Using Refprop to calculate a refrigerant state

[alhabeeb]

Hi,

I would like to know how can I calculate a refrigerant state (e.g. subcooled or superheated)  using Refprop in labview? 

Thanks

Alhabeeb

[GerdW]

Hi alhabeeb,

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@alhabeeb wrote:

I would like to know how can I calculate a refrigerant state (e.g. subcooled or superheated)  using Refprop in labview?

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You can do so by using a proper interface to RefProp and by calling the right functions with correct parameters…

I recommend to use the FluidProp interface with RefProp as calculation library in the background.

(And based on your earlier messages I also recommend to learn more LabVIEW basics before starting this task.)

[alhabeeb]

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@GerdW  a écrit :

You can do so by using a proper interface to RefProp and by calling the right functions with correct parameters…

I recommend to use the FluidProp interface with RefProp as calculation library in the background.

(And based on your earlier messages I also recommend to learn more LabVIEW basics before starting this task.)

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I downloaded it from https://asimptote.com/afrekenen/order-received/7369/?key=wc_order_EhjXAKvIbFSLJ ,but it didn't work (not installing)!

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@GerdW  

(And based on your earlier messages I also recommend to learn more LabVIEW basics before starting this task.)

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 Yes I do in parallel.

Thanks

Alhabeeb

[GerdW]

Hi alhabeeb,

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@alhabeeb wrote:
I downloaded it from https://asimptote.com/afrekenen/order-received/7369/?key=wc_order_EhjXAKvIbFSLJ ,but it didn't work (not installing)!

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When you bought software and the software doesn't work (as expected) then you need to contact those who sold the software! What does Asimptote say about your problem?

[alhabeeb]

Is it possible without Fluidprop?

Thanks 

Alhabeeb

[GerdW]

Hi Alhabeeb,

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@alhabeeb wrote:

Is it possible without Fluidprop?

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Yes. RefProp/NIST used to provide a basic LabVIEW example VI!

(IMHO the FluidProp API is much more comfortable than using the RefProp API directly…)

[rolfk]

There's also another thread here (not the only one mind you), that shows how to call the RefProp DLL directly. But remember, the VIs presented therein do not support everything the RefProp DLL can do. For the functionality they support it is fairly ready to use, but if you need other functionality it's going to be a serious effort. The existing VIs are a good way to show how it can be done for other functions but you need to know quite a bit about how to call the RefProp.dll, including what is needed when calling it in another environment like from C.

https://forums.ni.com/t5/LabVIEW/refprop/td-p/272079

Also this github repository has a wrapper available for a lot of the RefProp functions.

https://github.com/usnistgov/REFPROP-wrappers/tree/master/wrappers/Labview

Fluidprop is an ActiveX implementation of the RefProp library. Active X is an old legacy technique but has the advantage to not bother the user with having to configure a Call Library Node correctly (and punish any incorrect configuration with a potential crash).

[alhabeeb]

I used "call library function nodes"  then double click 

and I set like this.

in parameters 

I add manually the inputs and outputs?

Thanks

Alhabeeb

[rolfk]

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@alhabeeb wrote:

I used "call library function nodes"  then double click 

and I set like this.

in parameters 

I add manually the inputs and outputs?

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Basically, without knowing quite a bit about C programming, and being able to read the according header file for the refprop.dll, what you try to do is about the same as trying to ride your car with a blindfold on. You can try to do it, but the chance that you will be successful is not very big.

[alhabeeb]

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@Travis_M.  a écrit :

but please let us know if you have any questions on how to use the Call Library Function Node VI in LabVIEW with either calling convention.

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Hi Travis_M,

Yes I have questions on how to use Call Library Function Node. I have pressure and temperature and I want to calculate the refrigerant state (e.g. subcooled or superheated).

I used "call library function nodes" 

 then double click to configure like this. 

I got confused about how to add the inputs and outputs in parameters? I need to have pressure as an input to find saturated corresponding temperature as an output.

Thanks

Alhabeeb