摘要
提出了以R245fa/R152a为组元的按不同质量比例组成的Ca、Cb和Cc这3种典型的非共沸混合工质,在设定工况下对其应用于太阳能低温朗肯循环的性能进行了理论研究。针对非共沸混合工质相变时存在温度滑移,在系统中引入了内部换热器(IHE)。分析结果表明:使用混合工质可拓展太阳能低温朗肯循环工质选择范围;非共沸混合等熵工质在设定工况下的循环效率并非最高,但具有最小的膨胀比;非共沸混合工质应用于太阳能低温朗肯循环系统时,同时引入内部换热器和适当的过热度将使循环效率得到明显提高。
Different mass fractions of R245fa/R152a were chosen to compose three typical zeotropic mixtures Ca, Cb and Cc. In the proposed temperature range, the zeotropic mixtures were investigated as the working fluids of the low-temperature solar Rankine cycle. An internal heat exchanger （IHE） was introduced to the system because of the obvious tempera- ture glide during phase change for zeotropic mixtures. The results show that utilizing zeotropic mixtures can extend the range of choosing working fluids for low-temperature solar Rankine cycles. Among the proposed zeotropic mixtures, the Rankine cycle efficiency of isentropic working fluid is not the highest, while zeotropic mixtures a significant increase of thermal efficiencies can be gained the expansion volume ratio is lowest. For when superheating is combined with IHE.
出处
《太阳能学报》
EI
CAS
CSCD
北大核心
2009年第6期738-743,共6页
Acta Energiae Solaris Sinica
基金
国家高技术研究发展计划(863)项目(2006AA05Z420)
关键词
太阳能
低温朗肯循环
非共沸
工质
solar energy
low-temperature rankine cycle
zeotropic mixtures
working fluids
