微燃机天然气冷热电三联供系统热力学分析

THERMODYNAMIC ANALYSIS ON MICRO-TURBINE CCHP SYSTEM

天然气冷热电三联供技术(Combined Cooling Heating Power,CCHP)是指用天然气驱动发电机发电,回收余热用于冬季供热、夏季供冷的综合能量系统。同济大学与意大利国土资源部合作,搭建了微型燃气轮机现场实验机组,展开面向用户的微燃机CCHP系统应用与优化研究。为此,采用能量平衡、火用平衡等热力学分析方法,对CCHP系统进行了分析,得到了能流、火用流平衡情况。与常规能源系统(火用效率27%～28%)进行了对比,微燃机CCHP系统(火用效率33%～39.6%)不仅在能源利用的经济性方面更为合理,一次能源利用率也高于常规系统。在选择余热制冷设备时,要注意微燃机烟气量较大而温度水平偏低的特点,有针对性地进行合理设计。

Natural gas Combined-Cooling-Heating-Power(CCHP) is an integrated system that provides electricity generated by gas-turbine or gas-engine,while providing heating or cooling through exhaust-driven absorption chiller.Under the sponsorship of Italian Ministry of Territory and Environment,Tongji University set up a micro-turbine CCHP system to carry out research on its application and optimization.Energy balance and exergy balance were performed in this study.The calculation results were compared with conventional systems(exergy efficiency 27%-28%).It was concluded that micro-turbine CCHP system is more economically reasonable(exergy efficiency 33%-39.6%) and favorable in a more source energy-efficient manner.To enhance heat recovery efficiency,more attention should be paid to exhaust volume and corresponding temperature while selecting absorption chilling equipments.