Query HEOS Fluid Mixture R134a & Ethanol

[AidanHumble]

Hi using the Excel plugin for Coolprop

Running the base formula =PropsSI("D","T",293.15,"Q",0,"HEOS::Ethanol[x]&R134a[1-x]") where x is the ethanol fraction produces the following output

Ethanol | R134a | Coolprop HEOS
0 | 1 | 1225.333
0.1 | 0.9 | 1206.143
0.2 | 0.8 | 1183.969
0.3 | 0.7 | 1157.077
0.4 | 0.6 | 1124.357
0.5 | 0.5 | 1085.186
0.6 | 0.4 | 1039.281
0.7 | 0.3 | 986.584
0.8 | 0.2 | 927.1991
0.9 | 0.1 | 861.3506
1 | 0 | 789.3366

The curve produced does not match measured data which pretty much follows the ideal mixture curve eg, Ref: https://core.ac.uk/download/pdf/288360819.pdf.

is there an error in the basis of the formula that I am missing?

As far as I can tell installed version is 6.4.10 (IT managed install)

Regards

Aidan

[ibell]

Two things: 1. Please calculate deviations 2. What mixture model is being used in CoolProp? They are listed here: http://www.coolprop.org/fluid_properties/Mixtures.html#binary-pairs. If it is the model I made, no densities were used to parameterize the model. You can email me my day job ***@***.***) to discuss this model.