综合利用低品位余热与LNG冷能的复合循环系统

摘要

A combined energy recovery system which comprehensively uses both low-temperature waste heat and liquefied natural gas (LNG)cold energy was proposed.This system can realize better temperature matching of different cycles and cascade utilization of the waste energy.Thermodynamic laws were adopted to analyze thermal performance of the system.Also,parametric analysis was performed to evaluate the effects of key factors on the system performance.The results show that this proposed system exhibited good performance,which can achieve the net electrical efficiency and exergy efficiency of 39.4% and 47. 33%,respectively.The system performance was influenced by both the state parameters and mass flow rate of working fluids,and the competition between both effects determined the overall system performance.%提出了一种可以实现低品位热能与液化天然气(LNG)冷能综合利用的复合式循环系统，以实现不同温度区间的循环匹配及热能梯级利用，并运用热力学定律对循环系统各部分性能进行热力性能分析，研究了复合循环系统各部分关键参数对系统性能的影响.结果表明：在给定工作条件下，系统的净发电效率和可用能效率分别达到了39．4％和47．33％；系统性能受循环工质状态参数和质量流量变化的共同影响，两者的综合作用效果决定了系统的优化方向.