3. Solid sorption thermal machines

Solid sorption refrigeration machines use thermal compression instead of mechanical compression. The energy source is no longer mechanical energy or electricity, but heat. In the case of solid sorption, the adsorber (or reactor) replaces the mechanical compressor. But the adsorber needs two temperature levels to operate, hence the use of trithermal cycles (or quadrithermal cycles if condensation and adsorption temperatures are not equal) rather than dithermal cycles as with mechanical compression.

There are two types of solid sorption cycles:

• hermetic closed cycles ;

• open cycles or desiccant cycles.