On Sep 15, 2011, at 9:11 AM, Peter Heckert wrote:
Am 14.09.2011 22:31, schrieb Horace Heffner:
Sticking the one and only output measuring thermometer down inside
the device is still as useless as ever for calorimetry purposes.
It likely is directly heated by its metal surroundings. The water
pulsing out of the device is clearly not 130°C.
I think with this new method this is not so important.
With only one thermometer for measuring output, located in a hidden
place, what it reads does not make for credible calorimetry.
There cannot be a large temperature difference between water steam
and metal.
This is false when more energy is being continually supplied than
required to boil all the water to steam (ignoring through insulation
losses). The excess energy has to go into heating the steam.
So we can assume the water and the steam are at 120 degree or more.
The pressure is above air pressure always.
We can assume no such thing. The water shown coming out of the exit
port at the top was clearly not at 130°C. The pressure clearly was
not high. The pressure appears highly variable, indicating the
possibility of some kind of flow control mechanism.
When 120 degree water comes out, at air pressure it will
immediately start to boil until the water temperature is 100 degrees.
This did not happen at the top exit port in the video.
Fortunately they do now measure the amount of water coming out.
This opens a simple method for calculating:
To calculate the energy we dont need to know all these values. We
must only know how much water /finally/ comes out of the hose,
because the hose is thermical isolated. We must measure at the end
of the hose, then the water has time to vaporize and the steam has
time to expand its volume or time to condense until the temperature
is 100 centigrade and the pressure is air pressure.
So we can assume the outcoming water is at 100 degrees and the
(almost dry) steam is at 100.xxxx degrees.
If we know the input water flow and temperature and the output
water flow the and temperature then we can calculate the energy
because the difference must be vaporized at airpressure and 100
degrees.
(When output flow < input flow then temperature of steam and water
at air pressure must be about 100 centigrade. If this is not the
case, then something is wrong)
Best,
Peter
I'll have to agree with Jed on this one, regarding using a barrel.
Much easier to put a kWh meter on the input and sparge all the output
into an insulated barrel. Not exactly a professional or high level of
calorimetry, but way better than what has been done. Could use two
barrels and switch to permit long term operation.
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
