Stickied a drawing thread.,,,
http://www.xtremesystems.org/forums/...ad.php?t=46096
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Stickied a drawing thread.,,,
http://www.xtremesystems.org/forums/...ad.php?t=46096
I think r290 is already a pretty high pressure gas for an autocascade. You should consider that the CO2 also raises the discharge pressure although it doesn't condense. CO2 is also relative low pressure second stage refrigerant. Most of us will make a autocascade for the first time, if it works with these gasses you could later on try with other gasses outside of the contest.
@kayl: an explosion without fire at a pressure of 20 bar is still really dangerous!! It can kill you easily!
The preasures kill. Not the flames. Few years ago a tractor tire blew up and a man standing a few meters away flew about 10 meters to a pile of logs and died that second...Even truc tires are filled inside a safety cage if something goes wrong. Imagine what kind of damage it would make if it was between your legs(like most of us keep car tires when filling them) and expleded...
Well the idea behing R290 and CO2 is that anyone can obtain theese gases.
Yeah that way it's fair. A lot of people might want to compete who don't have access to refrigerants like Ethylene or R23. This way everyone has the same chances and the builder with the best design will win instead of the builder with the best refrigerant.Quote:
Originally Posted by berkut
Due to the fact that some people don't want to use flammable gases, I think it's only fair to open the selection of first stage gas.
As far as the second stage , I think we should all use CO2. Is this agreed by everyone?
Like I said earlier, I think we should have two classes for compressor sizes.
The smallest up to 1/3hp. Then for 1/2 hp and up. Are we agreed on this?
I know load temps are the most important thing, but this could really get complicated trying to determine what load temps are.
How about if we start off with simply the lowest temp? And then latter along if we all come up with an agreeable way to test load temps , we'll do that.
I think the autocascades should be judged on performance ,design and overal looks.
If can come up with enough prizes, we can have winners for each.
small compressor class would have two winners.
1. lowest temps
2. design and looks.
big compressor class
1. lowest temps
2. design and looks
We could say that one person can't win both prizes in a class. ;)
above sounds like a good idea
limit to co2 is good idea with what eva first stage gas up to ppl.
as its the co2 limit that makes it fair (if ya use either r404a/c02 or r290/c02, its the co2 thats the coldest)
what about these points from before
Quote:
Originally Posted by runmc
This is a great idea, I planned this weekend to build myself an auto cascade :)
I'd be down on building my first cascade.. or autocascade for that matter, if someone could provide me with the details and a diagram with a captube metering device. I've built 4r22/r290 single stages so I think I might give this a go.
Is a desuperheater needed on an autocascade?
What pressure cutoffs/safety devices are needed?
How large a condenser will it require?
Can a DIY Phase separator be built? I was thinking of using the condenser as one (gas CO2 out the top, liquid r22/r290 out the bottom)
I've got an extra 1/4hp compressor and i'd like to try this, maybe I can get some parts from chilly1.
I think that above 1/2hp should be the high range. Anyone have any ideas for the prize or whatever?
How about you guys take your time to build them maybe a few weeks. I am not going to enter as I think I have an unfair advantage. The ??/Co2 option is a good one it is all about the boiling point of Co2 and who can push the envelope the farthest.. a -77 degree autocascade at 200W would be a very amazing thing. Keep it as simple as possiable. And plat safe. Follow all the saftey rules. I will talk with Fugger and see if we can come up with a good prize for this one like some refrigeration tools or something??? MAybe we need to set this up as a longer contest and we need some more criteria to judge this on like best of show for attentian to detail best temps (you will need to show a refrence of teh temp meters calibration like a screen shot of the temp meter in an ice bath at 0C. Some one needs to judge. That would be me and a few of themods that won't enter the contest... Hows that sound?
Sounds good to me. I think berkut achieved -78c under some load, maybe not 200w with his regular CO2 cascade, but it would be harder with an autocascade because you cant pull as deep a vacuum.
How about an autocascade safety guide?
\Quote:
Originally Posted by pc ice
go on make one just ya dont count in competition.
ya too good, but would be a good judge
and ya need a lot of time at least next year.
As ppl have to source stuff and order/get parts
I would like to see you building one too PC-ice. Not for the competition maybe, but for the common good and guideance (uhmm spelling ?) for the rest of us :).
So in fact you will have to make 2 oil separators?
Can any1 give a design for a regular phase-separator. Then i can twist my creative mind on a maybe even better design :D.
So far the FFA I stage refrigerants and CO2 wins. I think we will stick to that.
PC ICE i think you should join in. Its more fun when someone really good as you will be here to competate against. I find it more exiting working on my system and think "gotta beat pc ice, gotta beat pc ice ]:->" :D and besides, the chances are equall for everyone.
Chilly1 you could be the judge if you feel you have such a advantage.
Ok rules for now:
-R290/R22/R404A/R507/R134A for I stage refrigerant, CO2 as II
-All the parts must be DIY, commercial oil separators, liquid separators, HX'es can not be used. The only commercial parts that can be used are safety devices as: expansion tanks, cut off swiches etc.
-only DIY evaporators can be used. Copys of commercial evaporators are allowed
-compressors up to 1hp may be used. After seeing what compressor do peapole use in their systems the judges will make classes (probably there will be 2 classes, up to 1/2hp and 1/2- 1hp)
-PEV's, TXV's, EEV's etc can be used.
Am i missing anything here ?
Condenser sizes :)
There is no difference in condenser sizes. But you made me remember 1 more thing:
-Ambient temps above 20C
Sounds good. How about the winnner gets like a chilly1 block or like a single stage sys from chilly or something like that...
Why should you have to make your own block? The whole point of this contest is to experiment with auto cascading, not build a block.
beacause we want you guys to be more crative when making your systems, this includes evaporators.
a good evaporator design may give you a advantage even if you have a small compressor over a higher power system with a bad evaporator.
i dont know about the prizes.
exept prizes there are a few more things, much more imporatant to me: that someone will use my idea (if its good enough). beacause it was the best. peroid.
So, who wants to sigh in ?? We need to make a estimate how mant peapole will try their powers here. Post what compressors will you guys use too.
me: tecumeseh rk5510 3/4hp rotary or sanyo 3/4hp rotary
It is also to show off your skills ;) Using other peoples work just isn't as much fun.Quote:
Originally Posted by JSU
by the way dabit has a pdf on his site of some guys that made an autocascade and wrote down their findings. look at www.icecoldcomputing.com and then librabry (below).
I agree completely with pythag on this - there should, at the least, be a no restriction catagory. If the purpose is to further our knowledge on autocascade construction and working out the right mixture level for gases - then there at least be a catagory that is left be open, so that these guys can show you just what u need to build the coldest running autocascade possible.
Having all catagories restricted in some way is going to hinder exprimental discovery of what makes the best autocascade.
Actually if you think about it there is a way to build an autocascading block so the whole HX and Evap will be one.Quote:
Originally Posted by JSU