||
Line 82: | Line 78: | ||
Flowsheet | Flowsheet | ||
− | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Let's now model the mixer in '''ASCEND.''' | + | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Let's now '''model''' the '''mixer''' in '''ASCEND.''' |
− | |||
− | The outlet stream consists of 100 moles of '''ethane''' | + | In '''mixer''', a fresh feed of '''ethane''' with '''n0 (n knot)''' '''moles''' is mixed with a recycled stream of '''ethane''' with '''n6 ''''''moles''' |
+ | |||
+ | |||
+ | The outlet stream consists of 100 '''moles''' of '''ethane'''. | ||
|- | |- | ||
Line 92: | Line 90: | ||
Equations for Mixer | Equations for Mixer | ||
− | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Thus the equation for mixer is | + | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Thus the equation for '''mixer''' is |
'''n0+n6 =100''' | '''n0+n6 =100''' | ||
− | I already have the code for | + | |- |
+ | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| | ||
+ | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| I already have the '''code''' for'''mixer''' in a text file. | ||
Let me explain the code. | Let me explain the code. | ||
Line 102: | Line 102: | ||
|- | |- | ||
| style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Open code file in text editor | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Open code file in text editor | ||
− | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Open the file '''flowsheet.a4c '''in a text editor | + | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Open the file '''flowsheet.a4c '''in a text editor. |
|- | |- | ||
Line 108: | Line 108: | ||
MODEL mixer; | MODEL mixer; | ||
− | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Here we require '''atoms.a4l''' to use the | + | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Here we require '''atoms.a4l library''' to use the '''variable type 'mole''''. |
− | I have named the model as '''mixer'''. | + | I have named the '''model''' as '''mixer'''. |
|- | |- | ||
Line 116: | Line 116: | ||
IS_A mole; | IS_A mole; | ||
− | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Let’s | + | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Let’s name the three '''streams of mixer''' as: |
− | '''n_0, n_6 and n_tot'''. | + | '''n_0 (n knot), n_6 and n_tot'''. |
− | Define the | + | |
+ | |||
+ | Define the '''streams''' as a '''mole'''. | ||
|- | |- | ||
− | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| | + | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| n_0+n_6=n_tot; |
− | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Now we define the equation for | + | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Now we define the equation for mixer by simple''' mole balance''' as : |
− | + | '''n_0+n_6 = n_tot'''<nowiki>;</nowiki> | |
− | + | |- | |
+ | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| | ||
+ | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Note that label like ''''equation 1'''' is not necessary to write. | ||
− | |||
− | + | But this helps in debugging the '''code.''' | |
|- | |- | ||
Line 140: | Line 143: | ||
END specify; | END specify; | ||
− | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Let's now define '''METHODS''' for solving the | + | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Let's now define '''METHODS''' for solving the '''mixer'''. |
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
+ | Under '''METHOD specify''', we fix the variable '''n_tot''' | ||
|- | |- | ||
Line 155: | Line 154: | ||
END values; | END values; | ||
− | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Under '''METHOD values''', | + | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Under '''METHOD values''', '''n_tot''' is assigned the value 100 '''mole'''. |
− | + | ||
− | '''n_tot''' is assigned the value 100 mole | + | |
− | + | ||
− | + | ||
− | + | ||
|- | |- | ||
Line 174: | Line 168: | ||
END mixer; | END mixer; | ||
− | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| '''METHOD seqmod '''signifies setting the model in sequential modular simulation. | + | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| '''METHOD seqmod '''signifies setting the '''model''' in '''sequential modular simulation'''. |
− | This signifies that given feed stream and unit operations specification, | + | This signifies that given '''feed stream''' and '''unit operations specification, ASCEND''' will calculate the intermediate and outlet '''streams.''' |
