When using Unism for dynamic simulation, is it necessary to first establish a steady-state model and then convert it into a dynamic model?
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When using Unism for dynamic simulation, is it necessary to first create a steady-state model and then convert it into a dynamic model? But when I’m building the steady-state model, I need to use a fired heater, yet that module can only operate in the dynamic model – which is a contradiction; I can’t debug the heated heater in steady state! ! Do I have to use dynamic modeling for the entire process from the start? ? But for beginners, direct dynamic modeling is a bit difficult. I would appreciate some advice from experts, thank you!
If you have detailed and reliable PFD data from a design package, and the simulation subject is a non-polar substance made up of real components, it is generally not a problem to use the UniSim dynamic model directly without establishing a steady-state condition； However, for simulating oils or polar substances, the steady state is of great importance for choosing the property package and adjusting the BIP.
When a heating furnace is in a steady-state condition, it’s simply just a heater; in steady-state design, the furnace merely supplies a certain amount of heat to the process stream. But things are completely different in dynamic conditions – if you want to design a heating furnace, you have to do so within a dynamic framework, which is indeed challenging for beginners.
Thank you for your answer! ! Since I am simulating a relatively simple heating-throttling gas production process, I first emptied the heating furnace; the other processes were set up in a steady-state condition, after which the steady state was changed to a dynamic one, and then the heating furnace was added back. I am currently tuning the heating furnace to make the flow rate and temperature of the process gas being heated equal to their steady-state values.