Product flash

The product stream of any CAPE-OPEN unit operation must be in phase equilibrium. The XFlowLoader unit operation must therefore perform a phase equilibrium calculation on the product stream. The type of phase equilibrium specification can be configured from the Settings page of the XFlowLoader user interface.

The following options are available:

Automatic (default)
Pressure and Temperature (TP): the product stream is flashed using a pressure and temperature specification
Pressure and Vapor Fraction (P-VF): the product stream is flashed using a pressure and vapor fraction specification
Pressure and Enthalpy (PH): the product stream is flashed using a pressure and enthalpy specification. The enthalpy is calculated from the corrected enthalpy and reference state specifications in the XFlow file.

Automatic flash

By default, the flash type is automatically determined. If an AutoFlash recommended flash entry is present in the XFlow file, this will be used. Such a flash recommendation is written by the XFlowSaver unit operation if the recommended flash options is enabled.

If an AutoFlash entry is not present in the XFlow file (or if its content is not recognized), the XFlowLoader unit operation will perform:

a P-VF flash if a phase with state of aggregation "Vapor" is present in the XFlow file with a "Phase Fraction" of 0 or 1, and multiple phases are present.
a PH flash if the number of compounds is less than the number of phases (e.g. 1 compound in 2 phases). The number of compounds is determined from non-zero compositions after compound mapping, where a composition is considered zero if smaller than 10^-10.
a TP flash if none of the above conditions hold