[HN Gopher] Heat exchanger header with fractal geometry
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Heat exchanger header with fractal geometry
Author : themodelplumber
Score : 32 points
Date : 2023-01-11 20:48 UTC (2 hours ago)
(HTM) web link (patents.google.com)
(TXT) w3m dump (patents.google.com)
| steeve wrote:
| Related: "3D Printed Heat Exchanger Uses Gyroids for Better
| Cooling"
|
| In short: 2x smaller, 2x more efficient
|
| https://www.youtube.com/watch?v=1qifd3yn9S0
|
| In general, algorithmic engineering and AI designs are where 3D
| printing can really shine.
| hinkley wrote:
| 1/2 the volume, which is 40% smaller diameter (Assuming the
| length is kept, which as a drop-in replacement it would have to
| be?)
|
| The inventor talks about how the internal structure is based on
| minimizing surface area. That would of course reduce the
| material but in a heat exchanger don't you want to _maximize_
| surface area, not minimize it? Especially if your heat
| exchanger has a higher thermal transfer rate than the fluids.
| It makes me wonder if there 's an answer to this design that's
| another 20% smaller.
| fnordpiglet wrote:
| Yeah I did this about 3 years back using thermally conducting
| filament, the goal is exactly that - maximize surface area
| while maximizing float through the manifold. It's actually
| stupidly easy to do these days with cura. Make your heat sink
| shape, say a cube, and slice it with zero wall thickness and
| gyroid infill. Then attach to a copper plate, and add a fan
| to the top. The problem is materials. Most people don't have
| the ability to print in copper or aluminum. The thermally
| conducive filaments are absurdly expensive (like $120/kg) and
| the conductivity isn't that great, so you can generally do
| better with a fin based thing in copper or aluminum. I think
| it would be possible to make a filament with aligned graphene
| in the filament that does really well, but I'm not that hard
| core. Another idea I have is building these out of graphene
| aligned in a super critical bath of silver. But that requires
| some serious equipment for the pressures and temperatures.
| ZeroGravitas wrote:
| I believe 'minimal surface' is a technical term for these
| types of shapes:
|
| https://en.wikipedia.org/wiki/Minimal_surface
| mechhacker wrote:
| Would like to see how it handles thermal cycles
| wwqrd wrote:
| Good example of when obvious patents harm innovation.
| pifm_guy wrote:
| I 3d printed this well before 2019... Made in plastic as a
| prototype heat exchanger designed in openscad.
|
| Is there anything I can do, or must I now shelve my project
| because I didn't see this patent be filed?
| elil17 wrote:
| Did you publicly publish your work? E.g. blog post, youtube
| video, etc. Could be as simple as a single photo or a brief
| written description of the design.
|
| If so, you're good to continue your work. You could even try to
| help the patent examiner find your work by publishing it and
| using keywords related to the patent.
| FatActor wrote:
| Is that really fractal in the sense of fractional dimension? Or
| is it just self-similar? I watched a video on this for 3b1b and
| it undid 30 years of thinking I knew what "fractal" meant and now
| I know nothing.
| sfpotter wrote:
| If you really want something to be fractal, there needs to be a
| limiting process. You can't refine something infinitely in
| physical space, because of fundamental physical limits. So, you
| could say it is "only" self-similar. But this is kind of
| missing the point. The engineering benefits of something
| "being" fractal are realized in this case even though the
| limiting process terminates below a certain point.
| prvc wrote:
| No material object can be "fractal"--- it is just being used as
| a buzzword here.
| elil17 wrote:
| FYI, this is not something that people are looking to use outside
| of aerospace. The heat exchangers in homes, factories, power
| plants, etc. are designed to be energy efficient and cheap. This
| is designed to be extremely light weight and 3D printed. It's
| much, much more expensive than anything used outside of
| aerospace.
| s_tec wrote:
| I feel like this is an obvious idea, but we simply haven't had
| the 3D printing technology to make things like this before.
| Casting this using traditional methods would be extremely
| difficult. Nobody bothered making stuff like this, not because
| they never thought of it, but because it was always too
| expensive.
| Taniwha wrote:
| It's essentially how any mammal cools itself - so yeah, pretty
| obvious
| elil17 wrote:
| The header is not actually meant for cooling, just to
| distribute the fluid evenly across the heat exchanger. 3D
| printed heat exchangers use shapes like gyroids.
| sacnoradhq wrote:
| Seems pretty obvious: maximum surface area with minimum
| backpressure, the design becomes like "lungs" or "placenta"
| branching from "artery" down in steps to "blood vessels". It
| looks like some early jet turbine combustors.
|
| "Kidneys" and reverse osmosis cartridges OTOH appear to function
| for optimizing for different constraints involving liquids and
| pressure.
| jhallenworld wrote:
| It seems like it would massively complicate heat exchanger
| repair..
|
| I learned of an obscure tool recently- a roller tube expander.
| You use this to tight-fit a tube in a boiler's tube-sheet. So you
| can install or replace tubes in pressure vessels such as a
| boilers or heat exchangers. Check it out:
|
| https://www.youtube.com/watch?v=u7UQKNapTBE
|
| Failure:
|
| https://youtu.be/HlXVP2HHTfo?t=696
|
| Repair:
|
| https://www.youtube.com/watch?v=7znd-hpy2Vc&t=708s
| elil17 wrote:
| This is for aerospace heat exchangers, where weight is the
| primary concern. This would not be used along-side tube-base
| heat exchangers, but rather with 3D printed heat exchangers.
| nixonpjoshua1 wrote:
| I think this is why this application is a military helicopter
| part where weight savings are at a premium and budgets are not.
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