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“wait a second, what is the steam made of?”
“Tin. Why, what do you guys use?”
“Erm, nothing, just, continue please.”
“Okay, so given the Strontium sulfide needed to balance the vapor out, we ended up with a Strontium-Tin mixture.We boys in the shop call it the Stin engine. Ain’t that a blast?”
"Nevermind "
I don’t know why this is constantly criticized as a method of energy capture. Liquids allow for maximum surface area contact, creating more efficient heat transfer from the irradiated rods.
Armchair nuclear physicists should release an improved model before being so critical of the most effective and reliable method of energy generation we currently have.
I don’t think it’s a criticism? It’s more about highlighting the slight absurdity of super-high tech power generation still using the same method that has been used since the very start of electricity generation. A turbine spun by evaporated water.
Hey now, sometimes it’s a turbine spun by falling water!
Easy there future man… One life-changing generation method per century
Behold…the future of green power. No steam or water needed at all!
Also an excellent workout, good for cardio.
What about a turbine spun by the convection of evaporation from a large body of water being pulled toward a dry landmass?
That’s madness
Well seeing as any and all cells in our body are powered by something you could very reasonably call an electron/charge turbine I think it’s fair to say turbines are really frickin great though!
Also, water is an amazing coolant. At the molecular level its hydrogen bonding contributes to a bulk property called heat capacity that ends up much higher than most other substances, meaning it can soak up a ton of energy per unit volume (and later release that energy, e.g. into a turbine). And there’s even more of that heat capacity in the phase transition from liquid to steam and back. It’s crazy good.
It’s also super cheap and abundant. The main reason water isn’t the coolant for nearly everything is that it can be corrosive. Also steam can be quite dangerous due to all that energy it carries.
The heat of vaporization is also a huge negative of using water as you need to condense the water and then reboil it which wastes a bunch of energy
If we were a smarter species, we’d consistently use further heat exchange to use that waste heat for something else, like heating homes. The Blue Lagoon in Iceland uses it to heat a massive outdoor spa.
Water desalinization projects sometimes do. Most of them use reverse osmosis because it’s less energy intensive, but boiling the water can work if you have something else that produces a lot of waste heat. Also, the water on the cooling side of the desalination path can help warm up the incoming water through a heat exchanger.
We do sometimes do that! The problem is the condenser water is usually in the mid 100Fs which by the time you pump that somewhere it cools even more and then most people don’t like living near power plants so the cost of running the pumps and the piping is generally more than the energy saved. Iceland has a lot of geothermal heat that people are much less opposed to living near vs O&G or nuclear
I mean it does seem kinda weird that running a heat engine to run a generator is more efficient than using a thermoelectric generator with no mechanical inbetween step.
Thermodyanmics in practice is weird like that. You would think solid state peltiers would be more efficient than a machine. Solid state usually is in any other application. Just this once, no, pelts kinda suck. They’ve been around for two centuries now and nobody has made a significant breakthrough to improve them.
Diagram please?
The problem that I see is that unless that magic semiconductor is 100% efficient, turning all the heat energy into electrical energy, then there’s gonna be some left over, and things are gonna get too hot too fast too furious. So you’ll need to cool the thing, or part of it, maybe similar to a TEG using the Seebeck or Peltier effect?
I have a few of these kicking around somewhere. They work, just not super efficient, at all, with current technology.
My point is I feel like no matter what you’re gonna need extra parts to cool the thing. Water pumps etc etc. Why not just use steam? 🤷♂️
Edit: nice diagram though!
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where does hotty water go. If hotty water always hot can we always use the same water
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are there no reactors that convert particle interactions into photons and capture it with photovoltaics?
- Firefly make glow from food
- Solar panel make power from glow
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Not only that, but we’re harnessing the humble yet awesome power of phase-changing matter. The same phenomenon breaks mountains down to rubble, constantly chews apart our infrastructure, and keeps our homes and food cool. It makes a lot of sense to use that same phenomenon to do work.
Armchair nuclear physicists should release an improved model before being so critical
They would, but there are limited options for directly generating electricity. Outside of manipulating magnetic fields with kinetic motion, all we have are betavoltaics, photovoltaics, and thermocouples. And they’re all kind of awful in terms of efficiency. Even chlorophyll is awesome at converting air, light, and water, into… sugar, which then has to be oxidized (burned) to be useful.
