Issue evaluating Temperature from Pressure and Enthalpy

[LugPaw]

In an Excel/VBA simulation that I was running, REFPROP complained about a “type mismatch” trying to extract the temperature of WATER from the given pressure and enthalpy input in the shaded row of the table below.

This is weird because the inputs are nowhere near edge of the range of validity. In fact, perturbing the enthalpy by 0.5 and 1 kJ/kg on the minus side gives the correct values, while I have to perturb it by a full 1 kJ/kg to get it to evaluate correctly on the plus side.

Is there a patch that I need to download to fix this issue?

Thanks

[ianhbell]

Yes, this is a bug, and we have a beta version that fixes this bug, but it has some other regressions (new bugs) so I cannot recommend the beta without reservation. If you want to try the beta, please email me at: ian.bell@nist.gov

[ianhbell]

Mysteriously your bug does not appear to be present on my mac with REFPROP 10.0. On my machine:

import os 
import ctREFPROP.ctREFPROP as ct
root = os.getenv('RPPREFIX')
RP = ct.REFPROPFunctionLibrary(root)
RP.SETPATHdll(root)
RP.SETFLUIDSdll('WATER')

p = 21.82990e6 # [Pa]
for h_kJkg in [137.5115, 138.0115, 138.5115, 139.0115, 139.5115]:
    r = RP.REFPROPdll('','HP', 'T', RP.MASS_BASE_SI,0,0, h_kJkg*1e3, p, [1.0])
    print(r.Output[0]-273.15)

yields no failures

28.06610446422252
28.1873315134373
28.308564081043983
28.429795268751946
28.551025071499396

[LugPaw]

I wonder if it has something to do with REFPROP 10 and Windows. One of my colleagues has REFPROP 10 and has the same issue whereas the other who uses REFPROP 9 (NIST-Steam) does not. I was able to circumvent the Temperature issue by using an external iteration, but noticed that density, viscosity, and other thermophysical properties also cannot be evaluated by REFPROP at this particular P,h combination. Any suggestions as to a robust workaround? From: Ian Bell ***@***.***> Sent: Tuesday, September 26, 2023 2:11 PM To: usnistgov/REFPROP-issues ***@***.***> Cc: Sharat Chandrasekhar ***@***.***>; Author ***@***.***> Subject: Re: [usnistgov/REFPROP-issues] Issue evaluating Temperature from Pressure and Enthalpy (Discussion #615) You don't often get email from ***@***.******@***.***>. Learn why this is important<https://aka.ms/LearnAboutSenderIdentification> Mysteriously your bug does not appear to be present on my mac with REFPROP 10.0. On my machine: import os import ctREFPROP.ctREFPROP as ct root = os.getenv('RPPREFIX') RP = ct.REFPROPFunctionLibrary(root) RP.SETPATHdll(root) RP.SETFLUIDSdll('WATER') p = 21.82990e6 # [Pa] for h_kJkg in [137.5115, 138.0115, 138.5115, 139.0115, 139.5115]: r = RP.REFPROPdll('','HP', 'T', RP.MASS_BASE_SI,0,0, h_kJkg*1e3, p, [1.0]) print(r.Output[0]-273.15) yields no failures 28.06610446422252 28.1873315134373 28.308564081043983 28.429795268751946 28.551025071499396 — Reply to this email directly, view it on GitHub<#615 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/BC2W4J736E65RSDRZURCN43X4MSEPANCNFSM6AAAAAA5H3XNRA>. You are receiving this because you authored the thread.Message ID: ***@***.******@***.***>> *** CAUTION: This email originated from outside your organization. Exercise caution when opening attachments or clicking links, especially from unknown senders. *** ------------------- Notice & Disclaimer: If you have received this email in error please notify the system manager at ***@***.*** and/or notify the sender immediately by e-mail. This email and message are confidential and contains confidential information that is intended only for the individual(s) or entity(ies) addressed and named. If you are not the named addressee, do not disclose, disseminate, distribute, copy, or save this e-mail and/or its attachments, files, links, and trail (except as requested herein). Please delete them from your system, and do not take any action in reliance on the contents of this information, as any action or reliance is strictly prohibited and expressly disclaimed. -------------------