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The key to success with thermo electronics is getting a higher ZT. At present the best materials have a ZT of 4.5. These are new materials created using nanotechnology. You can see on slide 3 if the hot side is 1000 C or 1273K then with cold side at around 320K we can get 45-50% effeciency. The reason they show at lower temperatues is because the technology is being developed for Cars to extract energy.
Not sure about suitability for space however JPL has done some work on Thermoelectronics and believe that it is a good solution for radio isotope power systems see slide below. This is slightly out of date as it talks about older technology than the systems discussed above you can see that they are talking about ZT of 1.2 or 1.4. The research done by the car industry has realy changed the ballpark as far as thermoelectronics is concerned
http://trs-new.jpl.nasa.gov/dspace/bits … 5-1662.pdf
So with Hyperion we are taking about a 27MW Elect and 70 Mw Thermal assuming 45% eeffecient themo electronics we need to radiate 38,5 Mega watts Thermal and can use about 60 Mwe to drive the VASIMR engine. That is a lot of thermal energy to radiate but with this system we are getting to Mars in about 6 weeks and potentially Jupiters moons inside 6 months using technologies which are under development by private industry at present. Obviously there are large hurdles to put this stuff in space but it is not like starting from scratch.
Not sure how all this effects radiator size but if this sort of technology can be scaled to the type of appplication we are talking about it must have a significant effect on the viability of Mars mission using
This link is to some research done on radiator size for multi megawatt radiators in space aplications
Well Obama listened to a preacher guy who has been slagging off America for 20 years. That along with his wife saying that she is proud of America for the first time in her life, brings me to only one conclusion this guy is out to create change in America in a big way. This guy doesnt like America much and i bet that he will be the worst president in American history. Evan worse that G W Bush.
Here is another qauntum well thermo electronic technology that pushes effeciency up from 5-10% today to 50-60%. It is especially effective the larger the change between hot and cold and that suits our space application very well. See slide 3 and 14 of below presentation. This also looks like real technology that has been demonstrated in the lab
When was the work on SNAP 100 done. One company Powerchip reckons there technology can get conversion rates as high as 70-80% carnot Efficeincy. Even at 50% this would reduce the radiator size quite significantly. Go to this site input to calc
http://www.powerchips.gi/technology/pcalc.shtml
However i am dubious about this technology it appears to be to good to be true. I wonder how big the company is and what they have done to date. A lot of these companies are slideware although they have a number of patents
The Hyperion reactor produces about 70 MW thermal and around 27MW Electrical energy
Regards Thorium Hydride it is mentioned by Hyperion guys as part of there patent i think. I am not sure how they do it but they appear to think they can.
So if we assume a 50% Thermal to Electrical conversion as described by Power chip and if we can get the reactor to 1900 degrees. Would this be a practable solution?
See the first 12MWe VASIMR mission to mars here
http://www.youtube.com/watch?v=Zj53rVWK5z0
I have seen that INSPI stuff before but there is no detail at the site on the solution. I dont think they have any real funding behind their research. If someone elses technology developed for everyday use on earth can be doctored to space it would provide a much more likely solution
Well I am no Reactor Engineer although i am an electronic's one. You can use thermo electronics to convert the power. There is a lot of work going on in this field in the car industry to raise the effeciency of gas vehicles
These things are not space ready but they are plausable answers to they may be plausable answers to thermo electric problem
With regard to core temp. It is true that the current design envisages using uranium hydrates and operates at 400 to 800 degrees. However there is another design which uses thorium hydrates and this can operate at 1900 degrees. I think nerva was planned to operate at 2800.
I am not sure of the calculations around heat readiators in space but this has got to help.
What do you reckon, is this a possible near term solution say 10-20 years
I wonder has anyone seen detaisl on the new Hyperion reactor.
This reactor is the size of a bath tub and produces around 100MWe. A version of this may just be what NEP and VASIMR in particular needs. The other good thing is it is a start up from Los Alamos and is privately funded therefore more likely to come to fruition.
I can't post URL butsearch under reactor name should leed you to info on this project
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