Optimization of Irreversible Cogeneration Systems under Alternative Performance Criteria

Abstract

In this study, an exergy optimization has been performed for a cogeneration plant consisting of an irreversible Carnot heat engine. In the analysis, different objective functions have been defined based on alternative performance criteria and the optimum values of the design parameters of a cogeneration cycle were determined for different criteria. In this context, the effects of irreversibilities on the exergetic performance are investigated, and the results are discussed. List of SymbolṡE Exergy ratė Q Rate of heat transfer I Irreversibility parameter R Power to process heat ratio S Entropy T Temperaturė W Power generated from the cogeneration system M. Atmaca (B) · M. Gumus · A. T. Inan

Two Examples of Exergy Optimization Regarding the “Thermo-Frigopump” and Combined Heat and Power Systems

“…These results gives a more general upperbound for the exergetic efficiency compared to the results given by Erdil [29] and Atmaca et al [30] due to the fact that finite heat source and sink have been considered here, but without heat leakage (adiabatic case). This will be considered in the future.…”

“…The set of equation is adapted to take account of system internal irreversibilities, according to entropy analysis or experimental identifications. The obtained results are not limited to linear heat transfer law, or by the fact that the model imposes to introduce two irreversibility ratios [29,30]. We reiterate that it has been proposed in preceding papers that the entropy analysis method preferable to the ratio method [33,34].…”

Thermoeconomic optimization of gas turbine cogeneration plants

“…The majority of the work produced by the turbine (work produced by the turbine to the compressor is called back work rate and is around 50-60 %) is spent by the compressor so that the pressure ratio (compressor work) are very effective on the cycle efficiency (Najjar, 2001;Atmaca et al, 2016). Many publications are based on finding better evaluation criteria and the most effective parameters on efficiency for gas turbine cogeneration cycle (Atmaca et al, 2009;Atmaca, 2011). These studies generally contain fewer criterions, parameters and cycles therefore they are not satisfactory as a rule of thumb.…”

Finite-time exergoeconomic optimal performance for an irreversible gas turbine closed-cycle cogeneration plant

“…Erdil (2005) investigated the Downloaded by [University of Guelph] at 01:10 11 October 2012 optimal exergetic output rate and exergetic efficiency performance of an irreversible combined Carnot cycle cogeneration plant with heat resistance, heat leakage and internal irreversibility and concluded that the performance is independent of the consumer-side temperature. Atmaca et al (2009) investigated the optimal exergetic output rate, energy utilization factor, artificial thermal efficiency and exergetic efficiency performance of an irreversible Carnot cycle cogeneration plant. Yilmaz (2006) optimized the exergy output rate of an endoreversible simple gas turbine closed-cycle cogeneration plant with the sole irreversibility of heat resistance by optimizing the temperature ratio of the working fluid and concluded that the lower the consumer-side temperature, the better the performance.…”