− | Under this method, | + | |- |
+ | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Under this '''method''', | ||
'''RUN specify''' and | '''RUN specify''' and | ||
Line 184: | Line 180: | ||
'''RUN values''' | '''RUN values''' | ||
− | Now END the model | + | |- |
+ | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Now '''END''' the '''model mixer''' | ||
− | |||
− | Thus one can’t solve the '''model | + | Note that '''model mixer '''is not '''square''', as there is one equation and two unknowns. |
+ | |||
+ | |||
+ | Thus, one can’t solve the '''model mixer''' separately in '''ASCEND'''. | ||
|- | |- | ||
Line 194: | Line 194: | ||
Flowsheet | Flowsheet | ||
− | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Let us now model the second component of the flowsheet i.e. the reactor | + | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Let us now '''model''' the second component of the '''flowsheet''' i.e. the '''reactor''' |
− | As you can see there is one stream entering the reactor | + | |- |
+ | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"|Point as per narration. | ||
+ | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"|As you can see, there is one '''stream''' entering the '''reactor''' and four '''streams''' leaving it. | ||
− | Here '''ethane '''is dehydrogenated to '''ethylene''' and '''acetylene''', so the | + | |
+ | Here '''ethane '''is dehydrogenated to '''ethylene''' and '''acetylene''', so the '''outstream''' consists of '''ethane, ethylene, acetylene '''and''' hydrogen'''. | ||
|- | |- | ||
Line 204: | Line 207: | ||
Equations for Reactor | Equations for Reactor | ||
− | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| These are the set of equations to be used for modelling the reactor | + | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| These are the set of '''equations''' to be used for '''modelling''' the '''reactor'''. |
− | |||
− | Now let’s look at the code for reactor | + | To understand these '''equations''', please refer the textbook. |
+ | |||
+ | |||
+ | Now let’s look at the '''code''' for '''reactor'''. | ||
|- | |- | ||
| style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Open flowsheet.a4c in a text editor and highlight the code text sequentially | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Open flowsheet.a4c in a text editor and highlight the code text sequentially | ||
− | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| I have named the model as reactor | + | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| I have named the '''model''' as '''reactor'''. |
− | |||
− | + | Define all the input and the output '''streams''' as a '''mole'''. | |
− | + | |- | |
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| The reaction extent''' ksi1''' and '''ksi2''' is also defined as '''mole''' | ||
− | + | |- | |
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Equations 2-6 are defined as shown in the slide | ||
− | + | |- | |
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Note that equations 7 and 8 are written as | ||
+ | *numerator of the left hand side equal to | ||
+ | *right hand side into denominator of the right hand side | ||
− | + | We don’t use division to avoid a poor '''initialization''' for solving the problem. | |
− | + | |- | |
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Now under '''METHODS''' section, we define '''methods''' in a similar way as that for '''mixer'''. | ||
− | We also set '''upper bound''' for '''ksi1''' and '''ksi2.''' | + | |- |
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Under '''values '''section, instead of giving a direct value, we initialize the value of the reaction extent '''ksi1''' and '''ksi2'''. | ||
+ | |||
+ | We thus give a '''nominal''' value of '''ksi1''' and '''ksi2''' | ||
+ | |||
+ | |- | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| We also set '''upper bound''' for '''ksi1''' and '''ksi2.''' | ||
For assigning the nominal value, we write | For assigning the nominal value, we write | ||
Line 234: | Line 256: | ||
'''ksi_1.nominal is equal to ksi_1''' | '''ksi_1.nominal is equal to ksi_1''' | ||
− | + | |- | |
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Similarly, for assigning the '''upper bound''', we write | ||
'''ksi_1.upper_bound is equal to n_tot into 2''' | '''ksi_1.upper_bound is equal to n_tot into 2''' | ||
− | Now, | + | |- |
