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Holy crap! Raven does it again with another killer cpev based SS... Why do you use a cpev anyway? I haven't seen anyone other than and and berkut do it on a single stage. What kind of difference is there between a cpev setup and a cap tube setup other than being able to vary your load?
Hi afireinside :)
In this system cpev is very usefull. Its all about evap, it will work fine with small loads but when you're going to bench p4 you can see that not all amount of refrigerant stays in evap. It work like that because in high loads refrigerant evaporate a lot faster. Gas bubbles crowd out most of liqiud refrigerant (dont now if its correctly written but its hard to explain it in english :P ). That liquid refrigerant cools cap tube and goes to compressor or stays in accumulator.
But if you do quite big slhx all liquid refrigerant will be used for subcooling and when you're using cpev you can adjust that evap overflooding to do some nice temps for u. With powerfull compresor you can condense high pressure gas this way, just give some liquid refrigerant to slhx.
It works almost like a watercooler because only small part of refrigerant evaporate in evap. Subcooling is so high that there is only few degrees difference between liquid going to cpev and going from it.
Sorry its really hard to explain it, maybe i'll paint it later :)
That condensor and compressor is seriously oversized for a SS. Some cascades don't even have that hardware. :D
Very nice job! I would love to see that loaded with 200W.
I would have to say that this design makes an autocascade even more pointless than it already is. It does everything an autocascade does, but much simpler and probably much more efficiently.
I don't see an oil separator. Is it just not a problem at -70C?
incredible SS.... :clap:
Except for the fact that auto's do -100C and less... :rolleyes:Quote:
Originally Posted by labrat23
I know cascades do -100C or less, but I thought the best autocascade did about -90C unloaded. Now I havent been following the forums too closely, so if someone did better, I might have missed it. Could you point me to the auto that did -100C?
Raven, what model cpev is that? I think I am going to go with a cpev on my next system and really don't know which one to get.
i didnt have any problems with oil so far but i will see after some more time, maybe oil sep will be needed.
I'm using FACH cpevs 1 or 1,2mm. Made by polish company, it costs about 18 euros :)
congrats on a very impressive tidy unit :toast: looking forward to some load testing.
C-BuZz
IIRC that polycold autocascade really kicked some arse. Other than that I haven't seem alot of autocascades that have been terribly successful in entering the -100 club. I'd assume the load handleing of a massive single stage like this might be a little bit better. (although I've never tried building an autocascade myself, so I'm not really in a position to give a well informed opinion)
When are you gonna heatload it?
I think my dummy load will be ready tomorrow. I'll test it on pure r507 for now but berkut will give me some r23 next week :).
I would test it faster but i'm doing other ss atm so i dont have much time, sorry.
I would love a little more info on the: slhx...heat ex of some sort, but how does it work? cpev... expansion valve obviously, but how is it different from a tev (are they the same)? How are you constructing you heat load?
I am a bit of a novice who is trying to get info on how to build better phase change systems and this one really interests me as it is a bit more involved.
Nice work!! :)
Awesome single stage lets see some results
thats a nice slHX.
cant wait to see some r23 in there or 1150.
Hope ya have better luck than i did at load.
you will be albe to condenser 1150 in the SLhx and get some nice noload temps forshore. Will be interesting though what happens when loaded.
I found at load low side pressure will inscreas and temps go crap (well with 1150 anyway) r23 would be a better gas htough, not so high pressure.
what low side pressure did you run to get those temps noload??
If I remember correctly, CPEVs are very similar to TEVs but you manually change it instead of having the suction line temperature change it. The SLHX uses the suction line to further cool the discharge line. It also helps boil off any liquid that may be left in the suction line.Quote:
Originally Posted by Shyfty
Carlz0r - yes thats true, thx ;)
kayl - i've tried with 1150 and temp + refrigerant flow was more than fine but that pressures.... I'm waiting for r23 from berkut but he have some exams so i guess it wont come fast. btw -71C was on 1150 + r507 and about +0,4-0,5bar on suction side.
If you dont know what/where/how sth works just look at my scheme. numbers should be useful when you'll ask about sth.
http://gorajec.net/raven/deepblackxtreme/schemacik.png
and about dummy load, i've used three 82ohm 50W resistors connected in series but its a huge overkill (250W) for normal ss so i reccomend to use 100ohm (it will give about 180W)
How to mount it? its rly easy, just look at pics below
resistors
http://gorajec.net/raven/deepblackxtreme/dummy1.jpg
and resistors with cutted out mounting *things*
http://gorajec.net/raven/deepblackxtreme/dummy2.jpg
and finally done dummy load
http://gorajec.net/raven/deepblackxtreme/dummyload2.jpg
simple, isn't it? :) i will put some insulation there of course ;)
http://gorajec.net/raven/deepblackxt...ummyload22.jpg
i havent tested system yet because i'm out of space, time etc
and sorry for all mistakes but i'm so tired that i cant think in english
load test on pure 507 done.
i havent counted resistors good, its not a 250W dummyload but 225..
225W/235v=0,957
235v/0,957=245,5ohm /3 = ~82ohm
evap was -37 - -39C loaded. it's not a good result i think but it was only pure 507. i also think that this evap isn't designed for that big loads but dont worry, i dont belive that any processor will push that much heat ;)
http://gorajec.net/raven/deepblackxtreme/dummytest.jpg
and this how resistors looks after 3 hours of testing
http://gorajec.net/raven/deepblackxtreme/dummytest2.jpg
what now? i can only wait till r23 arrive. i wont sell this system before r23 tests but if it will work fine i will post it in right forum section (if mods will tell me that i can do it of course :) ).
btw i remember that berkut did -22C on modded prommy with similar load :)
in case u used TXV where do u put the bulb?
i've used cpev, manual pressure regulation
I know...I saw it
I asked...in case u used TXV....
sorry, i've missed it ;)
i think before slhx (after flexible stainless hose)
Raven where is end of job in Your ss ? The 631 ordered already and we wait 1-2 ~week's. P5WD2 will be moded and ...
and u need some sub-zero temps? :P dunno exactly about r23 yet but if it wont arrive we can bench on pure 507 always ;)
Sub-zero temp and no other :toast:Quote:
Originally Posted by RaVeN155
100% o/c Cedar Mill - 631 maybe possible
:cool: