Bug Issue with R245fa

[MP253]

Dear Ian

Thank you for the CoolProp software it is fantastic. I have been using for several months but I have found an issue. I have checked in Python and Matlab and encountered the same problem:

T = Props('T','S',1.8244,'H',470.04,'R245fa')

Gives: Error using Props CoolProp Error: CoolProp error: Invalid values for inputs p=0.0103819 h=470040 for fluid R245fa

Whilst NIST gives T as 354.89 K.

I am at a loss as I cannot understand where the issue is coming from. I am also getting similar discrepancies when comparing data to NIST whilst not actually generating any errors.

Many Thanks

Mark

[ibell]

Interesting. At first I thought it was an issue of reference states, but its seems REFPROP and CoolProp use the same reference state for enthalpy and entropy. Seems like a bug in CoolProp. Where is this state point? Liquid, vapor, two-phase, close to critical point, etc?

On Fri, Jun 13, 2014 at 8:22 PM, MP253 [email protected] wrote:

Dear Ian

Thank you for the CoolProp software it is fantastic. I have been using for several months but I have found an issue. I have checked in Python and Matlab and encountered the same problem:

T = Props('T','S',1.8244,'H',470.04,'R245fa')

Gives: Error using Props CoolProp Error: CoolProp error: Invalid values for inputs p=0.0103819 h=470040 for fluid R245fa

Whilst NIST gives T as 354.89 K.

I am at a loss as I cannot understand where the issue is coming from. I am also getting similar discrepancies when comparing data to NIST whilst not actually generating any errors.

Many Thanks

Mark

— Reply to this email directly or view it on GitHub https://github.com/ibell/coolprop/issues/221.

[MP253]

Thanks for quick reply. This point is a superheated vapour quite close to the saturation line but i have run the same set of equations starting at a closer point to the sat line without problem. I had a similar issue whilst building a lookup table array that I use to implement Coolprop into Simulink, here the calls to Props are all using TP as input.

I have rolled back to a previous version of CoolProp and the results are fine. No errors are generated and the results are with acceptable tolerance to Refprop.