Fran, Yes you could be exactly right! Nanopowder or nickel black or Raney is poor for heat transfer, and passing current through it as Dennis suggests, could risk damaging the nanostructure. It would not be very conductive electrically anyway.
This may indeed be one major key to the thermodynamics of this device: an internal gas pressure wave, based on pulsation of the pressurized hydrogen, such that it increases heat transfer to the tube wall, in order to cycle the powder temporarily over and under the threshold. Ironically the high pressure of the sine wave serves to increases cooling, not heating, and immediately the heat begins to increase as the wave crest passes through. The wave is working with the high flow rate of coolant, so the control is via the coolant working against the inversion temperature (hotter towards the middle of the tube). In looking at the data charts of inversion temperature in a similar ongoing experiment - yes, the thermal transfer rate seems to be way too low to control rapidly via external cooling (or heating) alone! A pulse of gas would be considerably more effective, and that dynamic rationale also meshes with the need for 5 controllers. He must want to set up a travelling wave, and five is about the minimum number it would take. It is possible to do a travelling wave with three but five gives redundancy. If it were only controlled via current - you would not need five. This is my best guess for TGIF, but it is good for only the next 15 minutes, until someone comes up with a better suggestion :) This still does not answer the looming question of why is he going to 100 modular units. If we can get a handle on that, it might tell us a lot. I think there is a valid reason for the 100, but again - I see Rossi as a genius who also got lucky, whereas others write him off as just a lucky crank. Try to imagine why an inventive genius would want to risk so much, with all of the unanticipated pitfalls which can happen, in order to convert a good demo at 10kW into a shockingly impressive demo at 1MW. There must a valid reason, but it could relate more to the funders than to Rossi himself. Jones -----Original Message----- From: Roarty, Francis X Jones Beene wrote >I wonder if a magnetic pulse, or a pulse wave is involved in the operation. Jones, I am now coming to this same conclusion, thermal transfer rates from 5 PLC heaters spread throughout 1 liter of powder doesn't seem fast enough. If the PWM were just accumulating an average temp over many cycles it would only represent a fine temp control and not be turning the reaction on and off each cycle as I think it needs to do to prevent runaway. The pulse wave, be it mechanical, electrical or magnetic needs to push the gas very briefly over the reaction threshold and then go away. As long as the average temp and cooling loop are able to pull it back under the threshold before the next cycle you have a valid control system. The energy originally required to bring the mass up close to this threshold only has to be invested once because iterative PWM cycles can take over this "housekeeping" chore and then progress to even higher levels in lockstep with increased heat exchange. Regards Fran
