At 02:46 PM 6/19/2011, Stephen A. Lawrence wrote:
On 11-06-19 02:40 PM, Abd ul-Rahman Lomax wrote:
At 08:08 AM 6/19/2011, Stephen A. Lawrence wrote:
On 11-06-19 05:34 AM, Akira Shirakawa wrote:
On 2011-06-18 16:07, Akira Shirakawa wrote:
Today Rossi posted on his Blog some interesting info:
When E-Cats work without a drive, Rossi has to operate alone on
them for safety reasons.
This is such a facile explanation ... We mustn't unplug it from
the wall because that would be dangerous.
It's facile, to be sure. But that doesn't mean it's false. And
that's not actually what Rossi said. If you were operating an E-Cat
the way it was operated in the demos, and unplugged it, the thing
would cool off. The danger would arise if we heat it up to a
certain point, at which the heat generated is enough to keep it
that hot, so that it needs no input power.
Rossi has never stated that, as far as I know.
Good, you got that down. But you inferred this from what other wrote:
Only those attempting to "explain" his assertion that running
without input power is too dangerous have said that.
I can't be responsible for what many commentators might have said,
people have said all kinds of things about the device. The problem is
one of intepretation here, though. What does "running without input
power" mean? Under what conditions would it be safe and under what
conditions would it be dangerous?
It's easy to answer that question, and it's a harmonizing intepretation.
"Running without input power" requires raising the reaction cell
temperature to the point where no heat input is needed, where the
cell maintains its own temperature from generated heat. This is quite
certainly not the operating temperature in the demonstrations, it
must be a higher temperature. We can know this because, in fact,
input power was maintained at all points, so the temperature must
have been below a self-sustaining point (or the temperature would
have risen higher and we'd have been in runaway.)
Yes, if we don't believe that the reaction is capable of being
self-sustaining, this wouldn't make sense, which is why some might
reject this out-of-hand, losing context, which is understanding how
heat could control the reaction *if it's real*. It only makes sense
if the operating temperature is below the self-sustaining
temperature. If that heat is removed, we are, by definition, not at
the self-sustaining temperature, and we have been dependent on
additional heat to reach the current operating temperature, so it's
easy to predict that, then, the temperature would fall, thus lowing
even further the generated heat, until the whole thing cools to ambient.
"Running without power" would require running at the self-sustaining
temperature, which, then, creates the possibility of runaway, if we
exceed that temperature by even a very small margin. Hopefully, we'd
have time to see it happening and flood the thing with nitrogen,
which is apparently what they have done. It's possible that there is
some chaotic effect on the temperature, so a temperature that might
work at one time might be too high, as some rearrangement takes place
in the nickel, say.
And if the temperature is too low, then it will start to cool, and
again, the cooling runs away until it's not generating any power at all.
Controlling this through controlling cooling is an alternative, but
that requires moving parts, perhaps. Cooling through boiling water
can possibly work, since the heat carried away will increase with
temperature. It could be pretty complicated, and Rossi may be
sticking with control through heat, because no moving parts are
involved and it's fail-safe.
I.e., power failure, the additional heating stops, so the reaction
chamber cools off and it shuts down. If the normal cooling is through
boiling water, this is quite safe, because to fail, you'd have to run
dry, and that can be easily avoided (with shutoff of the heating
power if water is running out.)
It's pretty straightforward.
Ditto the alleged feedback loop which keeps the device at the exact
temperature needed to heat the effluent to 101C, not more, not less,
which has never been mentioned by Rossi.
Oh, I'm not particularly interested in the exact steam temperature.
I'm suspicious about what that means.
As far as I know Rossi has never given any explanation for why the
device becomes dangerous if run "unplugged", nor given any
explanation for why the steam temperature never rose above 101C.
But it's obvious, Stephen. Whether he has explained it or not.
First of all, you need to distinguish betweeen "running" unplugged,
and the device being unplugged while running. The latter is not
dangerous at all, the way they are running it. (There would be a
danger if some circuit failure turned on the heater and left it on.
Let's hope he's got some good design there! A really good design
would still limit the temperature below the runaway point -- the
equilibrium temperature at which no input power is needed to maintain
the temperature -- even if the heater is on, full. That has to do
with thermal resistance between the reaction chamber and the cooling
chamber, which is designed to be at the boiling point. You'd engineer
the cell to control that thermal resistance.)
Please understand this, it's crucial, it's behind the diagreement you
have been running. To run "unplugged," it's obvious, one must raise
the temperature to the point where the generated heat sustains the
temperature. That is not a a positive equilibrium point, it is, I'm
not sure I have the language down, a negative equilibrium point. That
is at the point, there is no force in either direction, its like a
ball sitting on the top of a hill with slope of zero at the very top,
but downward slope increasing with distance from the very top.
(In fact, above the equilibrium point, the temperature will run away,
perhaps to melt-down or explosion, and below it, the thing will shut
itself off. If the reaction is at all chaotic, there is no true
equilibrium point, rather, there would be a region where the
probability of increase matches the probability of decrease, with
both being possible.)
A self-sustaining design would have to have positive equilibrium at
the operating temperature. I have no idea, right off, how to design
that, but designing an E-Cat to run below the equilibrium temperature
seems easy, and this matches the information we have.
For example, some have noticed, in the experimental data for one of
the tests, that the E-Cat started to cool, and they had to increase
the input power to keep it running. Obviously, they are running below
the self-sustaining temperature.
The "unplugged" E-Cat is no more dangerous than one plugged in *if
they are operated at the same temperature.* But to get this thing to
stay hot, unplugged, you have to run it at a higher temperature,
which is, by definition, the point at which it becomes dangerous!
If you have seen anything from Rossi asserting what you said above,
I would really appreciate it if you'd quote it here, or provide a link to it.
I don't know what you would be looking for here. What I've written is
obvious from all that Rossi has said and what others have reported
about the E-Cat.
1. I assume that the reaction has a positive response to heat, that,
over the range of interest, the reaction rate increases with temperature.
2. A "self-sustaining" E-Cat must be operating at a temperature where
the generated heat matches heat loss through coolant or other losses.
Otherwise it will cool, lowering generated heat, further lowering
temperature, etc. Without specific data on the reaction relationship
with heat, it could be possible that there would be a positive
equilibrium point at a lower temperature, but my sense is that the
reaction would not work this way, and there is a temperature not far
below the temperatures they are operating at where the reaction
essentially shuts down.
3. The E-Cats we have seen have all been operated with input heat,
the heat was never turned off. It follows from this that they are
operating below the self-sustaining temperature. To get self-heated
operation, then, the temperature would have to be increased.
4. And given the positive effect of temperature on energy generation,
this would then be dangerous. Only if we were *exactly* at the
equilibrium temperature (which depends on the reaction itself and the
cooling mechanism and characteristics) would we have sustained
operation without runaway, and there is the rub: there isn't any such
thing as "exact." Rather, even if the system is well-behaved, there
is measurement error, and in this case, there is only a control
influence in one direction, there is no negative feedback. Negative
feedback, as far as I can tell, would require moving parts and more
risk of failure, or, at the least, something more complicated to engineer.
Look, no blame on anyone for being skeptical about Rossi! I'd say
he's designed the skepticism in, he actually needs it at this point.
He has *no obligation* to be forthcoming and open. He can legally
lie, if he's careful about certain kinds of lies, as long as he's not
taking money or other valuable consideration from those he lies to.
Even some kinds of lies to customers are legal, though that gets much
shakier and depends on jurisdiction and a lot of details.
That doesn't give him the right to slander or libel others.
