I am working on LNG liquefication in Aspen HYSYS, the internal design of main cryogenic heat exchanger (MCHE) was done using EDR, inlet conditions (Temp , pressure and flowrate ) were specified , outlet conditions were calculated in EDR and then the design is imported to hysys to continue simulating the rest of the process. I am using cutters to specify "Aspen properties Database" for the MCHE and I am having some recycles also. My problem is that HYSYS takes 5 mins to open and lags every 15 mins.
I am using V11 and my computer specifications : i7-8700 CPU @ 3.2 GHz 3.19 GHz with 16 GB RAM
How Can I solve this problem please?
Are you trying to use Hysys to control the tower? You should not continuously run Hysys to set control targets. Run a grid of cases to understand responses and use those cases to set am operating and control strategy.
Hi Rick Manner , thank you for your response, I am not using a tower, the MCHE is designed using EDR and then exported to hysys so I can connect it to the rest of LNG process simulated in hysys. I have tried multiple options like removing clutters, removing recycles to make it faster but in vain.
Mr Mkacher,
Could you say why you have to access the Aspen Properties Database instead of specifying a specific Aspen Property Set for this problem. Are you doing some property estimation or other actions that are in a loop that could slow things down.
Dave Modeste, I am constrained with specific results and could not achieve that only with Aspen properties
Mr Mkacher, from your comments above you may have already tried this option but if not, you may also want to consider decoupling sections of the model and test them separately to see if you can isolate the source of the issue. Treatment/separation may have trouble converging due to the purity specifications, and the Cryogenic section could also be challenging because of the recycles involved. Breaking apart major sections may be a bit more work than you want to do but could help with isolating and identifying the problem.
Dave Modeste, Yes I did already and I found out that the section of EDR is the cause of the slow simulation, unfortunately nothing can be done, I have to simulate this section in that way.
Did you by any chance use multiple "pipe segment"s within the flow sheet? In V9 slowed loading time and running time horribly....
Steve Langley , Yes I did then I have separated that section in another hysys file, I am trying to get rid of all unnecessary sections for the optimization and still slow.
Mr Mkacher, as you mention, including the EDR in the model would slow things down since the EDR routine would have to run several design or rating cases per pass, this would significantly slow down the performance of the model. An option to explore may be to create a "design" version model to get an exchanger design for a specific process case - then have an "evaluation" version of the model that uses a heatx or maybe mheatx block with stream temps, duties, Delta P, and UA (specified from design case) so you don't have to invoke EDR. This may allow you to use the model to evaluate the overall system with a set design for the exchanger.