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Now, '''END''' the '''Method values'''. | ||
− | Define the ''' | + | |
+ | Define the '''METHOD seqmod''' and '''END''' the '''reactor'''. | ||
|- | |- | ||
Line 246: | Line 273: | ||
Assignment: Equations for Separator | Assignment: Equations for Separator | ||
− | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Now these are the set of equations for separation process | + | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Now these are the set of equations for separation process. |
− | Using these model the separator on similar lines as that of | + | |- |
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Using these, model the '''separator''' on similar lines as that of '''mixer.''' | ||
− | Once we have modelled each component of the flowsheet | + | |- |
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Once we have modelled each component of the '''flowsheet''', let’s now wire them together. | ||
− | |||
− | Let me explain the logic of connecting different components via code. | + | I have the '''code''' for '''modelling''' the '''flowsheet'''. |
+ | |||
+ | Let me explain the logic of connecting different components via '''code'''. | ||
|- | |- | ||
| style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Open flowsheet.a4c in a text editor and highlight the code text sequentially | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Open flowsheet.a4c in a text editor and highlight the code text sequentially | ||
− | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| I have named the model '''flowsheet''' | + | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| I have named the '''model''' as '''flowsheet''' |
+ | |||
We define | We define | ||
Line 266: | Line 299: | ||
'''r1 IS_A reactor; '''and | '''r1 IS_A reactor; '''and | ||
− | '''s1 IS_A separator''' | + | '''s1 IS_A separator'''; |
− | Note that the variable mixer, reactor and separator is used by '''ASCEND '''from the models defined before | + | |- |
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Note that the variable mixer, reactor and separator is used by '''ASCEND '''from the models defined before. | ||
− | Now let us state that output from | + | |- |
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Now let us state that | ||
+ | *output from '''mixer''' is same as input for the '''reactor''' and | ||
+ | *the output of the '''reactor''' is same as the input to the '''separator'''. | ||
− | We equate the two by the help of the operator | + | |- |
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| We equate the two by the help of the operator | ||
− | ''' | + | '''ARE underscore THE underscore SAME''' |
− | '''ARE_THE_SAME''' is a merging operator | + | |- |
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| '''ARE_THE_SAME''' is a merging operator. | ||
− | |||
− | ''' | + | It merges different '''models''' or '''variables''' into one. |
− | |||
− | + | For example, we write | |
− | + | '''m1.n_tot,r1.n_tot ARE_THE_SAME'''; | |
− | |||
− | + | This saves us from creating additional different equations. | |
− | + | |- | |
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Under''' METHODS section''', we will again write the same methods as '''specify, values and seqmod'''. | ||
− | + | |- | |
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Note that under '''METHODS specify''' and''' values''', we run '''methods''' for each individual component under each '''method'''. | ||
+ | For example, under '''METHOD specify''' we have written | ||
+ | '''RUN m1.specify''' and | ||
+ | |||
+ | '''RUN r1.specify''' | ||
+ | |||
+ | This command will execute the '''specify method''' for '''mixer''' under the '''METHODS specify''' for '''flowsheet''' | ||
+ | |||
+ | |- | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"|Now define the '''method seqmod''' and '''END''' the flowsheet | ||
|- | |- | ||
| style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Open the model in '''ASCEND''' | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Open the model in '''ASCEND''' | ||
− | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Open this model in '''ASCEND''' | + | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Open this '''model''' in '''ASCEND'''. |
− | |||
− | Now | + | Now click on '''m1 mixer'''. |
− | + | You will see '''ASCEND''' has assigned some default values to the '''streams n_0, n_6 and n_tot''' | |
− | + | |- | |
