kayls Autocascade

i went down to boc gas and got a D size c02 bottle.
after reading berkuts post i just couldn’t wait for my copper pipe.
i just grabbed the 1Hp system and gave it a upgrade. :toast:

i gave it some bbr290, hc22/502 and some c02.
pressure is 20psig/330psig and -46c, so i must be autocascadeing.
i switched off and are now adding some insulation.
:banana:

It took me 4.5 hrs to upgrade and to a test run.
I have a long way to go though.
http://www.xtremesystems.org/forums/...chmentid=23001
http://www.xtremesystems.org/forums/...chmentid=23002
http://www.xtremesystems.org/forums/...chmentid=23003

Ghetto style ;) god luck with it. Do you have ethane btw?

no. well there is some in the bbq gas and some in the hc22/502 about 1% maybe and 6%

yeah ya always have to do it that way for fun, cause you know you are gonna change it later to another idea.
i will be getting a 35cm tall 5" pipe with a 12 foot coil 1/4 inside as a replacement.
then a 30cm seperator. i am also getting end caps made.
along with some new evaps stuff should be ready 2 weeks i hope, guy just got back from holiday turesday.

when i was making everything i pressure tested everything under water for a few seconds no leaks then gave it a bash.
then the map gas hx at the base (not where i brazed) at the base of the can leaked. i patched it and no leaks.
then i just noticed its leaking in a differnt place.
i think that eventually the bottom of the mapgas can is going to pop unless i braze it all up. but im all out of solder damit.
and i just went to the parts store today.

i got 30m of 0.028" first time i have been able to find it.
i should of got 0.031" though, owell, i just wanted to try it.
it doesnt come in small packs 0.028".


dd evap is about 8-9' of 0.031"
and r290 1st is 7.5' of 0.028", i think i might shorten that and patch this thing.
but really i need that copper pipe as these things are too big.

I remember berkut using around 2m of 0.031 for both the 1st and 2nd stage gases.

btw kayl I used one of those condensors for my auto-cascade and it wasnt large enough :( . You have a desuperheter so it might be ok though.

Did you static charge it? How are you charging the CO2?

where is your hx. i cant tell from the pictures, could you take a few more (maybe from all sides). thanks

gkiing i will be shortening the r290 capillary line next time to about 6'.
and leave the dd evap along as that length seems to match my cpu heat load well.

the way i charged depended of me regulator used. i got an industrial c02 one for mig and tig welding, so max out is 50psig, so i charged to 50psig and rest r290 to 110psig and turned it on. it started to pull a vacuum straight away, so i added heaps of r290 until low side reached 0psig. then let it cool. i then added some c02 until high side pressure was getting to a limit i could handle 330psig for now.
i hope once i get this thing Wright pressure will go down to about 250-280psig.

Jsu just one of those chilly condensers isn’t enough. I like them though cause they are so small, and I only have 120m,m fans so they match well. I may add another desupaheater for the r290 yet, will see when I get the new copper pipe for the hx.

Foot the map gas bottle on the right is the HX. I used a 1/4OD copper coil inside the map gas bottle as the condenser to condense the c02, and the actual map gas bottle is the evap. I did it this way as I couldn’t bend 3/8”OD pipe with out kinking it as the evap. The second reason as I though it would increase the chance of splitting this mapgas bottle trying to condense c02 in it cause of the cut in the middle of the bottle.

Here is how I did it, forget the temps on the pipe and stuff, I edited one of chillys drawings and put what temps I thing everything should roughly be at if working perfect to explain it to a friend.

http://www.xtremesystems.org/forums/...id=23158&stc=1

Lower temps please :D

I should finish my rev. 2 autocascade in a couple of days, the one based on a more powerfull compressor and with a PEV controlled HX

yeah colder temps to come i promise.
this was made quick and well not very well, but i just wanted to use some c02 and the cascade wasn’t ready for it.

sounds good berkut a pev and a bigger compressor should make a great difference, are you going to feed it with 1/8OD tubing.

unfortunately i will be only using capillary line as pev's and txvs are so expensive.
i did get a 30m coil of 0.028" capillary line to play with though.


with the rules is there anything to stop me getting a friend to use a lath to machine a few rings in a copper rod say about 30cm long, rings about 5mm wide and about 1cm deep into the rod, the rest well ill show if i can do it, other wise i may use it in a cascade one day.
as i have a really sweet hx in mind the key to my autocascade.
but dont want to break any rules , ie DIY.
i remember i can’t buy commercial hx for the competition, does this fit same category.
i still have to design it and make it myself.

