2 replies to this topic

[Seung]

Hi

 

I want to simulate a two stage brayton cycle with Aspen HYSYS V11 for H2 liquefaction plant.

So, I build a simple two stage example and run it. But, when I start it  in dynamcis, it has a negative mass flow (seems like flow is reversed).

 

It looks good in steady state (with 204 g/s of helium). How can I fix it ??

 

This is my flowsheet and workbook

Attached Files

•  KakaoTalk_20220922_203356502.png   200.31KB   1 downloads

Edited by Seung, 22 September 2022 - 06:29 AM.

[Pilesar]

Try putting a flow control loop in the dynamic simulation. Dynamic simulations are picky about details. It may be worth your time reviewing some training materials.

[latexman]

I use a simulator occaisionally.  I am no expert.  And, I have never used a dynamic simulator.  The mass/molar flow is positive.  That's good.  The temperature of the stream is decreasing from start/inlet to finish/outlet.  That's good.  And, the heat flow is decreasing from start/inlet to finish/outlet, which, in my mind, aligns with the temperature decreasing.  Yes, steady-state looks good.

 

Try putting a check valve in the line.