Air cycle thermodynamic conversion system

Abstract

An air cycle thermodynamic conversion system compresses a compressible gas in a multi-stage compression process with intercoolers between each adjacent pair of compressors. The intercoolers return the compressed gas temperature to about ambient temperature before each succeeding compression operation. The compressed gas is heated in a heat exchanger passing a heated exhaust gas in counterflow with the compressed gas to increase the thermal energy of thereof. A minimum temperature gradient is maintained between the heating compressed gas and the cooling exhaust gas by establishing the two flows such that they both have about equal heat capacities. The heated compressed gas is expanded in a turbine to produce at least enough torque to drive the multi-stage compression system. Additional torque may be produced in the turbine for driving a using process. Alternatively, an excess of heated gas, beyond that required for driving the turbine, may be fed directly to a using process. Further heat capture may make use of the effluent heated medium from the intercoolers as well as the exhaust from the turbine. In the preferred embodiment, the working gas in the compressors, intercoolers and turbine is air.