crazy submersion phase change system

Discussion in 'Extreme Cooling Solutions' started by technogiant, Oct 19, 2013.

  1. technogiant

    technogiant Limp Gawd

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    High guys....just thought I'd link you to my latest project.
    It's an evolution of my previous chill box build...but this time....well where do I start.

    The chamber is basically like a huge actively cooled vapor chamber with the motherboard submerged in the bottom of the chamber in the working fluid which is liquified gas.

    ...perked your interest?

    Here's a youtube link to the web cam footage from inside the chamber.

    http://www.youtube.com/watch?v=ZUVWAdSnYuw

    So the chamber is completely sealed and made of 1.5cm alu plate as it has to withstand negative pressures of -10psi.

    The evaporator of my 3.6kw air con unit is sealed inside the chamber and the chamber is filled with the gaseous refrigerant.

    When you turn the ac unit on the temp drops, liquifies the vapor causing a partial vacuum which is used to draw liquified refrigerant from a pressure bottle into the chamber sump where the pc mobo becomes submerged.

    So the mobo is submerged in liquified refrigerant....the refrigerants boiling point at normal temp and pressure is -1c but because the cold in the chamber is causing a pressure drop the liquid boiling point also drops.....in fact the liquid is in a state of equilibrium balanced right on the edge of a variable boiling point the value of which depends on the pressure/temperature of the chamber.......you can see this in the video...the liquid is in a constant bubbling state even with no load...like a witches cauldron. The lowest temp the chamber produces is about -30c.

    The components are cooled by the liquid phase changing...this is where it's good to have the liquid on the edge of liquid/vapor equilibrium as it's always ready to boil off given a heat input.

    I have to contain the liquid in a pressure cylinder between uses as the chamber was not designed to withstand expansive pressure...just compressive pressure.

    So I basically reverse the filling process.....the cylinder is place in a chest freezer so causing a low pressure inside....the chamber cooling is turned off and as it warms the liquid is transferred across through a linking pipe because of the pressure differential.

    You like.....I think this is a first....:eek:
     
  2. dragonstongue

    dragonstongue 2[H]4U

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    dude, intense.

    Are you not worried the refrigerant will cause corrosion or possible damage from the change of temperature extremes(cracking of solder joints etc)?

    I also read not that long ago of IBM and a few others doing warm water cooling as in instead of trying to keep the working fluid as cold as possible, they tried to keep it around ambient or slightly above to minimize thermal shock as well as reduce power requirements. various metals of course expand and contract at different rates and their conductivity also changes depending on temperature and amount given, some parts simply are much better when working "cold" and others due to way they are built have an upper and lower range and going beyond this does not help and could damage things over time.

    I would just imagine the corrosive nature of the refrigerant in question would be something to think about as there is a lot of different materials being used here, the aluminum/copper or whatever is one thing but all the caps and such and direct electricity and possibly even EMF could be very bad?

    Very neat though imagine the possibility of this is huge, I always wanted to do a submerged oil one myself but I would think of doing the mobo in a full cover type block and just have the rad or something in the oil with a secondary rad in a bong type cooler or maybe if you pair this with the AC type idea, have the oil cool the hot parts indirectly(full cover) primary rad cooled via AC/tek and secondary rad is submerged in the oil

    oil-rad-pump-parts-prime rad-ac-oil and so forth. Anyways lol, nifty to watch it boil like that.
     
  3. technogiant

    technogiant Limp Gawd

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    I've lived on chemical compatibility check sites for the last year.....no the refrigerant won't cause corrosion, it is completely non polar molecularly, and non conductive electrically.

    There is little chance of thermal shock to the build itself, it has a lot of heat buffering, the chamber is aluminium and weighs 62Kg.....and as regards expansion/contraction I've put it together using a high modulus polyurethane sealant/adhesive which being high modulus will stretch with any contraction/expansion cycling.

    The electrical components are a mixed bag and more unknown...I'll look for designs with all solid caps....but basically its the same as submerging in oil...but this oil phase changes.

    The only thermal shock may be that of the components....say for instance your running a cpu stress test and then you stop it....bang the cpu temp rockets back down again when the cooling system is so powerful. But I have been running a chill box prior to this at -30c for about a year and in practice this doesn't seem to occur.
     
