AQSol Direct Calc Model

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Navigation: Models -> TPS Models -> AQSol Models -> AQSol Direct Calc Model

AQSol Overview AQSol Model Configuration AQSol Direct Calc Model AQSol Side Calc Model AQSol Reactor

See also: AQSol SysCAD Project Workflow


New for Build 138. Currently in BETA - contact SysCAD for demonstrations or further information.


General Description

The AQSol Direct Calc model allows the user to 'call' the AQSol solver to determine the state of an aqueous solution at a given temperature/enthalpy and pressure. The user enters the mass or molar makeup of the 'Feed' stream, and the unit will then determine the equilibrium conditions of the resulting stream at the user defined temperature/enthalpy and pressure.

The model has no links to any other models in SysCAD. Therefore, this model is not a part of any SysCAD network, but is a stand-alone calculation that allows the user to check the status of an aqueous solution.

Notes

  1. The user MUST have added and configured an AQSol Model Configuration unit in the SysCAD project before this unit can function.
  2. The user MUST have installed a version of AQSol on their computer to make use of the AQSol functionality in SysCAD. Please see www.phasediagram.dk for more information.

Diagram

TPS Direct Calc.png

The diagram shows the default drawing of a AQSol Direct Calc unit model.

Inputs and Outputs

There are no connections to this unit.

Model Theory

The AQSol Direct Calc Model uses the AQSol algorithms and data to determine the status of the aqueous solution.

The DInput, Input, Output and RxnSummary pages are displayed using AQSol species, as defined in the database (dat) file specified in the corresponding AQSol Model Configuration unit model. The species used in the SysCAD project are not used in this model.

The calculations performed are similar to using AQSol directly. Please see [www.phasediagram.dk] for more information.

Workflow

The suggested workflow for configuring the model is:

  1. Make sure the project contains at least one of the AQSol Model Configuration model, and the model is loaded with the correct AQSol database file you would like to use for the direct calculation.
  2. On the Direct Calc DInput Tab page, type in the required feed properties for T, P and composition.
  3. Perform an equilibrium calculation based on constant Temperature or constant enthalpy (by pressing the corresponding "Calculate" button).
  4. The Results are displayed in the Results and Output tabs.

NOTES:

  1. The AQSol Direct Calc Model does not require species mapping between AQSol and SysCAD.

Data Sections

The tabs and variable names are described in detail in the following tables.

  1. AQSolDirectCalc tab - This first tab allows the user to choose the corresponding AQSol Model Configuration unit and set some general options.
  2. DInput tab - This tab allows the user to set the final conditions, specify the Input composition and perform calculations.
  3. VLE - Optional tab, only visible if the UseSysCADVLE/VLE.On option is enabled on the first tab page.
  4. Results tab - This tab displays the key results of the calculations.
  5. Input tab - This tab displays a summary of the Input stream.
  6. Output tab - This tab displays the Output stream results including the amounts of each species present in the final solution.
  7. Diff tab - This tab displays the amounts of each species which are formed or reacted as part of the calculations.
  8. ParamSweep tab - This tab allows the user to generate sets of data.
  9. SelectSpForPlot tab - Optional tab, only visible if the SelectSp option is enabled on the ParamSweep tab. This tab allows the user to select which species to be reported in the sets of data to be generated.
  10. ElemBal tab - This tab displays an elemental balance between the Input and Output streams.
  11. Deportment tab - This tab shows the mass movement of elements for the Solid, Liquid and Gas phases.
  12. TargCalc tab - This tab allows the user to target a variable in the final solution.
  13. Info tab - contains general settings for the unit and allows the user to include documentation about the unit and create Hyperlinks to external documents.

AQSolDirectCalc tab page

Unit Type: AQSolDirectCalc - The first tab page in the access window will have this name.

