3 replies to this topic

[hamed2020]

Hello to everyone

I want to optimize hydrogen liquefaction cycle. After the help of this forum I could run the cycle but now I want to optimized this liquefaction cycle which it's PFD is attached to this message. Please let me know how could I do optimization automatically by hysys, by changing any parameter the others will be changed. I need to change 2 or 3 parameter to gain the minimum power consumption in compressor but just there is Adjust operation which is applicable to three parameter.

could any one help me in this problem?

Thanks to all.

Attached Files

•  complete.png   101.18KB   2 downloads

[Bobby Strain]

The separator is still upside down!  No one is taking you seriously when you present a PFD such as this.  And we like to help.

 

Bobby

[hamed2020]

Dear Bobby

 

I rectified the PFD schematic as you indicated.  So please let me have your tip for the optimization of this cycle.

Thanks

 

Hamed

Attached Files

•  complete.png   87.05KB   0 downloads

[Bobby Strain]

      Now, that looks like a proper presentation. This is quite a small system, so you can likely only optimize by minimizing compression power. In a real project one must balance initial cost vs operating cost. You have a single stage compressor, which seems unrealistic. The number of stages should be selected such that the discharge temperature from a stage is no greater than about 300 F. For an industrial size system one would use multiple flash separators to reduce the compressor power. For the size you have displayed, one would probably import liquid nitrogen for pre-cooling. And maybe use a refrigeration unit for higher level pre-cooling.

 

    If I undertook an optimization, I would use an excel VBA program to manipulate the liquefaction pressure and the cooling pressure. Maybe you can use case studies in HYSYS to run multiple cases.