Natural Gas Processing

Hopefully everyone will be doing well. I have a query regarding Sub flow-sheet. I have added sub flow-sheets in my simulation. After doing everything for transfer basis (been set at T-P flash) and fluid packages for corresponding sub flowsheets, I am getting this transition error. "  one or more prod transitions have warnings".

Anyone here who will sort out this issue? I have added an image of the said issue. 

Thanks in Advance. 

Please review the following:

1- What property packages have you selected for the main flow sheet and the sub flow sheet? ARE STREAM CONDITIONS (T,P) WITHIN THE SPECIFIED LIMITS OF THOSE PROPERTY PACKAGES?

2- Is the inlet gas stream near phase transition. In this case, TP flash would not be valid. Try using VF-P flash instead.

3- Does the error persists if you select same property package for the main and the subflow sheet

@Waqar1989

thank you for giving your time.

 

Ans1. Main flow sheet is for Natural Gas sweetening process so FP is Amine package. Sub flow-sheet is assigned for Natural Gas dehydration process. Yes stream conditions are with in the specified limits for respective FP.

Ans3. In that case, keeping the fluid package same for main and sub flow sheets, convergence couldn't be achieved. 

Seems that problem is somewhere else. Can you acess HYSYS file? If i remember correctly, there is an example case of LNG terminal in Aspen resouces.

I would side-step the problem and break the amine unit out as a separate simulation. Then set the feed gas to the dehydrator. This gets you to a solution much sooner.

 

Bobby