[HN Gopher] A photon-recycling incandescent lighting device
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A photon-recycling incandescent lighting device
Author : adrian_b
Score : 24 points
Date : 2023-04-14 21:46 UTC (1 hours ago)
(HTM) web link (www.science.org)
(TXT) w3m dump (www.science.org)
| dexzod wrote:
| The short lifetime of incandescent bulbs was by design
| https://spectrum.ieee.org/the-great-lightbulb-conspiracy.
| Otherwise they can last pretty long. This one is on since 1901
| https://en.wikipedia.org/wiki/Centennial_Light
| philipkglass wrote:
| Running the filaments hotter makes the bulb more efficient but
| also shortens the life span due to filament evaporation. You
| could get very long life by under-powering the bulb but then
| the already-low efficiency of incandescent lighting would go
| lower. That's the other remarkable thing about this paper. They
| use a ceramic instead of tungsten as the hot emitter, and
| calculate that it should have a very long lifetime.
| hashmash wrote:
| The Centennial Light produces very little light and isn't very
| practical. https://www.urbo.com/content/the-lightbulb-
| conspiracy-shinin...
| philipkglass wrote:
| That's remarkable. I was afraid this was going to be a pure
| theory/simulation paper, but they built an incandescent light
| source that selectively recycles infrared photons back to the hot
| emitter, thereby dramatically improving the luminous efficacy.
| It's a white light source that produces a continuous spectrum in
| the visible range, like other incandescent light bulbs, but has
| efficiency comparable to LED lighting.
| adrian_b wrote:
| TLDR:
|
| This paper demonstrates quite convincingly (because the
| descriptions are very detailed) that the ancient Edison light
| bulb (i.e. with light emitted by incandescent carbon) can be
| revived by using modern technologies in a form that can be better
| than the current LED lamps.
|
| The first incandescent lamps had 2 disadvantages, short lifetime
| and low efficiency.
|
| The evaporation and oxidation of the incandescent carbon can be
| avoided by a structure made of carbon nanotubes that works in
| argon. The claimed lifetime (based on accelerated aging tests) is
| as good as for LEDs.
|
| The low efficiency is solved by using a lossless optical filter
| (i.e. one that transmits the visible light and reflects back the
| infrared light) to prevent the heat loss from the lamp by
| radiation other than the useful light output.
|
| This method can reach the maximum energy efficiency determined by
| the human vision characteristics, unlike the current LED lamps,
| which are unavoidably limited to a value lower than that by the
| losses caused by the fluorescent light conversion.
|
| The design of the lossless optical filter is a difficult
| optimization problem due to the large number of parameters. Their
| solution, which is completely described in the paper, is claimed
| to have been found by a machine-learning algorithm.
| maicro wrote:
| I'm not going to read the paper to check your work, but
| excellent TLDR - thanks X)
| muser8 wrote:
| Fantastic summary!
|
| I wonder if the economics will make enough sense to overcome
| entrenched interests and the legislation backing them.
|
| It be great to have efficient incandescent light and put the
| failed promises of LED longevity behind us.
| UncleOxidant wrote:
| I don't see any discussion of manufacturing costs, anything
| here that might be more expensive than current LED lighting?
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