There’s plenty of room for advancement in alternative energy for sure. My comment about critics was referring more to the method of capturing and converting irradiated rod heat to electricity. Water vapor is still the standard for a reason. It’s like being critical of a jet engine because it’s basically just a compressor.
I feel like the next big technological achievement will just be replacing water with some other fluid.
“Steam cycle? No, this is the much more advanced glycol cycle.”
It’s why photovoltaics are so cool. Direct electricity generation without having to spin magnets in circles like neanderthals.
“Direct” (from energy created by a massive nuclear fusion reactor in space).
I mean to be fair, “add hydrogen to space, and wait” is a pretty simple reactor.
Solar is no doubt the coolest.
Hydro and wind are also very neat, going directly from mechanical to electric via generator, without a steam-turbine.There is also a very cool fusion-category based on dynamic magnetic fields, that basically form a magnetic piston which expands directly due to the release of charged particles via fusion and then captures the energy from that moving electric field by slowing it back down and initiating the next compression.
A fully electric virtual piston engine in some sense, driven my fusion explosions and capturing straight into electricity.
Feels so much more modern than going highly advanced superconducting billion K fusion-reactor to heat to steam to turbine.Yes! That is super cool tech. If I remember correctly, only about half of the fusion reaction energy was produced as charged particles though. The other half was free neutrons which are notorious for not interacting with the EM field.
I love the idea, it is such a cool direct energy capture method, but it is inherently inefficient.
I’d love to be proved wrong. I did a quick search and couldn’t find the company I’m thinking of, so I’m going off memory.
Kind of, it’s more complicated.
There are different fusion reactions, one example would be ²H-³He fusion used by Helion.
²H-³He is aneutronic, so doesn’t produce chargeless particles (every clump of stuff is either an electron or contains a proton). It is also an easy to achieve fusion reaction with good energy yield, with the downside that we don’t have ³He. Helion therefore has to split their fusion into two steps, producing ³He via ²H-²H fusion in a breeder-reactor and then fusing it in their energy-reactor. The first step would then emit neutrons and not really produce energy, the neutrons here could be used to further breed fuels.
Not having neutron emissions is quite useful because it allows you to make your fusion generator a lot smaller and safer around people, so it’s certainly something you want to avoid for far more valuable reasons than improving efficiency.If we get very good with fusion we could also use the much harder to achieve ¹H-¹¹B reaction, which produces some neutrons but at very low energy (0.1% of total energy output), and is effectively aneutronic for safety concerns (neutrons have low penetration power and don’t really activate material, so can’t be used to breed say weapons-grade fission material). ¹H and ¹¹B are common so require no further steps to produce them.
There might still be directly-to-electricity pinch-fusion approaches that use neutronic fusion, I tried looking for any but didn’t find an example. We’ll see what ends up being done in practice, but close to 100% energy utilization is at least possible using pinch-fusion.
On the other hand, the losses in heat-conversion are inevitably huge. The higher the temperature of the heated fluid compared to the environment the higher the efficiency, but given that our environment has like 300 K we can’t really escape losing significant amounts of our energy even if we use liquid metal (like general fusion) and manage to get up to 1000 K. The losses of going through heat are <environment temperature>/<internal temperature> (carnot efficiency), so would still amount to 30% energy loss if we manage to use 1000K liquid metal or supercritical steam to capture the fusion energy and drive a turbine. In practice supercritical steam turbines as used in nuclear plants hover around 50% efficiency at the high end.
The magnetic field in pinch-fusion interacts with the (charged) particles directly, which are emitted at (many many) millions of K. Therefore this theoretical efficiency will be at over 99.99%. In effect in heat-based fusion we loose a lot of that energy by mixing the extremely hot fusion results with the much colder working fluid.
They can’t control which particles fuse though. The Helion energy reactor still has the particles for deuterium to deuterium fusion. 50% of the time that gives your tritium+p and 50% is He3+n. I don’t know the preference of each fusion event in their reactor, but not all events will produce charged particles.
Fair point, though there are ways to change the probabilities of fusion paths, just not ever fully to 0.
Reaction probabilities scale with reactant concentration and temperature in ways we can exploit.
I tried to find some numbers on the relative probabilities and fusion chains, and ran into The helium bubble: Prospects for 3He-fuelled nuclear fusion (2021) which I hope is a credible source.This paper contains a figure, which gives numbers to the fusion preferences you mentioned.
