kayls Autocascade

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Originally Posted by berkut

Yep JSU is right.

I charge R290 untill i get some cold and i slowly add R744. The moment when R744 kicks in looks like someone had put the temp probe in to liquid nitrogene.

kayl i think you ran in to the same problem as Jan did with his HX. The R290 part is far too large. That wouldnt be any problem but oil puddling will occur. And the both of you guys use too restrictive cap tubes.

go ahead and copy my HX and cap tube lenghts and everything should work :P

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i knew that the hx wasn’t going to work well before i made it, these no restriction and well its just too large to cool the hole thing down.
i dont think its that much to do with capillary line, its all in the hx.
just have to tune to correct supa heat, that shouldn’t be too hard once the hx is functioning correctly.

for now im gonna go in my own direction, there is still about 4-5months left in the competition, so no use copying after the second night in the shed.
But I am still noting what ppl say and can incorporate the ideas into mine.
i have a long list of ideas in my head to try.
as Tonic and Unknown_road said

Quote:

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Originally Posted by jan

Nice cascade so far, kayl. I've the same problem with the hx as you have.
I've changed the cap tube to what berkut suggestet but I need to redo the hx also. Just changing cap tube didnt' help. :(
At the moment I'am trying with a tube in tube hx.



First I want to get my a-cascade running :D Now I'am at -53,7°C ...

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i have been following yous as well, i hope ya over come the problems with the new HX. yeah shorten my r290 line didnt make much difference also.

I'm waiting ;) Autocascade should be a nice condenser for high pressure gas
on second stage with something around -50*C at load..

Quote:

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Originally Posted by kayl

i have a long list of ideas in my head to try.

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yeah lots of ideas but not enough time to try them all out :(

Quote:

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Originally Posted by Tonic

I'm waiting ;) Autocascade should be a nice condenser for high pressure gas
on second stage with something around -50*C at load..

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I think berkut has gotten -70C loaded

not on a autocascade.

-67C unloaded

On test autocascade, which was a huge. Rev2.0 will be a lot smaller and have higher
temperatures, right? ;)

Quote:

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Originally Posted by berkut

-67C unloaded

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ah. So ~-60c loaded?

I remember you breaking -100c unloaded with co2.

It was Australia day yesterday so I though it would be a good time to go down to local hardware store, (Bunnings) and look for some copper pipe.
I managed to find some tubing, got a 60cm length.

Previous hx was too large, this one is nice and small (Diameter wise) and I have rammed some ¼” OD pipe and some 3/8 in there. I will evap into the shell and remove the r290 with the 3/8 pipe, the ¼” OD will be used to condense the c02.
I hope the hx gets a little colder than -5c like the last one.
Friday night is shed night and I will finish it and im aiming for at least -60c at the evap, if not I think its time to work on suction line hx to help cool the co2 before it gets to the hx.

One thing I have also noticed testing the last hx is that the r290 seems to be heading off to the dd evap a lot instead of doing its work in the hx. So I might include a hand valve to shut off the feed to the dd evap unill pull down has happened.
not sure whats going to happen though with the co2 and high pressure that might occur.

Quote:

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One thing I have also noticed testing the last hx is that the r290 seems to be heading off to the dd evap a lot instead of doing its work in the hx. So I might include a hand valve to shut off the feed to the dd evap unill pull down has happened.
not sure whats going to happen though with the co2 and high pressure that might occur.

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I've the same problem and don't know how to solve it yet. :( But most r290 is going into the dd evaporator. I hope I've some time on saturday. I want to get that thing working. :D

Lengthen the captube going to the evap so it doesn't get as much refrigerant as the hx.

I tried the lengh berkut suggested. But I'll try also with a longer cap tube for dd evap. hope it works.

ok hx is ready and pressure tested
its a little long but this is only for a little while until the lath 35cm one is ready that will do as good as this i hope just smaller.
oh and im starting 7' 0.028" capillary line on the hx and im going to add some to the dd evap and see if i can get some cold temps. :toast:

:stick:

http://www.xtremesystems.org/forums/...id=23448&stc=1

Maybe bend it in half with a U bend if you can to reduce the size.. or cut if down. It looks a bit like a berkut hx.

im having alot of trouble balancing this thing.
its really hard to tune it hey, first i ran it and hx didnt get that cold, so i added some 0.028” capillary to the dd evap and shortened the r290 capillary line.
hx ran at -47c 4Hg and then filled with c02 and it was too restrictive on the dd evap and only -25c on the evap. so i took off what i added capillary to the dd evap. Then the hx isnt getting below 0c. so i added capillary to the dd evap.
this is what i got at 10psig / 280psig
suction is about -47c on the suction so i think the trick is to add a suction line hx onto the r290/co2 hx this will give the hx the extra boost to get it to 0c. from here its like dragster, once its gets going it gets cold really quick.

basically im finding that most of the gas is going to the dd evap and the hx is taking absolutely for eva to cool down. i wish i had cpevs and another txv it would make these things much easier. I am really thinking of adding a hand tap to the co2 line for statup to get it a kick start

the next hx will contain a suction line hx but wont be ready for a week or so.
my wife is due to have her baby in a week :toast:
then I have 3 weeks off

http://www.xtremesystems.org/forums/...id=23449&stc=1

I see you guys have some trouble with CO2 in your autocascades :D

Try try try, sooner or later you will sort it out

making great progress
i see you have a proper temp monitor now :D

thanxs guys
yeah reject i got a new temp gauge and a few other goodies :toast:

i think that this will help, a little smaller
http://www.xtremesystems.org/forums/...id=23525&stc=1
http://www.xtremesystems.org/forums/...id=23526&stc=1
http://www.xtremesystems.org/forums/...id=23527&stc=1

ok i built the autocascade from scratch, properly :toast:
vacuuming now.
http://www.xtremesystems.org/forums/...id=23797&stc=1

good luck. hope it will function now. :)

thanxs jan, yes its working but it need alot of capillary line to be cut.
well this is what i got on just r290.
i had a little trouble though the 1st drier froze at the tip?? capillary line is $%@#& too long, that has never happened before?

http://www.xtremesystems.org/forums/...id=23806&stc=1
http://www.xtremesystems.org/forums/...id=23803&stc=1
http://www.xtremesystems.org/forums/...id=23804&stc=1
http://www.xtremesystems.org/forums/...id=23805&stc=1

when it hits zero its off falling quickly.
-27c 1st stage and -57c second stage, with some capillary line tunning i should be set.
20psig/~320psig

AUTOCASCADE :toast:

http://www.xtremesystems.org/forums/...id=23808&stc=1
http://www.xtremesystems.org/forums/...id=23809&stc=1

this is the suction line just before the accumulator and the temperature of the drier just before the hx.
these little chilly condensers rock.
thanxs chilly1
http://www.xtremesystems.org/forums/...id=23811&stc=1

How's loaded temps?