The Curzon-Ahlborn efficiency for three different energy converters

In this work we present three energy converters which have the same efficiency under certain optimum conditions of performance. The first one is the well-known Curzon-Ahlborn finite-time heat engine. The second one is an infinitetime cycle operating between two thermal bodies with finite heat capacities. The last case is a water mixer working as engine, which is designed with two stationary fluxes of water at different temperatures, T1 and T2, with only one exit, at temperature T, the specific heat capacity, c, is considered as a constant. The three converters under maximum power output, maximum work and maximum kinetic energy output, respectively, have the same Curzon-Ahlborn effiency, that is, 1 2 / 1 T T CA − = η , being T1 and T2 the extreme absolute temperatures involved in the performance of each converter.