teatchme

So since my previous thread/build i was tossing the idea on how to improve my chiller for quiete a while and during my research came over a very interresting build on coolitsystems forums which was a dual boreas cascade chiller (but the boreas heatsink was not used for hot side cooling but a radiator, since the mod was liquid to liquid type). And the results seemed quiete good actually.
Please refrain from comments regarding TEC inefficiency especially in cascade config as i am well aware of those.
Today I decided to put my idea down on paper and downloaded google sketchup for that purpose (lovely piece of easy to use software). Since today is my first attempt at using this software some parts of my design are missing and are inaccurate, but for the most part the dimensions are correct (except for fittings size, tubing, and 5 1/4 inch bay is larger then usual and has a transparent window on purpose).

So firts i'll upload some pics, then the explanation:

Attached Thumbnails

         

teatchme

More pics of the assembly in the case with a meanwell psu (the tubing is wrong) and 1 480 and 1 240 rad.

Attached Thumbnails

     

teatchme

Now to the fun part the explanation:
N.B: i did not create everything from scratch and used sketchup database alot so i do not claim everything u see as my own work.

The idea is to have an assembly of 3 heat exchangers and 4 series of 4 TEC cascades in parallel.

it goes like this:
hot side WB
cascade tecs
cold side wb
cascade tecs
hot side wb

sealed with neoprene

the tecs used are cascades of 40mm tecs (and btw all the dimensions are quiete accurate in my sketches) around 5 mm tall (10mm total), i should include a few extra mm for arctic ceramic though. The WB design is NOT perfect but should be along those lines. the cold side heat exchanger also needs more work since it is not optimised for heat exchange on both sides.

the dimensions of the unit are 56.7mm tall, 214.2 cm long (no fittings), 100.2 mm large (corners) 125.3 large at the widest part.
basically very similar to a meanwell psu and will fit in 2 or 3 drive bays depending on the thickness of copper chosen.

The way it works is hot side heat exchangers are in the loop with one d5 pump, one 240 and 1 480 rad. and the cold side HE goes to the cpu, the second d5 and other cooling needs (the reservoirs are missing for the moment).

The mounting bracket will make the unit fit in the drive bay but i did not include it in the illustration.

Now to tecs. something i have not thought through completely yet, but i can say a few things:
the tecs in cascade will run at same V to use the same psu, and the upper tec will be a slightly more powerful one. i plan to run those at around 50% but am not sure yet.

this is just the first draft of the design so is a little rough around the edges, WB design is yet to be improved.

DuckieHo

Cascading TECs is pretty inefficient. Why not just make a single larger block with more TEC in parallel? Have this thinner block be the length of the bottom of your case.

__________________
To answer most of your questions: (1) a fridge cannot cool a PC (2) 64-bit OS for over 3.4GB (3) If a PCIe card fits, it should work (4) Resolution, not screen size (5) If you have a question, it is not news (6) Report, not respond to Spam (7) Single-Rail/Non-Modular PSUs are not always better than Multi-Rail/Modular

teatchme

mmmm, i kinda said i KNOW it is not very efficient. the idea is to get a bigger dT. why? because hot side cooling gets better the higher the dT of hot side is from ambient. this was one of the probs i had with my previous build, no matter how many rads i threw at id the cooling of hot side would improve only marginally.

I know i can get better dT by upping the V but not as much as cascade tecs

Random\/

Can't really comment with any technical advice but seems like a very interesting setup, also very nice sketches! Hope it works out

Scarlet Infidel

I would urge you to do some real calculations here.

Stacking peltiers is a reasonable way to get great dT when you come close to the ~70c dT possible with a single module. For this application I do not think you will improve temperatures by doing this and would be better of with a single layer at higher voltages.

When I get home from work I will run some rough numbers. I'd be interested if you can give some approximate numbers too so we can see if we are on the same lines.

teatchme

I was about to do some number crunching later as well.

p.s: Check out the boreas cascade boreas build at coolit forums, really interresting stuff.
Thanks for the encouraging comment RandomV

edit: a slight improvement pic

Attached Thumbnails

 

__________________
my first TEC chiller:
http://www.overclock.net/peltiers-te...d-attempt.html

Scarlet Infidel

Ignoring the stacking issue for now. This doesnt look like a bad start. The copper and TECs are going to cost a lot.

The middle section is going to be cold so it would be wise to extend the insulation around a smuch of it as possible (but not he hot sections).

As always with chiller designs, good luck, I genuinely want it to work well.

teatchme

new pics:
made a psu combo in a mounting bracket

Thanks scarlett. i know the price is going to be just CRAZY, but for the sake of the discussion well leave it out of the picture for the moment.

the dimensions are around 115mm (without controller) high and 241 long

edit: added a controller (its a schyte but its for illustration purposes only, should be a pid controller)

edit 2: uploaded with pump rez combo just for fun, the height becomes an issue as is about 193 mm, should fit in a fulltower nonetheless.

Attached Thumbnails

       

__________________
my first TEC chiller:
http://www.overclock.net/peltiers-te...d-attempt.html