DWSIM Automation Sample in Python - Create a Flowsheet with a Distillation Column for Water/Acetone/Ethanol Separation (requires DWSIM v8.4.5 or newer)

dwsim_automation_sample2.py

# remove the following two lines to run on linux
import pythoncom
pythoncom.CoInitialize()     

import clr

from System.IO import Directory, Path, File
from System import String, Environment

dwsimpath = "C:\\Users\\danie\\AppData\\Local\\DWSIM\\"

clr.AddReference(dwsimpath + "CapeOpen.dll")
clr.AddReference(dwsimpath + "DWSIM.Automation.dll")
clr.AddReference(dwsimpath + "DWSIM.Interfaces.dll")
clr.AddReference(dwsimpath + "DWSIM.GlobalSettings.dll")
clr.AddReference(dwsimpath + "DWSIM.SharedClasses.dll")
clr.AddReference(dwsimpath + "DWSIM.Thermodynamics.dll")
clr.AddReference(dwsimpath + "DWSIM.UnitOperations.dll")
clr.AddReference(dwsimpath + "DWSIM.Inspector.dll")
clr.AddReference(dwsimpath + "System.Buffers.dll")
clr.AddReference(dwsimpath + "DWSIM.Thermodynamics.ThermoC.dll")

from DWSIM.Interfaces.Enums.GraphicObjects import ObjectType
from DWSIM.Thermodynamics import Streams, PropertyPackages
from DWSIM.UnitOperations import UnitOperations
from DWSIM.Automation import Automation3
from DWSIM.GlobalSettings import Settings
from System import Array

Directory.SetCurrentDirectory(dwsimpath)

# create automation manager

manager = Automation3()

myflowsheet = manager.CreateFlowsheet()

# add compounds

cnames = ["Water", "Ethanol","Acetone"]

myflowsheet.AddCompound("Water")
myflowsheet.AddCompound("Ethanol")
myflowsheet.AddCompound("Acetone")

# create and connect objects

feed  = myflowsheet.AddFlowsheetObject("Material Stream", "Feed")
dist = myflowsheet.AddFlowsheetObject("Material Stream", "Distillate")
bottoms = myflowsheet.AddFlowsheetObject("Material Stream", "Bottoms")
column = myflowsheet.AddFlowsheetObject("Distillation Column", "Column")

feed = feed.GetAsObject()
dist = dist.GetAsObject()
bottoms = bottoms.GetAsObject()
column = column.GetAsObject()

# change number of stages - default is 10

column.SetNumberOfStages(12)

# connect streams to column

column.ConnectFeed(feed, 6)
column.ConnectDistillate(dist)
column.ConnectBottoms(bottoms)

myflowsheet.NaturalLayout()

feed.SetOverallComposition(Array[float]([0.4, 0.4, 0.2]))
feed.SetTemperature(350.0) # K
feed.SetPressure(101325.0) # Pa
feed.SetMolarFlow(300.0) # mol/s

# allowed specs:

# Heat_Duty = 0
# Product_Molar_Flow_Rate = 1
# Component_Molar_Flow_Rate = 2
# Product_Mass_Flow_Rate = 3
# Component_Mass_Flow_Rate = 4
# Component_Fraction = 5
# Component_Recovery = 6
# Stream_Ratio = 7
# Temperature = 8

column.SetCondenserSpec("Reflux Ratio", 3.0, "")
column.SetReboilerSpec("Product_Molar_Flow_Rate", 200.0, "mol/s")

# property package

nrtl = myflowsheet.CreateAndAddPropertyPackage("NRTL")

# request a calculation

errors = manager.CalculateFlowsheet4(myflowsheet)

# get condenser and reboiler duties

cduty = column.CondenserDuty
rduty = column.ReboilerDuty

print("Condenser Duty: " + str(cduty) + " kW")
print("Reboiler Duty: " + str(rduty) + " kW")

dtemp = dist.GetTemperature()
dflow = dist.GetMolarFlow()
btemp = bottoms.GetTemperature()
bflow = bottoms.GetMolarFlow()

print()
print("Distillate Temperature: " + str(dtemp) + " K")
print("Bottoms Temperature: " + str(btemp) + " K")

print()
print("Distillate Molar Flow: " + str(dflow) + " mol/s")
print("Bottoms Molar Flow: " + str(bflow) + " mol/s")

# product compositions

print()

distcomp = dist.GetOverallComposition()
print("Distillate Molar Composition:")
for i in range(0, 3):
	print(cnames[i] + ": " + str(distcomp[i]))
	i+=1

print()

bcomp = bottoms.GetOverallComposition()
print("Bottoms Molar Composition:")
for i in range(0, 3):
	print(cnames[i] + ": " + str(bcomp[i]))
	i+=1

# save file

fileNameToSave = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "python_column_sample.dwxmz")

manager.SaveFlowsheet(myflowsheet, fileNameToSave, True)

# save the pfd to an image and display it

clr.AddReference(dwsimpath + "SkiaSharp.dll")
clr.AddReference("System.Drawing")

from SkiaSharp import SKBitmap, SKImage, SKCanvas, SKEncodedImageFormat
from System.IO import MemoryStream
from System.Drawing import Image
from System.Drawing.Imaging import ImageFormat

PFDSurface = myflowsheet.GetSurface()

imgwidth = 1024
imgheight = 768

bmp = SKBitmap(imgwidth, imgheight)
canvas = SKCanvas(bmp)
PFDSurface.Center(imgwidth, imgheight)
PFDSurface.ZoomAll(imgwidth, imgheight)
PFDSurface.UpdateCanvas(canvas)
d = SKImage.FromBitmap(bmp).Encode(SKEncodedImageFormat.Png, 100)
str = MemoryStream()
d.SaveTo(str)
image = Image.FromStream(str)
imgPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "pfd.png")
image.Save(imgPath, ImageFormat.Png)
str.Dispose()
canvas.Dispose()
bmp.Dispose()

from PIL import Image

im = Image.open(imgPath)
im.show()

On linux include the following two lines as well (before import clr)

from pythonnet import load
# On Linux/macOS, use 'coreclr' as the runtime
load("coreclr") 

Can we set boil up ratio in this for reboiler specification as i have tried to set it and solver fails for the column like gets stuck and does not converge. On the other hand in dwsim if we directly use boil up ratio and reflux ratio for reboiler and condenser spec and then if we try to solve the flowsheet it indeed gets solved but is there any way to set boil up ratio and calculate in python script while not overwhelming the solver