At 02:36 PM 8/17/2011, Alan J Fletcher wrote:
But I specifically indicate that the "dryout" is the point at which
there is no liquid water on the tube wall. There IS still liquid
water in the form of droplets in the vapour.
I made a mistake in responding to Mr. Fletcher's work, I didn't
actually follow the link and somewhat assumed that what he'd posted
to the list was his work. This is now responding to the actual
document, http://lenr.qumbu.com/rossi_ecat_steam_v410A.php
If the eCat is operating BELOW Xdryout, then the flow contains
liquid water: the chimney will fill with water and overflow down the
outlet hose.
Yes. However, this does not mean that liquid water could be observed
from examination of the hose, because Mr. Fletcher has defined
Xdryout with regard to the interior. It is quite possible that liquid
water reaching the outlet port will then be atomized and carried with
the steam flow.
Note: "Xdryout" means that flowing liquid water is absent, not that
the steam is "dry."
If the eCat is operating ABOVE Xdryout, then there will be NO liquid
water in the output.
I will agree, but with a caution. No liquid water will be presented
to the outlet port, because there isn't any. At this point the Rossi
reactor would be operating as a normal tube boiler, where water
inflow is matched or exceeded by steam outflow (wet steam, probably).
During the start-up phase any water left in the chimney will
probably be evaporated by the steam passing through it.
No. Absolutely not. If the steam is wet, it cannot evaporate any
water, unless that water is at a lower temperature than boiling. Only
if the steam is superheated could it do this.
Mr. Fletcher should pay closer attention to the sequence. A
horizontal tube boiler, short like the Rossi horizontal tube, could
only evaporate all the water if the whole assembly rises above the
boiling point. (I'm not on very firm ground here, but try to follow
this.) To be able to transfer heat like Mr. Fletcher proposes, we
must have superheated steam, which requires that the steam be in some
contact with superheated materials. While it's possible that one
could design a boiler so that this happens, there is no sign of any
superheated steam being generated. The chimney temperature is constant.
When the system is stable the output will be a combination of
water Vapour and Water droplets. (As assumed by the NASA calculation).
In other words, saturated steam.
There is NO evidence that the chimney was full, or that substantial
amounts of liquid water left the eCat.
The eCat was therefore operating above the Drypoint.
I'd say that there is no substantial evidence as to the water level
in the E-Cat. There is no substantial evidence as to the actual
enthalpy of the outlet flow.
I have seen only one piece of evidence that the chimney was not full,
a visual examination, by Galantini, of a probe withdrawn from the
E-cat chimney. Details not give; and it's entirely possible that the
examination was done at a point when the chimney was not full!
However, much more likely, it was not done with due caution as to
what might actually test the water level under the conditions
(temperature elevated above ambient boiling?
As many have pointed out, the demonstration setup does not provide
Rossi with any substantial indication of water level. Lack of
overflow water would require an exact steering between overflow and
underflow, leading to superheated steam and possible loss of control.
While this is possibly rebuttable, some level of overflow is to be
expected. And thus the Krivit/NASA comments are true, the output
"steam" could be anything between 0-100% steam quality. But the
serious extremes are unlikely. In particular, better than 95% would
be unusual, for any boiler. On the other hand, an ad hoc
seat-of-the-pants estimation leads me to consider that steam quality
as low as, say, 5% or so, might be consistent with established observation.
One more point. I've noted that the fixed flow with the output
arrangement might create very wet steam, because of fast steam flow
over a tiny trickle of water pouring over the lip of the outlet port.
But it's also possible that some internal arrangement could do this
*without* there being water in the chimney. We actually know nothing,
if I'm correct, about the internal arrangement of the cooling channels(s).
The Krivit diagram that Mr. Fletcher produces could easily be quite
inaccurate. I've assumed that the cartridge heater heats the reaction
chamber and the band heater heats the coolant (which is strange,
isn't it?). But it might be the reverse. Or what? Once again, we don't know.
If we had clear enthalpy measurement, we wouldn't need to know. But
many analysist have assumed that the steam would be of reasonable
quality, i.e, 95% or even more, but 90% at the very least (in a
recent analysis by a steam expert asked by NyTeknik). I don't think
that expert was informed about fixed water flow and the possibility
of very substantial insertion of liquid water into the outlet flow.
Basically, nobody would ever design a boiler this way. To an expert,
this would be completely unexpected.
One other problem with the analysis. The input power is stated as 770
watts, taken from the Rossi notes showing 3.5 A and calculating 770
watts by multiplying the amperage by a presumed 220V. That's not the
correct value for voltage for the Italian system. I'm given to
understand that it is at least 230V. So the power would be 805 W.
This leaves a little more room for dissipation in the electronics and
thermal losses.
