基于超临界CO2布雷顿循环的有机朗肯联合循环特性研究

An Investigation on Characteristics of an Organic Rankine Cycle （ORC） Combined with a Supercritical CO2 Brayton Cycle

使用ASPEN通用流程系统设计软件,在超临界CO2布雷顿循环(SCO2)和有机朗肯循环(ORC)的循环特性研究的基础上,进一步探究了SCO2-ORC联合循环的影响因素和影响结果。研究表明,联合循环中SCO2透平出口压力、ORC透平入口压力和压气机入口温度对循环系统的热效率均有着重要影响。对比不同工质可以发现,最大效率排序为R22>R32>R125>R134a>R115。此外,通过统计分析发现,在变ORC系统参数和变SCO2系统参数时,联合循环热效率与ORC功率占比分别表现出一次线性关系和二次抛物线关系。为进一步使用和推广SCO2-ORC太阳能光热发电技术提供了理论支持和设计基础。

In this paper,the ASPEN,a general flow system design software,is used to investigate the influential factors and the impact results of the SCO2-ORC combined cycle on the basis of the study of the cycle characteristics of the supercritical CO2 Brayton cycle(SCO2)and the organic Rankine cycle(ORC).The results show that the outlet pressure of the SCO2 turbine,the inlet pressure of the ORC turbine and the inlet temperature of the compressor have significant impacts on the performance of the combined cycle system.Additionally,when comparing the performance of different organic working fluids,it can be found that the maximum thermal efficiency of the combined cycle under the present studied conditions is in the order of R22,R32,R125,R134 a and R115.Furthermore,through the statistical analysis,it is found that the relationship between the thermal efficiency and the ORC power ratio presents a linear relationship and a two parabola relationship as the parameters of the ORC system and the parameters of the SCO2 system change,respectively.Overall,this work provides a theoretical support and a design basis for further use and promotion on the SCO2-ORC solar thermal power generation technology.