Column.SetStreamFeedStage Method (String, String)

[Mustafa Anıl ÖZ]

Hello Everyone,
I have been trying to create a distillation column simulation but I'm stuck in setting a stream as feed that will enter the column at stage 7. Could you help me find out what is the problem with the following script ?

# create and connect objects

m1 = sim.AddObject(ObjectType.MaterialStream, 50, 100, "inlet")
d1 = sim.AddObject(ObjectType.DistillationColumn, 150, 50, "column")
e1 = sim.AddObject(ObjectType.EnergyStream, 400, 50, "condenser duty")
m2 = sim.AddObject(ObjectType.MaterialStream, 400, 110, "distillate")
e2 = sim.AddObject(ObjectType.EnergyStream, 325, 140, "reboiler duty")
m3 = sim.AddObject(ObjectType.MaterialStream, 400, 250, "bottom")

sim.ConnectObjects(m1.GraphicObject, d1.GraphicObject, -1, -1)  
sim.ConnectObjects(e2.GraphicObject, d1.GraphicObject, -1, -1)
sim.ConnectObjects(d1.GraphicObject, m2.GraphicObject, -1, -1)
sim.ConnectObjects(d1.GraphicObject, e1.GraphicObject, -1, -1)
sim.ConnectObjects(d1.GraphicObject, m3.GraphicObject, -1, -1)

# Distillation Column Parameters

d1.SetNumberOfStages(14)
d1.SetStreamFeedStage(m1.Name, "Stage7")

Output:

Initializing DWSIM Automation Interface...
DWSIM Automation Interface initialized successfully.
Initializing the Flowsheet, please wait...
start creating workbook...
creating workbook done: 2 ms.
start creating worksheet...
init srm takes 404 ms.
creating worksheet done: 457 ms.
Set ScrollBarHorizontalLargeChange to -1
Set ScrollBarVerticalLargeChange to -1
Renderer Dispose Time: 22,0001 ms
update new visible region text takes 38 ms.
update viewport bounds done: 61 ms.
Traceback (most recent call last):
  File "distillation_sim.py", line 89, in <module>
    d1.SetStreamFeedStage(m1.Name, "Stage7")
System.NullReferenceException: Nesne başvurusu bir nesnenin örneğine ayarlanmadı.
   konum: DWSIM.UnitOperations.UnitOperations.Column.SetStreamFeedStage(String streamName, String stageID) C:\Users\Daniel\source\repos\DanWBR\dwsim\DWSIM.UnitOperations\UnitOperations\RigorousColumn.vb içinde: satır 1931

[Daniel Medeiros]

You need to setup the role of the connected streams in the context of the column through the MaterialStreams column property: https://dwsim.org/api_help/html/P_DWSIM_UnitOperations_UnitOperations_Column_MaterialStreams.htm

[Daniel Medeiros]

This might help: https://github.com/DanWBR/dwsim/blob/windows/DWSIM.UnitOperations/EditingForms/Supporting/EditingForm_Column_Connections_New.vb#L76

[Mustafa Anıl ÖZ]

Thanks a lot for the reply, Daniel. I appreciate your time.

[Albert Emil]

I am trying to achieve this as well and am stuck at exact the same point. Unfortunately, I did not figure out how to define the feed stage.

My current approach looks like this:

column.NumberOfStages = 20
column.SetStreamFeedStage(feed_stream.Name, 1)

Is the issue due to passing .Name or passing the stageIndex to the method? How could I resolve it?

I tried to iterate over column.MaterialStreams to get some more information about the stream(s), but this did not print anything at all:

for stream in column.MaterialStreams:
    print(stream)