On Sun, Jun 2, 2013 at 4:10 PM, David Roberson <[email protected]> wrote:
> Eric, > > Model 1 appears to be more in line with what I suspect is happening > except for the explanation of the lack of external heat for control issue. > You need to consider that the peak heat power being generated inside the > core is only about 2 times greater than the resistor heating required to > control it at the turn around point. Rossi has stated this on several > occasions and it matches my model. > > But it's not consistent with the December hot cat, in which case the overall COP was 6, and as I've argued, less than half of the input power will reach the core, the rest directly heating the outer ceramic. So, in that case, you probably have at least a peak power in the core at least 10 times larger that the external heat that is controlling it. > When such a large percentage of the net power at that node is taken away abruptly, a turn around in temperature direction occurs. This is a complicated positive feedback system where a large fraction of the internally generated heat is being absorbed by the thermal mass of the device. Enough external heat is removed to force the core to be "starved". That reverses the temperature path. Once reversed, the positive feedback works in a manner that accelerates the falling core temperature toward room. Could you provide the temperature dependence of the reaction rate and the heat loss that would produce such an effect. And also explain how the December hot cat was stable with constant input power. > If you are very good, or lucky, you can reverse the core at just below an optimum point which will allow the temperature to languish there for an extended time before it begins it rapid decent. This is how you achieve a high value of COP. The core has a lot of time during which it puts out large values of heat energy before requiring a refresh drive pulse. The drive remains off for a longer time while the high temperature lingers. > Does this help to explain the operation according to my model? Not to me. It's all just hand-waving. Could you quantify things a little? And explain why constant power was used in December.
