Eric,
I was suspecting that might be the case, but the explanations in the
other articles were way too vague to be sure of that. The NextPlatform
provided much better pictures. If that's the case, this thing operates
like a direct-expansion (DX) refrigeration system, where the refrigerant
is air and does not change state from liquid to gas, like a typical DX
refrigeration system, and the induced-draft fan provides the shaft work,
and those tiny channels that allegedly line up the molecules act as many
tiny offices for the throttling process. Based on the pictures in the
Next Platform article, here is a crude drawing of cross-section of one
of these devices that I drew in Google Draw. It should help you
understand what's going inside this thing:
https://docs.google.com/document/d/1UK94PxVlQtVSb2ns5TbCqHjPJ1vYSOmkGSeSorvHyaM/edit?usp=sharing
Given this design, you can only have an induced-draft fan on the outlet.
A forced-draft fan on the inlet would compress the air, heating it up
and negating the throttling (or Joule-Thompson) effect on the
low-pressure side.
At the end of the day, thermodynamics still says X amount of shaft work
has to be done to provide Y amount of cooling through this process, so
I'm still skeptical of it, especially at scale.
And for those of you looking for something really boring to read rather
than work, here are the related patents. I haven't read them myself.
https://patents.google.com/patent/US8414847
https://patents.google.com/patent/US8986627B2
https://patents.google.com/patent/US10113774B2
Prentice
On 1/25/19 2:26 PM, Eric Moore wrote:
Actually, it looks like Joule-Thompson cooling to me (Especially given
the "Joule Force" name). You've got the air intake (ambient), then an
expansion nozzle, into a low-pressure region, which is created by the
fan at the end. So the outlet velocity of the air (and thus it's
kinetic energy) is higher than the inlet velocity, which would lower
the internal energy, and thus the temperature. Instead the
fins/nozzle/heatsink transfer heat to the expanding gas, which exits a
little above ambient temperature. I imagine the drawback is you really
need to get rid of that high velocity hot air, and can't recirculate
it, or the kinetic energy would be converted back to thermal energy,
and mess it all up. The descriptions do all involve the exhaust air
being ducted to the outside. This article has the most technical
detail:
https://www.nextplatform.com/2018/12/04/the-leading-edge-of-air-cooled-servers-leads-to-the-edge/
On Fri, Jan 25, 2019 at 11:33 AM Prentice Bisbal via Beowulf
<beowulf@beowulf.org <mailto:beowulf@beowulf.org>> wrote:
You all know how much I like talking about heat transfer and
server cooling, so I decided to do some research on this product:
Here's their website:
https://forcedphysics.com
and here's their YouTube channel with 5 videos:
https://www.youtube.com/channel/UClwWeahYGuNl0THWVz1Hyow/videos
This is really nothing more than an air-cooled heatsink. I'm
afraid I'm going to have to call BS on this technology for the
following reasons:
1. It still uses air as the primary cooling medium. I just don't
think air has adequate thermal conductivity or thermal capacity to
serve modern processor, no matter what you do to it.
2. In the videos, they present highly idealized tests with no
control to use for comparison. How do I know I wouldn't get the
same results doing the same experiment but using a similar duct
fashioned out of sheet metal.
3. Using this technology means a complete redesign of your server
hardware and possibly your racks.
4. None of the information in the videos or on their website
really explains how this technology works, and what really
differentiates it from any other air-cooled heat sink. Most people
with a good invention are usually excited to tell you how it
works. Since they brag about 30 international patents for this,
there's no need to try to protect a trade secret.
5. This statement:
The fins work like teeth in a comb, neatly orienting air
molecules to point in the same direction and arranging them into
columns.
Based on my education, this statement seems to be completely
devoid of science.
This statement seems to defy the laws of physics. Last time I
checked, unless an atom or molecule is at absolute zero, it has
movement, whether it's spinning or vibrating, or both, so how can
they get air molecules to line up all in neat little rows, where
the molecules are all pointing the same way?
This also implies very laminar flow. As fluid velocity increases
that the diameter of the channel decreases, the Reynolds Number
increases. As the Reynold's number goes up, turbulence increases,
so mathematically, I would expect this flow to be tubulent, and
not laminar. From my classes on heat transfer, turbulent flow
around the heat transfer surface increases heat transfer, so
laminar flow in this case wouldn't be a good thing.
Until they can provide better comparisons with real servers in
real data center environments, I'm going to classify this as
"snake oil"
https://en.wikipedia.org/wiki/Snake_oil
Prentice
On 1/24/19 3:54 PM, chuck_pet...@selinc.com
<mailto:chuck_pet...@selinc.com> wrote:
Well, this is interesting.
"According to Forced Physics’ <https://forcedphysics.com/
[forcedphysics.com]
<https://urldefense.proofpoint.com/v2/url?u=https-3A__forcedphysics.com_&d=DwMFAw&c=-_uRSsrpJskZgEkGwdW-sXvhn_FXVaEGsm0EI46qilk&r=fawF3TRTwCqlaBkoLcxYCr4F4NRwCc64hmEgi9rHPpE&m=zr6lAlVphGxOQTXSElww9hGpqb9IZPik0_MN2v8Fqjs&s=lb4Hi9X8NKIYWe_e1RU3Cw4gr9Uz_B7n5pnCNY0ss3U&e=>>
chief technology officer, David Binger, the company’s conductor
can help a typical data center eliminate its need for water or
refrigerants and shrink its 22-MW load by 7.72 MW, which
translates to an annual reduction of 67.6 million kWh. That data
center could also save a total of US $45 million a year on
infrastructure, operating, and energy costs with the new system,
according to Binger. “We are solving the problem that electrons
create,” he said."
A Cooler Cloud: A Clever Conduit Cuts Data Centers’ Cooling Needs
by 90 Percent
https://spectrum.ieee.org/energy/environment/a-cooler-cloud-a-clever-conduit-cuts-data-centers-cooling-needs-by-90-percent
[spectrum.ieee.org]
<https://urldefense.proofpoint.com/v2/url?u=https-3A__spectrum.ieee.org_energy_environment_a-2Dcooler-2Dcloud-2Da-2Dclever-2Dconduit-2Dcuts-2Ddata-2Dcenters-2Dcooling-2Dneeds-2Dby-2D90-2Dpercent&d=DwMFAw&c=-_uRSsrpJskZgEkGwdW-sXvhn_FXVaEGsm0EI46qilk&r=fawF3TRTwCqlaBkoLcxYCr4F4NRwCc64hmEgi9rHPpE&m=zr6lAlVphGxOQTXSElww9hGpqb9IZPik0_MN2v8Fqjs&s=VuDTSuinKPMpF6NCztFZkSGOVo3LD7MLjroIj_sn0ao&e=>
Chuck Petras, PE**
Schweitzer Engineering Laboratories, Inc
Pullman, WA 99163 USA
http://www.selinc.com <http://www.selinc.com/>
SEL Synchrophasors - A New View of the Power System
<http://synchrophasor.selinc.com <http://synchrophasor.selinc.com/>>
Making Electric Power Safer, More Reliable, and More Economical (R)
** Registered in Oregon.
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