Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: refrigerator



At 18:38 5/7/98 METDST, you wrote:
Dear colleagues!

A few months ago your information and references were very helpful in
the preparation of an important (for me) lecture.

Now, I am writing again on the same problem. I was asked to prepare
a lecture for physics teachers in primary and secondary school about
heat engines as a part of a seminar about energy and entropy.
I will describe some funny heat engines like a drinking bird and
light mill, but I want to discuss also some more common things like
ordinary refrigerators. They will also make some efficiency measurements
and such things. Coming to the refrigerator, I could not find the data I
need for a crude quantitative picture of the cycle. As far as I know, the
the gas (which one) is expanded adiabatically below the transition
temperature
to the liquid state (the latent heat?) and that it is heated on the cold
side to evaporate again.

So, I am asking you for a reference where I could find some data like the
latent heat and maybe something else like typical thermal conductivities
of refrigerator walls and such things....
Dr. Mojca Cepic
Faculty of Education
Ljubljana
Slovenia


Mojca, I see that nobody seems to have responded to your note - at least by
way of this list. I was tempted to look through my personal resources in
your behalf. But I realise that this would not really be the sympathetic
help which I believe would be of most service to you.

This is what I have in mind. To obtain some answers to your questions, one
would wish to have access to a modest technical or engineering library, and
one would need to know how to peregrinate through several more of less
relevant texts, as a bee would gather honey.

When somewhat comparable questions to yours are posted on a variety of
technical newgroups one often sees a 'stock' response, that "we should not
do your homework for you".

It would be impertinent to insinuate such a suggestion in responding to
your particular need, but one can certainly ask this: is one of more
ingredient of this modest library search topic out of your reach: in brief,
is it the texts, or is it the initial plunge into them that is troublesome?
I would feel able to offer more if I learned more of your situation.
Respectfully,
Brian Whatcott