Applicability of cogeneration system in gas turbines used in natural gas storage facilities

Underground natural gas storage facilities are of critical importance on energy supply security. Storage activity in facilities performing underground storage is mostly carried out in spent natural reservoirs. In this study, the applicability of cogeneration system was investigated in order to generate electricity from flue gas at an average temperature of 500 degrees C and 144.4 t/h flow rate obtained from three gas turbines in storage facilities and to recover the waste heat we lost. This designed system would have three HRSGs and one steam turbine, 16.23 MW energy would be generated from each HRSG in this system. After a total of 48.70 MW energy, obtained from two HGRSs, enters into the steam turbine operating in 24% efficiency, 12.20 MW mechanic energy and 11.84 MW electric energy is generated. Therefore, a total of 97.05 MW energy entering into combined cycle power plant was transformed into a total of 42.25 MW useful energy, including 30.41 MW mechanical and 11.84 MW electricity, and the efficiency of system was calculated as 43.5%. It was aimed that the electric energy to be generated from this cogeneration system would contribute to the related facility and the electricity supply of the public against its price. [Received: October 17, 2020; Accepted: May 03, 2021]