It has been brought to my attention that my posts from January-April
have been discussed. I can sum up my position by simply saying that
RH probes do not measure steam quality. The following links provide
more detail.
http://www.mail-archive.com/[email protected]/msg41849.html
http://www.mail-archive.com/[email protected]/msg44947.html
http://www.mail-archive.com/[email protected]/msg44953.html
There are of course many more relevant links. Since few people seem
to read links I'll post some highlights below.
***
I believe the HP474AC probe actually measures the capacitance of the
air, and converts that to relative humidity. The more the
capacitance, the more water in the air, by volume. Another important
thing is heat content is carried in proportion to mass, not volume. I
have appended the computations I posted earlier showing the huge
proportion of mass that is contributed by a small volume of liquid,
and that estimates of the heat flow from the device can be off by
96%, i.e only 4% of the estimated heat value due to vaporization, if
only 1.4% of the volume flow is liquid water droplets. Therefore a
very small error, less than 1%, in measuring capacitance can produced
huge errors in calculated heat flow. The stated error of the probe is
+-3.5% where it counts, at 99% water content.
It is also notable the meter/probe requires calibration:
http://tinyurl.com/4z5985v
Most important is the fact the probe is designed to detect the
percent of water vapor in air, not percent of water microdrops in
pure steam. Pure vapor should have more capacitance than 100% humid
air, and be way beyond the meter's measuring limits. Adding water
droplet should push the capacitance even higher. Once the meter is
maxed, the question arises: can extra water droplets make any
difference to an already maxed out 100% reading? The +-3.5% error
could thus actually be irrelevant.
This whole issue may be of academic interest only. Even if all the
heat flow due to vaporization is negated, the COP is still over
unity, assuming the water is not heated much above 13 °C by ambient
conditions before entering the device. Further, if the device can run
without energy input at all, then none of this matters, provided the
total energy to start up the device is way less than the device
produces. This would clearly be the case if the device can run 6
months as stated.
Here again is my analysis showing the importance of the huge
difference in mass vs volume ratios:
From:
http://en.wikipedia.org/wiki/Water_(properties)
http://en.wikipedia.org/wiki/Specific_heat_capacity
http://en.wikipedia.org/wiki/H2o
http://hypertextbook.com/facts/2007/DmitriyGekhman.shtml
The following approximate values for water can be used from the above
refs:
Liquid Density: 1000 kg/m^3 = 1 gm/cm^3
Heat of vaporization: 40.6 kJ/mol = 2260 J/gm
Heat capacity: 4.2 J/(gm K)
Molar mass: 18 gm/mol
Density of steam at 100 C and 760 torr: 0.6 kg/m^3 = 0.0006 gm/cm^3
Now to examine the importance of mass flow vs volume flow
measurements for the steam.
If x is the liquid portion by volume, then x/((x+(1-x)*0.0006)) is
the portion by mass. This gives the following table:
Liquid Liquid Gas
Portion Portion Portion
by Volume by Mass by Mass
--------- ------- -----------
0.000 0.0000 100.00
0.001 0.6252 0.3747
0.002 0.7695 0.2304
0.003 0.8337 0.1662
0.004 0.8700 0.1299
0.005 0.8933 0.1066
0.006 0.9095 0.0904
0.007 0.9215 0.0784
0.008 0.9307 0.0692
0.009 0.9380 0.0619
0.010 0.9439 0.0560
0.011 0.9488 0.0511
0.012 0.9529 0.0470
0.013 0.9564 0.0435
0.014 0.9594 0.0405
We can thus see from this table that if 1 percent by volume of the
steam is entrained water micro-droplets, easily not seen in tubing or
exhaust ports, that only 5.6 percent of the heat of vaporization is
required to produce that mixture.
Rough calculations based on Rossi specifics:
Suppose for the Rossi experiment the mass flow of a system is 292 ml/
min, or 4.9 gm/s, the inlet temperature 13 °C.
The delta T for water heating is 100 °C - 13 °C = 87 °C = 87 K.
