4 ms·

And just using a heat pump will have vastly lower total energy usage. It could be interesting in niches like say have some thermal storage (that say gets recha

• kgermino 4y ago
  I suspect heat pumps are the future for domestic heating, but I’m not sure it’s feasible for industrial uses. Very hard to get a heat pump that can make a 1000* difference between the hot and cold side. My comment probably shouldn’t have even mentioned home radiators.
  • olivermuty 4y ago
    It’s actually starting to perk up on the industrial side as well! https://norwegianscitechnews.com/2021/04/developing-the-worlds-hottest-heat-pump-ever/ https://norwegianscitechnews.com/2021/04/developing-the-worl...
    • adwn 4y ago
      > producing temperatures of up to 180 degrees celcius That's a bit short of the 1000°C that Rondo's system promises, so these approaches are useful for very different applications.
  • contravariant 4y ago
    It's not that heat pumps aren't capable of making a 1000K temperature difference, but with an ambient temperature of around 300K even the theoretical advantage of using a heat pump instead of straight up heating is just ~40%. It's not nothing, but getting close to the theoretical limit tends to be incredibly annoying when it comes to thermodynamics. Typically it requires doing stuff extremely slowly (so you're always close to thermal equilibrium), which means it's nowhere near fast enough or you need almost perfect insulation etc.
    • choeger 4y ago
      Why is the ambient temperature important? Isn't it about thermal energy? So wouldn't a heat pump just need to be much larger to work up to 1000 degrees or more? Say, I have a heatpump that heats up water to 100°C at ambient temperature of 10°C. Couldn't I feed that hot water into another heat pump that heats up water to 200°C and so on?
      • Freestyler_3 4y ago
        If you have the liquids with the properties to handle that you could. To make it easier you would have to halve each next heat pump specs, so that the earlier pump can deliver to both the condensor and the evaporator.
      • contravariant 4y ago
        You could, though the combined setup of two heat pumps is still subject to the theoretical limits of a single heat pump. This particular law holds for any conversion from work into a temperature gradient (or the reverse). Any setup that is more efficient would violate the second law of thermodynamics, which results in a nigh infinite supply of energy. You can make heat pumps 10x more efficient by using 10x smaller increments of temperature, but then you also need to pump each unit of heat 10 times so in the end it doesn't cost less energy to make a bigger temperature gradient.
      • Schroedingersat 4y ago
        At each 90 degree jump you might, say, put in one unit of work to move two units of heat. The problem is at step two you have three units of heat, two of which came from ambient heat. At step three you have 4.5 units of heat, two of which came from ambient heat. Step five there are 6.75..and so on. You're expending a lot of energy moving energy you put in so you get diminishing returns. The theoretical limit is T_hot / T_change (in absolute units like kelvin). If your change is roughly the hot temperature, there's no benefit.
• dzhiurgis 4y ago
  If using heat pump - can you have an additional container to store pressurised refrigerant? Or that only works for cooling?
• Schroedingersat 4y ago
  No reason not to combine them. Have a big brick or water thing inside. Heat it while it is sunny with a heat pump. Hell you could even melt a few tons of sodium acetate during summer and use it for december/january