A new performance criterion for heat engines: efficient power

Abstract

Many performance analyses have been carried out based on two comparative criteria namely maximum power (mp) and maximum power density (mpd). Researchers involved in power maximization studies have utilized the thermal efficiency at mp ( Curzon - Ahlborn efficiency) as an efficiency standard for practical heat engines. On the other hand, maximum power density studies showed that the efficiency at mpd is always greater than that at the mp, while the power output from heat engines reduces. In this study, a new performance analysis is applied to a reversible Carnot cycle based on a new criterion which is proposed for all kind of heat engines. The proposed criterion, called efficient power, is defined as the multiplication of power by efficiency. This criterion considers not only the power output, but also the cycle efficiency. Maximizing the efficient power gives a compromise between power and efficiency. The results showed that the design parameters at maximum efficient power (mep) conditions lead to more efficient engines than that at the mp conditions and the mep criterion may have a significant power advantage with respect to mpd criterion.