Heat Absorbing Materials

[DocOck]

Thanks Freestar, would molten sodium be a practical substance to handle by a lay person, either using special equipment or a special loader? Or is it too volitile to be practical, this is including the building of special equipment to handle it. Reason I"m asking is I'm curious in energy storage and I was wondering if heat could be stored and utilized for the same purpose in essence in utilizing a bunch of coal burning to produce heat/steam/pressure etc., thanks again.

[Mercedes Benzene]

Originally Posted by DocOck

Thanks Freestar, would molten sodium be a practical substance to handle by a lay person, either using special equipment or a special loader? Or is it too volitile to be practical, this is including the building of special equipment to handle it. Reason I"m asking is I'm curious in energy storage and I was wondering if heat could be stored and utilized for the same purpose in essence in utilizing a bunch of coal burning to produce heat/steam/pressure etc., thanks again.

I would definitely recommend NOT attempting this. While it is possible, the risks far outweigh any benefits. I'll take a look in my CRC tonight and see if I can find something practical for you.

[DocOck]

Thanks! What I was thinking something along the lines of a large bar of some type of metal or other material, that could be heated to extreme temperatures, then placed in a compartment for the heat storage area to utilize in a heat engine, preferably something that could be used over again, after its cooled down, you could place it in a special heater and re-heat it, trapping the heat in again, kind of like a battery, but this would be essentially a heat battery.

[UncleAl]

1st Law of Thermodynamics: You cannot win.
2nd Law of Thermodynamics: You can only break even on a very cold day.
3rd Law of Thermodynamics: It never gets that cold.

All you can grab is efficiency (co-generation). You confabulate heat (energy) with temperature (one of the things heat does). If you want a large thermal reservoir at a given temperature you need a first order phase transition to store energy as something other than temperature. Typically one melts a storage medium then gets back the heat as it solidifies (large latent heat of fusion, enthalpy of fusion).

However... First order phase transitions are typically accompanied by substantial volume changes - look up the densities and enthalpies of fusion of molten and solid paraffin; photographer's hypo; sodium acetate trihydrate, calcium chloride hexahydrate, sodium sulfate decahydrate; ice, water, steam). All schemes to store cold (freeze a big tank of water in winter then refrigerate in summer) or heat (molten nitrate-nitrite eutectic) look much better on paper than in steel. Such systems are remarkably clever about destroying themselves in large scale installations. The real world is non-linear.

[DocOck]

I don't know if this makes a difference, and I'm well aware of the laws of thermodynamics, including experiments I've seen that seem to violate those laws, but that's another conversation.

Point was is to heat something portable by conventional electricity (plugged into the wall) granted it would take a lot of juice to store your heat in your substance, but who cares about taking power from the grid. Point is to store it in a substance to then transport to a vehicle. Use the heat at one end to create steam/pressure whatever to spin a turbine to spin a generator, just like steam from burning coal, except your not necessarily burning anything, just heating something to extreme temperatures that creates a similar amount of heat as burning coal or what not. If that makes any sense, and I do appreciate you indulging a non-engineer.

Also, would it serve an efficient enough purpose to also utilize an extremely cold end (with say dry ice, a substance readily available) to draw an extreme at one end to help with the pressure?

Also, I realize your heat source would eventually cool down and the dry ice would eventually evaporate, but if you could get enough working time out of it, it may be worth it.