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Salty_Peaks
@as54203.net

Salty_Peaks

Anon

Speedstream 4200 DSL modem in Mineral Oil (99.9% USP)

While I'm not 100% certain this is the right place for this I figured it was as good a place as any since I frequently post here in ATU and hopefully most of the regulars know me.

Apr 15 2014 - First attempt, why did I do this? Boredom.

graysonf
MVM
join:1999-07-16
Fort Lauderdale, FL

graysonf

MVM

I've seen PC motherboards, including fans, running under mineral oil.

Maxo
Your tax dollars at work.
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join:2002-11-04
Tallahassee, FL

Maxo to Salty_Peaks

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Is this supposed to provide some sort of super-cooling or something?
pablo
MVM
join:2003-06-23

pablo

MVM

I just learned: »pandawhale.com/post/3219 ··· l-cooled

Kinda cool.

El Quintron
Cancel Culture Ambassador
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join:2008-04-28
Tronna

El Quintron to Maxo

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said by Maxo:

Is this supposed to provide some sort of super-cooling or something?

Pretty much, you can stick an entire PC in the stuff and it'll run at room temp:

»www.youtube.com/watch?v= ··· ihoPWvVA

Salty_Peaks
@as54203.net

Salty_Peaks

Anon

I got more pics coming just waiting on the mods to approve 'em.

El Quintron
Cancel Culture Ambassador
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join:2008-04-28
Tronna

El Quintron

Premium Member

Do it! (I thought you were reg'd under some other name)
Expand your moderator at work

Salty_Peaks
@as54203.net

Salty_Peaks to Salty_Peaks

Anon

to Salty_Peaks

Re: Speedstream 4200 DSL modem in Mineral Oil (99.9% USP)

Oh wow, ok let me try this time

Apr 15 2014 - A few minutes later I decided to cover it and make it a closed system. A couple of hours later I hit up Wal-Mart and picked up some more mineral oil; I felt the oil and it was luke warm so I decided since this was a closed system I needed some type of thermal radiator/heatsink so I made one from about 3 ft of 12 ga copper and coiled it around a pipe. It should do nicely while still keeping the system closed and free of debris. The gap in the coil is intentional to use the least amount of copper in the air gap between the lid and mineral oil. The container is made from polypropylene or polyethylene and isn't vulnerable to mineral oil.

Thane_Bitter
Inquire within
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join:2005-01-20

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Interesting but that modem doesn't make much heat, the power it consumes is just a few watts. I recall this model of modem making a high pitched sound, I wonder if the oil cuts down on that noise?

cowboyro
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join:2000-10-11
CT

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How do you clean it if you decide you don't want it in oil anymore?
lutful
... of ideas
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join:2005-06-16
Ottawa, ON

lutful to Salty_Peaks

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I have seen tech geeks put whole motherboards in oil. I myself would be reluctant to do that because there are so many other ways to cool hot electronics.

I wonder if there is any chemical reaction over long periods with plastic IC packages.

garys_2k
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join:2004-05-07
Farmington, MI

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I have to wonder about fire safety, would a good arc possibly ignite the oil? A "dramatic" failure may cause some of the oil to splash into a mist, I could see that being pretty flammable.

leibold
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join:2002-07-09
Sunnyvale, CA
Netgear CG3000DCR
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leibold

MVM

Intel seems to think the idea has merits: Data Center Knowledge: Intel explores mineral oil cooling .

There are also articles about the US military using oil filled data center containers: Data Center Dynamics: US military servers to be submerged in oil in data center containers .

SparkChaser
Premium Member
join:2000-06-06
Downingtown, PA

1 edit

1 recommendation

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I used to use it for cooling a Dummy Load on 6 meters when I was a kid. Marconi showed me.
lutful
... of ideas
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join:2005-06-16
Ottawa, ON

lutful

Premium Member

said by SparkChaser:

I used to use it for cooling a Dummy Load on 6 meters when I was a kid. Marconi showed me.

Now, there are oil-free solutions even for 5KW.

