Refprop using labview

[PHILLIM1111]

Hello

In the attached VI I am using the SETUP.dll and SATP.dll to set the refrigerant type and do the superheat and subcool calculations respectively. The current method works fine for Fluids however whenever you enter a mixture it outputs incorrect calculations. I would apricate any help with solving this issue. Unfortunately, the attached VI pulls information from multiple systems so it will not continuously run without being ran on the computer connect to those systems. I am new to using LabVIEW as all my experience is hands on learning OTJ. This is using LabVIEW 2020 32 bit.

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[altenbach]

You did not include any subVIs or DLLs so we cannot test. It would also help to populate all controls with reasonable default value and the expected result.

(I what way are the results incorrect? Slightly off? Completely wrong?)

[PHILLIM1111]

My bad I've never posted before. I will attach all the Sub VIs. The calculations are completely wrong when using the mixture. If you use 250 for the LXP and 91 for the LXT values the expected result for the subcool is 9.2. The main problem i can see is it seems that the DLL is not reading the file as it is not looking in the correct location. it is looking in the fluids folder inside of refprop and not inside the mixtures folder and I do not see a way to change that based on what is being used as their is no input for that on the call dll function.

[PHILLIM1111]

Hello,

I made a post before, but I have made some further discoveries with my own personal research. I am trying to get Super Heats and Subcools from various refrigerants. I believe all I need to make this work is a functioning VI for calling the SETMIXdll function of the refpropdll. ideality all i will need to input is the refrigerant name. I am using labview 2020 32 bit. I am newish to labview and have no experience when it comes to formating dlls or VIs that call them. I have attached the entire project if that helps. Expected results for subcool is standard to online subcool calculators.

[altenbach]

Sorry, my experience with third party DLLs and modern text based code is nonexistent. Hopefully someone else can help you with that.

OFFTOPIC: I did have a look at your main.vi and found serious race conditions and way too much duplicate code due to blatant overuse of local variables. The only place you really need locals is for updating controls, not disconnected indicator terminals.

I did a quick refactor with some mild suggestions. No guarantees that I did not make minor mistakes crossing some wires, but you should get the gist of it all. 😄