Hi everyone,

I am trying to simulate a heat exchanger where a hydrogen stream is cooled by a mixed refrigerant stream(the mixed refrigerant is a hydrocarbon blend).

The issue I have is I would like to simulate the hydrogen stream using the REFPROP property method as it is more accurate at modelling ortho and para hydrogen. However, I receive this error for the mixed refrigerant stream.

*** SEVERE ERROR IN PHYSICAL PROPERTY SYSTEM                 (REFPROP.11)

ESTIMATION OF MIXING PARAMETERS IS NOT POSSIBLE

FOR MOST MIXTURES CONTAINING WATER, HEAVY WATER,

HELIUM, HYDROGEN, PARAHYDROGEN, DEUTERIUM, NEON,

AMMONIA, ACETONE, FLUORINE, METHANOL, OR ETHANOL.

REFPROP MODEL CANNOT BE USED FOR MIXTURE ABOVE.

Would it be possible to use a different equation of state (I would choose Peng-Robinson) for the streams with mixed refrigerant in, while still calculating the hydrogen stream properties with REFPROP?

I know it is possible to use different property methods for different blocks but is it possible to use different property methods for different streams in the same block?

Or should I try to add mixing rules to the REFPROP method?

Thank you so much,

Matt