On 11-06-20 03:35 PM, Abd ul-Rahman Lomax wrote:
At 04:02 PM 6/19/2011, Stephen A. Lawrence wrote:
I've asserted recently that it was "obvious" to me that the steam was
wet, and I've said, several times, that it would take too long to
explain why. I've got a few minutes, so I'll see if I can fit in a
coherent explanation.
I think you have made some unwarranted assumptions, but let's see. By
the way, I do think, from all the evidence, that there was some
effluent water, it was not all dry steam. I'm not disagreeing with
that conclusion, only with how you get there, which may very much
affect our understanding of *how much* this was a problem.
The attached graph (with my annotations) is from the paper
http://lenr-canr.org/acrobat/EssenHexperiment.pdf
It has several interesting points.
Aw, these reports drive me nuts. I'd not read this one, I think. They
have a pump for cooling water, it seems. So when they start up, they
are pumping an estimated 6.47 kg per hour of water. They assume that
this flow rate remains the same. Why?
It's a constant displacement pump. That's what it does.
I'm banging my head against my desk. I have to stop doing that.
However, it's not a *terrible* assumption. It merely raises its own
problems. What I'd worry about, here, is in the other direction. They
have this thing boiling away all the feed water. That means they
cannot guarantee that the chamber cools at a constant rate, I suspect,
as there comes to be less water in the chamber, the cooling rate will
go down. Control problem. This thing gets hotter, the cooling
declines, so it gets even hotter .... Unless they back way off on the
input power, quickly.
You have put your finger on the problem. There is no need to go any farther.
Unfortunately, you took your finger off the problem later on, where you
apparently forgot about the "constant flow rate" assumption... it's that
CD pump which at the heart of all of this.
First, as I've said in previous email, the total power dissipated in
the device can be estimated from the slope of the curve and the
temperature of the effluent. The power needed to heat the output
water goes up linearly with the temperature of the output water, and
the power needed to heat the device goes up linearly with the slope
of the curve.
Okay.
There was a claim of "ignition" at about 60C, at which point the
device started generating power.
Looks like that.
In fact, the graph says that can't be right. If the device generated
no power before it hit 60 degrees, the temperature would not have
gotten to 60 degrees so quickly, because (as stated in the paper) the
heater temperature was only adequate to maintain it at 60 degrees
with the flow rate used in the experiment. So, the heating curve,
instead of looking like a straight line, would look like a capacitor
charging curve, and it would have taken much, much longer to reach
"ignition".
This is the problematic assumption: that the input power "was only
adequate to maintain it at 60 degrees with the flow rate used." This
is derived from their statement: "If no additional heat had been
generated internally, the temperature would not exceed the 60 °C
recorded at 10:36."
That's preposterous, as you note. Had there been no generated heat,
there would have been a continued rise in temperature, at the previous
rate of increase, declining asymptotically, as you state. Quite
simply, there is no stated basis for this claim.
Of course there's a simple basis for it (but not a *stated* basis,
admittedly, but it's an awfully simple step to get here):
The flow rate (which is *fixed* by the CD pump), times the coolant
temperature rise (scaled by the specific heat, of course), gives the
power carried off by the coolant. They're claiming that the heater power
and power carried off by the coolant match at 60C.
If they don't, then the paper is in error. It would be pretty simple to
check their arithmetic on this one but it didn't occur to me to do so;
so, they could very well be wrong about this, which would in turn throw
off my calculations (but not the overall conclusion).
It should therefore, be discounted. The experimental evidence shows
otherwise, so I assume this was a simple error on their part. I'll
assume that they intended to say that "
the rate of increase of temperature would not have increased."
You can assume they said something other than they said, but it's not
what they said.
The steam was claimed to be dry in this experiment.
Yes. That claim comes from a visual examination of the steam valve,
and assumes that there was no flow out of the hose at this point.
Again, they are not explicit about this, but they only talk about
"visual checks of the outlet tube and the valve letting out steam from
the chimney." If there is no flow out of the outlet tube (the hose?}
and there is live steam at the valve, easily seen by the short gap
where the steam is invisible, the physical arrangement would be
adequate for this assumption to be at least approximately correct.
They measure steam quality:
"Between 11:00 and 12:00 o’clock, control measurements were done on
how much water that had not evaporated. The system to measure the
non-evaporated water was a certified Testo System, Testo 650, with a
probe guaranteed to resist up to 550°C. The measurements showed that
at 11:15 1.4% of the water was non-vaporized, at 11:30 1.3% and at
11:45 1.2% of the water was non-vaporized.
Did they measure this inside the "outlet tube," i.e., inserting the
probe through the thermocouple access port? I notice no gap in the
temperature recording from the thermocouple. So there is a question
there.
However, this is where we rely on "authority." I don't see any reason
to suspect that Essen and Kullen didn't know what they were doing.
What I can say is that *from the report alone,* there are questions.
Let's see what Stephen comes up with.
In that case, the output power was something on the order of 10 kW
once it started producing steam. But the output power before that
point, which we can read from the graph, was about a factor of eight
less than that. So, once it hit boiling, the output power must have
increased eight fold, very rapidly -- certainly more rapidly than the
power had been increasing up to that point. But then, since the
effluent temperature did not rise above 101C, the power generation
must have stopped its meteoric rise at exactly the core temperature
needed to keep the effluent at 101C, no more, no less.
There is a problem, but the effect of boiling water isn't being
considered. When you boil water, the temperature of the water (at
atmospheric pressure) wlll not increase beyond 100 C, and the steam
will be at that temperature. Because of effects from the cooling
chamber walls being at slightly higher than boiling (it must be,
average), the temperature will be *slightly* above 100, which will,
aside from bulk water, if present, dry steam. Assuming the temperature
measurements are accurate, this is a confirmation of (mostly) dry steam.
GAAAH -- No! You are forgetting that there is a CONSTANT FLOW RATE from
the CD pump!
Get that straight, or you totally miss the point. The situation is
*entirely* *different* from the situation in a boiler with a fixed
allocation of water.
Since you apparently misunderstood that, there is no point in reading
the rest of this, aside from a quick skim which indicates to me that the
misunderstanding of the flow rate does indeed persist.
<snip>
