2 replies to this topic

[Sara77]

Hello everyone, 

I'm trying to do a dynamic simulation on Aspen Hysys. I have 3 streams: two are controlled with ratio controllers and the third has a PI flow controller. For this third stream, when I start the integrator, the valve opens at 100% and nevertheless it is uncapable of letting pass the correct quantity of flow. I tried to increase the valve Cv but the result is the same. Apparently I am doing some mistakes but I don't understand where. 

I hope to have been clear and I hope someone can help me. 

 

Thanks 

Sara                          

[Pilesar]

Dynamic simulations should mimic real life constraints. Check your pressure drop across the valve. Fluid flow always requires pressure drop. Try a larger diameter pipe, a shorter pipe, higher source pressure, lower downstream sink pressure, warmer (lower viscosity liquid) source fluid... things that would increase flow in the real world. Check your units of measure -- perhaps the 'correct quantity of flow' is unreasonable. Check your fluid phases -- is your sim fluid vapor when you expected liquid? Do you need a larger pump or compressor? (I'm not a Hysys user, so cannot offer step-by-step.) 

[Sara77]

Thanks for your suggestion!