SpreadSheet
Introduction
Spreadsheets are fully supported in dynamics mode, and can be used to perform custom calculations or export setpoints to various other operations.
Spreadsheet Dynamics
Spreadsheets continually recalculate (update), as appropriate, in dynamics mode. Their behavior can be set on the dynamics tab in the spreadsheet view:
The first three options determine when and how often the spreadsheet updates (calculates):
- Calculate on Pre Process Step - Calculate before each integration step, frequently.
- Calculate on Post Process Step - Calculate after each integration step, frequently.
- Calculate on Composition Step - Calculate on each composition step, which is typically about ten times less frequently.
Always push outputs determines whether the spreadsheet always pushes all of its exported variables each time it resolves as the integrator runs, or only if one has changed.
Note that spreadsheets do not generate inconsistencies in dynamics mode. The output is generally specified (overridden) so that the user can also change it if need be. If the spreadsheets export an inappropriate value, such as the pressure of a stream that is not set to use a pressure specification, then the spreadsheet exported value will simply be overwritten.
To find out if a spreadsheet is operating on a unit operation, open its view. Then on a blank spot in the view, right click and choose Show Attachments. This will show a list of spreadsheet that are linked to the unit operation in question. Double click on an item in the list to open its view.
For more general information about the spreadsheet, press F1 in Petro-SIM.