UAS Thermo Methods

User-Added Subroutines (UAS) may be linked into the PRO/II simulator for the prediction of K-values, enthalpies, entropies and densities.

Fifteen slots are available for these methods, the corresponding subroutines are UKHS1 through UKHS15.

Considerations when using Water Decant

When Water Decant is active, PRO/II normally treats water separately from other components.

User-added routines UKHS1 - UKHS15 typically include special logic to call out for separate water property calculations.

Traditionally, user-added subroutines always called interface routine UH2OP to compute water enthalpy. For example:

SUBROUTINE UKHS6

. . .

! Perform this calculation ONLY if DECANT is ON

! Use subroutine UH2OP to compute a water property

IF( KDECNT .GT. 0 ) THEN

CALL UH2OP( 4, 1, TEMPX, PRESX, TDELTX, wProp, TDERIV )

Starting with PRO/II version 8.2, for water enthalpy only, users now may specify the same user-added subroutine to compute water enthalpy that is used to compute enthalpy for all other components.

1. Code a user-added subroutine to compute enthalpies, including water enthalpy.

2. In a thermo Method set, declare a user-added subroutine for both vapor and liquid enthalpy.

3. Add a Water statement with DECANT=ON and ENTHALPY=USER.

For example, assuming the use of user-added subroutine UKHS6,

THERMO DATA

METHOD ... ENTHALPY(VL) =U6 ! Instructs PRO/II to use UKHS6 for enthalpy

WATER DECANT=ON, ENTHALPY=USER ! Instructs PRO/II to use UHKS6 for water enthalpy.

Note the WATER ENTHALPY=USER entry forces use of the user-added method declared by the METHOD ... ENTHALPY(VL) entry.

For details about constructing User-added subroutines, consult the PRO/II User-added Subroutines User Manual.

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