Mirror Gas Turbines: A Newly Proposed Method of Exhaust Heat Recovery

A new conceptual combination of Brayton and inverted Brayton cycles with a heat sink by intercooling, which is dubbed the mirror gas turbine, has been evaluated and proposed in this paper. Prior to such evaluations, a preliminary test on the inverted cycle without intercooling was made experimentally to confirm the actual operation. The conventional method of recuperation in gas turbines can be replaced by the mirror gas turbine with a low working temperature of about 450°C at heat exchanger. The combined cycle of Brayton/Rankine for electricity generation plant may be improved by our concept into a system with steam turbines completely removed and with still high thermal efficiency. Ultra-micro turbines will be possible, producing the output power less than 10 kW as well as thermal efficiency of 20 percent.