Tag (Long/Short) Input / Calc Description/Calculated Variables / Options
Tag Display This name tag may be modified with the change tag option.
Condition Display OK if no errors/warnings, otherwise lists errors/warnings.
ConditionCount Display The current number of errors/warnings. If condition is OK, returns 0.
GeneralDescription / GenDesc Display This is an automatically generated description for the unit. If the user has entered text in the 'EqpDesc' field on the Info tab (see below), this will be displayed here. If this field is blank, then:
  • For pipes, SysCAD will use the text in the 'ConnectDesc' field - this displays the Source and Destination tags of the pipe;
  • For Feeders/Cross Page Connectors, SysCAD will display the state of the unit, i.e. if it is a Feeder or a Sink, etc.;
  • For other units SysCAD will display the unit class ID.
======== BETA VERSION ========
This program contains AQSol Copyright Aqueous Solutions Aps, Denmark
Chemistry Model
ChemModel...
UnitTag List The tag of the relevant AQSol Model Configuration unit model- this may be chosen from the drop down list of all AQSol Model Configuration unit models available in the project.
ChemModel.Selected Display The tag of the relevant AQSol Model Configuration unit model.
Check Check Tag.png If the user clicks on this button, SysCAD will check that the UnitTag is a valid AQSol Model Configuration unit model.
ConnOK Tickbox If SysCAD finds a valid AQSol Model Configuration unit model, then this field will be enabled.
Status OK The specified chemistry model (AQSol Model Configuration) has been initialised correctly and the database file has been found and loaded correctly.
ChemModel Tag not Specified No tag has been specified for the Chemistry Model. Specify the desired Chemistry Model (AQSol Model Configuration) in the UnitTag field.
Valid ChemModel Tag Required The tag specified for the Chemistry Model in the UnitTag field is invalid and needs to be corrected.
Init Required The specified Chemistry Model (AQSol Model Configuration) needs to be initialised.
ChemModel Load Required The database of the specified Chemistry Model ((AQSol Model Configuration) needs to be loaded.
DLL or Version Error There is a problem with the AQSol DLL or version.
Init Failed Initialisation of the specified Chemistry Model ((AQSol Model Configuration) has been attempted but failed.
UseSysCADVLE / VLE.On Tickbox This can be used to switch on the SysCAD Vapour Liquid Equilibrium (VLE) calculator. If this is 'On' then the associated page, VLE becomes visible and may be configured.
PhaseElemDeportment Tickbox If this is ticked, then the Deportment tab page will appear. This tab shows the mass movement of elements for the Solid, Liquid and Gas phases.
ShowRxnDiff Tickbox If this is ticked, then the Diff tab page will appear. This tab shows the mass movement of each species, positive value indicates the species has been created.
ShowPlotter Tickbox If this is ticked, then the ParamSweep tab page will appear.

DInput tab page

This tab is used to define the Inputs for the AQSol calculation, including the composition in terms of AQSol species. It also includes a button to perform calculations.

Tag (Long/Short) Input / Calc Description/Calculated Variables / Options
PasteFromClipboard PasteFromClipboard.png Click on this button to paste data copied from another AQSol stream (using the 'CopyToClipboard' button). The stream may be in the current SysCAD project, or another project.
Transfer Copy DInput.png Click on this button to transfer the inputs specified on the DInput tab page to the Input tab page.
CalculateEqmAtT Calculate.png Click on this button to perform an Isothermal calculation to determine the conditions of the final solution, including enthalpy, based on the specified temperature and pressure.
MoleInput Tickbox If this is ticked, then the user enters the molar amounts for the AQSol species on this page. If the box is NOT ticked, then the user enters the mass amount of the AQSol species on this page.
Temperature / T Input The required temperature of the aqueous solution.
Pressure / P Input The required pressure of the aqueous solution.
DFeed...
SpeciesName SpeciesLongButton.png
SpeciesShortButton.png
The Species:Long or Short button is used to change the display of the Species names between the Short form, the Chemical compound, or the longer species names.
(The following tables allow the user to specify the composition of the Input by specifying the mass or mole of the individual AQSol species.)
(Each table (one for each phase) has the following columns (one row for each species):)
MassFlow / Qm Input Visible when MoleInput is NOT ticked. The user specified mass flow of each AQSol species.
MassFrac / Mf Display Visible when MoleInput is NOT ticked. The mass fraction of the species in the total input.
PhaseMassFrac / IPh:Mf Display Visible when MoleInput is NOT ticked. The mass fraction of the species in the displayed phase.
MoleFlow / QMl Input Visible when MoleInput is ticked. The user specified mole flow of each AQSol species.
MoleFrac / Mlf Display Visible when MoleInput is ticked. The mole fraction of the species in the total input.
PhaseMoleFrac / IPh:Mlf Display Visible when MoleInput is ticked. The mole fraction of the species in the displayed phase.

TargCalc tab page

This tab allows the user to control the outcome of the AQSol calculation.

