有机朗肯循环与再热式循环低温热源发电系统热力性能研究

The Study on Thermal Performance of Power Generation System Using Organic Rankine Cycle and Reheating Cycle System

针对120℃以下的低温余热热源,探讨了基本有机郎肯循环发电系统和再热式有机朗肯循环发电系统模型的基本原理。从热力学第一定律角度出发,研究了纯工质R245fa和非共沸混合工质R21/R245fa在基本有机郎肯循环系统中,以及纯工质R245fa在再热式有机郎肯循环系统中,三种形式的有机郎肯循环系统热力性能随蒸发温度的变化情况。与纯工质基本有机郎肯循环系统相比,再热式有机郎肯循环最大可提高系统净输出功7.08%,而混合工质对提高整个系统热力性能具有较大的优势,净输出功和热效率最大可提高4.67%和2.91%。

Analyzed the basic fundamental principle of power generation system model based on basic organic rankine cycle and reheating organic rankine cycle,especially for temperature lower than 120 ℃ exhaust heat source.Based on first law of thermodynamics,pure working fluid R245fa and zeotropic mixtures R21/R245fa in basic organic rankine cycle system,pure working fluid R245fa in reheating organic rankine cycle were studied.The changes of system’s thermal performances with evaporating temperature of the three recycle systems were studied.Compared with pure working fluid basic organic rankine cycle system,the system’s net output work could improve 7.08% with reheating organic rankine cycle system.However,zeotropic mixtures R21/R245fa is superior in the improvement of overall system thermal performance,and the net output work and thermal efficiency could be improved by 4.67% and 2.91%,respectively.