Could you post the differential equations of the control system?
On Sun, May 26, 2013 at 6:44 PM, David Roberson <[email protected]> wrote: > My model demonstrates that constant temperature operation of the ECAT is > not going to work under normal conditions. The relatively high value of > COP when temperature control is used depends upon operation in a positive > feedback region. This can be thought of as related to the question that > always arises about why the device does not supply its own drive and > therefore run continuously in SSM. > > Once the loop gain becomes greater than 1, the device will tend to move in > the direction that it is currently heading. This allows it to heat up to a > relatively larger temperature than that due to the drive alone. When > rising in temperature, the device begins to put out additional heat, more > with time. The trick is to turn the process around at a good point before > it goes too far. The best turn around temperature is well defined and > shows up as a tendency for the device to continue putting out power at a > constant rate with time. Unfortunately, this exact point would be > impossible to achieve while maintaining control. It is a balance between > how long you want the temperature to remain nearly constant and the risk of > loosing control. > > Rossi chose a relatively safe turn around temperature for the last test > which caused the COP to drop below his desired value of 6. I suspect he > chose this because a COP of 3 well demonstrates that the process is real > and also has enough margin to keep the device safe from melt down. I think > I would have done the same under the same constraints. > > Dave > > >
