PHREEQC Side Calc Model

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Navigation: Main Page -> Models -> PHREEQC Models -> PHREEQC Side Calc Model

PHREEQC Overview PHREEQC Model Configuration PHREEQC Direct Calc Model PHREEQC Side Calc Model PHREEQC Reactor

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


General Description

The PHREEQC Side Calc model allows the user to 'call' the PHREEQC solver to determine the state of a defined SysCAD stream. The user defines the SysCAD stream of interest, and the unit will then determine the equilibrium conditions of the resulting stream at the user defined conditions such as temperature or enthalpy. This is similar to the use of the PHREEQC Reactor using the Side Calc model option.

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 a stream.

Notes

  1. The user MUST have added and configured a PHREEQC Model Configuration unit in the SysCAD project before this unit can function.
  2. The user MUST have installed a version of PHREEQC on their computer to make use of the PHREEQC functionality in SysCAD. Please see wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc for more information.

Diagram

TPS Side Calc.png

The diagram shows the default drawing of a PHREEQC Side Calc unit model.

Inputs and Outputs

There are no connections to this unit.

Model Theory

The PHREEQC Side Calc Model uses the PHREEQC algorithms and data to determine the status of the aqueous solution in the defined stream.

The Input, Output and RxnSummary pages are displayed using PHREEQC species, as defined in the database (dat) file specified in the corresponding PHREEQC Model Configuration unit model. The species used in the SysCAD project are shown on the optional Sp pages, shown as part of the QFeed, QBypass, QUnmapped, QRxnProdBypass and QProd pages.

The calculations performed are similar to using PHREEQC directly, except the contents of the SysCAD stream are mapped to equivalent PHREEQC species using the settings defined in the PHREEQC Model Configuration unit model. Please see wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc for more information.

WorkFlow

The suggested workflow for configuring the model is:

  1. Make sure the project contains at least one of the PHREEQC Model Configuration model, and the model is loaded with the correct PHREEQC database file you would like to use for the side calculation.
  2. On the Side Calc PHREEQCSideCalc Tab page, type in the name of the SysCAD stream or content you wish to evaluate (eg: P_001.Qo OR TNK_001.QFeed)
  3. Choose when to perform the calculation.
  4. Choose the Target Calculation Mode and fill in the required information based on the mode selection.
  5. select the correct ChemModel (to match step 1)
  6. Perform an equilibrium calculation by pressing the "Calculate" button or pressing Solve in SysCAD.
  7. The Results are displayed in the Results and Output tabs.

Suggestions on how to use the results:

  • The PHREEQC Side Calc results can be used to assist with the configuration of with a SysCAD unit, normally with Reactions sub-model switched on. Based on the results of the PHREEQC Side Calc, the reaction and reaction extents can be configured to match results from the PHREEQC Side calc. User can use the SetTag controller to transfer PHREEQC Side Calc results to the SysCAD unit RB block.

Data Sections

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

  1. PHREEQCSideCalc tab - This first tab allows the user to choose the desired SysCAD stream, corresponding PHREEQC Model Configuration unit and set some general options.
  2. QFeed - Optional tab, only visible if ShowQFeed is enabled on the first tab page.
  3. VLE - Optional tab, only visible if the UseSysCADVLE/VLE.On option is enabled on the first tab page.
  4. CFE - Optional tab, only visible if the UseCFE option is enabled on the first tab page.
  5. Bypass - Optional tab, only visible if the WithBypass option is enabled on the first tab page.
  6. Results tab - This tab displays the key results of the calculations.
  7. Input tab - This tab displays a summary of the mapped Input stream as PHREEQC species.
  8. Output tab - This tab displays the Output stream results including the amounts of each PHREEQC species present in the final mixture.
  9. Diff tab - This tab displays the amounts of each species which are formed or reacted as part of the calculations.
  10. ParamSweep tab - This tab allows the user to generate sets of data.
  11. 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.
  12. ElemBal tab - This tab displays an elemental balance between the Input and Output streams.
  13. Deportment tab - This tab shows the mass movement of elements for the Solid, Liquid and Gas phases.
  14. QBypass - Optional tab, only visible if ShowQBypass is enabled on the first tab page.
  15. QUnmapped - Optional tab, only visible if ShowQUnmapped is enabled on the first tab page.
  16. QRxnBypass - Optional tab, only visible if ShowQRxnBypass is enabled on the first tab page.
  17. QProd - Optional tab, only visible if ShowQProd is enabled on the first tab page.
  18. Info tab - contains general settings for the unit and allows the user to include documentation about the unit and create Hyperlinks to external documents.

