ABSTRACT Enhancing the thermodynamic performance of solid oxide fuel cell combined heat and power (SOFC–CHP) systems requires moving beyond parameter tuning toward systematic optimization of thermal‐integration architecture. For a methane‐fueled SOFC–CHP system, this study constructs a comprehensive layout space by combining flow paths of stack off‐gas and exhaust, and applies temperature–heat transfer diagram analysis for front‐end thermodynamic feasibility screening. Among 48 candidate layouts, only seven satisfy the feasibility criterion. The screening further shows that placing air preheating at the end of the heat‐integration sequence is necessary to prevent premature consumption of high‐grade heat and to maintain sufficient thermal driving force for reforming and evaporation. Detailed simulation models are developed for each feasible layout, and performance is compared under a baseline condition and across variations. Results demonstrate that system layout decisively governs overall performance, with a 12% difference in overall efficiency between the best and worst layouts. Specifically, the layout in which SOFC off‐gas is combusted directly and the resulting exhaust sequentially supplies heat to the reformer, evaporator, and air preheater achieves the best performance. This work confirms the benefits of layout‐level optimization and identifies a reference architecture for high efficiency methane‐fueled SOFC–CHP design.
Mei et al. (2026) studied this question.