  4. Diakonos

    Diakonos n00bie

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    So I guess Sapphire would call it Vapor-XXX? Very cool. There I go with the puns again...

    Any idea how much heat is actually being removed?
     
  5. technogiant

    technogiant Limp Gawd

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    Well the ac unit has a cooling power of 3.6kw...so that is the ultimate limit on the system.....I have no way of measuring this but the amount of condensate that is flowing gives an indication of the heat flowing through the system.....1ml of liquid equates to 220 joules...so 1ml/sec of condensate production equates to 220watts being cooled by the system.
    When I introduce the liquid to the chamber as it is slightly warmer and the chamber pressure is low it tends to boil off.....when that happens the condensate pours from the evap (cold radiator)like a monsoon...sort of shows that the chambers cooling capabilities are way sufficient.

    I'm not getting as good cpu temps as I hoped but could be several reasons for that which I need to look into.....possible the Tim I'm using, I had to use a home made one as commercial ones based on silicone grease would just dissolve. I may have just not done a good job applying it.....secondly I may need a special coating on the heat sink to enhance nucleation...that is the changing of the liquid to gas.
     
  6. lilfiend

    lilfiend [H]ardness Supreme

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    I've been following this over at ECOF for a while now and I didn't think you'd ever actually do it! How did you end up stopping air getting in through the cables?
     
  7. technogiant

    technogiant Limp Gawd

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    Yes that bit is a little bit of a potch....basically I've run cable extenders from the mobo through the chamber wall where they are sealed as they pass through....but obviously internally they are still open.
    They are then joined to the main cables inside an upward pointing 90 deg bend pipe which is sealed to the outside of the chamber wall at the pipes lower end...the pipe is then filled with oil...the idea being that the negative pressure will draw the oil into the cables where they connect and be pulled into the cables that lie within the chamber...there the cold will freeze the oil so that it prevents any more being drawn in.

    It works but I'm not 100% satisfied with the solution yet....trouble is that when turned off the negative pressure remains even when the temps have gone above the melting point of the oil...and I don't want it being drawn right into the chamber and messing it all up or worse blocking the fluid recovery line.

    Another problem is because of the cold condensation is forming all around there probably running into the pipe and pooling at the bottom....could short out my electrical connectors. I may pack the pipe with a thick body moistuiser...think water would just sit on to of that and it is thick enough I think not to be drawn in too far.....but like i said it's a bit of a potch.
     
  8. westrock2000

    westrock2000 [H]ardForum Junkie

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    In case any one is freaking out about -30*C. In my line of work we characterize computer chips all day long for development and the standard "cold temp" we run parts at is -40*C. So most computer chips *should* be stable at -30*C.

    And if your wondering, the opposite end of the spectrum is 125*C standard with some chips going up to 150*C.
     
  9. Joseph F

    Joseph F Gawd

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    Full system specs and OC results, please! This is an awesome idea.
     
  10. technogiant

    technogiant Limp Gawd

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    Hi Joe, I haven't done extensive testing with this new cooling system yet....but do have some results.

    http://imageshack.us/a/img27/7871/h8of.jpg

    http://imageshack.us/a/img35/2852/o4qy.jpg

    Temps aren't all I hoped they would be considering the mobo is submerged in a phase changing liquid at -30c
    But getting 5.5/5.4GHz on a 2700k at 1.51vcore

    I've got some tweaking I need to do with the heat sink, perhaps giving it a nucleation enhancing coating and swapping the TIM.....either may explain the larger than expected temp delta...but at this stage I'm just pleased the cooling methodology is working.
     
  11. W.Feather

    W.Feather Hard DC'er Of the Month Aug 2012

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    I merged the two identical threads, so they are now where they should be.

    -W.Feather
     
  12. pendragon1

    pendragon1 [H]ardForum Junkie

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    Nice necro. Working on your post count?
     
  13. sirgallium

    sirgallium Limp Gawd

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    Youtube is telling me the video is unavailable.

    "you can see this in the video...the liquid is in a constant bubbling state even with no load...like a witches cauldron"

    oh man you're killing me. I gotta see that video.
     
  14. acquacow

    acquacow Limp Gawd

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    Well, it's from 2013... Your best bet is to lookup some 3M Novec videos like this one:



    I've seen it a lot at the 3M Booth at nearly every show they attend.
     
  15. pendragon1

    pendragon1 [H]ardForum Junkie

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