Tag (Long/Short) Input / Calc Description/Calculated Variables / Options
Target Calculation
OpMode...
OpMode Temperature The target variable is the Temperature of the final solution.
FeedT The target variable is the Temperature of the feed solution.
Enthalpy The target variable is the Enthalpy of the final solution.
PhaseFormation The target variable is the amount of a particular phase present in the final solution.
TemperatureReqd / T_Reqd Input Only visible if OpMode = Temperature. The user specified target temperature for the final solution.
dEnth.Reqd / dH.Reqd Input Only visible if OpMode = Enthalpy. The user specified target duty.
Phase List Only visible if OpMode = PhaseFormation. The user can select one phase from the list of all phases in the AQSol database.
MoleBasis Tickbox Only visible if OpMode = PhaseFormation. Selecting this tickbox allows user to specify the target mole flow. If this is not selected, then mass flow is used.
MassFlowReqd / QmReqd Input Only visible if OpMode = PhaseFormation and MoleBasis = unticked. The user specified mass flow of the chosen phase that is to be formed.
MoleFlowReqd / QMlReqd Input Only visible if OpMode = PhaseFormationand MoleBasis = ticked. The user specified mole flow of the chosen phase that is to be formed.
Detailed Tickbox If enabled, displays additional parameters for the user to specify. See "AdjustVar" section.
Environmental Heat Transfer
HeatLossMethod None No heat transfer between the unit and the environment.
Fixed HeatFlow The user specifies a fixed heat loss between the unit and the environment.
Ambient SysCAD calculates the overall heat loss based on user specified HTC and Area and the temperature difference between the Feed and environmental temperatures. The environmental temperature is assumed to remain constant.
EHX.HeatLossReqd Input Visible when the HeatLossMethod = Fixed HeatFlow. The required heat loss.
EHX.HTC Input Visible when the HeatLossMethod = Ambient. The Overall Heat Transfer coefficient.
EHX.Area Input Visible when the HeatLossMethod = Ambient. The Heat Transfer area.
EHX.AmbientT Display Visible when the HeatLossMethod = Ambient. The ambient temperature. The ambient temperature is specified in the Plant Model - Environment_Tab
EHX.HeatLoss Calc Visible when the HeatLossMethod = Ambient. The calculated heat flowrate.
(The following fields are only displayed if the Detailed option has been enabled.)
AdjustVar...
Method AdjustT The chosen independent variable is Temperature.
AdjustQMl The chosen independent variable is flow of an individual species.
AdjustDuty The chosen independent variable is Duty.
InitTemperature / InitT Input Only visible if Method = AdjustT. The initial guess to be used for the temperature of the final solution.
MaxTemperature / MaxT Input Only visible if Method = AdjustT. The maximum temperature of the final solution.
TargSpAdjust List Only visible if Method = AdjustQMl. The user can select a single species to have limits imposed from the list of all species in the loaded database.
MoleBasis Tickbox Only visible if Method = AdjustQMl. If this box is ticked, user specifies the minimum and maximum mole flow of selected species. If this is not ticked, user can specify these flows in terms of mass flow.
MinSpMassFlow / MinSpQm Input Only visible if Method = AdjustQMl and MoleBasis is not ticked. The minimum mass flow of the selected species in the final solution.
MaxSpMassFlow / MaxSpQm Input Only visible if Method = AdjustQMl and MoleBasis is not ticked. The maximum mass flow of the selected species in the final solution.
MinSpMoleFlow / MinSpQMl Input Only visible if Method = AdjustQMl and MoleBasis is ticked. The minimum mole flow of the selected species in the final solution.
MaxSpMoleFlow / MaxSpQMl Input Only visible if Method = AdjustQMl and MoleBasis is ticked. The maximum mole flow of the selected species in the final solution.
MinDuty Input Only visible if Method = AdjustDuty. The minimum Duty (external energy added or removed from the model).
MaxDuty Input Only visible if Method = AdjustDuty. The maximum Duty (external energy added or removed from the model).
TargCalc...
UseRelaxation Tickbox
RelaxationFactor Input The relaxationFactor, used when UseRelaxation is ticked. Values limits: 0.001 < RelaxationFactor < 5.
Settings TargSolv Reset Button.png If the user clicks on this button, the all the target solver settings will be reset to their default values.
Solve Solve Button.png If the user clicks on this button, SysCAD will perform the Direct Calculation based on the chosen parameters.

Adding this Model to a Project

Insert into Configuration file

Sort either by DLL or Group.

 

DLL:

ScdAQSol.dll

Units/Links

AQSol: AQSol DirectCalc

or

Group:

General

Units/Links

AQSol: AQSol DirectCalc

See Project Configuration for more information on adding models to the configuration file.


Insert into Project

 

Insert Unit

AQSol

AQSol DirectCalc

See Insert Unit for general information on inserting units.