Refprop GUI Version 10.0 tool is not able to output complete temperature - pressure range for R-453A

[krushnaeicp]

Hi,

I want to generate temperature-pressure table starting -84.8F to 192.5F for R-453A but Refprop GUI table starts from -43.5 F and gives lot of warning while generating and stops output at 22.7F. I have seen many intermediate values missing in between provided input range. Please advise what I am missing or if there is any update to fluid or mixture file, please share those to krushna.bolenwar@copeland.com.

I am using English (IP) units and ASHRAE reference point.

[marciahuber]

What version of REFPROP are you using and what is your desired pressure? Can you provide a screenshot of your issue?

[NickAtNight62]

Technical-data-sheet-R-453A-RS70-Gas-Servei-1.pdf

I found a Pressure-Enthaply diagram for R453a (RS70) from Gas Services.

How do the calculated results compare to the published values?

[marciahuber]

You can get wildly different numbers for enthalpy and entropy depending on the reference state that is used, as discussed here https://pages.nist.gov/REFPROP-docs/#reference-states-enthalpy-and-entropy-differences It is difficult to compare tables as you need to use the exact same reference state. To add to the confusion, the REFPROP GUI and the REFPROP DLL have different default reference states. There are several discussions on this github site about the issue as well that may provide useful information.

[NickAtNight62]

You did not state the Pressure you were doing those calculation for I suspect the pressure was set at '5 bar' for the calculations.

From the p-H diagram, 5 bar, appears to be the where the fluid goes from full liquid (-5 C/ 22 F) to full vapor (6.4 C/ 43.5 F).

My hypothesis is that you only got results in the two-phase range. When the fluid was fully liquid (-84.8F to 22.7 /-65 to -5 C) and fully vapor (43.5 F to 192.5 F/6.4 C to 89 C). The cause of the crashes should be shown in the individual error reports.

I would try a default p-H diagram option to verify that the fluid calculations are working over a robust range. You can compare the results quickly to the published Industry values.

There is also a default vapor pressure table option. Perhaps try that second.

I don't have a version of the program available to me since I retired a few years back, so going from memory right now.

You could also try the Excel spreadsheet option.

[krushnaeicp]

Hello All,

I attached the screen shots of the steps I followed and the issue I am getting. Please advise what can be done to get the full range Temperature -> Pressure table generated for R453A for ASHRAE Reference Standard With English Units.

R453A Saturation Temperature - Pressure Table Generation Issue.pdf

[krushnaeicp]

Technical-data-sheet-R-453A-RS70-Gas-Servei-1.pdf

I found a Pressure-Enthaply diagram for R453a (RS70) from Gas Services.

How do the calculated results compare to the published values?

Thank you for the sheet but I need detailed full range Temperature -> Pressure chart with 0.1F steps

[krushnaeicp]

You can get wildly different numbers for enthalpy and entropy depending on the reference state that is used, as discussed here https://pages.nist.gov/REFPROP-docs/#reference-states-enthalpy-and-entropy-differences It is difficult to compare tables as you need to use the exact same reference state. To add to the confusion, the REFPROP GUI and the REFPROP DLL have different default reference states. There are several discussions on this github site about the issue as well that may provide useful information.

I am interested in Temperature and pressures at this point and changing the reference state didnt helped me.

[marciahuber]

You can send an email to REFPROP@nist.gov and they can give you a beta version that should fix your problem.

[NickAtNight62]

Ah, here is the problem !

On your calculations, change your Composition basis.
Specify Liquid at bubble point with coexisting vapor.

Here are the results:
A.txt

You do not have a pure fluid, but a mixture of about 5 components.

So there will be a slight change in the vapor composition from the liquid.

By demanding the compositions of the vapor and liquid MUST BE THE SAME at the SAME TEMPERATURE causes the program to crash.

There are still some issues at the limit of the calculations.

[NickAtNight62]

Additional point.
Under Options/Properties on Mixture tab, check "Composition" and I think "Bulk, liquid and vapor properties.

Then you can see the composition change from the small amount of flash when solving the problem for a saturated liquid. The R32, R125, and propane concentrate up by a factor of 2 in the vapor. I believe the R32/R125 act close to a single component because of their interaction in R32/E125/R134a mixtures. I suspect the propane is independent of them.

This calculation is a 'Specified State Point' with Temp set to -85.8 F and Quality at 0 (liquid)

Thank you for the sheet but I need detailed full range Temperature -> Pressure chart with 0.1F steps
Yes, but the point was to compare those results to the results that you did have to verify that the results you were getting were correct.

[NickAtNight62]

If we take the table and change the input conditions to Pressure of 4.2 psia and a Vapor Quality of 1 (pure vapor) we can see why the programed calculation crashes.

The temperature solves as -75 F if the vapor composition is the same as the original composition because the liquid composition is substantially different.