膨胀机约束下的组分调控非共沸工质ORC系统变工况运行研究

Study On the Off-design Operation of Composition Adjustable Zeotropic ORC System With the Expander Constraints

有机朗肯循环(ORC)在低品位热能发电领域里有着明显的优势。膨胀机作为ORC系统关键部件之一,其运行性能受热源和环境工况变化影响显著,而组分调控是提升膨胀机及ORC系统变工况运行经济性、安全性和适应性的新策略。本文建立了分液冷凝组分调控非共沸ORC系统(LCAZORC)变工况运行优化模型,在考虑膨胀机约束下,研究了LCAZORC的变工况运行热经济性和安全适应性。结果表明,与传统非共沸ORC系统(BZORC)相比,LCAZORC可避免膨胀机在不必要的高压或过低的膨胀比运行,同时提高系统热经济性,且LCAZORC变工况可运行的范围更广,具有更好的变工况适应性。

The Organic Rankine Cycle(ORC)is a promising low-grade thermal power generation technology.The operating performance of the expander,which is the most significant component of the ORC,is significantly affected under off-design working conditions.The composition adjustment is an emerging control strategy for improving the economical,safe,and flexible operation of the ORC system.An off-design operation optimization model of the liquid-vapor separated condenser-based composition adjustment zeotropic ORC(LCAZORC)is established in this paper.Considering the constraints of the expander,the investigation of thermo-economic performance and safe adaptability of the proposed LCAZORC is conducted.The results show that the excessive deviated operating pressure can be avoided in LCAZORC.Compared with the based zeotropic ORC(BZORC),the thermo-economic performance and the flexible operation of LCAZORC are improved.Compared with BZORC,the off-design adaptability of LCAZORC is better.