»RF wirewound resistors
TheMG
Premium Member
join:2007-09-04
Canada
MikroTik RB450G
Cisco DPC3008
Cisco SPA112

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TheMG to garys_2k

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to garys_2k
said by garys_2k:

I have to wonder about fire safety, would a good arc possibly ignite the oil?

In order for the oil to ignite, it needs to reach flashpoint temperature.

For mineral oil, that is about 160-170°C. Below this temperature, the oil will not ignite, unless it is sprayed into a fine mist. You can throw a lit match into a cup of warm mineral oil and it will not ignite.
said by garys_2k:

A "dramatic" failure may cause some of the oil to splash into a mist, I could see that being pretty flammable.

Unless the components are very close to the surface of the oil, I can't really see that happening, and even if it did, it might throw up a bit of flame, but then will quickly extinguish, the rest of the oil will not burn.

What COULD be a problem, however, is if the container holding the oil is made of plastic, certain kinds of plastics will melt below 100°C, potentially spilling the oil, and now you have components covered in a thin film of oil which can easily be heated to flashpoint. At this point, a catastrophic component failure or failure of the over-temperature shutdown of the components being cooled, could potentially satisfy those conditions resulting in a fire.

But of course, this is quite an unlikely chain of events if a little common sense is used in the design of the oil cooling system, particularly using a containment vessel which will not melt at low temperatures, and sizing the system appropriately so it can dissipate sufficient heat and keep the oil temperature within reasonable limits.
public
join:2002-01-19
Santa Clara, CA

public to leibold

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said by leibold:

Intel seems to think the idea has merits: Data Center Knowledge: Intel explores mineral oil cooling .

There are also articles about the US military using oil filled data center containers:

Evaporative spray cooling is vastly superior to liquid immersion.

mackey
Premium Member
join:2007-08-20

mackey

Premium Member

said by public:

said by leibold:

Intel seems to think the idea has merits: Data Center Knowledge: Intel explores mineral oil cooling .

There are also articles about the US military using oil filled data center containers:

Evaporative spray cooling is vastly superior to liquid immersion.

Yeah but evaporation of what? Water can't be used because it conducts electricity (it will short out the electronics you're trying to cool). What liquid are you suggesting should be used?

SparkChaser
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join:2000-06-06
Downingtown, PA

SparkChaser

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said by mackey:

Yeah but evaporation of what? Water can't be used because it conducts electricity (it will short out the electronics you're trying to cool). What liquid are you suggesting should be used?

Seems they cool a heat sink or the board w/o compponents not the electronics per se.

Here's a company that does it.
»www.rinitech.com/applica ··· ions.asp
Patent »www.faqs.org/patents/app ··· 90014562

Abstract from IEEE paper »ieeexplore.ieee.org/xpl/ ··· D4544290

A pressure atomized evaporative spray cooling nozzle array was used to thermally manage the power electronics of a 3 phase inverter module. The module tested was a COTS module manufactured by Semikron, Inc., and has a maximum DC power input of 180 kW (450 VDC and 400 A) with 25degC coolant. However, the standard heat sink that the module uses is a single phase liquid heat sink and when 100degC coolant is used (as in automotive applications), the maximum module power is de-rated to 45 kW so that the IGBT chips will not overheat. The module tested here incorporated a custom heat sink that allowed for the use of spray cooling nozzles, which were designed and developed by RTI. The spray liquid was a 50/50 mixture of water and propylene glycol (WPG) at a temperature of 100degC. The sprays impinged directly onto the bottom surface of the DBC boards to which the power electronics were mounted. This arrangement, combined with the high heat transfer coefficient of evaporative spray cooling, greatly reduced the thermal resistance of the power electronics material stack up, but did so without directly wetting the electronics. The results of this work were that the unique evaporative spray cooling nozzle design and patented electronics interface design allowed the module to be run to full power while keeping the IGBT junction temperatures acceptable, despite the high coolant temperature. The junction temperatures of the IGBT's were measured by electrically insulated type T thermocouples placed on top of the devices, and the thermocouple readings at the full load were within several degrees of one another. Consistent and uniform junction temperatures are an important factor in long term device reliability. For the standard heat sink, which uses single phase liquid cooling, the pressure drop and flow rate required for maximum heat removal would be 17 psi and 5.3 GPM. For the pressure atomizer spray nozzles, the module would require a pressure drop and flow rate of 40 psi and onl- y 2.7 GPM.

mackey
Premium Member
join:2007-08-20

mackey

Premium Member

said by SparkChaser:

said by mackey:

Yeah but evaporation of what? Water can't be used because it conducts electricity (it will short out the electronics you're trying to cool). What liquid are you suggesting should be used?

