Talk:Liquid Metal Concentrated Solar Power
Eric's Ideas/Rant
- So I was reading up about CSP and got onto the subject of heat transfer fluids. It seems like water or salt are the most common. Sodium Choride has a melting point of 801°C and a boiling point of 1,413°C (temp range of 612° C on napkin math). So it works, but you have that temperature ceiling of 1,413°C. So my mind got thinking, what else could you use? After reading a ton of wikipedia articles and lists I found Lead-bismuth eutectic (or LBE) to be optimal. It has a melting point of 123.5 °C and a boiling point of 1,670 °C (temp range of 1546.5°C on napkin math). So slightly higher operating temperature, HUGE temp range (so no freezing over issues really), sounds good wright? Then the problem is it is: Toxic, Corrosive, and quite hard to attain. So that's not the best option.
Then I went back to the charts and I thought of aluminium. It has a melting point of 660.32 °C, and a boiling point of 2470 °C (temp range of 1809.68° on napkin math). So that puts the melting point 140.68 BELOW sodium chloride, and its max temp is 800°C ABOVE LBE. Basically it has a greater temp range, but it is pushed up 536.82°C. So it can store/spread more heat, has a lower melting temperature than a commonly used material (sodium chloride), and has a wide temperature range. It also has wide availablility (assuming that you have access to electrolysed aluminium, or scrap), so not that problem that arrised with LBE, and is relitively non-toxic compared to LBE. Some problems may be corrosion (i'm no chemist, so i will leave that decision up to someone else), density (it (2.70 g/cm³) is slightly denser than sodium chloride (2.16 g/cm³), yet less dense than LBE (rough gestimation of 10 g/cm³ when liquid), so it isn't exactly drop in the same on the density front, which may effect some things.
All in all, in my non expert opinion, I think aluminium may be worth a try.
Also as a point of reference, steel melts around 1370-1510 degrees (and that is full on liquification, not loss of structual capability) so that is a limiting factor (if we use steel pipes and not some fancy metal/ceramic)
Tell me what you think + any other ideas (also check my math). Thanks!