PHREEQCSideCalc tab page

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

Tag (Long/Short) Input / Calc Description/Calculated Variables / Options

Common Data on First Tab Page

======== BETA VERSION ========
This program contains PHREEQC Copyright U.S. Geological Survey (USGS)
Requirements
On Tickbox If this option is deselected, the PHREEQC SideCalc model will not be operational and thus no calculations will be performed.
SourceTag Input The tag of the stream that the user wants to perform a PHREEQC side calculation on. The format is:

[Unit Operation Tag Name].[Tab Page Name]

Examples: XPG_1.QProd, P_1.Qo, X_1.QProd, TNK_1.QFeed

CalcWhen Manual The side calculation will only be performed if the user presses the Calculate button.
EachIter The side calculation will be performed at the end of each iteration during the model run.
OnStop The side calculation will be performed once at the end of the run when the model is stopped.
CheckTag Check Tag.png If the user clicks on this button, SysCAD will check that the SourceTag is a valid stream.
Calculate Calculate.png Click on this button to perform the side calculation to determine the conditions of the final solution, based on the specified target value.
AllowUnmappedDuringSolve / Slv.AllowUnmapped Tickbox If enabled, unmapped species will be ignored with no warnings given.
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.
SpeciesFormation The target variable is the amount of a particular species 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 PHREEQC database.
Species List Only visible if OpMode = SpeciesFormation. The user can select one species from the list of all species in the PHREEQC database.
MoleBasis Tickbox Only visible if OpMode = PhaseFormation or SpeciesFormation. 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 or SpeciesFormation and MoleBasis = unticked. The user specified mass flow of the chosen phase/species that is to be formed.
MoleFlowReqd / QMlReqd Input Only visible if OpMode = PhaseFormation or SpeciesFormation and MoleBasis = ticked. The user specified moles of the chosen phase/species that is to be formed.
Detailed Tickbox If enabled, displays additional parameters for the user to specify as explained below in 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.
Chemistry Model
ChemModel...
UnitTag List The tag of the relevant PHREEQC Model Configuration unit model- this may be chosen from the drop down list of all PHREEQC Model Configuration unit models available in the project.
Check Check Tag.png If the user clicks on this button, SysCAD will check that the UnitTag is a valid PHREEQC Model Configuration unit model.
ConnOK Tickbox If SysCAD finds a valid PHREEQC Model Configuration unit model, then this field will be enabled.
Status OK The specified chemistry model (PHREEQC 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 (PHREEQC 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 (PHREEQC Model Configuration) needs to be initialised.
ChemModel Load Required The database of the specified Chemistry Model ((PHREEQC Model Configuration) needs to be loaded.
DLL or Version Error There is a problem with the PHREEQC DLL or version.
Init Failed Initialisation of the specified Chemistry Model ((PHREEQC 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.
UseCFE Tickbox If this is ticked, then the CFE (Constrained Free Energy) tab page will appear.
  • This feature is available with the Full version of ChemApp only, and it requires a specially programmed CST file to enable this. If CFE is not available, this ticked box will be greyed out.
  • This option allows a portion of a species to be locked up and not allowed to react.
  • Applying CFE can have a significant effect on the final composition, use of this feature requires detailed knowledge of the process chemistry.
WithBypass Tickbox If this is ticked, then the Bypass tab page will appear.
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.
Options
ShowQFeed Tickbox Allows the user to view the QFeed and associated tab pages, showing the properties of the combined feed stream. See Material Flow Section. This will be prior to any sub-model (eg reactions) actions or PHREEQC calculations.
ShowQProd Tickbox Allows the user to view the QProd and associated tab pages, showing the properties of the products. See Material Flow Section. This will be after the actions of any sub-models and PHREEQC calculations.
ShowQUnmapped Tickbox Allows the user to view the QUnmapped and associated tab pages. See Material Flow Section. This is the SysCAD species flows which are not mapped to PHREEQC species, and therefore are not taken into account in the PHREEQC calculation.
ShowQBypass Tickbox Only visible when WithBypass is ticked. Allows the user to view the QBypass and associated tab pages. See Material Flow Section. This is the SysCAD species flows which bypass the PHREEQC calculation.
ShowQRxnBypass Tickbox Only visible when WithBypass is ticked. Allows the user to view the QRxnBypass and associated tab pages. See Material Flow Section.
ShowRxnDiff Tickbox Allows the user to view the Diff tab page. This shows the difference between the mapped input stream seen by PHREEQC and the PHREEQC calculation results.
ShowPlotter Tickbox Allows the user to perform a parameter sweep using the product stream of the side calculator. If this is ticked, then the ParamSweep tab page will appear.
PHREEQCInput PHREEQCInput button.png If the user clicks on this button, SysCAD will create the files PHREEQC_outputIn.pqi and PHREEQC_outputOut.pqi in the CfgFiles folder of the project. These files contain information relating to the PHREEQC input and output streams used in the model and can be opened with the PHREEQC software.

Adding this Model to a Project

Insert into Configuration file

Sort either by DLL or Group.

 

DLL:

ScdPHREEQC.dll

Units/Links

PHREEQC: PHREEQC SideCalc

or

Group:

General

Units/Links

PHREEQC: PHREEQC SideCalc

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


Insert into Project

 

Insert Unit

PHREEQC

PHREEQC SideCalc

See Insert Unit for general information on inserting units.