The fluid state submodel in a reaction submodel

All reaction submodels need access to variables calculated by the fluid state submodel. This fluid state submodel should be at the same conditions as the main fluid state submodel from the reaction submodel's parent model. To improve robustness and calculation speed, all Model Types that include reactions use a model connection from the parent model to the reaction submodel instead of solving the fluid state in the reaction submodel. The model connection passes the solved variables from the parent fluid state directly to the reaction submodel fluid state without the need for additional flash calculations.

The model connection expects the fluid state submodel in the reaction submodel to be named StateX. If your reaction submodel uses a different name for its fluid state submodel, it cannot communicate with the parent model to the receive the fluid state data. We recommend that you always name the fluid state submodel in your reaction submodel as StateX.

For Model Types that include reactions in multiple phases, such as the PFRElem submodel from the Process Library, each phase reaction has its own StateX submodel that connects to the fluid state submodel of the parent model.