Brief Description of the Calorimetry in the Rossi Experiment at U.
Bologna, January 14, 2011
by Jed Rothwell
The experiment has been underway at U. Bologna since mid-December 2010.
It has been done several times. Several professors with expertise in
related subjects such as calorimetry are involved.
LIST OF MAIN EQUIPMENT IN EXPERIMENT
A hydrogen tank mounted on a weight scale which is accurate to 0.1 g
10 liter tank reservoir, which is refilled as needed during the run
Displacement pump
Tube from pump to Rossi device (The Rossi device is known as an "ECat")
Outlet tube from the Rossi device, which emits hot water or steam
Thermocouples in the reservoir, ambient air and the outlet tube
An HD37AB1347 IAQ Monitor (Delta Ohm) to measure the relative humidity
of the steam. This is to confirm that it is “dry steam”; that is, steam
only, with no water droplets.
Alternating-current heater used to bring the Rossi device up the working
temperature
METHOD
The reservoir water temperature is measured at 13°C, ambient air at 23°C.
The heater is set to about 1000 W to heat up the Rossi device. Hydrogen
is admitted to the Rossi device.
The displacement pump is turned on, injecting water into the Rossi
device at 292 ml/min.
The water comes out as warm water at first, then as a mixture of steam
and water, and finally after about 30 minutes, as dry steam. This is
confirmed with the relative humidity meter.
As the device heats up, heater power is reduced to around 400 W.
RESULTS
The test run on January 14 lasted for 1 hour. After the first 30 minutes
the outlet flow became dry steam. The enthalpy during this last 30
minutes can be computed very simply, based on the heat capacity of water
(4.2 kJ/kgK) and heat of vaporization of water (2260 kJ/kg):
Mass of water 8.8 kg
Temperature change 87°C
Energy to bring water to 100°C: 87°C*4.2*8.8 kg = 3,216 kJ
Energy to vaporize 10 kg of water: 2260*8.8 = 19,888 kJ
Total: 23,107 kJ
Duration 30 minutes = 1800 seconds
Power 12,837 W, minus auxiliary power ~12 kW
There were two potential ways in which input power might have been
measured incorrectly: heater power, and the hydrogen, which might have
burned if air had been present in the cell.
The heater power was measured at 400 W. It could not have been much
higher that this, because it is plugged into an ordinary wall outlet.
Even if a wall socket could supply 12 kW, the heater electric wire would
burn.
During the test runs the weight of the hydrogen tank did not measurably
decrease, so less than 0.1 g of hydrogen was consumed. 0.1 g of hydrogen
is 0.1 mole, which makes 0.05 mole of water. The heat of formation of
water is 286 kJ/mole, so if the hydrogen had been burned it would have
produced less than 14.3 kJ.
