Umudike Journal of Engineering and Technology

This study presents an analysis of the environmental sustainability of different gas turbine inlet cooling systems. The research objectives involve the parametric modeling of the basic inlet turbine system in terms of thermo-sustainability consideration, determination of the environmental effect of various turbine inlet cooling system, and comparative analysis of the system with different turbine cooling methods. A base turbine was considered for the analysis were such operating data as ambient location temperature, isentropic efficiencies of compressor and turbine, turbine inlet temperature, and compression ratio were obtained. Three turbine air cooling methods were considered comprising systems (spray cooler and wetted media, fogging system technology, and mechanical chiller system. Additionally, thermodynamic models were presented to cater for the sustainability of these cooling systems. Using a developed program source code, the results showed that the extent of sustainability depends directly on the amount of turbine inlet reduction achievable in consonance with the design requirements. The Mechanical chiller (refrigerative method) of cooling, which achieves relatively lower inlet conditions (15 ^oC), has 2.243 Sustainability Index (SI) followed by sprayed cooling technique (2.17) and fogging (2.165). The least is the base turbine system, which has an SI value of 2.057. The sustainability index decreases for increasing ambient temperatures. This is attributable to higher total exergetic destruction in the plant at comparatively high ambient temperatures. Accordingly, both the Environmental Effect Factor (EEF) and Waste Exergy Ratio (WER) recorded an increasing trend in tandem with the ambient temperature since they both are functions of total exergetic destruction. The results point to a significant increase in the sustainability of the system by employing different turbine inlet cooling. Based on the results, the refrigerative method of air cooling, which achieves relatively lower inlet conditions and an SI of 2.243, is recommended due to its least overall exergy destruction.