变温热源的有机朗肯循环性能分析

Analysis of organic Rankine cycle performance of variable temperature heat source

研究用于变温热源(烟气余热)动力回收的有机朗肯循环。考察了6种候选有机物工质和不同循环形式(如有无过热、有无回热)。系统净功、热效率、效率作为热力学指标,换热总能效(U_A),透平尺寸因数(S_P),透平等熵容积流速比(V_(FR))可大概反映系统尺寸和造价,作为技术经济性指标。采用Matlab编程,以最大净功为目标对循环进行了热力学优化和分析,并对最大净功下系统的经济性做了初步分析。结果表明:采用回热的循环输出更高净功。苯的简单循环输出最大净功,137.14 k W;庚烷的回热循环输出最大净功,156.71 k W。从技术经济性分析,在最大净输出功下,回热循环U_A和V_(FR)更小,SP差别不大。

An organic Rankine cycle（ ORC） using for waste heat recovery of variable temperature heat source（ flue gas waste） was investigated. Cycle configurations like saturated and superheated,non-regenerative and regenerative are considered. Six organic compounds are selected as the candidates. The system net power output,energy and exergy efficiencies are considered to be indicators for the thermodynamic performance; the total heat transfer capacity（ UA）,turbine size factor（ SP） and turbine isentropic volume flow ratio（ V（FR）） are assumed to be the system tech-economy indices. Maximization of the system net power output is performed using a Matlab code,and system tech-economy is preliminarily analyzed. The results show that system net power output of the regenerative cycle is larger than that of the non-regenerative cycle. Benzene produces the largest net power output of 137. 14 kW for the non-regenerative cycle and heptane produces the largest one of 156. 71 kW for the regenerative cycle. As for economic evaluation,the regenerative cycles have smaller UAvalues and VFR,but a similar SPvalue with nonregenerative cycles at the maximum net power output.