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Hi,

I would be interested in the program object as well please.

Originally Posted by Ky_Clem

I’m looking for a block in workbench that can be interchangeable for different refrigerants.

Your not going to find one in the stock install. You do have all the math blocks that if you have the equation for whatever refer you can do this calc.

Can it be done, absolutely. Is there a free block that click, click done...nope.

I think you misunderstood. I’m looking for a block in workbench that can be interchangeable for different refrigerants. It would have the same logic behind it as the app you just shared but could be used for calculating superheat and controlling electronic expansion valves and other things.

Originally Posted by Ky_Clem

I can't believe a standard pt-chart conversion app doesn't already exist.

Google the Bitzer Refrigerant Ruler....

https://www.google.com/search?q=bitz...gerant%20ruler

Hello guys, I'm a transport refrigeration tech who is new to niagara and automation in general. I've just started a new career in automation about 6 months ago, and I wanted to make some test programs for fun (niagara training) for various different refrigerants and my google searches brought me here. I can't believe a standard pt-chart conversion app doesn't already exist. Looking into it seems like I would need to be a chemist to figure out how to go about this properly. Seeing that this post thread was created a long time ago I was hoping someone has already done this. Any leads would be appreciated.

Hats off for getting that together.

Should be able to take your formula and stuff it in a single ExprMath block cleaning up that block soup pretty quick.

Originally Posted by Chad Arnold

I know this is an old thread but is there any chance you still have that program object for R134a? I am taking over a chiller and need to control the EEV to superheat. Also hoping it will work with N4. Thanks

I have not used this in a long time. I will need to fix it to make it work in N4. Look in my profile and send me an email and I will try to get to tomorrow.

I know this is an old thread but is there any chance you still have that program object for R134a? I am taking over a chiller and need to control the EEV to superheat. Also hoping it will work with N4. Thanks

I'll send you an email here in just a second. Thanks

Originally Posted by noskilltech

I've been attempting to set this up all morning for R410A and I can't seem to figure out for the life of me how to get it to output properly. I know lynxspring has an actual conversion block in their lynxKitControl, but unfortunately it only works with their certificate on the JACE.

Anyone else sucessfully made this work for 410?

I have a program object for 134 that you could probably change the pressure-temp tables in for 410.

Originally Posted by DaveCR

This can be done with kitControl math blocks and a little help from excel's Trendline feature. Copy and paste the temperature vs pressure values in to excel. Convert to PSIA and Deg R (curve fitting works better). Create a graph and try the various Trendlines until you get a good fit. I came up with this for R134a. y = 0.00003561 x^3 - 0.01308796 x^2 + 2.12259171 x + 421.11910836 With x = PSIA and a range of 20.7 to 149.7 and y = deg R.
Attachment 349691

I've been attempting to set this up all morning for R410A and I can't seem to figure out for the life of me how to get it to output properly. I know lynxspring has an actual conversion block in their lynxKitControl, but unfortunately it only works with their certificate on the JACE.

Anyone else sucessfully made this work for 410?

Thanks. For 134a:
y = 9.20621E-10 x^5 - 6.26875E-07 x^4 + 1.65989E-04 x^3 - 2.26106E-02 x^2 + 2.14070E+00 x - 1.32707E+01
Input pressure range (PSIA) 14.7 to 244.7. Output °R. This turns out to be quite a good fit with R squared = 0.9999

Originally Posted by DaveCR

I came up with this for R134a. y = 0.00003561 x^3 - 0.01308796 x^2 + 2.12259171 x + 421.11910836 ]

nice work ... though I think it maybe time to make a generic curve-fit Program Object to the 4th or 5th order.

...maybe even have an Enum setting for different refrigerants

Could I get a copy of the program objects also, email is in my profile, Thank you.

This can be done with kitControl math blocks and a little help from excel's Trendline feature. Copy and paste the temperature vs pressure values in to excel. Convert to PSIA and Deg R (curve fitting works better). Create a graph and try the various Trendlines until you get a good fit. I came up with this for R134a. y = 0.00003561 x^3 - 0.01308796 x^2 + 2.12259171 x + 421.11910836 With x = PSIA and a range of 20.7 to 149.7 and y = deg R.
Attachment 349691

Me too, I would appreciate a copy of this program object. Thank you!

I would appreciate a copy, thank you.

Originally Posted by Norriski Tech

Any suction pressure transducers?? Suction line temp?? This could all help. R-22?? 410??

yes i have suction pressure transducers and suction line temp. This is r134, but i can take the r-22 table and edit all the values to change it to 134.

I don't see your email listed Matrix. Whoever wants it just send me an email.