Thoughts on Subcooler

[s0lid]

Well will this "idea" work in subcooling purposes?

Just for refrigrant mix like R404 + R744 and so on...

Orig pic by: SoddemFX

[godmod]

what do you exactly mean? i cant figure out the purpose of the high-lowside connection you added...

[s0lid]

what do you exactly mean? i cant figure out the purpose of the high-lowside connection you added...

Referring to EvoCarlos build:
http://www.xtremesystems.org/forums/showthread.php?t=215332

[[XC] gomeler]

I can't figure out why you have a valve connecting the high and low sides either. Those are typically used in systems with high startup pressures like autocascades.

Attempting to condense R744 in a single-stage just using capillary sub-cooling is a lost cause unless you are after insane no-load temps and insane load pressures. You need to use an autocascade setup to adequately condense a higher-pressure gas in a single-compressor system unless you go into more complex refrigeration systems using gradual expansion.

[EvoCarlos]

this is true as im toying with this atm and have found that a single stage with subcooler like i have made will produce temp's of -77.3c with r404a and r744.
but the co2 blocks the cap tube past this temp the pressures were just to hight to deal with when r1150 was in the system :)

the current build with r404/co2 has not been load tested yet but the pressures are low but im sure it will have a none sutable loadholing abilty as its co2 :)

i will exsperiment more when i have time im trying to improve load capabilty and keep the size of the unit to vapochill ls case size

carl..

[EliTE22]

this is true as im toying with this atm and have found that a single stage with subcooler like i have made will produce temp's of -77.3c with r404a and r744.
but the co2 blocks the cap tube past this temp the pressures were just to hight to deal with when r1150 was in the system :)

the current build with r404/co2 has not been load tested yet but the pressures are low but im sure it will have a none sutable loadholing abilty as its co2 :)

i will exsperiment more when i have time im trying to improve load capabilty and keep the size of the unit to vapochill ls case size

carl..
when using co2/ r404s mix what high side/ low side pressure were you using?
was the low in vaccum?

[EvoCarlos]

when using co2/ r404s mix what high side/ low side pressure were you using?
was the low in vaccum?

sorry elite i cant remember off the top of my head but i'll fire it up tomorrow and let you know :)

[EliTE22]

sorry elite i cant remember off the top of my head but i'll fire it up tomorrow and let you know :)
thanks, was thinkin about playin around with co2 and r290 in a autoC, have been trying to find out how to not have dry ice:D

[Duzter]

What kind of valve is that? And how is that supposed to subcool the liquid?

[[XC] gomeler]

thanks, was thinkin about playin around with co2 and r290 in a autoC, have been trying to find out how to not have dry ice:D

Please, learn from everyone else and don't use CO2. I think everyone here that's done an autocascade has tried CO2 and hated it. There is nothing more frustrating than fighting with dry ice, you are better off purchasing ethane or ethylene.

[teyber]

hey correct me if im wrong, but solid is trying to ask about putting refrigerant from the low side into the high side. but i can't think of how you would do this due to pressures. either i am misunderstanding it or carlos is pioneering again :)

[EliTE22]

hey correct me if im wrong, but solid is trying to ask about putting refrigerant from the low side into the high side. but i can't think of how you would do this due to pressures. either i am misunderstanding it or carlos is pioneering again :)

no i think he's talkin about a hx accumulator that Evo made, the thread that solid posted above show it, if not, a bypass like that would make no sense and theres no real subcooling either, other than cap tubing

[Duzter]

hey correct me if im wrong, but solid is trying to ask about putting refrigerant from the low side into the high side. but i can't think of how you would do this due to pressures. either i am misunderstanding it or carlos is pioneering again :)

If he bypass as you say, it would work as a liquid injection to cool the suction gasses.

This is used when you use hotgas bypass to regulate the capacity. This means higher discharge temps on the compressor.
Therefore you make a liquid injection to the suctionline. To cool the suction gas.

Since he hasn't got a hotgas bypass, this would risk a liquid crash on the compressor.

[EvoCarlos]

thanks, was thinkin about playin around with co2 and r290 in a autoC, have been trying to find out how to not have dry ice:Dmore of a 2nd refrigerant will stop dry ice but affect temps but have to agrre with gomeler


gomeler;3614778']Please, learn from everyone else and don't use CO2. I think everyone here that's done an autocascade has tried CO2 and hated it. There is nothing more frustrating than fighting with dry ice, you are better off purchasing ethane or ethylene.
even tho co2 is fun and cheap its cack for use in a system i had it in my cascade before i had r1150 :) unloaded temps were -80c but under 200w load it was only -50c hardlly worth the effort imo


Referring to EvoCarlos build:
http://www.xtremesystems.org/forums/showthread.php?t=215332
solid this is how i have done mine just so theres no confusion
all i did was put the discharge from the condencer thru the accumlatior to add subcooling :) and thanks to tom for the use of his image :)
http://i90.photobucket.com/albums/k262/evocarlos/subcooler.jpg

i think in your image above you were trying to do like a cascade coil affect but you would need to put a 2nd accumilaor to let the refrigerant boil off before it went back to the comp and a very long cap tube to keep the pressure in the hiside

[s0lid]

Oh now i got it clearly :D

[Jort]

filter after HX is a bad idea, you want to place the filter before the HX

And the HX is actualy not really needed because you allready wrap the captube around the suction line...

grtz