Energy Analysis of A Retrofitted Regenerative Gas Turbine Organic Cycle in Ihovbor Power Plant

Abstract

Gas turbines have gained popularity in power generation application because of its ease in operation, fuel flexibility and low emission of greenhouse gases. When in use as a simple gas turbine (SGT), it has the challenge of low thermal efficiency, which needs improvement to enhance its thermal efficiency and other thermal performances. This paper presents the energy analysis of incorporating a retrofitted combined regenerative gas turbine organic Rankine cycle (CRGTORC) to utilize the exhaust heat from the existing Ihovbor Power plant in Nigeria. The working fluid used in the Organic Rankine Cycle (ORC) section was cyclopentane and the analysis was carried out with the aid of ASPEN HYSYS and REFPROP. The performance of the proposed CRGTORC was compared with the existing SGT. The results obtained revealed that the CRGTORC model increases the net power output, thermal efficiency, overall cycle efficiency and work ratio of the system by 23.53%, 62.24%, 54.60%, and 10.21% respectively. Also, the flue gas losses, specific fuel consumption, and heat rate were reduced by 89.21%, 36.26%, and 36.26% respectively. Furthermore, it was observed that rise in compressor inlet air temperature lead to increase in specific fuel consumption and heat rate and decrease with net power out, thermal efficiency, cycle efficiency, flue gas losses, and work ratio. Thus, from the simulation results, the existing Ihovbor Power plant performance will be improved by integrating the CRGTORC system and its performance is significantly affected by the ambient inlet air temperature.