Binary Pairs Mixing Data

[Alhabeeb86]

You know R452A is a mixture of R32 , R125 and R1234yf. When I copy R452A.mix from Refprop10 to Refprop9.1 it worked but Refprop showed me a warning message that " no mixture data are available for one or more binary pairs ...". Thus, I copy HMX.BNC from Refprop10 to 9.1, but the warning still appears. How can I solve this problem? BTY, the interface of MATLAB does not work properly with Refprop10 that is why I have to use Refprop 9.1.

[ianhbell]

The REFPROP 10 HMX.BNC is not backwards compatible with 9.1. Better to update your MATLAB interface to the REFPROP 10 via python. That seems to work quite reliably.

[ianhbell]

https://github.com/usnistgov/REFPROP-wrappers/tree/master/wrappers/MATLAB

[Alhabeeb86]

Thanks a lot. Now I have Python interface for Matlab using Refprop 10. Is there a simple syntax to calculate a property like refpropm? Because I didn't fully understand this syntax:

MOLSI = RP.GETENUMdll(int8(1),'MOLAR BASE SI').iEnum; iMass = int8(0); % 0: molar fractions; 1: mass fractions iFlag = int8(0); % 0: don't call SATSPLN; 1: call SATSPLN z = {1.0}; % mole fractions, here a pure fluid, so mole fraction of 1.0 r = RP.REFPROPdll('Water','PQ','T',MOLSI,iMass,iFlag,101325,0.0,z)

[Alhabeeb86]

When I replace water by a mixture, it works just for the first time and when I just repeat the calculation it returns with -9999990?

[ianhbell]

REFPROPdll works much like refpropm. Please read the docs: https://refprop-docs.readthedocs.io/en/latest/DLL/high_level.html#f/_/REFPROPdll

[Alhabeeb86]

Thanks a lot, but is there a direct syntax to find the output property rather than , for example: 1- r = RP.REFPROPdll('CO2;R32;R1234yf','PQ','T',MOLSI,iMass,iFlag,101325,0.0,z); 2- rr=double(r.Output); 3- T=rr(1); Is there a way to use just one syntax rather than three syntaxes

[ianhbell]

double(RP.REFPROPdll('CO2;R32;R1234yf','PQ','T',MOLSI,iMass,iFlag,101325,0.0,z).Output)(1);

[Alhabeeb86]

My syntaxes: clear; clc; RP = py.ctREFPROP.ctREFPROP.REFPROPFunctionLibrary('C:\Program Files (x86)\REFPROP'); MOLSI = RP.GETENUMdll(int8(1),'MOLAR BASE SI').iEnum; iMass = int8(1); % 0: molar fractions; 1: mass fractions iFlag = int8(1); % 0: don't call SATSPLN; 1: call SATSPLN z = {0.03 0.215 0.755}; % mole fractions, here a pure fluid, so mole fraction of 1.0 T=double(RP.REFPROPdll('CO2;R32;R1234yf','PQ','T',MOLSI,iMass,iFlag,101325,0.0,z).Output)(1); But the code didn't work the error message was:

RefpropPy Error: File: RefpropPy.m Line: 7 Column: 3 Indexing with parentheses '()' must appear as the last operation of a valid indexing expression.

[ianhbell]

This is a MATLAB problem, not related to REFPROP

[Alhabeeb86]

Ok. How can I set the output unit like follow: Temperature (K) Pressure (kPa) density (kg/m^3) enthalpy (J/kg) entropy (J/kg k) Thanks

[ianhbell]

You can use custom units (read the docs), but I strongly advise against it. I would recommend you use mass-based SI units, which would be:

RP.MASS_BASE_SI

in your example code. Complete:

clear; clc;
RP = py.ctREFPROP.ctREFPROP.REFPROPFunctionLibrary('C:\Program Files (x86)\REFPROP');
MASSSI = RP.MASS_BASE_SI;
iMass = int8(1); % 0: molar fractions; 1: mass fractions
iFlag = int8(1); % 0: don't call SATSPLN; 1: call SATSPLN
z = {0.03 0.215 0.755}; % mole fractions, here a pure fluid, so mole fraction of 1.0
T=double(RP.REFPROPdll('CO2;R32;R1234yf','PQ','T',MASSSI,iMass,iFlag,101325,0.0,z).Output)(1);