Multi-objective optimization study of coupled solar-biomass heating system for northern farmhouses based on FAHP-HJ methodology

Solar-biomass coupled heating technology shows good energy-saving potential in farm buildings but still faces problems of mismatching technical parameters and a lack of system optimization in practical applications. This study constructed a multi-criteria comprehensive optimization and evaluation model with energy, economy, environment, and thermal comfort as the core using Fuzzy Hierarchical Analysis with Hooke-Jeeves algorithm to conduct an in-depth analysis of the solar-biomass coupled heating system in northern farm dwellings. The results show that the system multi-objective function value is optimized from 17.82 to 12.58, which is 29.41 %. The optimal configuration of the system: solar collector area 28 m2, collector inclination 60.81°, collector azimuth 10.25°, hot water storage tank volume 0.824 m3, and biomass boiler power 5.2 kW. The optimization results in a 19.9 % reduction in the whole life cycle cost, an increase in the proportion of solar heating from 46.7 % to 73.4 %, a reduction in the overall energy consumption of 44.28 %, and the Predicted Mean Vote between −1 and 1, reaching 99.79 %. Based on the synergy theory of different heat sources, this study explores the application potential of coupled solar and bioenergy heating systems, providing important insights for manufacturers, users, governments, and researchers in system customization and decision-making optimization.