如何用chemcad 关联UNIQUAC 模型参数。

如何用chemcad 关联UNIQUAC 模型参数。摘自chemcad help
In the UNIQUAC K model, the liquid phase activity coefficients for each species are calculated by the UNIQUAC equation. CHEMCAD supports up to 8 parameters ( Aij, Aji, Uij-Uji, Uji-Uij, Cij, Cji, Dij, Dji) for the UNIQUAC model.

where:
ϕi = xi * ri / (Σ xj * rj)
θi = xi * qi / (Σ xj * qj)
τij = exp [Aij - (U ij - Ujj) / RT + Cij*Ln(T) + Dij*T ]
T = Temperature in degrees Kelvin
li = (z / 2) * (ri - qi) - ri + 1
z = 10 (coordination number)
qi = van der Waals area parameter (Awi / (2.5 * 10E9) where Awi is the van der Waals area)
ri = van der Waals volume parameter (Vwi / 15.17 where Vwi is the van der Waals volume)

For comparison to DECHEMA format values aij and bij:
aij + bij/T = Aij + (Uij - Ujj) / RT
bij = - (Uij - Ujj)/R
aij = Aij

The UNIQUAC binary interaction parameters Aij, (Uij - Ujj) and (Uji - Uii) are in cal/gmol.
The binary interaction parameters (BiPs) Cij and Dij are optional.
Several binary interaction parameters (BiPs) are in the UNIQUAC program. The Thermophysical menu command Edit BIPs can be used to view existing BIPs for the system, if the K-value model is UNIQUAC.
The UNIQUAC equation uses qi, the van der Waals area parameter, and ri, the van der Waals volume parameter. Values for qi and ri are required for each component in the mixture.
Values of qi and ri stored in the databank were computed for use with the UNIQUAC model. If qi and ri are not in the databank for the component (i.e., a user-added component) they will be computed using the UNIFAC group Qk and Rk (see UNIFAC).
Earlier versions of CHEMCAD (before Version 3.0) did not store values for qi and ri in the databank. Therefore, whenever UNIQUAC was used, these values were calculated by summing UNIFAC group surface and volume parameters over all of the groups in the molecule.
If the user selects UNIQUAC method and wants to use the UNIFAC values Qk and Rk to calculate qi and ri, select the VLE method called UNIQUAC / UNIFAC on the K-value menu.
When regressing BIPs for UNIQUAC in the default condition, CHEMCAD calculates only (Uij - Ujj) and (Uji - Uii).  Aij and Aji are set to zero. If you want to calculate all four BIPs during the regression, simply include initial estimates for Aij and Aji during the regression analysis.