turn heat into electricity

[Jolly Roger]

As focus fusion creates waste heat, we need a way to convert heat to electricity.

A sound way to turn heat into electricity

http://www.eurekalert.org/pub_releases/2007-06/uou-asw060107.php

;-)X

[annodomini2]

Interesting idea, would like to know the efficiency of such a system and obviously cost will be a determining factor.

[Jolly Roger]

annodomini2 wrote: Interesting idea, would like to know the efficiency of such a system and obviously cost will be a determining factor.

Sorry, I don’t know anything more about it than what is in the article.

I do like the Rodriguez Ring. It seems to be the most efficient design they have so far.

… Ivan Rodriguez … built a resonator from a … hollow steel tube bent to form a ring … .

In cylinder-shaped resonators, sound waves bounce against the ends of the cylinder. But when heat is applied to Rodriguez

[Transmute]

I’ve heard of heat to sound to electricity before, I don’t think its has the efficiency or energy density to compete with a Rankine cycle steam turbines. Steam turbines aren

[texaslabrat]

I

[Transmute]

I didn’t consider cogen, sure why not in that case its best competition is high Z thermoelectrics.

texaslabrat wrote: It’s great to capture all that waste heat, but if doing so requires the equivalent cost of a whole separate focus fusion reactor just to capture a few extra megawatts of heat…I’ll take another reactor instead and just vent to the environment.

That assuming they can be energy positive without a heat engine, from what they have been saying I think DPF can’t be: most of there energy is still lost in x-rays and they need a means if extracting it, either direct x-ray photovoltaic (how?) or x-rays to a heat engine of some kind (and that heat-sound-electricity qualifies as a heat engine, as it produces pv work though the movement of its piezoelectric components).

[texaslabrat]

Good point..and I’m indeed working under the assumption that DPF will succeed as intended. If it requires integration with traditional power generation heat engine cycles to be energy positive…it won’t necessarily be a failure but its impact on our society will be severely blunted. Here’s to hoping things work out according to theory 🙂

[Transmute]

no no not even theory, they admit they need x-ray conversion: see this thread: https://focusfusion.org/index.php/forums/viewthread/107/

[texaslabrat]

Transmute wrote: no no not even theory, they admit they need x-ray conversion: see this thread: https://focusfusion.org/index.php/forums/viewthread/107/

I understand that. However, you are making some assertions that a heat engine (Rankine or otherwise) would be necessary for net positive energy generation. That’s where we differ. I think everyone here understands that x-ray conversion has always been part of the plan. And that isn’t nearly as bleak as some are making it out to be..there has been a ton of research into X-ray detectors in photovoltaic modes of operation that I’m sure will be leveraged. This is not some new untested science here..just a new application for stuff that’s already here. Not only that, but if they are successful in capturing upwards of 90% of the ion beam energy (which “they” say is reasonable)…break-even occurs at x-ray conversion of only 22%. Hardly a “high-efficiency” requirement for x-ray conversion. The proof is the pudding, of course..but so far I haven’t encountered any hard evidence to cause me to doubt “The Plan”.

Skepticism is a healthy thing. But defeatism before we even see the details from the patent application is not.

[Transmute]

I wouldn

[texaslabrat]

The efficiency of photovoltaics is closely tied to the wavelengths being collected. Since x-rays are so much more energetic, they have the potential to use a far larger array of bandgaps than visible light…so I have no trouble believing that 80% efficiency is possible in theory…with a lower % efficiency most likely being achieved in practice.

I can’t point you to a x-ray photovoltaic technology meant for power production because, up to now, there hasn’t been a need for anyone to build one. However, there are a great number of x-ray detector research projects around the world. Some use scintillation, others use direct photovoltaic effects, and some a hybrid of the two. Here is a patent of one such project:
http://www.freepatentsonline.com/7161155.html

There are a lot more out there that some google searching can dig up. But, taking this one as an example, they claim a collection efficiency of 50%, and production of 276 electrons/keV (correct me if I’ve read it wrong). I’m not an expert in this field, but at first glance this seems like the type of tech that could be adapted to power generation. So while it’s not proof positive that power production from such a mechanism is feasible, at the same time it represents a marked lack of concrete proof that would tend to disprove such a device.

Anyway, like I said before, I’m going to withhold the majority of my “judgment” until the patent information becomes public and can be subjected to a more general review. But from what I’ve seen so far, I’m encouraged.

[AaronB]

texaslabrat wrote: So while it’s not proof positive that power production from such a mechanism is feasible, at the same time it represents a marked lack of concrete proof that would tend to disprove such a device. Anyway, like I said before, I’m going to withhold the majority of my “judgment” until the patent information becomes public and can be subjected to a more general review. But from what I’ve seen so far, I’m encouraged.

Wow, that is one of the most honest and non-judgemental appraisals of our work that I have ever heard! I wish everyone was as willing to hear us out and not dismiss the ideas based on preconceived notions and current technologies. You’re right. The patent application will clarify the proposals, and the means will then be open to evaluation. It is important to realize that none of our ideas require new physics or particles. All we are doing is taking an old device and applying new ideas to it to raise the overall output efficiency. The DPF is not a fairy tale machine. Its potential has not been researched enough, although its basic operation is pretty well understood, and it has a long track record already. The magnetic field effect is also real, but hasn’t been applied to the DPF before. Injecting angular momentum is also an old idea, but it hasn’t been applied to a DPF before. The x-ray capture device requires no special physics either, as will be seen later. The combination and refinement of these ideas will hopefully produce a lot of net energy. Defeatism may be appropriate in situations where the writing is on the wall that failure is certain, or when success is dependent only on a miracle, but that is certainly not the situation with Focus Fusion. I appreciate the open-minded attitude.

[Transmute]

Yes but high energy x-rays will also destroy the crystalline structure of any normal p-n junction semi-conductor used for photovoltaics, so it won’t last long enough to be worth it. I’m very hopeful for this technology I would just like to know more about how it will work and defeat problems like x-ray conversion, implying I

[texaslabrat]

Yes but high energy x-rays will also destroy the crystalline structure of any normal p-n junction semi-conductor used for photovoltaics, so it won’t last long enough to be worth it. I’m very hopeful for this technology I would just like to know more about how it will work and defeat problems like x-ray conversion, implying I

[AaronB]

Transmute, my earlier comments were meant as a compliment on texaslabrat’s openness, and not as an attack on you. You have a good understanding of the potential benefits and challenges that face our work, and we welcome your involvement. I don’t see you as a defeatist at all, nor close minded. You bring up good questions and relative facts. That’s what this project needs if we are to actually succeed, and I hope we do. Let’s not get tied up over the defeatism concern. I don’t see any defeatism here. Critical questions and concerns are certainly welcome.

[Author]

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