Exhaust-powered alternator by ThinGap Automotive

[Tango Charlie]

A company that goes by the name ThinGap has developed an exhaust-powered alternator. Pretty cool.

here's the linky; ThinGap Automotive

[DonR]

Very interesting. No reason it can't work. VG could be incorporated to help keep generator RPM more constant to help with efficiency. I'll bet it ends up being one expensive alternator.

Don

[Christ]

Hm... that's funny - the last time I thought about something like this, I was told it wouldn't work... I didn't believe the people that told me that, but I never tried it either... guess I should have.

Either way, it's not a complex design... take the scroll (exhaust side) of a turbo, mate it to a generator from an old VW bug, and drive it off the exhaust gasses. Obviously, we need to size the scroll wheel and housing so that we can scavenge enough energy from the exhaust to keep the generator moving at a decent clip constantly, and there needs to be a bypass system to allow the excess exhaust gasses to bypass the scroll housing while maintaining a given speed.

[cfg83]

Tango Charlie -

I remember other threads talking about this, but I don't remember a specific manufacturer. Looks like a company to watch.

CarloSW2

[Tango Charlie]

Yeah, I searched "ThinGap", but didn't get any results. Figured it was discussed on a conceptual level at some time, but here's a company pursuing it. It sounds as if they've configured the alternator for the desired output at the higher speeds the turbo will drive it at.

[Christ]

My idea was just the opposite of the belt driven turbo... two small centrifugally adjustable pulleys, with a belt/chain driven between them... the exhaust wheel spins up, and the pulleys gradually change gearing based on load and available torque generation.

I had originally thought about using a VNT from a Chrysler car for this, since they're capable of spooling at very low speeds, and holding full spool without over-boosting for a relatively long RPM range.

[jamesqf]

Maybe what people were thinking of was this: Green Car Congress: TIGERS: Exhaust Gas to Electricity for Reductions in Fuel Consumption

Shouldn't be any need to mess with complicated mechanical linkages, just use electronics to control the alternator field current, and thus the amount of generation. At idle, no current, thus no load other than a bit of bearing friction.

Would be neat if it could be made dual-purpose, to function as alternator and turbocharger. Instead of a waste gate, you'd control boost by varying alternator load... So where's the aftermarket kit for my Insight?

[dcb]

"Power recovery turbines"/ Turbo-compound, been used since the days of radial engines. This one on the left would recover about 600hp at takeoff (direct injection too):

[Ryland]

The problem with building something like this and they look like they took care of it, is the cooling and the lubrication of the alternator and that with the high speed of the turbo the alternator has to be built in such a way that it will not fly apart at 200,000 RPM seeing as how the turbo has to be built in such a way as it doesn't seize up as the metal bends and stretches out as it spins up to speed.

[DonR]

My guess would be that they geared it down. Similarly to how Paxton Gears up their belt driven centrifugal superchargers. I did see the oil ports as well.

Don