Direct Generation of Compressed Air from Waste Heat by Cascaded Thermocompressors with Self-Excited Overdriven Free Displacers

Compressed air is a widely used but expensive and inefficient industrial energy source. At the same time, large amounts of
waste heat remain unused. In order to exploit and utilize this waste heat potential at low production and operating costs,
a novel concept based on reciprocating thermocompressors has been developed. It focusses on maximum constructional
simplicity by arranging a cascade of identical stages, and on the application of self-excited, overdriven free displacers, the
frequencies of which may adapt independently of the pressure to ensure optimum operation of all stages, while largely
maintaining or even exceeding thermal similarity to the first stage. In order to prove the feasibility of such a system, it has
been investigated by means of an analytical and a numerical analysis.