Modeling and 6E analysis of a novel quadruple combined cycle with turbocompressor gas station

Natural gas compressor stations have a significant potential for waste heat recovery. In this paper, a novel quadruple combined cycle has been proposed based on a turbocompressor gas station. In this regard, Serajeh gas station in Qom (Iran), including three 25 MW nominal gas turbines that each turbine provided power requirement for compressor, has been considered. Steam and organic Rankine cycles have been used to recover waste heat and generate more power, which uses exhaust gas turbines. Seven organic fluids have been examined. Energy, Exergy, Exergoeconomic, Exergoenvironment, Emergoeconomic, and Emergoenvironmental (6E) analyses have better understood the system from different perspectives. In this regard, computer code has been developed in MATLAB for 6E analysis. Verification of thermodynamic simulation of developed code has been compared with THERMOFLEX software and reference data with high accuracy. Also, sensitivity analysis was carried out based on main parameters. Advanced exergy-based analysis associated with endogenous/exogenous and avoidable/unavoidable parts has been performed for deep analysis of each component. The results show an increase of approximately 16% in the integrated cycle's thermal efficiency compared to gas turbines. The combustion chamber has the highest exergy destruction rate, and the LP superheater and economizer have the lowest exergy efficiency. R113 was selected as the best organic fluid from thermodynamic and R141b from an economic and environmental point of view. Cost rates and environmental impacts of the entire system will be approximately 3300 $ h−1 and 2038 pts h−1, respectively.