Aspen Physical Property System - Physical Property Models

DIPPR
DIPPR equation 105 is the default DIPPR equation for most substances:
This equation is similar to the Rackett equation.
DIPPR equation 116 is the default equation for water.
� = 1 - T / Tc
Other DIPPR equations, such as equation 100, may be used for some
substances. Check the value of THRSWT/2 to determine the equation used.
See Pure Component Temperature-Dependent Properties for details about
DIPPR equations.
In either case, linear extrapolation of �i *,l versus T occurs outside of
temperature bounds.
Parameter
Name/Element
2 Thermodynamic Property Models 203
Symbol Default MDS Lower
Limit
Upper
Limit
Units
DNLDIP/1 C 1i — x — — MOLE-DENSITY †
DNLDIP/2 C 2i 0 x — — †
DNLDIP/3 C 3i T ci † x — — TEMPERATURE †
DNLDIP/4 C 4i 0 x — — †
DNLDIP/5 C 5i 0 x — — †
DNLDIP/6 C 6i 0 x — — TEMPERATURE
DNLDIP/7 C 7i 1000 x — — TEMPERATURE
† For equation 116, the units are MOLE-DENSITY for parameters DNLDIP/1
through DNLDIP/5 and the default for DNLDIP/3 is 0. For equation 105,
DNLDIP/5 is not used, and absolute temperature units are assumed for
DNLDIP/3.
PPDS
The PPDS equation is:
Linear extrapolation of �i *,l versus T occurs outside of temperature bounds.
Parameter
Name/Element
Symbol DefaultMDS Lower
Limit
Upper
Limit
MW M i — — 1.0 5000.0 —
Units