Rich Murray wrote:
"probably, the Rossi demos have a complex control box with thermal controls that lower the electric input heater power when the reactor gets too hot" You concede to easily. I don't believe there is any feedback in that system because the wires are all heavy power cables, not control wires, and because when the power was shut down (in test 1), the temperature remained pinned to the boiling point (without any regulation), and because the input power is varied manually (in test 2) over a wide range 1.2 kW -> 400 W -> 1.5 KW, completely inconsistent with a fine temperature control. But the obsession with the control box is a red herring anyway. Even if it is regulated, my thesis is not weakened. 1. The wetness of the steam is unknown The fact that the temperature is pinned at the boiling point (slightly elevated because of increased pressure in the conduit) means we don't know how much liquid is present in the exiting fluid. If it were substantially above the boiling point, then there would be a case to argue that the steam is dry. No evidence is presented in Levi's report that the steam is dry. He simply states that it is based on an "air quality monitor" (scare-quotes are his). But the point of a demonstration is to demonstrate, not to pronounce. He doesn't say what physical quantity is measured, nor what the value is, let alone how it changes with time. It would be so easy to allow the temperature to go to 110C to *demonstrate* that the steam is dry, but failing that, if there is some reason that 100C is an optimum temperature, they could have proved dryness by showing the reading on that monitor, and then showing (off-line) what it reads when steam is wet and when it is dry. Dry steam can be produced by boiling water and passing the steam through a conduit heated to 110C (say) in a flame. It would also be useful to see how that measurement evolves after the boiling begins, because the exiting fluid should change gradually from pure liquid to drier and drier steam as the power increases. 2. The power gradients are not believable. It is a simple truth that heating the water to boiling requires about 1.2 kW, and vaporizing all of it requires > 10 kW. The only way to increase the power delivered to the water is to heat the conduit to a higher temperature. An 8-fold increase in the power delivered requires an 8-fold increase in the temperature difference between the fluid and the heating element (the conduit presumably). But this takes time, and we have an idea of how fast things heat up by looking at the gradient before boiling is reached. By that measure, the power might increase by at most a factor of 2 in 40 minutes; far short of what is needed for complete vaporization. We know it doesn't even increase that much, because in mid plateau, the temperature actually dips below boiling for a few minutes. (The dip seems to correlate with the reduction on the input power to 400W.) The obvious and reasonable interpretation, based on the mid-plateau dip, and the fact that the temperature (in test 2) decreases immediately when the power is shut down, is that the temperature of the heating element(s) is just above that necessary to maintain boiling temperature in the exit fluid. That means that only a small fraction of the fluid is being converted to vapor. The steam is very wet.
