NASA to test prototype Kilopower nuclear reactor
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NASA to test prototype Kilopower nuclear reactor
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Re: NASA to test prototype Kilopower nuclear reactor
#2Thermo-acoustic stirling engines have long been a niche product. Seems like a great environment for them to shine, and far better efficiency than RTG's.
Re: NASA to test prototype Kilopower nuclear reactor
#3Thermo-acoustic stirling engines have long been a niche product. Seems like a great environment for them to shine, and far better efficiency than RTG's.
What's the advantage over direct thermoelectric conversion?
Re: NASA to test prototype Kilopower nuclear reactor
#4Thermo-acoustic stirling engines have long been a niche product. Seems like a great environment for them to shine, and far better efficiency than RTG's.
What's the advantage over direct thermoelectric conversion?
An RTG uses the Seebeck effect, which gets you microvolts per degree kelvin. A Stirling engine can theoretically extract many times more energy from the same temperature differential, but with a larger complexity.
Re: NASA to test prototype Kilopower nuclear reactor
#5Thermo-acoustic stirling engines have long been a niche product. Seems like a great environment for them to shine, and far better efficiency than RTG's.
What's the advantage over direct thermoelectric conversion?
> What's the advantage over direct thermoelectric conversion?
Stirling engines can approach 50% efficiency [1], whereas thermocouples are usually less than 10% [2].
[1] https://en.wikipedia.org/wiki/Stirling_engine
[2] https://en.wikipedia.org/wiki/Thermoelectric_generator#Effic...
Re: NASA to test prototype Kilopower nuclear reactor
#6This is similar to the "Stirling radioisotope generator" [1] but it is an actual nuclear reactor (albeit a small one). Both systems are a response to the same fundamental problem, the dwindling supply of Plutonium-238 [2]. The Stirling radioisotope generator uses Pu-238 more efficiently than thermoelectric RTGs, and the nuclear reactor from the article dispenses with Pu-238 altogether.
[1] https://en.wikipedia.org/wiki/Stirling_radioisotope_generato...
Re: NASA to test prototype Kilopower nuclear reactor
#7Re: NASA to test prototype Kilopower nuclear reactor
#8This is a very cool technology, but frankly I have a hard time imagining that it will see much use. NASA sees public protests and scare mongering whenever it tries to fly an RTG, which is based in the radioactive decay of (usually) plutonium, and does not use a nuclear chain reaction. They did fly one on Mars Science Lab, because it was the only way to get enough power for the rover. But it takes a PR hit every time it does so. RTGs are therefore only used when no other technology will work.
It think it's likely that the public relations nightmare NASA would have to go through to fly an actual reactor will be through the roof.
Re: NASA to test prototype Kilopower nuclear reactor
#9Anyone know the approximate size of that thing? Hard to tell from the picture.
Re: NASA to test prototype Kilopower nuclear reactor
#10Thermo-acoustic stirling engines have long been a niche product. Seems like a great environment for them to shine, and far better efficiency than RTG's.
Huh, interesting device: https://en.wikipedia.org/wiki/Thermoacoustic_heat_engine
Is this actually a thermo-acoustic engine, or some other kind of sterling engine? Or are they equivalent? The article doesn't seem to mention "acoustic" (or an equivalent).