On Mon, Nov 21, 2011 at 12:59 AM, Joshua Cude <joshua.c...@gmail.com> wrote: >> What I meant is that the flow rate may have been lower at the >> beginning during the starting phase. Maybe it was zero. > > Then what were they measuring at the output?
I'm under the impression that the temperature sensor was connected to the steam pipe, and that therefore Tout is the temperature of the pipe. > In fact, the output increases gradually throughout the warmup period from > about 30C to the boiling point. This suggests the ecats and pipes etc are > filled, and the water is flowing through the system. The pipe is cooled at the other end by the air condensers. Maybe it is slowly heating up with heat transferred by larger and larger amounts of steam, and not water. > There is no indication anywhere that the flow rate was changed Why wouldn't it change? Were you there? There are electrical pumps, valves, a control system and sensors. > and Rossi's calculation assumes a constant flow rate. Which calculation? All you need is the quantity of water vaporized; it doesn't matter if they were vaporized at a constant rate or not. And flow rate may be stable once the stable regime has been reached. >> 4) Water temperatures in the modules rise. Steam production starts >> little by little and the sensed "output steam temperature" increases. > > If the ecats were not full, there would be nothing flowing out of them until > the onset of boiling, No, unless you meant "empty". As long as the amount of water in the ecats was not zero it is conceivable to get steam. > and then there would be a very steep increase in temperature. "Very steep" is very qualitative. Someone should try to run some numbers. > Then, to reach > a rate of vaporization of 675 kg/h, from the onset of boiling (0 kg/h) would > take much longer than to reach the boiling onset. So, you would see a rapid, > almost step increase, then a very much longer plateau. How do you know the water in the ecats wasn't already at boiling temperature for a long time? > Or, if the heating elements were not submerged, the steam temperature would > exceed the boiling point. And if they started submerged, the boiling would > reduce the level, exposing them and then increasing the temperature of the > steam. So? The output temperature fluctuates between 105 and 112 degrees. And, again, you assume that there is no mechanism to regulate the water level. > In any case, there doesn't seem to be nearly enough time. Nearly all of the > pre-heat period (2 hours) is used up in bringing the temperature up to the > onset of boiling. That's probably the temperature of the pipe. > Increasing the power transfer by another factor of 8 > cannot happen in a few minutes. Care to explain this? >> 6) Pumps are turned on. Flow rate matches vaporization capacity. > > It would be surprising if Rossi would know this rate beforehand, since he > doesn't actually calculate the power until the end. He would need to get it (a) he probably did test runs and (b) there is a frigging control system. -- Berke Durak
