5 ms·
> I don't know how they mitigate the radiation losses (huge amounts of insulation?) My guess is a vacuum flask made of tungsten. Tungsten sheet metal is a thi
by lazyier 5y ago
> I don't know how they mitigate the radiation losses (huge amounts of insulation?)
My guess is a vacuum flask made of tungsten. Tungsten sheet metal is a thing and it has the second highest melting point of currently known elements, which is 3,422C.
Then for the 'battery' you will want to find a material that has a phase change around the temperature required for this heat engine to operate. The energy required for water to go from 100c water to 100c steam is considerably more significant than the energy required to go from 0c water to 100c water.
Graphite will likely come into play because you need to have electrodes to heat the material up to storage temperature. Graphite is a good for this sort of thing. Although gradual erosion will likely limit the life of the battery.
- danans 5y agoIf that's the case, would the tungsten flask heat up to 2000C and give off the photons that are absorbed by the TPV? I still don't understand how they will control transmission of the heat at those temperatures.
- jandrese 5y agoMaybe insulate with reinforced carbon-carbon? I'm not an expert on this, but it doesn't seem outright impossible on the surface, but the details are always what get you.
- namibj 5y agoYou need vacuum super insulation. Basically take a thermos, and fill the vacuum with (mostly) non-touching reflective foil. It's the golden stuff satellites are wrapped in.
- danans 5y agoThe insulation I sort of understand. It's how they temporarily breach the insulation to let out the photons to strike the TPV that I don't understand. With normal heat->electricity conversion, you transfer heat to a turbine via a fluid (i.e. water) that is allowed to contact the exterior of a heated vessel, but in this case you need to somehow open a slot to let the photons radiate out.
- zardo 5y agoYou put the TPV on the wall of the insulated container behind a mirror that can be slid out of the way.
- jandrese 5y agoInstall a hinge on the side of the insulation box, swing it open then swing closed a different section that includes the thermocouples? Or just slide the insulation down in front of the thermocouples when they aren't needed. I have to assume these things mostly work on radiant heat at those temperatures.
- BlueTemplar 5y agoAh, I was wondering this - 2000°C graphite in a oxygen rich environment like air doesn't seem to be a good combination !