Theories Behind MDI Compressed Air Technology

Thermodynamics and Mileage

In industry, cylindrical expansions are between the isothermic and the adiabatic. Isothermic expansion is defined by a constant temperature during the increase in volume. Adiabatic expansion is characterized by a lack of thermic exchange with the exterior.

In our system, we use three polytropic expansions which correspond to real life, to which we added two thermal exchanges during the expansion phase to come as close as possible to isothermic expansion which produces near-unity, avoiding friction.

The polytropic expansions work to the following formula:

and the volume after expansion is:

The energy used corresponds to the minimum energy a compressor uses to refill the tanks. This energy is that of isothermic transformation, being as it is the compressor efficiency. This work is obtained by:

Applying this formula to tanks of 300 litres at 300 bars results in 46 MJ (Y 52.1 MJ with 340 litres at 300 bars ).