[HN Gopher] Heat exchanger header with fractal geometry ___________________________________________________________________ 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. ___________________________________________________________________ (page generated 2023-01-11 23:00 UTC)