Jed--
I think you assume that the reaction did not change the differential pressure
that the pump sees as the reaction occurs. (In other words the "baseline"
energy is a constant during the reaction.) What I have suggested is that the
differential pressure across the pump should be measured, and it should be
constant, if your assumption is valid.
If it is not, the pump energy input would have changed during the reaction. I
thought that might occur, if boiling happened as a result of the energy input
from the reaction.
Local two phase flow in a water stream will change the pressure drop in that
region where two phase flow occurs. Changes in the water viscosity (and
resulting pressure drop) with the small changes in temperature of the test
should be negligible compared to potential two phase flow conditions--i.e.,
steam bubbles plus liquid water.
The pump could give off a small amount of energy as radiant energy that is not
picked up by the temperature monitoring of the system. The measurement of
power to the pump would, however, be a pretty good estimate of the energy
consumed by the pump at any time, including the reaction period. I would rely
on those measurements to establish a baseline condition and I would monitor
power to make sure it does not change. Then one could be sure that the only
increase in temperature (and associated energy) is caused by the reaction.
Even then some of the energy produced by the reaction may escape the system and
never be determined nor add to the temperature that is monitored. The result
would be an under-estimate of the energy produced by the reaction.
In summary it is my conclusion that the pump head curve vs power should be
specified, the differential pressure across the pump should be recorded and
reported, and the electric power used through out the test by the pump and any
other electrical inputs should be monitored and reported as a function of time
like the temperatures were reported.
Finally, your reasons for removing the test results from your web page are
fuzzy. The test report should be replaced consistent with your objective of
providing such information for review by the public. In this regard I am at
somewhat a disadvantage in commenting, since I do not have the test setup at
hand and all the monitoring that was accomplished.
Warm regards,
Bob Cook
----- Original Message -----
From: Jed Rothwell
To: vortex-l@eskimo.com
Sent: Friday, January 09, 2015 7:18 AM
Subject: Re: [Vo]:"Report on Mizuno's Adiabatic Calorimetry" revised
Bob Cook <frobertc...@hotmail.com> wrote:
Mixuno would see a temperature differential as you say, however what
fraction of energy introduced by the reaction is above the input energy of the
electrical pump and or other electrical inputs?
You do not need to know this as long as you are sure the pump input is
stable. With the method Mizuno uses, he measures the difference between the
reactor starting baseline temperature which includes the pump input and the
ending temperature.
If the reaction energy is introduced totally as heat, the determination
should be pretty good assuming the calibration of the pumps input energy is
well known.
What else could it be but heat?
The calibration of the pump input is well-known because it was run for 18
hours with nothing else running.
That calibration is the question that is being debated I believe. In
Mizuno's test I believe the differential pressure that the pump put out did
not change much; hence, the energy used should follow the specification for the
pump in the pump head curve accurately.
We know it did not change much because there was no measurable variation
during the time the pump was running. If the pump did more work during some
hours than other hours, the temperature would vary. It does not. Really, that
is all you need to know.
However, if the reaction caused a significant change in the differential
pressure and, hence, the flow . . .
The reaction produces heat only, raising the temperature of the circulating
water at most 5°C. This cannot possibly affect the pump performance.
. . . such information would be necessary to accurately extrapolate the
total energy, pump plus reaction to temperatures above that produced by the
pump alone.
You do not need to extrapolate the total energy. It is irrelevant. This
method does not measure total energy; it measures only additional energy on top
of the baseline.
- Jed
