3 ms·
The article doesn't state why they are using helium. Could the same be accomplished using some other cheaper, less leaky gas like N2? I'll speculate that since
by KSteffensen 4y ago
The article doesn't state why they are using helium. Could the same be accomplished using some other cheaper, less leaky gas like N2?
I'll speculate that since it's compression and decompression (as opposed to phase change) that's being exploited, you need a small gas whose behavior is as close to the ideal gas law as possible. Smaller gasses are also more volatile and leaky though, so there is probably some tradeoff.
- Someone 4y ago> The article doesn't state why they are using helium FTA: Because helium remains a gas until -200 C, we can achieve higher temperatures inside our heat pump core N₂ boils at −195.8 °C, but that will be higher at 30 bar.
- jabl 4y agoA quick look at a phase diagram I found online suggests the boiling point would be somewhere close to -160C at 30bar. Hard to see how that would be a problem in this application.
- jabl 4y agoI would suspect that N2, being diatomic, has vibrational and rotational modes which would cause a bit of inefficiency in the cycle. Would be interesting to see how much.