Chemical heat transfer systems Chemical Passive Solar Cooking (ie. Salts) Technology

Chemical heat transfer systems Chemical Passive Solar Cooking (ie. Salts) Technology

"Chemical Cookers

Solar cookers using chemicals have been popular since 1961. However, the need was felt much earlier as solar energy is very intermittent in nature. Many ideas have been proposed but none of them appear to be promising."

Other interesting stuff on this page... BIOGAS IS SOLAR GAS
IN regards to cost of Salt systems:
This one is most worthy of explorations and experimentation:
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"the cost of salt to store sufficient heat to cook two square meals a day may also be prohibitive.

Under IDT 9, the author has included the biogas digester. Plant product of any type could be used here and as plants use and store solar energy. The inclusion of this type of cooker should not be out of place. The Government of India has supported this type of cooker and it has solved fuel problems in many a household.
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******* MY COMMENTS ********
Given the nasty nature of these salts, corrosion of the piping is a huge operational problem. The Newer Stirling Solar Engine uses Liquid Hydrogen as the Heat transfer material creating a less corrosive fluid with a smooth vapor curve due to smaller molecules of the solution. This is the greatest solution, I have seen, to this heat transfer technology, in addition the Stirling Engine can use ANY external heat source, the best Solar technology for this of course is still Parabolic Mirror Concentrators. This Technology is highly suspect but some of the designs are interesting but most are incompletely solutions. The most interesting of these Chemical heat transfer systems could be this one:

"Hall et al. (1977) propose the use of simple salts like MgC12 or Cacl2 (Type IDT 8a). Ammoniated MgCl2 and CaCl2 are kept in separate but interconnected boxes. Solar heat was used to drive away the ammonia from MgCl2 which would then combine with CaCl2 in the other box. Now, the system could be considered as charged. When heat is required the box containing CaC12 is slightly heated, this releases the ammonia which would then move to the other box, combine with MgCl2, and release heat at 300 degrees Celsius. This apparently simple system has not been studied in detail."

Ammoniated MgCl2 in the Solar Heated Compartment and CaCl2 in the final heat use chamber. The reaction to release the latent heat is started by slightly heating the final heating implement but the question remains "how do you turn it off?". 300 degrees Celsius in HOT Baby that's like 570 degrees Farenheit good enough to heat an oven. Perhaps you could incorporate this type of technology into apartment buildings with good solar resources but ammonia leaks could be disasterous. Personally I perfer the danger of explosion to the chemical burning fumes that an Ammonia Leak could create in an apartment building. Probably the reason the system has stalled. -TMF