Known migration issues

AVEVA Help

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We no longer require AVEVA Help to view the AVEVA Process Simulation Online Help. Therefore, we no longer distribute AVEVA Help with the AVEVA Process Simulation installation package. We no longer install the AVEVA Process Simulation documentation in a location that AVEVA Help can access. Any browser bookmarks that open the AVEVA Process Simulation documentation in AVEVA Help will be broken.

Remove any browser bookmarks that point to the AVEVA Process Simulation documentation hosted on AVEVA Help.

General

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In general, snapshots taken in previous versions of AVEVA Process Simulation should continue to solve in the latest version. As new features are added, old snapshots require more iterations to converge. In some cases, especially for large simulations, reverting old snapshots (taken more than 2 versions earlier) may result in convergence issues.

We recommend periodically re-capturing older snapshots between versions of AVEVA Process Simulation to ensure fast performance and smooth convergence after upgrading.

General: Reaction Submodels

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We have renamed the Fluid Type submodel in the default reaction rate submodels to be StateX instead of State.

We have also added a model connection to each Model Type that supports reaction submodels so that they pass their Fluid Type submodel to these reaction rate submodels. That is, if a model instance includes reactions, then the replaceable reaction rate submodel reuses the fluid state submodel from the parent model. This means that each model instance includes flash calculations for only one fluid state submodel instead of performing flash calculations at both the model instance level and the reaction submodel level.

This change improves robustness and solver speed.

If you previously created custom reaction rate submodels, we recommend that you make a similar change in your custom reaction rate submodels.

In your reaction submodels, rename the Fluid Type submodel to be StateX.

Fluids and Gas Treating Libraries

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We have moved the Model Types and Fluid Types for amine-based gas treating processes from the Fluid Library to the new Gas Treating Library. If you import any simulations from versions earlier than AVEVA Process Simulation 2025 that use these Model Types or Fluid Types, you now see error messages that indicate that you should switch to the corresponding Model Type or Fluid Type from the Gas Treating Library.

The Gas Treating Library is an example Model Library distributed with AVEVA Process Simulation. You must import the Gas Treating Library to use it.

Import the Gas Treating Library, and then replace the affected Model Types and Fluid Types for the model instances in your simulations to use the corresponding Model Types and Fluid Types from the Gas Treating Library.

You can replace the Fluid Types by dragging the Fluid Type from the Gas Treating Library onto the corresponding model instance in the simulation.

You can replace the Model Types by pressing and holding Ctrl and then dragging the Model Type from the Gas Treating Library onto the corresponding model instance in the simulation.

Gas Treating Library

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The stream submodels in the Gas Treating Library now uses a corrected formulation for the solvent mass fraction (xam). This modification results in a higher molar fraction for the solvent, which in turn results in a higher CO2 recovery for a specified solvent rate or a lower solvent rate for a specified CO2 recovery. Simulations that specify the solvent mass fraction variable now solve to new results.

Simulations from versions earlier than AVEVA Process Simulation 2025 that used the stream submodels may no longer open in a solved state. You can switch your simulations to an open-loop configuration to help drive your simulations to the new solution results.

To move any unsolved simulations to the new solution results:

1. Change your simulation to an open-loop configuration for any recycle streams.

   Typically, you can use the configuration options in a Recycle model to switch to an open-loop configuration. Your simulation should solve in the open-loop configuration.

2. Change your simulation back to a closed-loop configuration.

   Your simulation should now solve in the closed-loop configuration.

   If you chose to specify the CO2 recovery, you should see a different solvent rate. If you chose to specify the solvent rate, you should see less CO2 recovery.

Model Types

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The software now uses stricter validation for variables connections. In versions earlier than AVEVA Process Simulation 2025, you could create a valid variable connection between two variables that used different Variable Types if one of the variables came from a replaceable submodel. Starting from AVEVA Process Simulation 2025, you can no longer create valid variable connections between variables that use different Variable Types.

If you import a simulation from a version earlier than AVEVA Process Simulation 2025 and your imported simulation is no longer properly specified (square), your simulation may use a Model Type with a variable connection that is no longer valid in the latest version.

Check any custom and example Model Libraries for red badges on any of the Model Types. If any of your Model Types have red badges, ensure that all the variable connections in the Model Type are still valid.

If your Model Type includes any invalid variable connections, update the variable connections so that the connected variables use the same Variable Type.

Process Library: Analyzer

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We have removed the Analyzer model from the Process Library.

