Daniel Rocha wrote:
You must not forget the losses due the conversion between the heat
exchangers. If it was 70%, that means around 5KW for the core.
I pulled 70% out of a hat, by the way. I do not know what the overall
efficiency is. I am just guessing, based on large, crude experimental
calorimeters I have seen in various labs and at Hydrodynamics, Inc.
McKubre's calorimeter is superb, and it recovers something above 95% of
the heat, as I recall. Or was it 98%? Anyway, the Rossi's reactor is the
opposite of superb. It has a large surface area which must be hot and
must be radiating a great deal of heat. Large, uninsulated boxes like
this that are not engineered with multiple tubes inside and lots of
internal heat transfer surface area recover no more than 80% in my
experience.
I do not know how efficient the heat exchanger is, but top-notch good
industrial ones are about 90% efficient according to on-line sources. I
have no idea what this heat exchanger looks like but if it is
experimental equipment put together by Rossi or by professors in the
last month I'll bet it is well below good industry equipment. So I am
guessing maybe 80% again.
That would be 64% recovery overall.
The right way to do this is to perform a calibration with a joule heater
boiling water. That would tell us the recovery rate. Knowing Rossi I'll
that they did not do that.
Anyway, it can't be anything close to 100%. You can bet the surface of
that machine and of the heat exchanger was hot. How hot? I asked several
people who attended the demonstration to try to measure that surface
temperature but I doubt any of them did it. I don't think they had time
to prepare for that.
As I said this test was an improvement over previous ones but I expect I
will find plenty of ways in which it could have been done better, such
as calibrating and using a IR sensor.
Having said that, we should not lose sight of the fact that finding out
how much heat is lost from the system unaccounted for can only improve
the numbers for Rossi. It can only strengthen the claim. I am sure that
total output energy exceeded total input by a large measure. With 4
hours of heat after death no other result is possible. You cannot begin
to store 4 hours of heat at 3.5 kW in a device this size. That notion is
preposterous. If the heat recovery was 98% (which it could not be; that
is far too high) this result is definitive. If the recovery was 70% or
40% it is even more definitive. You do not actually need to know what it
was. Knowing it would be icing on the cake.
In some early cold fusion experiments, there was only excess heat if you
took into account of the measured losses from the calorimeter, which are
measured by calibrating with a joule heater. In other words, you would
only believe there was excess heat if you trusted the calibrations were
done right, and the recovery rate was correctly measured. Such results
were close to the margin. In Rossi's case, you can ignore the recovery
rate. You could pretend it is 100% (which is impossible) and you still
get large excess in most tests. This inspires much more confidence than
the early marginal tests. Rossi does not trust precision measurements or
complicated methods, so he would never ask anyone to trust his recovery
rate, and he probably does not even bother to measure it. Still, it
would be a good idea to establish the performance of the instrument.
- Jed