If the output gas is 100% gas, we have the heat flow P_liq given by:
P_liq = (4.9 gm/s)*(87 K)*(4.2 J/(gm K))= 1790 J/s = 1.79 kW
and the heat flow H_gas for vaporization given by:
P_gas = (4.9 gm/s)*(2260 J/gm) = 11.1 kW
for a total thermal power P_total of:
P_total = 1.79 kW + 11.1 kW = 12.9 kW
Now, if the steam is 99% gas, we have:
P_liq = 1.79 kW
P_gas = (0.1066)* (11.1 kW) = 1.18 Kw
P_total = 1.79 kW + 1.18 kW = 2.97 kW
or 23% of the originally estimated power out.
It thus seems reasonable to do calorimetry on the steam-liquid out.
***
The isotopic analyses and contradictory claims about isotopic
abundances thus far make Rossi's claims look absurd. The theories
proposed do not match results. For example:
http://www.nyteknik.se/incoming/article3080659.ece/BINARY/Rossi-
Focardi_paper.pdf
ignores the highly radioactive nature of the outputs.
Rossi's main claim of utility is excess heat. Yet no one has made any
effort at even very basic calorimetry measurements on the output.
Estimating heat output is really very simple to achieve, as I have
noted here before. Simply direct the output into an insulated barrel
and keep track of the temperature. If the output is in the form of
steam, pre-load the barrel with cold water and run the steam trough a
copper coil in the barrel and sparge any steam output of the copper
coil by releasing it at the bottom of the barrel. Stir the water in
the barrel. Measure the temperature change of the water in the barrel
through time. Direct the water output from the top of the barrel to a
sink, as is done now. This is chidren's science fair difficult. All
that is required is a barrel with a water drain hole and fitting
installed at the top, and maybe some insulation, though even that is
not required if a no-flow temperature decline curve is obtained after
the experiment. The thermocouple presently used can be moved to the
barrel. A stirring device driven by a low wattage motor could be
used, but the water could even be stirred by hand periodically.
Measure the volume of water in the barrel.
It is incredible that it could be expected that anyone would invest a
dime in this technology without the most basic and inexpensive
science being applied.
****
This is a case of a lot of hoopla and maybe money changing hands,
when the basic science applied to the main claim, excess heat, is
laughable. The science applied to that issue is less than amateur.
Personally, I don't see any sense in wasting much time even
discussing further, because the evidence is so shabby. The whole
thing looks like a big joke at this point. It looks like a Barnum and
Bailey act, "the greatest show on earth!"
Rossi's main claim of utility is excess heat. Yet no one has made any
effort at even very basic calorimetry measurements on the output.
Estimating heat output is really very simple to achieve, as I have
noted here before. Simply direct the output into an insulated barrel
and keep track of the temperature. If the output is in the form of
steam, pre-load the barrel with cold water and run the steam trough a
copper coil in the barrel and sparge any steam output of the copper
coil by releasing it at the bottom of the barrel. Stir the water in
the barrel. Measure the temperature change of the water in the barrel
through time. Direct the water output from the top of the barrel to a
sink, as is done now. This is chidren's science fair difficult. All
that is required is a barrel with a water drain hole and fitting
installed at the top, and maybe some insulation, though even that is
not required if a no-flow temperature decline curve is obtained after
the experiment. The thermocouple presently used can be moved to the
barrel. A stirring device driven by a low wattage motor could be
used, but the water could even be stirred by hand periodically.
Measure the volume of water in the barrel.
I discussed the wet steam issue here back in January, and also
another simple cheap enthalpy measuring method, ice calorimetry:
http://www.mail-archive.com/[email protected]/msg41703.html
http://www.mail-archive.com/[email protected]/msg41849.html
It is incredible that it could be expected that anyone would invest a
dime in this technology without even the most basic and inexpensive
science being applied to the most important aspect.
***
Despite my dismay at the calorimetry, or lack thereof, and lack of
due diligence, I should note that I have made an effort to understand
how Rossi's results might be real. For example:
http://www.mail-archive.com/[email protected]/msg44845.html
I still hope beyond all reason that Rossi's methods are real and
useful. If not, this could be the worst thing that has happened in
the field of LENR. LENR is clearly very real, if not useful yet. I
think everything is still purely a matter of speculation though
regarding Rossi's results, for those outside Rossi's inner circle. It
is thus best to simply wait and see what unfolds.
I can not hope to even read the many posts occurring now, much less
respond. Resuming lurk mode.
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
