1 reply to this topic

[asma1411]

 

 

Hello everyone,

 

I am studying process, instrumentation, and control engineering and I am working on my senior project which is controlling an ammonia plant with an MPC by using aspen hysys. 

 

I took the design of the plant from a research paper but when I want to start the dynamic simulation the following messages keep shown and I do not know what it is mean or how to solve these problems. 

 

1. Fast dynamic reaction calculations failed to meet tolerance, review your reactions and consider reducing the reaction set solver tolerance option or checking the accept best dynamics mode results option.

 

 

2. Zapped volume error!, The material may not be in balance. This message will only appear once per session unless Verbose Trace is turned on.

 

All the above messages are related to the steam methane reformer, I tried to reduce the step size of the integrator but nothing changes. 

 

 

I hope I was clear.

 

 

 

Thank you all!

 

[Pilesar]

I think your best avenue for help will be with the tech support of the software vendor. Getting dynamic simulations to work properly is an order of magnitude more difficult than with steady state simulations. Software error messages are put in place with good intentions, but do not necessarily provide proper pointers on how to fix the problems. You do not have time to flounder around hoping to find a solution by chance. Get help from those who have access to the software developers and can give you definitive answers.