On Sat, Nov 19, 2011 at 12:07 AM, David Roberson <[email protected]> wrote:
Here I do not agree that the ECAT is filled 11 times during the test. I > obtain 30000 grams/ECAT / 1.7539 grams/seconds = 17105 seconds/ECAT. This > is 4.75 hours to empty one cat. That is only a bit more than one refill in > the 5.5 hour period. Do you agree? > You're right about the flow rate. I slipped a decimal point, so the water only changes 1.1 times in 5.5 hours. It's a simpler calculation than you did though (and I still got it wrong): 675 L/h is 675/107 = 6.3 L/h per ecat, so in 5.5 hours that's 34.7 liters or about 1.1 ecat. That changes the requirement for accurate flow rate to satisfy your condition to 10%, but I no longer think that's relevant, and as it happens, unnecessary to counter your argument. Here's why. If you claim the heating elements are submerged, then I completely agree that if the steam were dry, fluctuations in power in the ecats would be accommodated by fluctuations in output flow rate, and variations in the water level. In this case, the steam has to be at the boiling point, because there is nothing to heat the steam after it is formed. If you agree that the measured output temperature is at the boiling point though, then the question about why it's so stable is not necessary. Because that's what I was trying to establish in the first place. If the output were 1% steam, it would also be at the boiling point. Since the temperature is the only thing measured, it does not constitute evidence for dry steam. The reason I asked the question about the stable temperature, was to counter the claim that the temperature was above the boiling point, and therefore the steam must be dry. I think F. made that claim in his interview with Lewan, or at least implied it. If the steam is above the boiling point, then part of the heaters must be exposed to heat the steam. And in that case the level would be regulated pretty tightly by the need to balance the ecat power with the output power, since the power transfer would depend strongly on the amount of the heater submerged. With the level relatively stable, the output flow rate would be pretty constant, and then fluctuations in power would result in fluctuations in steam temperature. An increase in the power would cause a brief increase in the boiling rate, but that would reduce the level, causing the boiling rate to decrease, restoring the level, so the increased power would have to be removed by hotter steam. It is undoubtedly not as simple as the formula I gave, but if the steam is already a few degrees above the boiling point, it seems pretty reasonable that power fluctuations would result in significant temperature fluctuations. So, the relatively stable output temperature indicates that it is at the boiling point (including in your scenario), or the power is stable to 1% (in the second scenario). But I think we agree that the output is at the boiling point. And to my mind, that means there is no evidence of dry steam. The issue of the 8-fold power transfer increase suggests that dry steam is not reached for at least several hours after the onset of boiling, and of course, there is no evidence that it is ever reached.
