auto cascade refrigeration system

[colder2016]

hello, i am john from China, and i am in industry of ultra low temperature freezer. if there is someone in the same job with me? really hope to talk about this technology with you guys.


http://a3.qpic.cn/psb?/V14Ps7KJ04CNw...c!&rf=viewer_4

[colder2016]

sooooooooooooooooooo quiet

[aenigma]

Yeah the forum is pretty much dead. I built the first working home built autocascade for overclocking about 12 years ago, I would love to discuss autocascade with you. Do you have skype? My skype is Vibrophil.

[Charles Wirth]

I am working on an Autocascade now, I had to run power just for it recently.

I will post when I am fully operational.

A source for gas is the deal breaker for most, do you see gas too?

Charles

[colder2016]

it is really great to get your message, maybe my English is not very good, just forgive that. er.... for my skype is johnzx001, my email is johnzx001@hotmail.com

[colder2016]

yeah, the core of autocascade refrigeration is the gas i think, i read a lot of thread in this forum, especially from mytek, that guy work for polycold before, at present, i make autocascade freezer -40~-135C , not for cpu overclocking, but basically , they are the same technology. Because of some political reasons, i can not google twitter or facebook, do you know what i mean, i mean it is difficult for me to get more information about this technology. and i like this forum, because of you guys who can share your ideals and experiment. But it seems that the forum is not alive as before,,,sadness

[colder2016]

[Raziel]

Hello,

I work for a (global) refrigeration company in the Netherlands. we engineer, produce and commision cooling and freezing installations. I do not assemble these machines, only mechanical engineering and 3D design.
The lowest I have engineered was -50?C using a two stage piston compressor with R507 gas. This was for a scientific experiment which required "extreme" conditions.
Guess we have some common ground regarding our workplace.

What cooling principle is used for your ultra low temperature freezer?

[colder2016]

hi Raziel, for autocascade, we use just one compressor and mixed gas for -86c

[Patrickclouds]

i think it was you who contacted me on youtube?
https://youtu.be/8m-cyajujD4?list=PL...kAuVOnQQSGJhRd

i'm going to improve this unit to get higher massflow and holding more load.
during cool down process the compressor becomes very hot.
work will be shorten the captube(s), changing the percentage composition (R600a, R1150, R50, R740) or maybe add some R290 and of course a better insulation of the heat exchanger

but first i need another testrun with temperature logging and that is the problem. i don't have enough time.

[colder2016]

hi patrickclouds, oh my godness!!! it's really a small world. i meet the same problem like you. I make a -150C LCD screen seperator, the compressor is over heat and just stop working during pulldown. Do you have skype or something like this. hope discuss about it with you.

[colder2016]

i think it was you who contacted me on youtube?
https://youtu.be/8m-cyajujD4?list=PL...kAuVOnQQSGJhRd

i'm going to improve this unit to get higher massflow and holding more load.
during cool down process the compressor becomes very hot.
work will be shorten the captube(s), changing the percentage composition (R600a, R1150, R50, R740) or maybe add some R290 and of course a better insulation of the heat exchanger

but first i need another testrun with temperature logging and that is the problem. i don't have enough time.

hi patrickclouds, oh my godness!!! it's really a small world. i meet the same problem like you. I make a -150C LCD screen seperator, the compressor is over heat and just stop working during pulldown. Do you have skype or something like this. hope discuss about it with you.

[Patrickclouds]

my nickname is also my skype name.

I work with a bypass from phase sep gas out to expansion tank when the high pressure passes a defined value. but the problem is the higher the value the larger the pressure ratio for the compressor. thats why the compressor becomes hotter and hotter and finally it halts and the current consumption increases from around 7A-8A to finally 12A.

when I set the bypass pressure to 17 bar the compressor also becomes very hot but it didn't halt. the cooldown is much slower and when I use that bypass function more often (because of the lower bypass value) I have only the low boiling gases in the expansion tank and thats why I am a few Kelvin warmer on the evaporator compared to a cool down prozess with a bypass pressure of 22 bar.

the solution is the mass flow. more mass flow in the cycle for a better cool down means less refrigerant composition in the expansion tank. controllable expansion tank inlet and outlet. shorter captubes or maybe a second captube parallel from the first phase seperator. maybe controlled by solenoid valve. maybe only to cool the auxillary heat exchanger faster or only an after injection for the compressor cooling. or change the captubes with adjustable electronic stepper valves. but here is the question which parameters control the expansion valve. manually, by temperature probes, by pressure, by "superheat" or by fluid level in the phase seperator?

my design:


here is the cool down diagram with bypass pressure value of 19 bar:




and finally the load test (50 watt) diagram. look how long it takes to reach a steady state. so lot of work to do

[Charles Wirth]

I am about to bring mine online, I have it in its new home and I will take plenty of pictures when I complete it.

I took this when I took it out of storage, I cleaned it up, re lapped the block straight, built new mounting and insulation.

Test fired and ran power into my office last week. This was rebuilt by Chilly1 and I and gassed by Mytekcontrols from Polycold. It has a modified Polycold blend in it now.

[colder2016]

great fugger, we are looking forward to it

[Raziel]

Hey Fugger
Nice cabinet. The Polycold gases would be difficult for me to acquire here in the Netherlands. Though every "standard"refrigerant would be no problem.
Some weeks ago I got a small freezer. maybe make a brine or glycol cooler some day soon. just for the heck of it. starting with auto-cascade would be a bit much maybe.

The machine I mentioned before. my brainchild
'
Evaporator in a stainless steel jacket
Stepless variable temperature from 0 to -50 degrees C


Compressor with intermediate liquid injection

[Charles Wirth]

Holy !

Very nice, braided stainless too.

Gas is pretty easy here, crazy what you can buy on ebay.

[aenigma]

Very nice Raziel, what a beast! Is that a Bitzer?

I too look forward to see your autocascade running FUGGER. You guys and all your money to afford these gasses :P

[Raziel]

Very nice Raziel, what a beast! Is that a Bitzer?

I too look forward to see your autocascade running FUGGER. You guys and all your money to afford these gasses :P

Yeah a Bitzer S4T-5.2, Displacement 1450 RPM 50Hz 12.60 m?/h

[aenigma]

Very nice, I could use one of those. Go ahead and ship me one, I wouldn't mind.

[Raziel]

The shipping quotes are insane, so pick-up is required. for a mere 8150 dollars this awesome compressor can be yours.
Think about the amount of ice you could make

[aenigma]

Only 8150? Better get out my wallet! :P It certainly is an awesome semi-hermetic though, they are a thing of beauty. I used to have a big copeland semi hermetic I scavenged from an appliance junkyard but it was 220 and I didn't have 220 available so I ended up tossing it when I took a break from refrigeration. I threw a lot of stuff away because I thought I was done with the hobby, I regret that.

[colder2016]

fugger, do you have skype or email? hope that i can contact you

[Charles Wirth]

charles @ xtremesystems . org

Damn nice laptop, over 2 TB of SSD.

4K display?

[chispy]

I am about to bring mine online, I have it in its new home and I will take plenty of pictures when I complete it.

I took this when I took it out of storage, I cleaned it up, re lapped the block straight, built new mounting and insulation.

Test fired and ran power into my office last week. This was rebuilt by Chilly1 and I and gassed by Mytekcontrols from Polycold. It has a modified Polycold blend in it now.

Charles any updates on this monster of yours ? I am drooling over here , post some pictures when finish please. Since my last 2 stage Cascade died all i can do now it's watch other peoples built.