@berkut: Do you know the ratio of CO2:R290 that worked well in your autocascade?

Kayl if your hx is -40 you shouldnt need more than ~200psi to condense the CO2 your pressures seem a little high. Perhaps a larger condenser/condenser fan would be in order, or a desuperheater?

i didnt get to -40c on hx. (not really sure what temp it was, it was frosted at the bottom of the hx and warm at the top) but some c02 was condensing, the poor hx doesn’t really have much of a chance at working at the moment due to lack of insulation (none on hx) and the fact that its too big doesn’t help as well.
berkut was having too much fun with his so i could wait to do mine properly yet.
once pull down is complete and the hx is working properly (with the new hx) i hope pressures to go down alot.

i think you used too much CO2. My pressures go sky high once i push too much CO2 in the system.

as long as you make the hx i think it can be approved. chilly1 has to express his opinion.

Thanx berkut, im gonna give it another bash tonight, will try more r290 and less c02. i shortened the r290 capillary line to 5.5' of 0.028" that should help too.
if temps are good an no leaks after a while of running i will add some insulation to the HX and see what new temps are.
I think I should add my HPCO soon since I have it here.

this is where the map gas bottle was leaking, it also leaked on the other side.
so i brazed the hole thing all the way around. if the other one leaks i will do the same.
im getting a little better brazing these map gas bottles, its definitely an art.

well the autocascade finally held pressure and i gave it another go.
its crap hey. i think i am going to scrap it.
need new hx
0psig i had -50c evap and -6c liquid co2 line coming out of the map gas hx :confused:
the suction line for r290 is -2c so supa heat is real bad at 5.5' of 0.028 caplillary line?
i think itsthe hx cause there is too much volume inside the bottle to cool the 1/4 co2 line through it.
i used bbq r290 and co2 the above doesnt make sense pressures and evap temp

Quote:

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Originally Posted by berkut

i think you used too much CO2. My pressures go sky high once i push too much CO2 in the system.

as long as you make the hx i think it can be approved. chilly1 has to express his opinion.

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How many psig of CO2 do you reccomend static charging?

You dont static charge with co2. You first get the hx going then slowly add co2

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

I thought all high pressure refrigerants had to be static charged...?

So 0.028" or 0.026" wont work well in an autocascade?

My 1/2hp compressor was getting me around -50c so you guys with the big compressors should be able to pump out alot more than that. O my hx was -20c

They should but its not that easy with a autocascade and especially with CO2.

Quote:

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Originally Posted by berkut

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

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that would be a boring and non educative competition ;)

You're right, that's why I'm trying, trying and trying to create a new HX's construction
or combinations of other's HXs

Did someone with autocascade think about rebuilding autocascade (after comptetition)
to cascade?

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.

Quote:

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Originally Posted by Tonic

Did someone with autocascade think about rebuilding autocascade (after comptetition)
to cascade?

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

Quote:

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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?

frozen cap tube can mean its clogged. You should evac a ton of times.

looks ok

could we please see a set of temps/ pressures ?

Quote:

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Originally Posted by JSU

frozen cap tube can mean its clogged. You should evac a ton of times.

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Also when it is only frozen at the last few inches? Or is this Ok?

Very well done kayl, temps are getting better and better with the autocascades.

When its frozen in the last few inches its usually moisture related. If there's moisture in the system it will turn to ice at the very tip of the captube and block it. It could also mean your cap tube is too long and the refrigerant is evaporating before it reaches the end of it.

Quote:

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Originally Posted by gkiing

How's loaded temps?

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loaded temps will come once i get more close to -70c if that eva happens, or if i find i cant get any lower temps will test load temps.
for now i have some work tunning it.

Quote:

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Originally Posted by JSU

frozen cap tube can mean its clogged. You should evac a ton of times.

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i will evac again, i hope not as i dont have a real vacuum pump, i did use 2 new driers though, one in the r290 line and one in the c02 line.
I hope it isn’t moisture.

Quote:

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Originally Posted by gkiing

When its frozen in the last few inches its usually moisture related. If there's moisture in the system it will turn to ice at the very tip of the captube and block it. It could also mean your cap tube is too long and the refrigerant is evaporating before it reaches the end of it.

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yeah i think in my case the capillary line was way to long and the thing its backing up on itself
i cut the r290 line from 2.1m of 0.028" to 1.7m and it didn’t frost anymore, it also enabled me to get the hx to current temperature.

