matt, close but no cigar. the unit needs to be more or less vertical so that
the liquid drains all the way back to the burner. If the liquid does not get
back there they burner pot gets scorched and the unit is ruined.

but yes, a cigar regarding efficiency. gas absorbtion refrigerators are much
less efficient than compressor reefers, when comparing energy input vs cooling
capacity. One a boat, electricity is incredibly expensive to make per
kilowatt, and HUGELY expensive compared to the same kilowatt purchased as
propane.

A kilowatt of electricity produced on a boat can cost $2 to $5 dollars EACH,
while a gallon of propane (about 90,000 btu's, or about 30 kilowatts) goes for
maybe a couple bucks (? I can't remember how much I paid for 10# of propane
last summer, but it certainly was pocket change)

You people seem to have missed two things in the thermodynamics part of
your education.

A Servel Cycle (the identifier for water/hydrogen/ammonia abortion
refrigeration) requires both the persistance of two liquid/vapor seals
and a lot of vertical room.

The vertical height is required so the ammonia can get condensed and
then be run down into the evaporator by gravity.

The two sealing loops separate a: ammonia vapor from ammonia liquid and
hydrogen and b: water from hydrogen.

The "household" units - these include RV - do not have seals that work
well out of vertical. Seals for these have been designed that do just
fine at a considerable offset. If the seals get blow out, they will
re-establish themselves with a reasonable amount of running time.

A one time I was employed by a company that was in the process of
developing a refrigeration system that could used the exhaust heat of an
RV to be the motivating heat for the refrigeration (apart from the fact
that the system had real flexability issues as far as installaion) the
whole program went down in flames whent he bottom fell out of the RV
market during the original Arab Oil Embargo.

Another issue for sailors would be that the COP (co-efficient of
performance - sort of the effieciency) of Servel units was not as good
as an R12 or R22 unit.

Matt Colie


Horace Brownbag wrote:
On 04 Jul 2004 02:05:22 GMT, (JAXAshby) wrote:


The
real problem with absorption cycle refrigeration (gas refrigerators) is
that they must stay within 5 to 7 degrees of vertical.

not true. unless the vehicle is NOT moving side to side.


lateral forces mimic inclination.