Hi,
Just starting out but the program looks very promising. I have a basic process that I want to model. Just heating and pressure reduction of natural gas. Layout is below (ignore the fact that the herater is acting as a chiller in this screen shot ;) )
I want to plot the phase envelope to make sure I don't head into 2-phase teritory during the pressure cut. For some reason the phase envelope utility never works for me. This happens:
I have tried most of the flash algorithems availible but with no luck. Any ideas?
Also, one of the other recent posts mentioned a "Natural Gas properties plugin". What is this and how do I get it?
Comment: suggest you make velocity an option for the table for "pipe segment".
Last, is there any way to calculate the lower heating value (LHV) and wobbe index of the natural gas?
Many thanks,
Adam L
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This is a bug. While it isn't fixed, try disabling CPU Parallel Processing
in General Settings. The diagram will look a little weird closer to the
critical point but you'll have what you need.
Go to Plugins > Natural Gas Properties and select the material stream, it
will show the relevant properties in the plugin window.
Many thnaks Daniel, I'll try that tonight. No issues with the critical point are being a bit off. I'm concerned with the cricondentherm area which will be a fair bit away from the CP.
However, I don't think I have Natural Gas Propoerties under Plugins. From memory, all I have when I click on the plugin button is "CAPE-OPEN plugin" or something like that. Have I missed something?
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
The natural gas properties plugin should've been installed automatically and available in the Plugins menu. Did you download the installer or the zip package?
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Moderate sucess. I turned off parallel processing and some natural gas compositions will solve in the phase envelope utility and look sensible but others still won't solve. For the ones that fail I get the following message:
(https://dl.dropboxusercontent.com/u/35563082/Untitled.jpg)
I still can't find any natural gas plugin. I must be blind.
Cheers,
Adam
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Phase envelope utility works now for gas compositions it failed on previousl;y. I can leave multi processors on too. The phase envelope looks good though the top of the envelope is missing. However, this probably won't mater to many people. The hydrate lines look off though. I'd expect them to be about 50-70° lower than what they are.
Maybe I've been a little too heavy on the line termination criteria...
I'll see if I can make the dew line continue to the critical point.
Regarding the hydrate line, uncheck "vapor only" and see what happens.
Phase envelope utility works now for gas compositions it failed on
previousl;y. I can leave multi processors on too. The phase envelope looks
good though the top of the envelope is missing. However, this probably
won't mater to many people. The hydrate lines look off though. I'd expect
them to be about 50-70° lower than what they are.
Hi,
Just starting out but the program looks very promising. I have a basic process that I want to model. Just heating and pressure reduction of natural gas. Layout is below (ignore the fact that the herater is acting as a chiller in this screen shot ;) )
Gas composition:
Species Mol %
C1 96.0875
C2 1.7147
C3 0.757
iC4 0.1452
nC4 0.2231
iC5 0.0835
nC5 0.0803
C6 0.0751
C7 0.0351
C8 0.0025
C9 0.0016
CO2 0.4849
N2 0.3085
H2O 0.001
I want to plot the phase envelope to make sure I don't head into 2-phase teritory during the pressure cut. For some reason the phase envelope utility never works for me. This happens:
I have tried most of the flash algorithems availible but with no luck. Any ideas?
Also, one of the other recent posts mentioned a "Natural Gas properties plugin". What is this and how do I get it?
Comment: suggest you make velocity an option for the table for "pipe segment".
Last, is there any way to calculate the lower heating value (LHV) and wobbe index of the natural gas?
Many thanks,
Adam L
Not sure why only the left hand side of the images are showing...
Here's a link to their location:
https://dl.dropboxusercontent.com/u/35563082/image%201.png
https://dl.dropboxusercontent.com/u/35563082/image%202.png
This is a bug. While it isn't fixed, try disabling CPU Parallel Processing
in General Settings. The diagram will look a little weird closer to the
critical point but you'll have what you need.
Go to Plugins > Natural Gas Properties and select the material stream, it
will show the relevant properties in the plugin window.
Regards
Daniel
2015-10-24 5:01 GMT-04:00 Adam Langman adamlangman@users.sf.net:
Many thnaks Daniel, I'll try that tonight. No issues with the critical point are being a bit off. I'm concerned with the cricondentherm area which will be a fair bit away from the CP.
However, I don't think I have Natural Gas Propoerties under Plugins. From memory, all I have when I click on the plugin button is "CAPE-OPEN plugin" or something like that. Have I missed something?
Which DWSIM version are you running?
V 3.4 Build 5740, 19/9/2015
ok?
The natural gas properties plugin should've been installed automatically and available in the Plugins menu. Did you download the installer or the zip package?
Moderate sucess. I turned off parallel processing and some natural gas compositions will solve in the phase envelope utility and look sensible but others still won't solve. For the ones that fail I get the following message:
(https://dl.dropboxusercontent.com/u/35563082/Untitled.jpg)
I still can't find any natural gas plugin. I must be blind.
Cheers,
Adam
Yesterday I fixed some bugs regarding the phase envelope. I'll generate a new installer ASAP and make sure that the plugin is included.
Regards
Daniel
Download build 5778 beta: http://sourceforge.net/projects/dwsim/files/DWSIM/DWSIM%203.5/DWSIM_bin_v35_b5778_beta.zip/download
Wow, thanks !
I'll give it a try now.
Much better!
Phase envelope utility works now for gas compositions it failed on previousl;y. I can leave multi processors on too. The phase envelope looks good though the top of the envelope is missing. However, this probably won't mater to many people. The hydrate lines look off though. I'd expect them to be about 50-70° lower than what they are.
(https://dl.dropboxusercontent.com/u/35563082/Phase%20envelope%201.png)
The Natural Gas Utility is there now as well and it gives some very useful info!!!
Donation sent :)
Thanks for the donation, Adam!
Maybe I've been a little too heavy on the line termination criteria...
I'll see if I can make the dew line continue to the critical point.
Regarding the hydrate line, uncheck "vapor only" and see what happens.
Regards
Daniel
On Oct 28, 2015 10:37 PM, "Adam Langman" adamlangman@users.sf.net wrote: