25.12.2012 Views

Aspen Physical Property System - Physical Property Models

Aspen Physical Property System - Physical Property Models

Aspen Physical Property System - Physical Property Models

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

IK-CAPE Vapor Pressure Equation<br />

The IK-CAPE model is a polynomial equation. If the parameter PLPO is<br />

available, the <strong>Aspen</strong> <strong>Physical</strong> <strong>Property</strong> <strong>System</strong> can use the IK-CAPE vapor<br />

pressure equation:<br />

Linear extrapolation of ln pi *,l versus T occurs outside of temperature bounds.<br />

Parameter<br />

Name/Element<br />

2 Thermodynamic <strong>Property</strong> <strong>Models</strong> 185<br />

Symbol DefaultMDS Lower<br />

Limit<br />

Upper<br />

Limit<br />

Units<br />

PLPO/1 C 1i X PRESSURE<br />

TEMPERATURE<br />

PLPO/2, ..., 10 C 2i , ..., C 10i 0 X TEMPERATURE<br />

PLPO/11 C 11i 0 X TEMPERATURE<br />

PLPO/12 C 12i 1000 X TEMPERATURE<br />

PML Vapor Pressure Equations<br />

The PML vapor pressure equations are modified versions of the Antoine and<br />

Wagner equations. Each equation comes in two alternate forms, identical<br />

except for the use of natural or base-10 logarithms. Parameter LNVPEQ/1<br />

specifies the number of the equation used. Each equation uses a separate<br />

parameter: LNVP1 for equation 1, LOGVP1 for 2, LNPR1 for 3, LOGPR1 for 4,<br />

LNPR2 for 5, and LOGPR2 for 6.<br />

Equation 1 (natural logarithm) and 2 (base 10 logarithm):<br />

Equation 3 (natural logarithm) and 4 (base 10 logarithm):<br />

Equation 5 (natural logarithm) and 6 (base 10 logarithm):<br />

Where:<br />

Tri = T / Tci<br />

pri *,l = pi *,l / pci<br />

LNVPEQ/2 and LNVPEQ/3 are the lower and upper temperature limits,<br />

respectively.<br />

In equations 1-4, if elements 4, 7, or 8 are non-zero, absolute temperature<br />

units are assumed for all elements.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!