NIST REFROP - Thermodynamic calculations in Labview

[MSIEV]

Hello,

I currently use Labview 2018 64 bits. NIST REFPROP 9.1 is also installed.

I have to write a VI which can access to thermodynamic properties of R134a & R1234yf fluids and perform calculations.

However, I do not find any Labview package for Refprop.

I saw some Labview Refprop wrappers available for Labview 2021 and Refrop 10.0.

Should consider an upgrade to be able use these wrappers ?

Is there any other solution (in order to run thermodynamic calculations) compatible with my current software versions ?

Thanks

[GerdW]

Hi MSIEV,

---

@MSIEV wrote:

Should consider an upgrade to be able use these wrappers ?

Is there any other solution (in order to run thermodynamic calculations) compatible with my current software versions ?

---

I used RefProp with LabVIEW 2014 and 2017 successfully, so you don't need to upgrade. I used LabVIEW-32bit, this might be an issue with your 64bit version!

Other solutions I used are FluidProp, which was used as the wrapper around RefProp to employ a more simple API.

[MSIEV]

Hello GerdW,

Thanks for your reply, I will investigate for FluidProp solution.

[d_mc]

Hi MSIEV, I know this is an old thread, but I was wondering if you had any luck getting the thermo table to work in Labview.  I need to do the same thing but with R290.  I need to be able to calculate and use thermo properties from temps and pressures I will be measuring.  I would like to get them dynamically as the temperature and pressure data is measured in order to calculate capacities at the evaporator and condenser with changing conditions.  Thanks

[MSIEV]

Hello,

My current solution is to make thermodynamic calculation in Excel Refprop via ActiveX.

This is not 100% satisfying because I can not get the thermodynamic data updated in dynamic.

However, now I have updated Labview version to 2025 so I have to continue to investigate how to implement Refrop in a VI.

[d_mc]

Just wanted to say thanks for your reply.  I got coolprop to work in LabVIEW.  It was a little tricky with the DLL but it will calculate anything dynamically with regards to thermo properties.

[GerdW]

Hi,

the bandaid solution is to calculate the needed thermodynamic properties in advance and to create tables of those values. Your VI can then interpolate using the p,T measurement data and the tables.

This will be mostly accurate as long as you don't cross any phase change borders…

(I used this approach when I needed thermodynamic data on cRIO.)

One can also create two (or more) tables, (one for fluid, one for gaseous state) and switch between them based on p,T conditions.

[MSIEV]

Hello,

Last update from my side:

Finally, based on the Refprop VI examples that I got from Refprop wrapper, I could adapt the VI and use them dynamically in my application.
The only tricky part was the manual update of the dll path, otherwise, it works as expected.