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Good morning,
I'm writing to seek your expertise on a coding challenge I'm facing. I'm currently working on a component that involves calling temperature values from CoolProp based on given pressure and enthalpy inputs.
However, I've encountered an issue where, when both pressure and enthalpy values don't exist in the CoolProp database, the returned temperature is infinity. To handle this scenario gracefully, I'd like to implement an if condition within my FORTRAN code.
Unfortunately, I'm unsure how to accurately define this condition. Directly checking for "T = infinity" isn't feasible in FORTRAN. I've explored the CoolProp interface and error messages, but haven't found a suitable solution yet.
I would be grateful if you could provide guidance on how to formulate the if condition to effectively identify and handle this infinity temperature issue.
Thank you for your time and assistance.
Best regards,
I've used catch-all code for illegal values in the past like
If((Temperature<=-1000000).or.(Temperature>1000000.).or.ISNAN(Temperature)) Then Call Messages(-1,'The temperature value is invalid','Fatal',getCurrentUnit(),getCurrentType()) Return End
You could also try Googling for intrinsic Fortran functions that will catch +infinity and -infinity conditions.
Gehad Azmy Topic starter
29/10/2024 1:58 pm
@a_weiss okay
i'm working on this values in certain code
nRef = 729!Air
prop(3) = 104.040
prop(2) = 9998999!Pressure (Pa)
Call CoolProp_Fluid_Properties(prop,nRef,23,iFlagr)
If (ErrorFound()) Return
Temperature = prop(1)
If((Temperature1000000.).or.ISNAN(Temperature)) Then
Call Messages(-1,'The temperature value is invalid','Fatal',getCurrentUnit(),getCurrentType())
Return
End if
open(94, file = 'results.dat', status='old', position="append")
write(94,*) Temperature+273
close(94)
Call SetOutputValue(1, Temperature) ! Enthalpy
Return
End
and i thought that the temperature value was the reason of invalid floating point, can you tell me what the reason of the error? specially these values are working correctly on online coolprop and refprop
A_Weiss 29/10/2024 2:49 pm
@gehadrabee24 Try passing the pressure to CoolProp_Fluid_Properties in MPa instead of Pa. Also make sure your enthalpy is in units of kJ/kg, not J/kg. You can read more about how to use the CoolProp_Fluid_Properties routine beginning on page 7-82 of the ProgrammersGuide.pdf in the Documentation folder of your main TRNSYS directory.
A_Weiss 29/10/2024 2:55 pm
Edit: The documentation in TRNSYS version 18.6 is incorrect. The units of pressure should be in MPa, not Pa.
