Need help with a usage tip for the HYSYS optimizer, urgently!!!
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I am conducting HYSYS simulations and optimizations for a natural gas liquefaction project using mixed refrigerants, and I need to use the Optimizer for this purpose. I have run into a really tricky problem that I can’t figure out; I would be extremely grateful if any experts familiar with HYSYS could offer me some guidance. Thank you in advance! The optimization method I chose is Original, with the objective function being to minimize the power consumption of the compressor. The Primary Variables are the molar fractions of the mixed refrigerant components. To modify the Current Values on the Variables page, it is necessary to access Input Composition for Stream:XX (the molar fractions of the components in stream XX). The molar fractions need to be normalized in order for the modifications to take effect; otherwise, the Primary Variables cannot be automatically adjusted, and optimization cannot be achieved. I don’t know how to solve this problem; I’ve seen that the use of many optimizers still doesn’t resolve it, and I wonder if some of the variables in the process cannot be used as primary variables ? My QQ number is 27667600, and my email address is 27667600@qq.com. I hope experts in HYSYS can provide some guidance! Thank you again!
Why aren’t any HYSYS experts here? I’ll give it a try! Looking forward to it.......
Original poster, please simplify the question and send it over; I’ll help you take a look! The general approach is to overcome the limitation of HYSYS not being able to directly modify the composition of the stream, by using spreadsheets to achieve the functionality you need
I’m very grateful to the friend who posted above. The issue is roughly as follows: when performing optimization, the Primary Variables are the mole fractions of the mixed refrigerant components. However, these mole fractions need to be normalized in order for the optimization to work successfully; as a result, it’s not possible to automatically adjust these variables, and thus optimization cannot be carried out. After each optimization calculation, the optimal value is always the set of initial variables entered; moreover, by using the molar flow rate of each substance instead of its mole fraction as the variables, optimization still cannot be achieved! I would like to thank the members of the Haichuan Technology team for their guidance!
Send me your attachment; I still don’t quite understand what you mean. Don’t worry about any issues related to confidentiality – I work at Aspentech, and your questions involve some technical aspects, haha, just joking. Send it to the private mailbox: nunatak123@163.com