On Sep 21, 2011, at 11:18 PM, Horace Heffner wrote:
On Sep 21, 2011, at 7:40 PM, Jouni Valkonen wrote:
[snip]
I have snipped material, some of which I disagree with, but seems
not worth debating at this late date.
This is very good observation. If your calculations are correct, then
it should be very good evidence for inconsistencies. Perhaps this is
the reason why Rossi has said that his new E-Cat has more effective
heat exchangers than stainless steal. However this issue has been
discussed in Rossi's blog a lot and he is perfectly aware that
stainless steal is poor heat conductor. Perhaps this issue is under
control or perhaps not. Especially bad shadow this casts for Levi's
observed "130 kW power surge" during the 18 hour test. (I thought
previously that it was measuring error, but now I am sure that it was
measuring error)
However it would have been good question to ask how thick walls steal
reactor chamber had?
Yes, but can anything said about the inside of the E-cat be
believed? There are numerous self-inconsistencies in Rossi's
statements, and behaviors. These things may be justifiable in
Rossi's mind to protect his secrets. Whether justified or not,
such things damage credibility.
One thing is for sure: if the E-cat is operated at significant
pressure then 2 mm walls would be too thin at high temperatures.
Also, there are other limits to surface steam generation I have not
discussed, that take precedence at high power densities. One
limiting factor is the ability of the catalyst and hydrogen to
transfer heat to the walls of the stainless steel container, a
process which would likely be mostly very small convection cell
driven. Again, we know too little about the internals. Nothing
much new about that. A heat transfer limit is reached if a stable
vapor film is formed between the walls of the catalyst container
and the water. The top of the catalyst container may be exposed to
vapor, thereby increasing the thermal resistance, the effective
surface area. At high heat transfer rates bubbles can limit
transfer rates. It would be an interesting and challenging, though
now probably meaningless, experiment to put 4 kW into a small
stainless steel container under water and see what happens, see if
the element burns out, etc.
There are other issues that complicate the situation, that could
increase the heat transfer capabilities. We do not know if the
insides of the E-cat are as presented. The temperature curve seems
to indicate it is not. It is entirely possible there is more to it
than a 50 cc stainless steel box. The big area might simply house a
T fitting. There could be an internal heat pipe running throughout
the device, even into the flue. Hydrogen can conduct a lot of heat
by convection. Also, independent evaporative heat pipes of various
kinds can operate at high temperatures. Rossi himself referred to
the boiling occurring in the flue. The effective surface area could
be very large. The effects on the thermometer itself could be
large. We don't know. The problem is lack of information with
regard to internal structure. Independent black box calorimetry is
the only way to get convincing data.
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
