of precise time and frequency measurement"
>
> Sent: Wednesday, October 03, 2012 8:14 PM
> Subject: Re: [time-nuts] OT question about liquid cooling
>
>
> It actually takes supprisingly little water flow to dissipate 5 kW.
>
> Very roughly 5 kW = 1250 cal/sec (4.18 J/c
9 MVA is somewhat bigger than 5 kW.
I was assuming fairly short duration tests, perhaps a few hours, where
open-cycle water is practical.
If you are going to use a water loop, getting rid of the heat is certainly
an issue.
-John
==
> Perhaps, but unless you plan on just draining th
Perhaps, but unless you plan on just draining the water, you need a liquid to
air heat exchanger (LAHE) to cool the water in your loop. Perhaps for a lab it's
no big deal, but if you intend to operate where it can get cold (needing glycol)
or where there is very limited water supply (remote loca
If you let the water boil, it takes even (much) less.
Tom
- Original Message -
From: "J. Forster"
To: "Discussion of precise time and frequency measurement"
Sent: Wednesday, October 03, 2012 8:14 PM
Subject: Re: [time-nuts] OT question about liquid cooling
It actually takes supprisingly little water flow to dissipate 5 kW.
Very roughly 5 kW = 1250 cal/sec (4.18 J/cal)
so, for a 1 C degree = 1.25 liters/sec
at 50C degrees = 25 mL / sec. = 1.5 L/min.
-John
==
> BWIWY (back when I was young) we needed a dummy load for a super
BWIWY (back when I was young) we needed a dummy load for a supercomputer (think
Cray YMP size) that drew many many kw.
Our test load was about 250' of 3/4" copper tubing coiled at about 12" dia and
1" spacing. The load was varied by changing where the + and - leads were bolted
onto the coil wi
My day job is large industrial power supplies. The test racks have large
resistive loads with big fans exhausting to the outside. Cheap & simple.
Safety is by several strings of temperature cutouts wired in series. We
usually get work experience students in to wire them up.
Tip: to make a funny va
5KW of power but that is only 1/4 of the spec. What temperature will
the loads operate at? It is quite hard to cool anything to ambient
with water. The cooler the operating point the larger the heat sink.
Using a very oversize heat exchanger s not unreasonable of you want a
relative low tempera
Hello all,
Please excuse me for the OT, but since this list is plenty of very
knowledgeable colleagues, I'm tempted to ask...
I need to cool several resistive loads, in the order of 5kW, and I plan
to use a cold plate and a liquid-to-liquid heat exchanger like the
Lytron LCS-20, but this uni
