Pressure plot

A pressure plot is a plot of any thermodynamic or physical or reaction property that is known to a stream versus pressure.

To create a pressure plot, select Pressure Plot from the Create plot sub menu of the Plot menu. Once a pressure plot is created, you can add more series to the plot by selecting Add Series from the Plot menu if the plot is active, or press Ins.

To create a pressure plot with reaction properties, select Pressure Plot With Reaction Data from the Create plot sub menu of the Plot menu.

Before creating a pressure plot, you must create a stream. A series of a pressure plot always refers to a stream. Even if none of the streams conditions are used, the stream still serves as a reference for the thermodynamic models used by the stream type of the stream.

Before you can create a plot with reaction data, at least one reaction package also needs to be present in the simulation.

So you can create plots of properties using different thermodynamic properties by creating two stream types with different models, using each stream type for creation of a stream. Then create a pressure plot using one of the streams, and add a series to the plot using the other stream.

During creation of a plot or a series, you will be prompted for the following input:

Stream

The selected stream for plotting serves as the basis for the thermodynamics and as a reference point for all properties that are not varied (temperature, concentration, ...)

Reaction Package

If you have chosen to create a plot with reaction data, you will be asked for the reaction package to calculate the data.

Reaction

If you have chosen to create a plot with reaction data, you will be asked for the name of the reaction that the property is to be calculated for.

Property

The property to plot. In addition to the thermodynamic and physical properties that are exported by the property package associated with the stream type of the selected stream, you can plot "mass fraction", "mole fraction" and "phase fraction". For a reaction data plot, only reaction properties will be shown.

Phase

The identifier of the phase for which to plot the property for. Not all combinations of phases and properties are allowed (e.g. bubble point is only allowed for the Overall phase). Also, not all combinations of phases and properties make sense (some may not be supported by the property package, like surface tension for the vapor phase).

Note that overall properties are at phase equilibrium.

For a reaction plot, this will be the reaction phase as exported by the reaction package for the selected reaction.

Pure or Mixture

The calculation type for the property.

Depending on the above choices, the property may be a scalar, vector or matrix. For a vector and matrix you can choose which compounds you want to plot the selected property for. Selecting a compound for a vector property results a single plot series; selecting a compound for a matrix property results a vector of plot series.

This does not apply to reaction properties.

Composition type

The following composition types can be used:

• Specified Phase: use the composition corresponding the selected phase, as it appears in the selected stream.
• Overall Phase: use the composition corresponding to the Overall phase of the selected stream.
• Equilibrium: use the composition corresponding the selected phase, after calculating the equilibrium for each plotted data point.
• Override: specify the composition to use.

Temperature type

The following temperature types can be used:

• Stream: use the temperature of the selected stream.
• Override: specify the temperature at which to plot.
• Offset to stream: specify the temperature to add to the temperature of the selected stream.

Range

The pressure range for the independent axis.