Creating new user variable in hysys

In HYSYS, you can create a new user-defined variable (UDV) by following these steps:

1. Open your HYSYS model and navigate to the "Variables" tab in the "Tools" menu.
2. Click on the "New" button to create a new variable.
3. In the "Variable Properties" dialog box, enter the following information:
   • "Name": Enter a unique name for your variable. This will be the name that appears in the HYSYS interface.
   • "Type": Select the type of variable you want to create. Options include "Scalar", "Array", "Matrix", and "Struct".
   • "Units": Enter the units for your variable. This can be a standard unit (e.g. kg, mol, etc.) or a custom unit.
   • "Description": Enter a brief description of your variable.
4. Click "OK" to create the new variable.
5. Once the variable is created, you can assign a value to it by clicking on the "Assign" button next to the variable name in the "Variables" tab.
6. You can also use the "UDV" button in the "Tools" menu to create a new user-defined variable and assign a value to it at the same time.

Some examples of user-defined variables you might create in HYSYS include:

• A variable to store the temperature of a reactor outlet stream
• A variable to store the pressure of a compressor outlet stream
• A variable to store the flow rate of a pump
• A variable to store the concentration of a species in a mixture

You can use user-defined variables in HYSYS to simplify your model, improve readability, and make it easier to modify and maintain.