Paraphrasing the paper in chapter “Technical feasibility of D-3He fusion” here, first we see that up to 2 billion K, the discrepancy between ²H-³He and ²H-²H fusion grows, up to about 10x. ²H-²H reactions will either produce a ¹n (neutron) and a ³He, or produce an ¹H and an ³H, with the ³H then (effectively) immediately undergoing the much more reactive ²H-³H producing a neutron too.
In addition to picking an ideal temperature (2GK), we can also further, for the price of less than a factor 2 increase of pressure, use a 10:90 mixture of ²H:³He, or even more. This will proportionally make the ²H-²H branch a factor 10/90 ≈ 11% as likely as the ²H-³He correcting for reaction crossection.
Past that, reactivity goes about with the square of pressure and the inverse of ²H concentration, so another 10x in fusion plasma pressure would net another 100x decrease in neutron emission at equal energy output.
Given how quickly fusion reactivity rises with better fusion devices, we can probably expect to work with much higher concentrations than 10:90 when the technology matures, but 10:90 at 2GK would still have about 1/100ᵗʰ the neutrons per reaction and less than 1/100ᵗʰ per energy produced compared to fully neutronic fusion like ²H-³H.The problem is solvable, but there is definitely a potential for taking shortcuts and performing ²H-³He with much higher neutron emissions.
Wait, how can this possibly not involve a turbine? Maybe there’s a semantics thing I’m missing or we disagree on, but what’s turning the kinetic energy into rotational mechanical energy to spin the generator if not a turbine? Or are you saying the turbine is incorporated, as in a turbine generator?
Just so we’re seeing the same picture:
The way I understood it, the system used electromagnets to create a magnetic containment field to drive the fuel together to create the fusion event. That same magnetic containment field would experience a force from the produced charged particles. That force would produce a current in the electromagnets. That current would be stored in capacitors as a voltage which would be used as the energy source for the next magnetic compression cycle. The excess energy stored in the capacitor after the compression would be ‘generated’ energy.
It’s nlt mentioned in the text very clearly, but look at the link.
They were confused about what I said for hydro and wind, which I have now rewritten.
Yeah, not the right words. I intended to say no steam turbine.
Instead of turning energy into heat into turbinable fluid flow in form of steam, they directly use turbinable fluid flow.
The difference is really the lack of steps up to the turbine.Ahh gotcha, thanks for clarifying! And I agree, very cool stuff.
I swear those magnet spinners are so uncivilized.
Semiconductor gang rise up.
Molten Salt Generators are cool Solar power too.
That they are, but they’re still spinning magnets like our honorable ancestors did.
The nice things about steam is you can get as much water as could want on earth, but something like ammonia which we used as a refrigerant for years would probably work well too and there’s planets with ammonia rich atmospheres.
The interesting thing is the cycles are fairly similar at a high level, you just run out in one direction for power and the opposite direction for cooling.
yeah but s t i n k y
That’s how you know you’ve got a leak. The reason they stopped using ammonia in the first refrigerators was because of they had a leak it would kill the entire household.
What if we dunk the entire loop in bleach? Then we’ll be able to see where the leaks are as they happen.
Not if you’re asleep, that was actually when most people died because they weren’t awake to smell it.
You mean like how refrigeration and heat pumps operate?
We already use different fluids for different power cycles, for example organic rankine cycles or just power cycles that use organic fluids are good for low temperature heat sources like low temp geothermals
We could try Brawndo. It’s got electrolytes, which are great for making electrocity.
How do we go about “utilizing” the Brawndo?
I hate this. So much.
I can’t let this slander against Josiah Willard Gibbs stand.
It doesn’t have to be steam. You can also use the generated energy to pump water up to a location of higher gravitational potential, then use that to spin turbines as it comes back down.
https://en.m.wikipedia.org/wiki/Pumped-storage_hydroelectricity
Ah yes, liquid steam
Fantastic
How are you generating that energy though? Oh yeah, steam. :panic:
Why don’t they just let the steam rise on its own? Are they stupid?
Well yes assuming your reactor creates heat, you need to convert that to mechanical energy to run a pump. A steam turbine is very efficient for that lol
But how do you get the energy to pump the water up stream
Sometimes it’s wind or water, and photovoltaic panels don’t even use a dynamo. But classics sometimes are classics for a reason.
“gets” ? or “has” ?
he has to get it from the store because of other stuff the aliens did