Seems they cool a heat sink or the board w/o components not the electronics per se.

But that's completely missing the point of immersion cooling - cooling _everything_ and not just a few heat sinks. Evaporative spray is also not practical if density is too great and pumping all that water/glycol in close proximity to electronics can cause problems when leaks occur.

Evaporative cooling is great as the ultimate heat sink, not so great as an intermediate heat transfer medium.

/M

SparkChaser
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join:2000-06-06
Downingtown, PA

SparkChaser

Premium Member

said by mackey:

But that's completely missing the point of immersion cooling - cooling _everything_ and not just a few heat sinks. Evaporative spray is also not practical if density is too great and pumping all that water/glycol in close proximity to electronics can cause problems when leaks occur.

Evaporative cooling is great as the ultimate heat sink, not so great as an intermediate heat transfer medium.

/M

I totally agree.

I posted the info because I had not heard of it's use before and wondered how it was used.
lutful
... of ideas
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join:2005-06-16
Ottawa, ON

lutful to mackey

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to mackey
said by mackey:

... the point of immersion cooling - cooling _everything_ and not just a few heat sinks.

Mainly due to the Intel link from this thread, I was discussing oil immersion method with two friends who do advanced physics simulations.

A motherboard has a few hotspots that JUMP OUT in simulations and thermal images. Ideally, the high heat output from those locations should be removed as quickly and efficiently as possible.

The oil medium averages the TOTAL heat output from the whole board with significant temperature gradient near each hotspot. They would be visible in thermal images. The heat sinks, ironically installed for air cooling, is saving the day.

Even simple liquid cooling of CPUs and GPUs are not really necessary for a well designed motherboard dissipating less than 1000W total.

Even the hottest CPU available (the 600W Power8 for example) can be cooled directly using a layer of phase change material and a properly designed heat pipe. Lower wattage hotspots can be cooled just with phase change material and properly designed heat sink.

Once the heat pipes and heat sinks are installed, it is just a matter of sufficient air flow within specified ambient temperature range. The airflow can be pre-cooled using many methods including expansion of compressed air.

Salty_Peaks
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I think low TDP is the key here. Low TDP, large surface area, natural convection currents, and a thermal bridge via the 12ga copper. Oil temperature is 82F at 76F ambient.
public
join:2002-01-19
Santa Clara, CA

public to mackey

Member

to mackey
said by mackey:

said by public:

said by leibold:

Intel seems to think the idea has merits: Data Center Knowledge: Intel explores mineral oil cooling .

There are also articles about the US military using oil filled data center containers:

Evaporative spray cooling is vastly superior to liquid immersion.

Yeah but evaporation of what? Water can't be used because it conducts electricity (it will short out the electronics you're trying to cool). What liquid are you suggesting should be used?

A refrigerant compatible with the die attachment and interconnections.
While spray cooling may not be needed for cpus, it is needed for electric vehicle power levels.

Jason
Stowage Class Traveler

join:2001-01-24
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Im a firm beliver in straight water cooling. My company makes high temperature furnaces, (some in excess of 3,000C)

Recently, we designed, built, and sold a 36,000 amp "DCS" or a direct current version of an SPS (Direct Current Sintering, vs. Spark Plasma Sintering) It had about 750KVA of transformer in it, with huge hockey puck sized rectifiers on each phase output. All cooled with water... Even the secondary coils on the transformer were hollow soft copper tubes that flowed water through them (We work very closely with Warner Power, who designed this power system)

There are more exotic cooling methodologies out there, some with a lot more cooling potential, but simple water cooling is still the easiest to implement, and very effective with little to none upkeep or maintenance.

All that said, theres just something mesmerizing about seeing a PCB functioning while immersed in a bath of liquid.