INCOMP::AEG[0.5] is different from the ASHRAE HANDBOOK 2021 SI

[birdol]

Cooprop Ver 6.6
Windows 11 ，Excel 2016

I compared the differences in the calculations ，As shown in the figure

Is this normal? Or am I doing something wrong?

[ibell]

That is normal - the models are not identical. Did you look into which data are used in CoolProp and the handbook?

[birdol]

emm....I don't know how to determine what data coolprop uses

[ibell]

@jowr do you have any idea? Is it because the precise model used in the handbook is not used, rather the model is fit to the tabulated data?

[jowr]

The data we use is here: https://github.com/CoolProp/CoolProp/blob/master/dev/incompressible_liquids/CPIncomp/data/SecCool/xVolume/ASHRAE%2C%20Ethylene%20Glycol_Cond.txt

Are you sure you are comparing the correct fractions? Are you actually using volume fractions?

[jowr]

Furthermore, we used the ASHRAE Handbook 2001 - maybe the data changed in the meantime?

[birdol]

Furthermore, we used the ASHRAE Handbook 2001 - maybe the data changed in the meantime?

According to my current verification, you are correct. The content in the ASHRAE Handbook is the same in the 2017 and 2022 2021 versions, but it seems there are differences in the 2001 version, possibly due to some errors. Please refer to the image for more details.

[ibell]

Probably the models used to generate the tabular data have been updated, which is why the numbers are different. Is it stated what models were used?

[birdol]

In the 2021 version of the handbook, only the data source is indicated as Source: Dow Chemical 2001b. No detailed information.