Right, critical mode is not easy. for fission reactors, the resonance bells allow to have some working point where power/temperature curve create negative feedback (and also the hopeful unexpected delayed neutron that save the first reactors from fast divergence). Tchernobyl is the example of what happend when you are at the wrong point, with positive feedback.
for Ni+H LENR there does not seem to exist a reversible negative feedback, so like any engineer will know you have to stabilize the system with an outside control loop. I'm not suprized that defkalion find a solution... either by cooling, or controlling H pressure. it is basic engineering... You have to avoid delays since they cannot be compensated. of course controlling a hundred of reactor is another story (more about optimal command, than simple PID controlers), but less critical. a big leap for LENR could be to find a catalyst or additive, or maybe a mechanical device, that reduce efficiency quickly if temperature increase, leading to negative feedback. reactor could then be intrinsically stable, like nuke. 2012/1/22 David Roberson <[email protected]> > The core itself probably should be operating in the thermal run away > mode to get the COP into an acceptable range while the cooling needs to be > able to prevent additional heat energy from resulting in much higher core > internal temperature. The approach used by Defkalion appears to address my > issues. Their design includes a very tight thermal control of the core > region by the 6 coolant paths. To startup, they would reduce the coolant > flow to a minimum allowing the electrical heater to easily raise the core > temperature. Once the core reaches an unstable temperature, it will begin > to heat rapidly on its own. At that point the coolant flow rate can be > increased to absorb the excess heat and achieve the final desired operating > temperature. All of the heat energy required to keep the device operating > would now be supplied by the core. The overall COP at this point > is infinite in the core itself, but the control and pump energy drains > would make the net COP as specified. > >
