Exergy, exergoeconomic and environmental analyses and evolutionary algorithm based multi-objective optimization of combined cycle power plants

This paper focuses on the exergetic sustainability indicators of a medium-range commercial aircraft engine for constant reference environment and ground running conditions. First, a detailed exergy analysis of turbofan engine have been performed based on engine test cell parameters. Starting from the sustainability considerations and the second law of the thermodynamics, the paper presents six exergy-based sustainability indicators. The indicators of the turbofan engine developed here in conjunction with exergetic analysis and sustainable development are exergy efficiency, waste exergy ratio, exergy destruction factor, recoverable exergy rate, environmental effect factor, and exergetic sustainability index. The investigated sustainable indicators have been calculated by using exergy analysis outputs for aircraft ground running condition. Results from this study show that values of exergy efficiency, waste exergy ratio, exergy destruction factor, recoverable exergy rate, environmental effect factor, and ex...

Exergetic Sustainability Indicators as a Tool in Commercial Aircraft: A Case Study for a Turbofan Engine

This study deals with the exergetic performance assessment of a combined heat and power (CHP) system installed in Eskisehir city of Turkey. Quantitative exergy balance for each component and the whole CHP system was considered, while exergy consumptions in the system were determined. The performance characteristics of this CHP system were evaluated using exergy analysis method. The exergetic efficiency of the CHP system was accounted for 38.16% with 49 880 kW as electrical products. The exergy consumption occurred in this system amounted to 80 833.67 kW. The ways of improving the exergy efficiency of this system were also analysed. As a result of these, a simple way of increasing the exergy efficiency of the available CHP system was suggested that the valves-I–III and the MPSC could be replaced by a 3500 kW-intermediate pressure steam turbine (IPST). If the IPST is installed to the CHP system (called the modified CHP (MCHP) system), the exergetic efficiency of the MCHP system is calculated to be 40.75% with 53 269.53 kW as electrical products. The exergy consumption is found to be 77 444.14 kW in the MCHP system. Copyright © 2006 John Wiley & Sons, Ltd.

Exergetic performance evaluation of a combined heat and power (CHP) system in Turkey

SUMMARY This study deals with the energetic and exergetic performance assessment of a combined heat and power system with micro gas turbine (MGTCHP). Quantitative energy and exergy balance for each component and the whole MGTCHP system was considered, while energy and exergy consumption within the system were determined. The performance characteristics of this MGTCHP system were evaluated using energy and exergy analyses methods. The energetic and exergetic efficiencies of the MGTCHP system are calculated as 75.99% with 254.55 kW (as 99.15 kW}electrical and 155.40 kW}hot water@363.15 K) and 35.80% with 123.61 kW (as 99.15 kW}electrical and 24.46 kW}hot water@363.15 K), respectively. The maximum energy loss and exergy consumption occur at 44.03 kW in the stack gas and 129.61 kW in the combustion chamber, respectively. Copyright # 2007 John Wiley & Sons, Ltd.

Energetic and exergetic performance evaluation of a combined heat and power system with the micro gas turbine (MGTCHP)

We investigated the effect of dielectric filling in a V groove on the propagation parameters of channel plasmon-polariton (CPP) modes. In particular, existence conditions and critical groove angles, mode localization, field structure, dispersion, and propagation distances of CPP modes are analyzed as functions of dielectric permittivity inside the groove. It is demonstrated that increasing dielectric permittivity in the groove results in a rapid increase of mode localization near the tip of the groove and increase of both the critical angles that determine a range of groove angles for which CPP modes can exist. Detailed analysis of the field structure has demonstrated that the maximum of the field in a CPP mode is typically reached at a small distance from the tip of the groove. The effect of rounded tip is also investigated.

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Channel plasmon-polariton modes in V grooves filled with dielectric

An exergetic analysis was performed for a 116-MW gas-turbine power plant. Mass and energy conservation laws were applied to each component of the system. Quantitative exergy balance for each component and for the whole system was considered. In this study, the exergy of a material stream is decomposed into thermal, mechanical and chemical exergy and an entropy-production flow. The effect of a change in the inlet turbine temperature on the exergetic efficiency and exergy destruction in the plant was evaluated. The crucial dependency of the exergetic efficiency and the exergy destruction on the change in the turbine inlet temperature was confirmed.

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Mohamad Javad Ebadi

Papers

Exergetic analysis of gas turbine plants