Automated configuration synthesis of solid oxide fuel cell – gas turbine (SOFC-GT) hybrid systems: A fuel-syngas block state-mapping approach under SOFC safety constraints

The high-temperature solid oxide fuel cell – gas turbine (SOFC-GT) hybrid system is a research hotspot due to its high efficiency potential. However, directly coupling a GT downstream of an SOFC typically requires both components to operate at the same pressure level, increasing the risk of SOFC seal failure and constraining system reliability. To resolve the conflict between high efficiency and operational safety, this paper proposes a non-predetermined topology integration optimization method based on a Fuel-Syngas Block (FSB) state mapping mechanism. Unlike traditional approaches, this method performs multi-objective optimization by simultaneously coordinating energy conversion paths, operating parameters, and heat exchanger layouts without predefining configurations. Results demonstrate that the method successfully identifies a "multi-pressure level operation architecture," effectively achieving pressure decoupling to balance SOFC safety with the high expansion ratio required for GT efficiency. Under strict safety constraints, the optimized configuration increases the overall system efficiency from 66.10% to 72.64%, representing a relative improvement of 9.89%. Thermodynamic analysis reveals that by establishing an inter-component pressure differential of 993.23 kPa, the system prioritizes the extraction of high-grade pressure exergy over traditional passive heat recovery. This study provides theoretical support for the efficient integration and energy cascade utilization of complex energy systems.