基于沼气的热电气联供系统全工况模型与性能分析

为了解决我国城镇化进程中日益增长的能源需求，高效循环利用有机废弃物，缓解农村环境污染问题，构建了基于沼气的内燃机热电气联供系统，将生物质厌氧发酵、内燃机热电联产、补充热源、用户侧需求等有机联系起来建立系统全工况动态数学模型，并以兰州地区5户建筑面积226.8 m²的新农村建筑为例，进行系统全年逐日供需能量平衡分析及性能分析。结果表明：寒冷地区新农村建筑负荷与商业建筑存在明显不同，冬夏季热负荷差异大，全天电负荷波动很明显；在充分考虑厌氧发酵生物质能源转化效率、热量传输及换热效率和火电厂发电效率的情况下，联供系统全年一次能源利用率为37.85%；与传统农村分供系统相比，系统一次能源节约率为17.12%。系统性能分析结果可为我国生物质沼气集中热电联产在村镇的规模化应用提供一定理论依据。

All operation mathematical model and thermal performance analysis on combined heating power and biogas system

A combined heating, power and biogas (CHPB) system driven by internal-combustion engine was proposed, in order to relieve environmental problem and the sharply increase of energy demand and domestic waste in rural areas. The system could reduce domestic waste and supply heating, power and biogas all the year around through the anaerobic digestion, internal-combustion and air-source heat pump techniques. The all operation mathematical model of the system was constructed. The system thermal performance and energy balance of supply and demand were analyzed for 5 new rural residences in Lanzhou city, about 226.8 m² of each, as a case study. The results showed that the building loads of new rural construction, of which the heating load differs greatly between summer and winter and the power load fluctuations significantly all day long, are different from that of commercial building. The power load characteristics is not benefit for following the electrical load. The yearly average primary energy rate (PER) of the system is 37.85% considering the transformation efficiency from biomass to biogas in the anaerobic digestion, heat transfer efficiency and generation efficiency of thermal power plant. The yearly average primary energy saving (PES) index is 17.12% comparing with the conventional system in cold area of Northwest China. The results can provide theoretical basis for system scale application and promote the construction of the beautiful countryside.