Axil,
What you are describing would be a form of Super Cravens Sphere. He has shown
that the internal temperature of one of his devices becomes elevated when it is
embedded within a hot bath and that is pretty much what I understand as your
thought below. If the fuel mix were to be enhanced, in a manner such as seen
in the Hotcat, enough positive feedback could be designed into the pellet
system for it to snap upwards in power production once a threshold is reached.
The amount of positive feedback can be adjusted by establishing the proper
ratio of sphere surface area to volume. As the pellet becomes larger the
surface area varies as the square of the radius. At the same time the volume
varies with the cube of the radius. In an ideal case that suggests that the
feedback ratio would vary directly with radius. If some form of insulating
material is coated upon the outer surface the fuel volume can be reduced
considerably.
One of the main problems that needs addressing is how to produce these pebbles
so that they will recover to room temperature once the bath heating is
eliminated. A type 1 system of the type I have been simulating is restricted
in COP to a maximum of perhaps 4. A type 2 or 3 design would be much more
useful with an essentially unlimited COP possible with the type 3 device.
So far the Hotcat as well as the Russian replication have been demonstrated to
be of type 1. I suspect that when they toyed with the amount of fuel and its
activity they found out that it is extremely difficult to control or build a
reactor that is type 2 or 3. In either of these cases the magnitude of the
positive thermal feedback is great enough to produce a negative resistance
region within the operating temperature range. Whether or not anyone can
figure out how to prevent one of these devices from heading into thermal
runaway is a question left open so far. Both of the recent examples that we
have seen avoid that danger at the expense of COP.
Perhaps the ideal pebble would contain a fuel mixture that automatically enters
a mode of reduced generated power as the temperature reaches a designed value.
This would be a form of built in negative feedback. If anyone knows of a
method of achieving this in a manner that can be reversed as temperature is
reduced then they will have a true winner.
For reference:
A type 1 system has limited or no positive thermal feedback. It will operate
in a controlled manner at all temperature ranges and not exhibit any form of
latch up. This is what has been demonstrated by Rossi in the third party tests
and the Russian replication to date.
A type 2 system has a level of thermal positive feedback that results in the
existence of a negative resistance region somewhere within the operating
temperature range. One of these devices will demonstrate a snap in temperature
once a threshold of either input power or applied external temperature is
reached. Some method of reduction of positive feedback must exist to prevent
thermal destruction or damage and at the same time allow recovery once the
drive signal is discontinued. The geometry of the structure or perhaps a
boiling water like heat sink could be used to this end.
A type 3 system is just a type 2 system with a beefed up amount of positive
feedback. The difference from a type 2 is that once the negative resistance
region is reached by drive level or temperature input the device goes into
thermal latch up. If the drive is eliminated, the device will continue to
generate internal power and some form of strong cooling must be applied in
order to force the device to cool off. I suppose a pebble system could be
brought back to room temperature by spraying it with water or some other
coolant that extracts plenty of additional heat. From what I recall the
earlier versions of the ECAT tended to operate in this mode since the input
water flow rate had to be increased before the device would cool down. A truly
infinite COP is achieved by a device of this type and that is an important
consideration.
The above description of system types is according to the categories that are
demonstrated by my computer simulation models. I have a couple of different
simulation environments that exhibit these types of behaviors. I am excited to
see that both the Rossi Hotcat and the Russian replication device match my
expectations.
Dave
-----Original Message-----
From: Roarty, Francis X <francis.x.roa...@lmco.com>
To: vortex-l <vortex-l@eskimo.com>
Sent: Thu, Jan 15, 2015 7:31 am
Subject: RE: EXTERNAL: [Vo]:TRISO LENR pellet
Axil,
That is an elegant idea that makes all the construction
difficulties worthwhile if we could actually use present reactors and
technology to fast track adoption. I hope someone pursues this idea.
Fran
From: Axil Axil [mailto:janap...@gmail.com]
Sent: Wednesday, January 14, 2015 11:59 PM
To: vortex-l
Subject: EXTERNAL: [Vo]:TRISO LENR pellet
In the long run, Brillouin’s low energy nuclear reaction technology will beat
out Rossi's Hot cat reactor design. But there needs to be some design upgrades
to the Brilouin's current approach. A LENR TRISO fuel pellet design should be
invented. Like the Hot-Cat tube design, this pellet should be a completely
self contained unit including nickel or tunstun micro powder and the fuel
AlLiH4 just like Rossi's alumina reactor core tube.
The multi layered TRISO spherical pellet is a layered design featuring an inner
core of fuel consisting of nickel micro-powder and AlLiH4 surrounded by a
covering of alumina. Next, a thin coating of yttrium stabilized zirconium oxide
covers this core, then follows a thin layer of pyrolytic carbon (PyC) to
confine hydrogen, followed by a ceramic layer of SiC whose function is to
further confine hydrogen at elevated temperatures and to give the TRISO
particle a high degree of structural integrity, This LENR spherical pellet is
about the size of a queue ball where each layer of the composite is doped to be
electrically conductive to provide electrical heating of the alumina core.
As in the current Brillouin design, a very short but powerful electric pulse
heat the pellet pile in their bed where some hundreds of thousands of particles
take advantage of economies of scale the the utilities love so much. This
pellet can operate at 1400C and is used to retrofit existing nuclear and fossil
fuel generating stations using existing pumps and generators to feed the
existing grid using the existing grid interconnect power line network.
Now which design is more cost effective, 600,000 hot cats and there associated
micro processor controls or a nuclear station like 20 gigawatt centralized LENR
power station with a 600,000 pebble bed of dumb high temperature TRISO pellets.
