Quote:
Originally Posted by MEMPHIS91
HAHA WOW, sorry jeff after looking at it again I see what you mean. Thanks for having the faith in me to know I didn't do something that crazy. lol Here is a better picture for you. 
On to more test data, So this is a 40% R290, 60% R1270 mix. ONLY because I was out of R290. SO I need to look at the PT chart for R1270 as well to get closer guess as to the saturation temp. http://www.gas2010.com/pdfs/care45_pt.pdf
First Subcooling,
So 210psi equals 113.8F for R290 and 94F for R1270 so a good guess would be 105F saturation temp. My line temp was 97.7 was that's 7.3F subcooling. I really should have just stayed with R290 because it going to be very hard to know exactly what is going on with mixed pt charts. Plus I was using my cheap temp meter, I will use my nice one next time as well.
Next Superheat,
So 75psi equals 48F for R290 and 25F for R1270 so a good guess 38F saturation temp. My line was 62.2 so 24.2F Superheat.
So this clearly shows I'm still undercharged. I'll do more tuning tonight.
I know I am no where close yet, I just want to record my progress so others can learn as well.
More soon |
Your numbers are off for propylene. It looks like you translated bars to psi absolute instead of psi gauge. This throws your r1270 saturation temperatures off 1 bar low or about 15 psi. At condenser pressure, the effect is less than at evaporator pressure. My guess is 5 degF subcooling and maybe 19degF superheat. This mixture is very close to that of r22 as far as pt values go.
The puzzle piece missing here is your outdoor water temperature. If it is above say 45 degF, it is doing lots of boiling. If not, the ground is doing most of the work. Remember, now that you are running a txv, it can sense this kind of stuff as it happens. If it has a MOP charge, it isn't going to feed a lot more juice than it is now. Adding gas will just increase your subcooling.
For your convenience, and to boggle and amaze others, I highly recommend downloading the refrigerant slider app from Danfoss from the play store or the app store. It makes quick work of figuring out pt values for lots of gases. The only ones it doesn't do are the cfc "old school" gases, which can be found on an old gauge face anyway. I haven't actually ran through a chart for a while. The app just makes it too easy.