For the Rigorous toolbox-only procedures the PS toolbox options coincide with the respective options of the associated operations.
Each procedure in a process file has its own set of default options for the Shortcut and Rigorous toolbox as well as a default selection regarding which one of the two toolboxes will be used for the calculation of the physical state of material. These default options are automatically propagated to all of its procedure states and associated output streams unless the Overwrite option has been enabled for any of them. A detailed description of the physical state calculation options is given in Physical State Calculation Options.
By default, every procedure in the process is initialized with the Shortcut PS Calculation Toolbox. It is possible to change the default settings at the procedure level by modifying the assigned PS Toolbox selection as well the respective PS Toolbox options.
In addition, every procedure has its own set of default options for the calculation of liquid/solid and vapor density. By default, every procedure state is initialized with the density calculation options of the process file (unit procedures do not keep a set of default options for density calculations) and any change to the options of the process file will be propagated to the procedure. It is possible to deviate from the default procedure settings for the calculation of density in one of the following ways:
1. Modify the liquid/solid density calculation options
2. Modify the vapor density calculation options
1. While in select mode, right-click on the specific unit-procedure and select Default PS Calc. Options
2. Check the Overwrite checkbox in the Physical State (PS) Calculation Options frame.
3. Select between the Shortcut or Rigorous PS Toolbox option and if necessary, modify the respective PS Toolbox options in the same way as for the individual Procedure States (see Procedure State Physical State Calculation Options).
The following 4 unit procedures essentially require by nature the Rigorous PS calculation toolbox to carry out the modeling calculations of their respective operations.
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Flash |
Select Procedures } Phase Change } Flash |
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Rigorous Distillation |
Select Procedures } Distillation } Rigorous |
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Condensation |
Select Procedures } Phase Change } Condensation |
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Thin-Film Evaporation |
Select Procedures } Phase Change } Thin-Film Evaporation |
In these unit procedures, the Shortcut toolbox is not applicable and the Rigorous toolbox is employed as the only option..
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For the Rigorous toolbox-only procedures the PS toolbox options coincide with the respective options of the associated operations. |
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The physical state of streams coming out of Rigorous toolbox-only procedures is determined by the procedure itself. For example, the top output stream of the Flash procedure is considered to be exclusively in the vapor phase while the bottom stream is considered to be exclusively in the liquid phase. The physical state calculation options of such streams cannot be overwritten (see The PS calculation options of output streams of a Rigorous-toolbox only procedure.). This is done purposely to avoid energy balance inconsistencies (i.e., the creation or loss of enthalpy content on a stream) due to the discrepancy of the PS calculation options between the unit procedure and its associated output streams. |
The PS calculation options of output streams of a Rigorous-toolbox only procedure.
1. While in select mode, right-click on the procedure icon and select Default PS Calc. Options.
2. Check the respective Overwrite checkbox for the Liquid/Solid or Vapor Density (The procedure default density options.).
3. Make the desired changes regarding user-set density values, volumetric coefficients, etc.
The procedure default density options.
