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It's a very clever trick: a refrigerator without a compressor which uses heat as the energy source. It could run on either a gas flame or an electric heating el
by HPsquared 18d ago
It's a very clever trick: a refrigerator without a compressor which uses heat as the energy source. It could run on either a gas flame or an electric heating element.
There are three working fluids (butane, water and ammonia) and it works by exploiting differences in partial pressure (that is, the pressure contributed by each component of a gas mixture). Instead of using a compressor to change the overall pressure, it changes the composition of the mixture.
The cycle basically works by adding and removing ammonia at different points to make the butane refrigerant evaporate and condense in the appropriate places.
On the "condenser" side of things, water is used to remove the ammonia from the gas mixture by absorption. Because the total pressure is approximately the same throughout the system, removing ammonia increases the butane mole fraction and therefore its partial pressure, causing the butane to condense. This is the heat rejection side.
On the evaporator side, ammonia is added again. This lowers the butane partial pressure, shifting the equilibrium and causing the liquid butane to evaporate. That's where the cooling effect occurs.
The other part of the cycle is regenerating the ammonia by separating it from the water again. That's where heat is added, and that heat input is what ultimately drives the process.
- lstodd 17d agoUSSR made compact fridges like that, called Морозко. They are still made. No moving parts, very quiet.
- VladVladikoff 17d agoMan WTH? Now I want one. I hate how loud my fridge is!
- HPsquared 17d agoThey're not energy efficient so I'm not sure that type of fridge is available to buy now.
- lstodd 17d agoEnergy efficiency is secondary, that can be mitigated by solar power plus some thermal mass inside. That is actually most efficient use of solar from my pow. Their bane is hydrogen partial pressure dropping due to it leaking through the metal of the tubes. That .. is problematic. OTOH it'll last for like 20 years before you'd need to replenish.
- RobGR 17d agoThe Einstein-Szilard device doesn't use hydrogen, did the USSR device use it ?
- tingletech 17d agoin the US you can still buy hydrogen/ammonia/water gas absorption refrigerators such as "EZ Freeze". Propane/Natural Gas refrigerators use this cycle. I'm sure you can get them all over the world, the cycle is older than the one in the article.
- ninalanyon 16d agoYou can buy them almost anywhere where there is a need to keep food cold without electricity.
- grumbelbart 17d agoGet one with an inverter compressor, they are very quiet. They have a compressor that can be run at varying power levels, so instead of having one that goes of noisy at 100%, then sits off for a while, you have one that runs for example at 10% most of the time.
- VladVladikoff 17d agoInteresting. Is this better or worse for compressor life span?
- grumbelbart2 17d agoFrom what I know it's better for the life span. Less load, fewer start-stop cycles, less vibration.
- yencabulator 15d agoUsually that means either a fan or compressor pump is making a metal panel resonate; the pump itself is usually pretty quiet, and the fan is pretty much the same as a PC fan. You can usually add a sticky foam panel to the metal backpanel to eliminate the vibration.
- gonzalohm 17d agoThank you. I can't believe the main article doesn't bother explaining how it works
- throwaway198846 17d agoIs the other way possible - a heat pump which heat and similar to this setup? If so you attach a solar thermal panel to such pump and store the heat in thermal battery to be used by Einstein-Szilard Refrigerator for constant cooling.
- idontwantthis 17d agoWhat is the electromagnetic component?
- idontwantthis 17d agoIt sounds like the article completely mixed together two different inventions of theirs and the one you described was the much more important one.