On Mon, Nov 21, 2011 at 8:41 AM, Berke Durak <[email protected]> wrote:
> > > 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. The calculation in the report determines the quantity of output from the input flow rate and the time. He assumes it's constant. He doesn't measure the quantity of output vapor. That's probably because it would give a more accurate calculation, which he seems to be trying to avoid. As the power transfer increases, the output volume flow rate increases, the speed of the steam increases, the enthalpy of the fluid increases. All these things he doesn't measure. The one thing that *doesn't* increase as the power transfer increases up to complete vaporization is the temperature. But *that* he decides to measure every few seconds. And his expert seemed to be fine with that. That shows that the company he allegedly works for could have done better. > >> 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. > If there's steam, then that's after the onset of boiling, and then the temperature would be at the boiling point. > 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? > Because the temperature was below boiling. Going from the onset of boiling to full vaporization (675 kg/h) would result in an ever increasing rate of steam flow, but steady temperature at the local boiling point. > > 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. Right, but if it's at the boiling point that represents a pretty small fluctuation in pressure which is not difficult to imagine. On the other hand, if the steam is above the boiling point it represents unrealistically stable output power (within +/- 0.5%). > And, again, > you assume that there is no mechanism to regulate the water level. > Right. Because Rossi assumes it. And if there were regulation based on the output temperature, given the time constant, you would see some kind of regular oscillation. (The regulation Roberson refers to requires the heater be submerged, which means the output is at the boiling point.) > > 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. > Well, we're told it's the temperature of the output fluid. > > > Increasing the power transfer by another factor of 8 > > cannot happen in a few minutes. > > Care to explain this? > I have explained this many times, and people here are tired of repetition. Briefly, the power transfer is proportional to the temperature difference between the heating element and the water, So if it takes 2 hours at 170 kW to bring it to the temperature necessary for the onset of boiling, it could not produce a delta T 8 times as large in a few minutes with 470 kW. The thermal mass evident in the warm-up period would prevent that. > > >> 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. > Possibly, but he was talking 1 MW until the last minute, when he throttled back to 1/2 MW, so that throttling, which he doesn't explain, would have to be pretty accurate. And Rossi himself says the flow rate was constant from 12:30 on. A control system could not have known the output power until it reached its peak, which could not have happened until 12:35 at the very earliest (when the temperature went above 100C). And what would be monitored to control the power? Temperature wouldn't do it, because, like I said, the temperature is the same for 70 kW and 470 kW, and there is no indication in the report that anything else was measured. There could be a lot of behind the scenes stuff, but if it is necessary to prove (or even make plausible) that the power was 470 kW, then it should be in the report. What is in the report doesn't prove it. In fact, the report makes 470 kW highly implausible.