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"|Now under '''METHODS section''', click on '''seqmod''', then click on''' RUN''' | ||
− | Now click on | + | Now click on the '''Solve''' icon. |
− | + | |- | |
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"|You will see the message converged in the panel below. | ||
− | |||
− | We encourage the learner to observe the values of remaining two components before and after solving the flowsheet for better understanding. | + | |- |
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Highlight as per narration. | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"|Now click on '''m1 mixer'''. | ||
+ | |||
+ | You will see '''ASCEND''' has calculated the values for the '''streams n_0 (n knot) and n_6'''. | ||
+ | |||
+ | It is also satisfying the equation '''n_0 (n knot) +n_6 = n_tot''' | ||
+ | |||
+ | |- | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| | ||
+ | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"|We encourage the learner to observe the values of remaining two components before and after solving the flowsheet for better understanding. | ||
|- | |- | ||
Line 323: | Line 389: | ||
Summary | Summary | ||
− | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Let’s summarize. In this tutorial, we have learnt, | + | | style="border:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Let’s summarize. In this tutorial, we have learnt, how to |
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
− | + | ||
+ | * Model a '''mixer''' | ||
+ | * Model a '''reactor''' | ||
+ | * Connect different components in a '''flowsheet''' | ||
+ | * Run the '''flowsheet''' | ||
|- | |- | ||
Line 336: | Line 400: | ||
About the spoken tutorial project | About the spoken tutorial project | ||
− | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Information on spoken tutorial project is available on our website | + | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Information on spoken tutorial project is available on our website http://spoken-tutorial.org |
− | + | ||
− | + | ||
− | + | ||
|- | |- | ||
Line 351: | Line 412: | ||
Acknowledgements | Acknowledgements | ||
− | + | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Spoken Tutorial Project is funded by NMEICT,MHRD. | |
− | + | ||
− | + | ||
− | | style="border-top:none;border-bottom:0.5pt solid #00000a;border-left:0.5pt solid #00000a;border-right:0.5pt solid #00000a;padding-top:0in;padding-bottom:0in;padding-left:0.0069in;padding-right:0.0069in;"| Spoken Tutorial Project is funded by NMEICT,MHRD | + | |
|- | |- |
Latest revision as of 15:21, 7 July 2014
Tutorial 5: Model a Flowsheet
|
|
Slide number 1
Title slide |
Welcome to the tutorial on how to model a Flowsheet in ASCEND |
Show Slide 2 | In this tutorial,we will learn how to
|
Slide number 3
System Requirement |
Here I am using
|
Slide number 4
Pre-requisites |
To follow this tutorial, user must have basic knowledge of
To know more about ASCEND please visit ascend4.org
|
Slide number 5
Show the complete Flowsheet |
Let's begin the tutorial with the example problem 10.32 from the book 'Elementary Principles of Chemical Processes by Felder and Rousseau.'
|
We will model the 3 components of this Flowsheet- mixer, reactor and separator.
| |
Slide number 6
Reactions |
Here Ethane is dehydrogenated to ethylene and acetylene in the following pair of reactions.
|
Slide number 7
Flowsheet |
Let's now model the mixer in ASCEND.
|
Slide number 8
Equations for Mixer |
Thus the equation for mixer is
n0+n6 =100 |
I already have the code formixer in a text file.
Let me explain the code. | |
Open code file in text editor | Open the file flowsheet.a4c in a text editor. |
REQUIRE "atoms.a4l";
MODEL mixer; |
Here we require atoms.a4l library to use the variable type 'mole'.
I have named the model as mixer. |
n_0, n_6 and n_tot.
IS_A mole; |
Let’s name the three streams of mixer as:
n_0 (n knot), n_6 and n_tot.
Define the streams as a mole. |
n_0+n_6=n_tot; | Now we define the equation for mixer by simple mole balance as :
n_0+n_6 = n_tot; |
Note that label like 'equation 1' is not necessary to write.
| |
METHOD specify;
FIX n_tot ; END specify; |
Let's now define METHODS for solving the mixer.
|
METHOD values;
n_tot := 100.0 {mole}; END values; |
Under METHOD values, n_tot is assigned the value 100 mole. |
METHOD seqmod;
RUN clear; RUN specify; RUN values; END seqmod; END mixer; |
METHOD seqmod signifies setting the model in sequential modular simulation.
