Techno-economic analysis and multi-objective optimization of a low-temperature ammonia reforming based solid oxide fuel cell-gas turbine-organic Rankine cycle hybrid power generation system

Driven by global climate change and the "dual-carbon" goals, efforts are being made to address the challenges of ensuring reliable operation and efficient energy conversion in ammonia-based power generation systems. A low-temperature ammonia reforming based hybrid power generation system, integrated with waste heat cascading utilization and thermal self-balancing was proposed, comprises solid oxide fuel cell, gas turbine, and organic Rankine cycle is proposed. Through a sensitivity analysis of system parameters, the key factors influencing its performance were identified. The multi-objective sparrow search algorithm was used to optimize the equipment capacity and operational parameters under rated conditions. After optimization, the rated energy efficiency and exergy efficiency are 68.58 % and 60.04 %, respectively, efficiency increased by 28.09 % and 25.07 %. The initial investment cost of the project decreases by 8.52 %, while the net present value increases by 211.53 %. Additionally, the environmental impact load during the construction phase is reduced by 26.9 %. Subsequently, the system's operational parameters are optimized under different loads, achieving the optimal power distribution among multiple generation modules. Finally, a comprehensive life cycle economic and environmental evaluation of the system is conducted. The system's internal rate of return is 9.71 %, exceeding the inflation rate by 3 %. The levelized cost of electricity is 0.088 $/kWh. When utilizing gray ammonia, photovoltaic green ammonia, and wind power green ammonia, the system's carbon emissions are 716, 415, and 246 g/kWh, respectively. This hybrid power generation system balances efficiency, economic feasibility, and environmental sustainability, offering an innovative technological approach for ammonia-based distributed power systems and the utilization of renewable energy.