[work-log] Mini-cascade R-507/R-1150

[tiborrr]

This is a cascade i've been building for a month or two (on and off, mostly off due to € shortage), it's main purpose will be dual-core benching, those small compressors are too weak to cool anything hotter anyway. All components are brand new except for the oil sep which i got dirt cheap on eBay.

As the project went on i was forced to buy myself my own equipment which took me some time since my budget doesn't stretch as i would like.

High temperature stage:
- compressor: Danfoss NL11F (1/3HP)
- condensor: Empor 0.72kW (200mm, three-row) + 10W 220Vac motor + 200mm fan blade
- filter/drier: Castel 20g /w service port
- refrigerant: R-507
- metering device: TC-28 (0.7mm ID) capilarity tube

Interstage heat exchanger:
- 10-plate stainless steel (rated up to 5kW water-water)

Low temperature stage:
- compressor: Danfoss NL11F (1/3HP)
- desuperheater / oil cooler: Empor 0.72kW (230mm, one-row) + 10W 220Vac motor + 230mm fan blade
- oil separator: Danfoss OUB-1 (floated)
- filter/drier: Danfoss 40g copper
- refrigerant: R-1150 - ethene / ethylene
- metering device: TC-31 (0.8mm ID) capilarity tube
- 2m stainless steel flexible suction line
- evaporator: tiborrr's Maze GT1 EE (extreme edition)

Safety:
- Ranco high pressure cut-off @ 27bar (on low temperature stage)
- 2x high pressure bourdon type pressure gauge Wigam
- Fach 0.9L receiver to act as an expansion tank 0.9L on low temp. stage

Initial preparations - lining up the component on a mock-up board:


Backbone of this cascade - 3mm steel plate:


The evaporator / suction line / safety - HPCO:


Manual hot gas bypass (to compressor, not into evaporator) - ball valve:


Temperature monitoring - K-types & Voltcraft K102 K-type thermometer:


Interstage heat-exchanger enclosure is made out of scrap wood - three major plates are 5mm, rest is 2mm:


Brazing the first stage:


First frost on first stage @ ~ -43°C:


Insulated with poliurethane foam (great specs, temperature conductivity ~ 0.039W/mK, neoprene has 0.036W/mK) it does ~ -53°C:


Ran out of oxygene to complete the second stage. Will continue the next weekend as i am away from home during the week.

Best regards,
Niko

[EliTE22]

looks good, cant wait to see some temps on the sec stage

[teyber]

nice!

about time you posted this in a proper log!

What wattage will you tune it to?

cheers

[tiborrr]

Thank you, EliTE22!

nice!

about time you posted this in a proper log!

What wattage will you tune it to?

cheers

Thanks Teyber, i am planing on ~ 250W load holding ability, perhaps few watts more. Should be about -90°C to -95°C at 180-200W?

Here's the other equipment i use:
- Wigam Turboset 90 mini welding kit (MAPP/oxygen)
- Refco BM2-8-DS manifold
- no-name industrial single-stage Vacuum pump (3cfm, 1/4HP, rated to go down to 10Pa, enough for the application we use i think) - get one for ~ 108€ here



Thanks for reading,
N.

[PhilippF]

This is a very nice setup!

I keep my fingers crossed for the -100°C-border

Regards,

Philipp

PS: And be careful with the ethylene!

[Crazy666]

Nice looking unit, man

Should 0.72kW condenser on high temperature stage be enough for 250W load? I think you need no less then 1.5kW or I am wrong?

[tiborrr]

Thanks PhillipF, i do have similar hopes I will take extra caution when dealing with ethylene.

@Crazy666: These compressor draw about ~230W on idle each, so they aren't power hungry horses most of you guys use here. So two 0.72kW condensors (one acting only as gas cooler - desuperheater) should be enough. I know that gas cooling isn't as efficient as liquid cooling but it should do it's job - dump low temperature stage's heat of compression so there is substantially less heat (of compression) needed to be transferred to high temperature stage.

Well, at least that is my theory.

Thanks for your kind support! Greetings,
N.

[piotres]

I've VERY interested to see how NL11F will cope with R1150 , I've thought about it in past but never checked .

How long captube 0.7mm You have on 1st stage ?

I'm very worried about size of condenser in 1st stage ...

From where You get this poliurethane sheets ?

Looks to be VERY interesting project .

[bazx]

looking good tiborrr would love to see you pull it off with these comps

i can see yo have put some thought into the layout it shows

baz

[tiborrr]

I've VERY interested to see how NL11F will cope with R1150 , I've thought about it in past but never checked .

How long captube 0.7mm You have on 1st stage ?

I'm very worried about size of condenser in 1st stage ...

From where You get this poliurethane sheets ?

