Eur. Phys. J. Plus (2017) 132: 209
https://doi.org/10.1140/epjp/i2017-11485-9

Regular Article

Exergy-based ecological performance of an irreversible Otto cycle with temperature-linear-relation variable specific heat of working fluid

¹ Institute of Thermal Science and Power Engineering, Naval University of Engineering, 430033, Wuhan, China
² Military Key Laboratory for Naval Ship Power Engineering, Naval University of Engineering, 430033, Wuhan, China
³ College of Power Engineering, Naval University of Engineering, 430033, Wuhan, China

^* e-mail: lingenchen@hotmail.com

Received: 31 December 2016
Accepted: 3 April 2017
Published online: 9 May 2017

Abstract

Considering internal irreversibility loss (IIL), friction loss (FL) and heat transfer loss (HTL), an irreversible Otto cycle (IOC) model is built up by using air standard (AS) assumption. Based on finite-time thermodynamics (FTT), computing entropy generation rate (EGR) by using the irreversible losses in the cycle, the ecological function (EF) performance of the cycle is optimized when the specific heat (SH) of the working fluid (WF) varies with temperature with linear relation. Some important expressions, including efficiency, power output, EGR and EF, are obtained. Moreover, the effects of variable SH of WF and three losses on cycle performance are investigated. The research conclusion can provide some guidelines for the actual Otto cycle engine performance optimization.