If you want to import simulations from a version earlier than AVEVA Process Simulation 2025 and those simulations use the Analyzer model, you must replace the Analyzer model instances in your simulation with either the RefineryVP model or the Stream model to view the same stream properties.

For true vapor pressure (TVP) and Reid vapor pressure (RVP) calculations, replace any Analyzer models with the RefineryVP model. For dew point and bubble point calculations, use the Stream model with the DewBubblePoint parameter set to Both.

Renewables Library: Thermodynamics

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The thermo method for the default Renewables.GreenH2 fluid was changed to Ideal because it is more robust for renewables simulations with large time steps that do not require as much detail.

If you are currently using the default Renewables.GreenH2 fluid:

3. Ensure you have snapshot that use the original Soave-Redlich-Kwong Modified Panagiotopoulos-Reid (SRKM) method.

4. Switch to Process mode, and then close the application.

5. Open AVEVA Process Simulation 2024.2.

6. Create a copy of the Renewables.GreenH2 fluid in your Models Library.

7. Set the thermo method of the Renewables.GreenH2 fluid to SRKM.

8. Add the fluid to your sources, and then revert to your Process mode Snapshot.

Thermodynamic library improvements

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We constantly review and improve the thermodynamic data that we deliver in our thermodynamic libraries. If you import a simulation from an earlier version of AVEVA Process Simulation, these improvements may change your simulation results.

Review the thermodynamic library changes in Thermodynamic library data and verify your simulation results.

Thermodynamics: Electrolytes

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This migration issue applies to simulations from a version earlier than AVEVA Process Simulation 2025 that use an eNRTL Fluid Type with the Include activity coefficient in liquid fugacity for Henry's solutes checkbox selected. We recommend that you set the solver to manual mode for these types of simulations before you import them into the current version of AVEVA Process Simulation.

When you import this type of simulation, the new Henry Activity checkbox is selected for the following Henry’s solutes:

• Carbon dioxide (CO2)

• Hydrogen sulfide (H2S)

• Ammonia (NH3)

• Hydrochloric acid (HCl)

• Protonated piperazine carbamate (HPZCOO)

  The Henry Activity checkbox is clear for all other Henry’s solutes.

  These new Henry Activity checkbox selections may change the results for your imported simulation.

Review any eNRTL Fluid Types in your imported simulations to ensure that the Henry’s solutes use the desired selections for the Henry Activity checkbox.

If you want to see the same results for your simulation as in versions earlier than AVEVA Process Simulation 2025, you should do the following:

9. Select the Henry Activity checkbox for all Henry’s solutes that had available ternary interaction data in the previous version.

   To view ternary interaction data in the current version, you must first select the Henry Activity checkbox. If you do not see any ternary interaction data in the Method Data section of the Fluid Editor, you should once again clear the Henry Activity checkbox.

10. Clear the Henry Activity checkbox for all other Henry’s solutes.

    If your imported simulations encounter any convergence issues because of this change, we recommend that you select the Henry Activity checkbox for all Henry’s solutes that have available ternary interaction data and troubleshoot from there.

Wastewater Library: ADM1

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If you plan to use a version of the Wastewater Library earlier than version 2025 in the latest version of AVEVA Process Simulation, the ADM1 model has a syntax error in the R_Inerts_S equation that causes an internal error for the ADM1 model.

Update the earlier version of the Wastewater Library so that the R_Inerts_S equation in the ADM1 model includes a brace ("}") after "CO2" in the equation. Only Model Writers can modify the ADM1 model and fix the equation.

Wastewater Library: Pump

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We have changed the default specifications of the Pump, Split, and Clarifier models from the Wastewater Library to support Pumps for a flow-driven system. The model changes include providing a SetQ value for the outlet stream and connections to controllers. The WW1A, WW1B, WW4, and WW5 example simulations were impacted by these changes, and snapshots from AVEVA Process Simulation 2024 are not compatible with the Model Library changes in the latest version.

These changes cause three specifications errors in the Clarifier and Split models for imported simulations created in AVEVA Process Simulation 2024. In the latest version (2024.2), you can see the changes in the preceding models and the warning messages on the Mix and Outflow models to add Pumps in the required streams for transition to Fluid Flow mode and Dynamics mode.

Specify the sludge flow in the Clarifier and one of the outflows from the Split model to have a properly specified (square) and solved status in the wastewater example simulations from AVEVA Process Simulation 2024.