single stage with propane/ethane blend

[Unknown_road]

**disclaimer: mixing very high pressure refrigerants in a single stage is dangerous. Do not try this when your not fully aware of what your doing. Don't be a fool but be safe. **

a few years back I read about a refrigerant called care50 which is a blend of propane and ethane and boiled @ -50*C, 1 atm. The really good thing is that it would be (kind off) legal for me to use it without an expensive license. Since there is a company making these blends and using it in all sorts of refrigeration it appears to be safe. Since there is "only" 6% of ethane in the mixture and discharge pressures are relative low I didn't buy care50 but I bought a bottle of propane and a bottle of ethane and mix the gasses myself to get even better temps. <-- this is the really dangerous part.

long ago I promissed a few people here I would post results of my blends asap, so here they are "better late then never" . After building a few units and getting some practice, the result is that now the blend works better then r507.

Some pics of the unit:
silver evap:
http://www.overcooling.nl/images/silverevap.jpg

unit all brazed up:
http://www.overcooling.nl/images/singlestage1.jpg

http://www.overcooling.nl/images/singlestage2.jpg

insulated:
http://www.overcooling.nl/images/singlestage3.jpg

temp @ 200watt load:
http://www.overcooling.nl/images/singlestage4.jpg

edit: I almost forgot, because propane and ethane blend doesn't mean other high pressure refrigerants blend with propane or any other low pressure refrigerant!!

[LukeXE]

I want that ethane Unknown ! :D hehe

Great work mate

[Unknown_road]

@luke: :D I'm sorry I'm so slow!

@soddemFX: ambient was around 15*C I think, discharge pressure @ load was around 16barg. compressor displacement is 14cc. suction pressure @ load was around 0.5barg, without load I think it was 0barg and -54*C. The suction pressure without load is so high because this unit is really tuned for high loads so without load I have massive floodback and my compressor freezes over.

more info on the evap: http://www.overcooling.nl/evap.html

it is brazed with very high silver content brazing rods that is used by jewelers. I believe silver content in the rods is about 65% or something.

I braze a 35mm brass tube on the evap, inside this tube I place a solid brass piece in which I drilled holes for cappilair and suction line.

[wdrzal]

@luke: :D I'm sorry I'm so slow!

@soddemFX: ambient was around 15*C I think, discharge pressure @ load was around 16barg. compressor displacement is 14cc. suction pressure @ load was around 0.5barg, without load I think it was 0barg and -54*C. The suction pressure without load is so high because this unit is really tuned for high loads so without load I have massive floodback and my compressor freezes over.



Have you considered hoT gas bypass ?

[Unknown_road]

to prevent floodback?? nope :D , first off all those things are rediculous expensive. second, people shouldn't run the unit unloaded :D people should put it on there cpu.

[hatemi]

So do you know the rough presentages you used? That seems to be very good blend indeed, and enviromentally frendly too :)

[Unknown_road]

I don't know what percentage of ethane is in the system. I mix the gas in the running system.
brazing the evap indeed requires some practice, that's also the reason why I sell them brazed.

[Brettbeck]

Looks great performance!

Has anyone ever used that Care50 stuff? I can get hold of some if I need any. I can either use that or R290 for my 1st singe-stage. Can anyone suggest which would be best?

[Unknown_road]

Kayl once had it but it didn't work as well as he hoped.

[Mr. Popo]

Pretty cool work. :toast:
Pretty awesome evap! :banana:

[Ssilencer]

IIRC, Johann got the same -40@200watts with just r402, so maybe you can get some degrees over that extreme gas blend.
Looks like it is really difficult to find out the secret gas blend Drew keeps using :)

[kayl]

Nice looking unit there Unknown_road , good to see some results have been eagerly waiting for them hey. Not many ppl have used ethane before.

Kayl once had it but it didn't work as well as he hoped.
I still got the bottle, its empty now though, I didn’t find it as good as the spec sheet. Ie at 0psig was ment to be -50c, I only had -42 same as bbq propane (but it only contained 5% ethane). I wish I had it now though to see how well it can handle load on todays cpus and heat capacity removal.



IIRC, Johann got the same -40@200watts with just r402, so maybe you can get some degrees over that extreme gas blend.
Looks like it is really difficult to find out the secret gas blend Drew keeps using :)

Ya drew wont tell anyone hey, I gave up asking about a year ago hey. See his recent unit -70c ide (-42 die temps) -67c load ( -27c die temps). I think drew gets around -65c or so at 220w resistor load.
http://forums.extremeoverclocking.com/showpost.php?p=2472700&postcount=71

[n00b 0f l337]

Can't blame drew I beleive he's actually a helium cascade builder. He probably has access to refrigerants we barely know exist.

[Unknown_road]

IIRC, Johann got the same -40@200watts with just r402, so maybe you can get some degrees over that extreme gas blend.
Looks like it is really difficult to find out the secret gas blend Drew keeps using :)

Maybe I can get the temp even a little better and since the temp @ 0barg is already better then r402a it is safe to asume that with loads lower then 200watt the blend is already just as cold or even colder then r402a. Which I'm kind off proud off since this isn't an official refrigerant blended by a group off engineers and it is very enviromental friendly (r402a still contains r22). :)

[Brettbeck]

Can't blame drew I beleive he's actually a helium cascade builder. He probably has access to refrigerants we barely know exist.

Does anyone have a picture of one of these? Or even a diagram of how they work?

I want to see one :D !

I found this after searching on google quickly;

http://www.iop.org/EJ/abstract/0370-1301/63/7/304



A helium liquefier has been constructed with an output of 3.8 litres per hour and a starting time of 70 minutes. The liquid hydrogen needed to cool the helium below its inversion temperature is provided continuously by a hydrogen liquefier within the same machine. The advantages of the machine are (i) short starting time, (ii) simplicity of operation and ease of servicing, (iii) closed hydrogen circuit


I know see why it is so expensive :p.

Sorry about OT :(.

[Unknown_road]

making a helium cascade is a bit out of our range I geuss :D , search for Joule-Thomson cooler

[Brettbeck]

making a helium cascade is a bit out of our range I geuss :D , search for Joule-Thomson cooler

Hehe :p: . I know, but it would be interesting to see one :) !