This signifies that given feed stream and unit operations specification, ASCEND will calculate the intermediate and outlet streams. |
Highlight as per narration. | Under this method,
RUN specify and RUN values |
Highlight as per narration. | Now END the model mixer
|
Slide number 9
Flowsheet |
Let us now model the second component of the flowsheet i.e. the reactor |
Point as per narration. | As you can see, there is one stream entering the reactor and four streams leaving it.
|
Slide number 10
Equations for Reactor |
These are the set of equations to be used for modelling the reactor.
|
Open flowsheet.a4c in a text editor and highlight the code text sequentially | I have named the model as reactor.
|
Highlight as per narration. | The reaction extent ksi1 and ksi2 is also defined as mole |
Highlight as per narration. | Equations 2-6 are defined as shown in the slide |
Highlight as per narration. | Note that equations 7 and 8 are written as
We don’t use division to avoid a poor initialization for solving the problem. |
Highlight as per narration. | Now under METHODS section, we define methods in a similar way as that for mixer. |
Highlight as per narration. | Under values section, instead of giving a direct value, we initialize the value of the reaction extent ksi1 and ksi2.
We thus give a nominal value of ksi1 and ksi2 |
Highlight as per narration. | We also set upper bound for ksi1 and ksi2.
For assigning the nominal value, we write ksi_1.nominal is equal to ksi_1 |
Highlight as per narration. | Similarly, for assigning the upper bound, we write
ksi_1.upper_bound is equal to n_tot into 2 |
Highlight as per narration. | Now, END the Method values.
|
Slide 11
Assignment: Equations for Separator |
Now these are the set of equations for separation process. |
Highlight as per narration. | Using these, model the separator on similar lines as that of mixer. |
Highlight as per narration. | Once we have modelled each component of the flowsheet, let’s now wire them together.
Let me explain the logic of connecting different components via code. |
Open flowsheet.a4c in a text editor and highlight the code text sequentially | I have named the model as flowsheet
m1 IS_A mixer; r1 IS_A reactor; and s1 IS_A separator; |
Note that the variable mixer, reactor and separator is used by ASCEND from the models defined before. | |
Highlight as per narration. | Now let us state that
|
Highlight as per narration. | We equate the two by the help of the operator
ARE underscore THE underscore SAME |
Highlight as per narration. | ARE_THE_SAME is a merging operator.
m1.n_tot,r1.n_tot ARE_THE_SAME;
|
Highlight as per narration. | Under METHODS section, we will again write the same methods as specify, values and seqmod. |
Highlight as per narration. | Note that under METHODS specify and values, we run methods for each individual component under each method.
RUN m1.specify and RUN r1.specify This command will execute the specify method for mixer under the METHODS specify for flowsheet |
Highlight as per narration. | Now define the method seqmod and END the flowsheet |
Open the model in ASCEND | Open this model in ASCEND.
You will see ASCEND has assigned some default values to the streams n_0, n_6 and n_tot |
Highlight as per narration. | Now under METHODS section, click on seqmod, then click on RUN
Now click on the Solve icon. |
Highlight as per narration. | You will see the message converged in the panel below.
|
Highlight as per narration. | Now click on m1 mixer.
You will see ASCEND has calculated the values for the streams n_0 (n knot) and n_6. It is also satisfying the equation n_0 (n knot) +n_6 = n_tot |
We encourage the learner to observe the values of remaining two components before and after solving the flowsheet for better understanding. | |
Open slide number 12
Summary |
Let’s summarize. In this tutorial, we have learnt, how to
|
Slide Number 13
About the spoken tutorial project |
Information on spoken tutorial project is available on our website http://spoken-tutorial.org |
Slide number 14
Spoken Tutorial Workshops |
Details of the workshops based on spoken tutorials is also available on the website |
Slide number 15
Acknowledgements |
Spoken Tutorial Project is funded by NMEICT,MHRD. |
Slide number 16
Thanks you |
This is Priya Bagde from IIT Bombay signing off. Thank you for joining. |