[Stoves] Need help in designing a small refrigerator for rural huts.

[nari phaltan]

Thanks Crispin for, as usual, giving sane advice. The old kerosene
refrigerators worked on the principle of ammonia/water/helium mixture. BTW
this refrigerator was designed by Albert Einstein in early 1920s. He and
Silzard had almost 30 patents on it!

The disadvantage of this device was that it was continuous and had quite a
complex geometry. We need to charge our system in one or two hours from the
heat so that it provides cooling for 24 hours!

Garrett's system is quite poor in COP besides being extremely noisy!

All the best.

Anil

On Fri, Jan 18, 2013 at 10:09 AM, Crispin Pemberton-Pigott <
crispinpigott at gmail.com> wrote:

> Dear Anil
>
> Is it not true that modern paraffin fridges use heat to flex a metal
> compressor?
>
> Perhaps a better question is, 'How does a modern paraffin-powered fridge
> work?'
>
> The physics of it must be quite optimised by now. They are available as
> alternative power in South Africa. It might be much more expensive than you
> would guess, but they make large fridges that work on that system.
> The two other methods I can think of are thermo-acoustic refrigeration
> which can be quite simple and can have efficiencies similar to that of an
> air compressor (45%) as well as thermoelectric coolers which are used in
> recreational vehicles.
>
> There is a free downloadable computer programme available from Los Alamos
> Lab for the design of thermo-acoustic refrigeration units. Prof Steve
> Garrett, who sometimes can be found at ETHOS, wrote it +20 years ago. It
> will save you a great deal of work if you want to resign one.
>
> SCORE is working on one attached to a stove, and has been for several
> years. I haven't seen it work yet though.
>
> In operation you heat a sealed tube off centre and have cooling near the
> heating point. It rattles a high pressure wave back and forth. One end gets
> cold, like, -100 C. It is a form of Stirling engine, actually.
>
> Regards
> Crispin
> -----Original Message-----
> From: nari phaltan <nariphaltan at gmail.com>
> Sender: "Stoves" <stoves-bounces at lists.bioenergylists.org>
> Date: Fri, 18 Jan 2013 09:49:49
> To: Discussion of biomass cooking stoves<stoves at lists.bioenergylists.org>
> Reply-To: Discussion of biomass cooking stoves
>         <stoves at lists.bioenergylists.org>
> Subject: [Stoves] Need help in designing a small refrigerator for rural
> huts.
>
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-- 
Nimbkar Agricultural Research Institute (NARI)
Tambmal, Phaltan-Lonand Road
P.O.Box 44
Phaltan-415523, Maharashtra, India
Ph:91-2166-222396/220945
e-mail:nariphaltan at gmail.com
          anilrajvanshi at gmail.com

http://www.nariphaltan.org
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