I must say that there is significant amount of metallic thermal inertia, what is perhaps mostly in the thick metal boiler that can withstand the steam pressures of several megapascals. 25 kg water contains the most of the thermal mass, but in both respect this type of E-Cat is different to others what were lightweight and did not contain any stored liquid water due to percolator effect.
I made some calculations, we can assume that most of the metal is at the same temperature as water. Also we know that there is liquid water some 25 kg inside E-Cat. This means that liquid water stores the most of the thermal mass, by 10 fold more than metallic materials. We also know that when temperature was cut off, temperature declined 10°C in 35 minutes. This would indicate, becsuse temperature conducts very fast through metals and in water there are fast convection due to boiling, we can assume that there is no significant temperature gradient inside E-Cat. Therefore the amount of heat what ΔT 10°C held is straight forward to calculate to be 1.3 MJ. There should not be too much room for margin of errors, if it is assumed metal mass to be 70 kg and water mass 25 kg. However as we know that at 118°C about half of the water was boiled and during the cool down phase temperature was always above 123, this means that more than half of the inlet water was vaporized. That is because only the steam backpressure does keep up the internal pressure of E-Cat. If assumed conservatively that half of the water was evaporated, then we need 7.5 MJ energy to explain slow decline of temperature. As there is is no temperature gradients due to high thermal conductivity of metals, therefore we can assume that 6.1 MJ was definitive minimum requirement for excess heat production. But as I have previously estimated that 60-80% of inlet water was needed to vaporize in the temperatures above 123 to explain over 100 kPa steam pressure, therefore proper estimation for required excess energy during 35 minutes self-sustaining is 6.1MJ – 9.5MJ or 2.9kW – 4.5kW. Indeed, excess heat during power cut off was required and thermal inertia cannot explain it, because it can only provide ca. 1.3 MJ energy and that cannot explain any steam production at all to support .However high thermal inertia can explain, why there was not observable bump in the graph when input power was cut off, but temperature decline was smooth. However more tricky question is when did cold fusion or fuel cell process begin? We cannot find any kinks from the thermal graph that would explain the temporal point when the excess heat kicked in and overtook the electric resistor as primary heating source. This is very baffling. Here is the accurate temperature graph from input power and temperature made by Akira Shirakawa from the data: http://i.imgur.com/lU42G.png Some corrections to my original message: > This shows that Rossi can control and understands his reactor very > well, because he can push E-Cat to the limits of the cooling power of > water. If there had been any more heat production, it would have > vaporized all the water and that means that there is nothing that > cools down the reactor core. > This is not exactly true. Because new E-Cat operates in self-sustaining cycles and there is large liquid water reservoir, peak power can exceed well the water inflow rate. As Rossi suggested that this cycle is electronically controlled that it probably means that if water temperature rises above specific level, input power is cut off and reactor cools down as long as it takes. And again when temperature drops below certain temperature threshold, input power is activated again, to boost cold fusion reactions. Therefore unlike I assumed, we cannot keep total vaporization of inlet water as a ultimate limit that cannot exceed, because this E-Cat version has large water boiler and it is conventional BWR. Therefore 133 °C temperature may tell us, that more than 100% of inlet water was vaporized. We do not know this, since there was not done water trap experiment and steam sparging calorimetry, in >130°C temperatures. This will also mean that I need to extent upper limit for heating power from 7kW up to 9 kW that exceeds water inflow rate. More uncertainty, but this this time into good end, because lower limit stays the same. > That is because the pump pumps > water with overpressure of 300 kPa (IIRC). If it needs to do work > against up to 200 kPa steam overpressure, then flow rate should > decrease inversely proportional to the heating power of E-Cat. Peristaltic pump does pump water against 150 kPa pressure with 12 kg/h. This is very well in line with my analysis as when steam pressure was high up to 200 kPa water inflow rate drop below 12 kg/h. And was above 12 kg/h when there was not excess steam pressure. As we do not know when water inflow rate was measured, therefore we cannot establish exact relationship between water inflow rate and pressure. –Jouni
