At 07:38 PM 1/17/01 -0500, you wrote:
>My idea is to have large flywheels, say the size of a water softener or air
>conditioner. The flywheel are pretty heavy, maybe a couple hundred pounds,
>and are self-contained. Perhaps they would have to be mounted to the
>foundation of the building if they would ever hold very large amounts of
>power. So, throughout the year as power is available the flywheel draws power
>and accelerates. Perhaps it is magnetically levitated on superconductor so
>there is no friction inside the machine. So, the flywheel builds to a high
>level of power, and when there is any power outage, then it automatically
>compensates by slowing itself. If nanotechnology is available, then one
>monolothic flywheel can instead be many million in a relatively inert human
>layer physical state. The reason this would be better than a chemical battery
>or generator are some, although ome renewable power source like a few panels
>on the roof should also exist.
>
>Ross
Experimental versions have been made. The biggest problem is that energy
density goes up with the square of the rotational speed - to get the really
great storage numbers you need million RPM units and above. This requires
exotic materials for the flywheel rim. (Also, a pretty hard vacuum to spin in!)
Remember to put all the rotating mass (or as much as possible) at the rim...
Magnetic suspension bearings are 'de rigeur'. The best way to couple energy
in and out is to use three - phase induction motor / generator techniques.
This requires a variable speed driver / inverter system that outputs
regular house current.
One experimental power storage version I read about was designed so if the
filament-wound rotor should fail, it would expand relatively slowly in the
radial direction and spend its' energy in friction against the housing.
It's still not pleasant to be near, but at least there's no shrapnel.
My "dream home" design has a low-speed flywheel (~7200 RPM) driven by a
three-phase motor off the power lines - not much energy is used to keep it
spinning - that in turn drives a synchronous generator. Almost perfect
isolation for brown-outs and dropouts in the main supply line, and in case
of a blackout, a Diesel generator has ample time to start and speed up
before the flywheel slows too much...
All this brings to mind a non-chemical "grenade" described by Dean Ing: a
miniature flywheel running at some incredible speed - it has a sawtooth
pattern on it's rim. Encase it in a frangible vacuum housing with a
mirror-image sawtooth on the inside. The rotor axis is held rigid in the
"unarmed" state.
Once it's emplaced, the rotor axis is released - it's retained by magnetic
bearings in the center as long as no one moves the housing. If the thing IS
moved, precession causes the rotor and housing to come into rather violent
contact...
Chuck Kuecker
This archive was generated by hypermail 2b30 : Mon May 28 2001 - 09:56:20 MDT