Highlights
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Investigating the effect of natural gas and diesel on the power plant performance.
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Exergy, economic and environmental evaluation of a combined cycle power plant.
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Using life cycle assessment (LCA) to perform the environmental evaluation.
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Optimizing the power plant in terms of exergy and economic.
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Better performance of natural gas with respect to diesel.
The results show that the exergy efficiency of the plant with natural gas as fuel is equal to 43.11%, while this efficiency with diesel will be 42.03%. Furthermore, the annual cost of plant using diesel is twice as that of plant using natural gas. Finally, diesel utilization leads to more contaminants production. Thus, environmental effects of diesel are much higher than that of natural gas. The optimization results demonstrate that in case of natural gas, exergy efficiency and annual cost of the power plant improve 2.34% and 4.99%, respectively. While these improvements for diesel are 2.36% and 1.97%.