Function of Sankey Diagrams
Sankey diagrams visualize material and energy flows. Mass, energy, or exergy flows are displayed in their quantity proportions on the scheme (see following slider). The thickness of the grid lines corresponds to the relative quantity of the respective flow.
The underlying values for mass, energy, and exergy flux are displayed in a table as a tooltip when the mouse is over the corresponding pin (see the third figure in the following slider).
Activating the Sankey Representation
The Sankey representation can only be displayed after the simulation with the appropriate Material properties (Heat/Cooling: Temperature dependent, Fuel: Considering composition).
The following buttons in the ribbon are available for activating the various views of the Sankey diagrams.
Show Mass View
Show Energy View
Show Exergy View
To switch off the Sankey display and return to the normal view, click on the active (gray highlighted) view button again.
If required, the individual nets (arranged according to material models) can be shown or hidden.
Enthalpy and Exergy Flows
The enthalpy flows are represented in the energy view.
The enthalpy and exergy currents are calculated on the basis of the Reference and Environmental Conditions. These are specified in the form of the Simulation node. The reference point for the exergy calculation is the Ambient condition. The reference point for the enthalpy calculation in the simulation is the Reference state (generally 25 °C and 1 bar).
In order to realize a suitable Sankey representation, the absolute zero point (and not the reference state as in the simulation) is used as the reference point for determining the arrow strength of enthalpy flows.
The strength of the arrows represents the absolute value of the enthalpy difference to the zero point.
For example, a state at 20 °C and 1 bar can have a similar arrow strength as a state at 30 °C and 1 bar, even if the enthalpies calculated in the simulation (with the reference state as reference point) are once negative and once positive.