Quote:

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Originally Posted by berkut

looks ok

could we please see a set of temps/ pressures ?

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what full set did you want.
on the previous page i have pics of pressures and temps.
update though for ya

1st stage -27.2c
2nd stage evap -57.1c
pressure suction (just before the compressor for both suction lines) 20psig
high side after the condenser before the separator is ~320psig
suction line temperature before the compressor 6" is -29.7c
and the temperature of the drier just before the c02 line goes to the hx is 31c.
not sure on room temp but should of been around 25c or so.
Hehe I need more temp sensors.

Kayl what did you use to braze copper pipe to the mapp gas bottles? My mapp torch can't make the 45% silver flow well eneough, and 15% didnt flux :( Is there some secret i'm unaware of, or do you all have oxy acetylene torches?

hehe i got skills,
nar map gas torch should be fine, 15% solder and white flux all i used.
use white flux on area brazing, blast it till flux melts in area to braze, then when the copper takes solder and the map gas can is glowing hot, back torch off and apply in area you need to. by backing off flame the brazing material does flow as much, other wise it sort of flows every where but where you want it to and hard to fill areas.

[EDIT] Got my answer in the other thread.. thanks

Last night I awoke to a large bang. OMG the autocascade went band I thought.
Then I told myself it would have been way louder and I was dreaming.
This morning I go to the computer room to find that one of the home brew bottles blew the lid off. Heheheeh.


this morning before work i switch on the autocascade and temps started to fall straight away so i musnt have any leaks which is good.
i then had breadfast and came back and dd evap was -59c.
i let some gas out and came back later and this is what i got.
ps temp gauge is on temp with ice bath.

http://www.xtremesystems.org/forums/...id=23904&stc=1
http://www.xtremesystems.org/forums/...id=23905&stc=1

Nice! What's your low side running at?

woohoo way to go kayl! guess iam abandoning my valves :( they severd me well, just now on a system with so many variables. Its much easier to size captube for these systems b/c resistance goes up linearly.

Quote:

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Originally Posted by JSU

woohoo way to go kayl! guess iam abandoning my valves :( they severd me well, just now on a system with so many variables. Its much easier to size captube for these systems b/c resistance goes up linearly.

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thanx man
JSU if your gonna use capillary line instead of vales get yours self a bottle bbq r290 instead of r404 other wise ya gonna go broke.
Then use real refrigerant later. Thats what im gonna do, I wonder what temps would be if I switch the bbq gas out for HC22/502.
I ran out of bbq gas, got to stop using it on the bbq and going camping.


gkiing im not sure on pressures sorry, have to get those friday.

goon on ya mate :toast:

i have come to the conclusion that r404a isnt good for a auto-cascade anyway. It fractionates in a funky way so if you used it you wouldnt have a add any to the evap. The problem is its not controlable so you could get alot fo a little.

Quote:

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Originally Posted by berkut

Lower temps please :D

I should finish my rev. 2 autocascade in a couple of days, the one based on a more powerfull compressor and with a PEV controlled HX

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i think i cracked it
-69c 3psig/225psig i think i can live with that :toast:
http://www.xtremesystems.org/forums/...id=24082&stc=1

nooooo go lowerr!
:toast: very nice figure. thats loaded?

ok for you reject
and australia lowest i got is -72.2c i got a photo
http://www.xtremesystems.org/forums/...id=24086&stc=1
http://www.xtremesystems.org/forums/...id=24087&stc=1

:slobber:

:wiggle: nice

awesome work kayl

Or you can heat the tube and hand bend it, or use a lever bender.

Quote:

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Originally Posted by KaptCrunch

Kayl

to bend any tubing without kinking it, use DRY,CLEAN(oil free) silica sand. packet tight in the tube then cap ends (brazed) then bend to radius. after getting to where you want remove caps, blow out sand then flush remaining sand out with soap an water

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sound like a good idea, but not for refrigeration. you are going to kill the compressor if you do that,sand :eek:
and water is the last thing you want in there as well, moisture.



gkiing i dont like to heat pipes to bend (only time do that is say if crushing pipe end, like for autocascade hx) i really do need a pipe bender. i just dont think its worth what they are asking it for, i got a flair tool the other day though to fix the TXV valuve.

I got a pipe bender for $12 at canadian tire, it's just a cheap 1/4" - 5/8" bender but it works fine. Look around for a lever bender that has slots for different sized pipes, they can be found pretty cheaply.

edit i got a pipe bender today, they are a little hard to use, get in the way.
but i will use it every now and again.