Convert UOMs for Correlation 38

You may have coefficients for correlation 38 that you derived by using different UOMs for the saturated liquid density and vapor pressure than the UOMs that AVEVA Thermodynamic Data Manager uses (kmol/m3 and kPa, respectively). In this case, you must convert your coefficients before you use them in AVEVA Thermodynamic Data Manager.

Because the coefficients will change by constant conversion factors, we can consolidate the changes into only the first coefficient and therefore reduce the number of coefficients that we need to convert. The following equations show the mathematical derivation of the conversion for C1.

where

r* is the saturated liquid density in the original units

P* is the saturation vapor pressure in the original units

fr is the conversion factor that converts the original units for the saturated liquid density into kmol/m3

fVP is the conversion factor that converts the original units for the saturation vapor pressure into kPa

rL is the saturated liquid density in kmol/m3

VP is the vapor pressure

Ci* is the coefficient that you determined by using the original units for saturated liquid density and saturation vapor pressure

If we compare the converted equation to the equation for Correlation 38, we get the following equivalences for the coefficients: