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refprop

In order to get the REFPROP.dll file you need to first buy REFPROP from NIST

http://www.nist.gov/srd/nist23.htm

Message 21 of 45
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Hello,

 

Thank you for the reply.  I am looking at a VI that you wrote entitled "Gas Properties RefpropDLL 8.1 01-15-2009.vi".  On the front panel you state "This version requires a modified mixture file HMX.BNC that includes models for Ne/CO2, Ne/He, and Ne/H2O. This eliminates need for 3 different mole fraction definitions otherwise needed for Refprop.dll calls. Version 8.1 of Refprop.dll required for C* to work."  Is version 8.1 even released yet, on the FAQ page it says it will not be released for the next 6 months.  Is C* dependent on version 8.1 can it be made to work with refprop version 8 if the C* dll is modified?  I appreciate any help you are able to give, I get the feelin that I am just walking into the woods on this one.

Message Edited by jmcbee on 02-13-2009 10:00 AM
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Message 22 of 45
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I am beginning to understand this.  The refprop.dll has a list of available functions, version 8.1 is needed in order to call the C* function.  Did you use the excel spreadsheet to create your function calls or is there a manual somewhere?
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Message 23 of 45
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and where did you get version 8.1 from?
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Message 24 of 45
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Hello,

 

I am having trouble calling the function "THERM3dll" from Refprop, I am getting error 1097 (this is a LabVIEW error and not a Refprop error).  I have attached the VI I am using to call the function, let me know if you can see where went wrong.

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Message 25 of 45
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jacbenimble wrote:

 

I have used other DLL’s with the CIN tool but can not seem to make this REFPROP DLL work.

On the first hand, is this possible... ?! Smiley Indifferent

 

All these days I thought CLF nodes are meant to be used to call DLLs & CINs are meant to be used to call C code directly in LV.

 

Is the above thing possible too?

- Partha ( CLD until Oct 2021 🙂 )
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Message 26 of 45
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Hi,

 

attached you find a program to use the refprop.dll in LabVIEW. Put the LV-RP.llb in your Refprop installation folder or copy the folders "fluids" and "mixtures2 as well as the "Refprop.dll" in a separate folder. Maybe there will be a problem with the decimal separators. Then you have to edit the “Read Mixture file komma.vi”. I included an instruction in the block diagram.

Unfortunately some of the calculated values are a little different from the values I get from RefProp (and from the Excel macro that comes with Refprop). Can anyone tell what is wrong?

 

Philipp

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Message 27 of 45
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I don't know if this will help at all, but try switching the reference state from default to ashrea.  It is an input on the setup vi.  Excel and the labview vi agree after that.
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Message 28 of 45
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Hello,


Where abouts are you based. I did some work with refprop a couple of years ago with some C dlls.

What is it you are trying to achieve?

 

Regards


Peter

 

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Message 29 of 45
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We have used refprop for a while (using in excel spreadsheet form).  I am trying to consolidate the number of applications and windows needed to be open during a particular stands operation.  I have been using labview for a couple of years so it is the best choice for my situation.  I did a couple of quick comparison between the excel spreadsheets and the labview VI and they came out within .01% which I attributed to rounding errors by one of the two methods.  I used the example code provided with refprop and added subvis to convert to the units I needed.  In the directory with the example refprop code they include subvis to convert between units.
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Message 30 of 45
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