Looks to be VERY interesting project .

Hi there Peter,

i seem to remember cold_ice once tried 2x NL11F cascade with even smaller condensors, they did pretty well, i seem to recall he benched P4 Cedar Mill at 6GHz+ with it.

Cap tube is 1.9m or 1.95m.

Condensors, as i've have written in my earlier posts should suffice and the low temperature stage's desuperheater should be enough to dissipate the heat of compression. At least that's the theory

These aren't poliurethane sheets, this is poliurethane foam in pressurized can, works very well! The manufacturer is Slovenian TKK, commercial name is Tekapur (PDF about the programme in Slovenian language, you should be able to understand the most important parts).

looking good tiborrr would love to see you pull it off with these comps

i can see yo have put some thought into the layout it shows

baz

Hi bazx,

thank you very much. They should do decent job with dual-core chips, but only time will tell. Yeah, i've tried to minimize the footprint of this cascade as much as possible while still using a fairly large desuperheater / gas cooler on the low temperature stage.


Thanks for the interest guys, will keep this thread up-to-date

Greetings from Slovenia,
Niko

[kayl]

looks good, interested what sort of load it can move when its finished, good luck

[tiborrr]

@kayl: Thank you very much, i hope i'll be able to answer to this question by the end of the weekend.

P.S.: Brazing stuff stash restored, i bought one extra fuel (lasts about 3.5h) & one extra oxygen (lasts about 30min) can just to be safe. :P



Kind Regards,
Niko

[Dimas]

niko, you need a real oxy bottle, using this crap one is a pita, check the pm or come on msn

[tiborrr]

Hehe, thanks Dimas, we will talk tomorrow about it!

I made some progress today, brazed everything except evap, cap tube to exp. tank, compressor- and two HX ports on 2nd stage, which will be done tomorrow, i am too tired to go on tonight (it's 3 AM here):




Kind Regards,
Niko

[bartx]

Nice project, I'm waiting for finish

[godmod]

tiborrr, very nice cascade!

[tiborrr]

Thanks bartx & godmod, now let's see if this baby can run some decent temperatures!

2nd stage is now brazed except for the CPU evaporator (i am missinge one T-line 8mm), i bought whole fist of them but cannot find them now. Perhaps tomorrow Everything is now positioned on the final chassis board.



Kind regards,
Niko

[godmod]

You might want to fix the suction line on the chassis, the way it is now looks like it could vibrate strongly...

[kayl]

looking good, Might be fine the way it is, but bit of a coil on the second stage suction line before the compressor would of allowed for excess refrigerant to boil off before returning to the compressor, and not to freeze the compressor with all that cold return.
remember doing a small cascade and having the same problem, just have to play with refrigerant charges to ensure this doesnt happen

http://www.xtremesystems.org/forums/...22&postcount=5

[tiborrr]

@godmod: No worries, it will be attached to the chassis appropriately which will strenghten the whole suction line aswell. Thanks for the tip anyway

@kayl: Humm, you just might be right, we'll see what will hapen, it can still be modified later but with 2 metre suction line i hope returning liquified refrigerant won't be an issue.

Thanks once again.

Regards,
Niko

[Jack]

i seem to remember cold_ice once tried 2x NL11F cascade with even smaller condensors, they did pretty well, i seem to recall he benched P4 Cedar Mill at 6GHz+ with it.

Yes, Cold_ice made one:
http://www.xtremesystems.org/forums/...ad.php?t=81841

Overklokk once did a cascade with small compressors as well:
http://www.xtremesystems.org/forums/...d.php?t=123264

Cooling capacity and the ethylene pressure will be problematic with such small compressors tho´

Good luck anyway

[tiborrr]

Thank you Jack, let's hope it will all work out. Unfortunately i couldn't find any T-line couple, i guess i really run out of them So the charging will have to wait for next weekend as I am again away from home from monday to friday. All threaded joints are secured with appropriate amount of LeakLock sealant so there shouldn't be any leakage on the second stage now. Also I will have to buy some more of this armaflex self-adhesive tape.

I've also insulated the flexible suction line, man this sucker really is LONG 8-O:


Best Regards,
Niko

[piotres]

Overklokk once did a cascade with small compressors as well:
http://www.xtremesystems.org/forums/...d.php?t=123264

Cooling capacity and the ethylene pressure will be problematic with such small compressors tho´

That's why I'm afraid . We'll see how this cascade will perform .

[tiborrr]

The steel chassis frame has been completed, i may need to repaint it one more time and the original chassis plate is now being scraped for a wooden plate. 2nd stage charging will begin this weekend to come.

[teyber]

looks great! im confused though, why a frame if no case? and if your doing a case why the manometers above the case?

nice job there buddy