Abstract
• A new triple cascade gas turbine waste heat recovery system based on supercritical CO 2 Brayton cycle. • Evaluated the performance of an integrated system combining a gas turbine and a triple cascade cycle. • Analyze and optimize the system's thermodynamic and economic performance. A new triple cascade waste heat recovery system coupled with a supercritical CO 2 power cycle and transcritical CO 2 regenerative cycle is proposed for the high temperature exhaust waste heat generated during the operation of gas turbine, and thermodynamic and economic models are established to analyze the performance of the system, with the following performance indicators: the net output power is 5.67MW, the thermal efficiency is 24.94%, the exergy efficiency is 46.08%, the total investment cost rate is 126.06$/h, and the per unit energy cost is 6.31$/GJ. The thermal performance of the integrated system consisting of the gas turbine unit and the proposed triple cascade waste heat recovery system is evaluated, and the results show that the integrated system effectively utilizes the waste heat compared with the gas turbine unit alone, while the net output power of the integrated system is 22.17 MW and the thermal efficiency is 47.7%. Each component's exergy and cost analysis is performed. The heat exchanger accounts for a large percentage of the exergy destruction, and the investment cost rate of the turbine, compressor and other work-making components is high, indicating the direction of system optimization. The sensitivity analysis of the system's key parameters was carried out through the control variables method to reveal the influence of individual setting parameters on the system performance. Based on the research range of the set parameters, the system is optimized with multiple objectives, and the net output power, exergy efficiency and per unit energy cost are selected as the objective functions. The optimization results show that the combination of exergy efficiency and per unit energy cost resulted in better economic performance, with exergy efficiency of 50.37% and per unit energy cost of 4.66$/GJ. Comparing the system with the other two configurations proves the superiority of the proposed system.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
